Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/signal.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | * |
| 6 | * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson |
| 7 | * |
| 8 | * 2003-06-02 Jim Houston - Concurrent Computer Corp. |
| 9 | * Changes to use preallocated sigqueue structures |
| 10 | * to allow signals to be sent reliably. |
| 11 | */ |
| 12 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/slab.h> |
Paul Gortmaker | 9984de1 | 2011-05-23 14:51:41 -0400 | [diff] [blame] | 14 | #include <linux/export.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/init.h> |
| 16 | #include <linux/sched.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/tty.h> |
| 19 | #include <linux/binfmts.h> |
Alex Kelly | 179899f | 2012-10-04 17:15:24 -0700 | [diff] [blame] | 20 | #include <linux/coredump.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/security.h> |
| 22 | #include <linux/syscalls.h> |
| 23 | #include <linux/ptrace.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 24 | #include <linux/signal.h> |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 25 | #include <linux/signalfd.h> |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 26 | #include <linux/ratelimit.h> |
Roland McGrath | 35de254 | 2008-07-25 19:45:51 -0700 | [diff] [blame] | 27 | #include <linux/tracehook.h> |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 28 | #include <linux/capability.h> |
Nigel Cunningham | 7dfb710 | 2006-12-06 20:34:23 -0800 | [diff] [blame] | 29 | #include <linux/freezer.h> |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 30 | #include <linux/pid_namespace.h> |
| 31 | #include <linux/nsproxy.h> |
Serge E. Hallyn | 6b550f9 | 2012-01-10 15:11:37 -0800 | [diff] [blame] | 32 | #include <linux/user_namespace.h> |
Srikar Dronamraju | 0326f5a | 2012-03-13 23:30:11 +0530 | [diff] [blame] | 33 | #include <linux/uprobes.h> |
Al Viro | 9026843 | 2012-12-14 14:47:53 -0500 | [diff] [blame] | 34 | #include <linux/compat.h> |
Jesper Derehag | 2b5faa4 | 2013-03-19 20:50:05 +0000 | [diff] [blame] | 35 | #include <linux/cn_proc.h> |
Gideon Israel Dsouza | 52f5684c | 2014-04-07 15:39:20 -0700 | [diff] [blame] | 36 | #include <linux/compiler.h> |
| 37 | |
Masami Hiramatsu | d1eb650 | 2009-11-24 16:56:45 -0500 | [diff] [blame] | 38 | #define CREATE_TRACE_POINTS |
| 39 | #include <trace/events/signal.h> |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 40 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #include <asm/param.h> |
| 42 | #include <asm/uaccess.h> |
| 43 | #include <asm/unistd.h> |
| 44 | #include <asm/siginfo.h> |
David Howells | d550bbd | 2012-03-28 18:30:03 +0100 | [diff] [blame] | 45 | #include <asm/cacheflush.h> |
Al Viro | e139606 | 2006-05-25 10:19:47 -0400 | [diff] [blame] | 46 | #include "audit.h" /* audit_signal_info() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
| 48 | /* |
| 49 | * SLAB caches for signal bits. |
| 50 | */ |
| 51 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 52 | static struct kmem_cache *sigqueue_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 54 | int print_fatal_signals __read_mostly; |
| 55 | |
Roland McGrath | 35de254 | 2008-07-25 19:45:51 -0700 | [diff] [blame] | 56 | static void __user *sig_handler(struct task_struct *t, int sig) |
Pavel Emelyanov | 93585ee | 2008-04-30 00:52:39 -0700 | [diff] [blame] | 57 | { |
Roland McGrath | 35de254 | 2008-07-25 19:45:51 -0700 | [diff] [blame] | 58 | return t->sighand->action[sig - 1].sa.sa_handler; |
| 59 | } |
Pavel Emelyanov | 93585ee | 2008-04-30 00:52:39 -0700 | [diff] [blame] | 60 | |
Roland McGrath | 35de254 | 2008-07-25 19:45:51 -0700 | [diff] [blame] | 61 | static int sig_handler_ignored(void __user *handler, int sig) |
| 62 | { |
Pavel Emelyanov | 93585ee | 2008-04-30 00:52:39 -0700 | [diff] [blame] | 63 | /* Is it explicitly or implicitly ignored? */ |
Pavel Emelyanov | 93585ee | 2008-04-30 00:52:39 -0700 | [diff] [blame] | 64 | return handler == SIG_IGN || |
| 65 | (handler == SIG_DFL && sig_kernel_ignore(sig)); |
| 66 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | |
Oleg Nesterov | def8cf7 | 2012-03-23 15:02:45 -0700 | [diff] [blame] | 68 | static int sig_task_ignored(struct task_struct *t, int sig, bool force) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | { |
Roland McGrath | 35de254 | 2008-07-25 19:45:51 -0700 | [diff] [blame] | 70 | void __user *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
Oleg Nesterov | f008faf | 2009-04-02 16:58:02 -0700 | [diff] [blame] | 72 | handler = sig_handler(t, sig); |
| 73 | |
| 74 | if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && |
Oleg Nesterov | 794ac8e | 2017-11-17 15:30:04 -0800 | [diff] [blame] | 75 | handler == SIG_DFL && !(force && sig_kernel_only(sig))) |
Oleg Nesterov | f008faf | 2009-04-02 16:58:02 -0700 | [diff] [blame] | 76 | return 1; |
| 77 | |
| 78 | return sig_handler_ignored(handler, sig); |
| 79 | } |
| 80 | |
Oleg Nesterov | def8cf7 | 2012-03-23 15:02:45 -0700 | [diff] [blame] | 81 | static int sig_ignored(struct task_struct *t, int sig, bool force) |
Oleg Nesterov | f008faf | 2009-04-02 16:58:02 -0700 | [diff] [blame] | 82 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | /* |
| 84 | * Blocked signals are never ignored, since the |
| 85 | * signal handler may change by the time it is |
| 86 | * unblocked. |
| 87 | */ |
Roland McGrath | 325d22d | 2007-11-12 15:41:55 -0800 | [diff] [blame] | 88 | if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | return 0; |
| 90 | |
Oleg Nesterov | 1453b3a | 2017-11-17 15:30:01 -0800 | [diff] [blame] | 91 | /* |
| 92 | * Tracers may want to know about even ignored signal unless it |
| 93 | * is SIGKILL which can't be reported anyway but can be ignored |
| 94 | * by SIGNAL_UNKILLABLE task. |
| 95 | */ |
| 96 | if (t->ptrace && sig != SIGKILL) |
Roland McGrath | 35de254 | 2008-07-25 19:45:51 -0700 | [diff] [blame] | 97 | return 0; |
| 98 | |
Oleg Nesterov | 1453b3a | 2017-11-17 15:30:01 -0800 | [diff] [blame] | 99 | return sig_task_ignored(t, sig, force); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | } |
| 101 | |
| 102 | /* |
| 103 | * Re-calculate pending state from the set of locally pending |
| 104 | * signals, globally pending signals, and blocked signals. |
| 105 | */ |
| 106 | static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) |
| 107 | { |
| 108 | unsigned long ready; |
| 109 | long i; |
| 110 | |
| 111 | switch (_NSIG_WORDS) { |
| 112 | default: |
| 113 | for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) |
| 114 | ready |= signal->sig[i] &~ blocked->sig[i]; |
| 115 | break; |
| 116 | |
| 117 | case 4: ready = signal->sig[3] &~ blocked->sig[3]; |
| 118 | ready |= signal->sig[2] &~ blocked->sig[2]; |
| 119 | ready |= signal->sig[1] &~ blocked->sig[1]; |
| 120 | ready |= signal->sig[0] &~ blocked->sig[0]; |
| 121 | break; |
| 122 | |
| 123 | case 2: ready = signal->sig[1] &~ blocked->sig[1]; |
| 124 | ready |= signal->sig[0] &~ blocked->sig[0]; |
| 125 | break; |
| 126 | |
| 127 | case 1: ready = signal->sig[0] &~ blocked->sig[0]; |
| 128 | } |
| 129 | return ready != 0; |
| 130 | } |
| 131 | |
| 132 | #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) |
| 133 | |
Roland McGrath | 7bb44ad | 2007-05-23 13:57:44 -0700 | [diff] [blame] | 134 | static int recalc_sigpending_tsk(struct task_struct *t) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | { |
Tejun Heo | 3759a0d | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 136 | if ((t->jobctl & JOBCTL_PENDING_MASK) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | PENDING(&t->pending, &t->blocked) || |
Roland McGrath | 7bb44ad | 2007-05-23 13:57:44 -0700 | [diff] [blame] | 138 | PENDING(&t->signal->shared_pending, &t->blocked)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
Roland McGrath | 7bb44ad | 2007-05-23 13:57:44 -0700 | [diff] [blame] | 140 | return 1; |
| 141 | } |
Roland McGrath | b74d0de | 2007-06-06 03:59:00 -0700 | [diff] [blame] | 142 | /* |
| 143 | * We must never clear the flag in another thread, or in current |
| 144 | * when it's possible the current syscall is returning -ERESTART*. |
| 145 | * So we don't clear it here, and only callers who know they should do. |
| 146 | */ |
Roland McGrath | 7bb44ad | 2007-05-23 13:57:44 -0700 | [diff] [blame] | 147 | return 0; |
| 148 | } |
| 149 | |
| 150 | /* |
| 151 | * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up. |
| 152 | * This is superfluous when called on current, the wakeup is a harmless no-op. |
| 153 | */ |
| 154 | void recalc_sigpending_and_wake(struct task_struct *t) |
| 155 | { |
| 156 | if (recalc_sigpending_tsk(t)) |
| 157 | signal_wake_up(t, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | } |
| 159 | |
| 160 | void recalc_sigpending(void) |
| 161 | { |
Tejun Heo | dd1d677 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 162 | if (!recalc_sigpending_tsk(current) && !freezing(current)) |
Roland McGrath | b74d0de | 2007-06-06 03:59:00 -0700 | [diff] [blame] | 163 | clear_thread_flag(TIF_SIGPENDING); |
| 164 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | } |
| 166 | |
| 167 | /* Given the mask, find the first available signal that should be serviced. */ |
| 168 | |
Linus Torvalds | a27341c | 2010-03-02 08:36:46 -0800 | [diff] [blame] | 169 | #define SYNCHRONOUS_MASK \ |
| 170 | (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \ |
Will Drewry | a0727e8 | 2012-04-12 16:48:00 -0500 | [diff] [blame] | 171 | sigmask(SIGTRAP) | sigmask(SIGFPE) | sigmask(SIGSYS)) |
Linus Torvalds | a27341c | 2010-03-02 08:36:46 -0800 | [diff] [blame] | 172 | |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 173 | int next_signal(struct sigpending *pending, sigset_t *mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | { |
| 175 | unsigned long i, *s, *m, x; |
| 176 | int sig = 0; |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 177 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | s = pending->signal.sig; |
| 179 | m = mask->sig; |
Linus Torvalds | a27341c | 2010-03-02 08:36:46 -0800 | [diff] [blame] | 180 | |
| 181 | /* |
| 182 | * Handle the first word specially: it contains the |
| 183 | * synchronous signals that need to be dequeued first. |
| 184 | */ |
| 185 | x = *s &~ *m; |
| 186 | if (x) { |
| 187 | if (x & SYNCHRONOUS_MASK) |
| 188 | x &= SYNCHRONOUS_MASK; |
| 189 | sig = ffz(~x) + 1; |
| 190 | return sig; |
| 191 | } |
| 192 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | switch (_NSIG_WORDS) { |
| 194 | default: |
Linus Torvalds | a27341c | 2010-03-02 08:36:46 -0800 | [diff] [blame] | 195 | for (i = 1; i < _NSIG_WORDS; ++i) { |
| 196 | x = *++s &~ *++m; |
| 197 | if (!x) |
| 198 | continue; |
| 199 | sig = ffz(~x) + i*_NSIG_BPW + 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | break; |
Linus Torvalds | a27341c | 2010-03-02 08:36:46 -0800 | [diff] [blame] | 201 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | break; |
| 203 | |
Linus Torvalds | a27341c | 2010-03-02 08:36:46 -0800 | [diff] [blame] | 204 | case 2: |
| 205 | x = s[1] &~ m[1]; |
| 206 | if (!x) |
| 207 | break; |
| 208 | sig = ffz(~x) + _NSIG_BPW + 1; |
| 209 | break; |
| 210 | |
| 211 | case 1: |
| 212 | /* Nothing to do */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | break; |
| 214 | } |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 215 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | return sig; |
| 217 | } |
| 218 | |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 219 | static inline void print_dropped_signal(int sig) |
| 220 | { |
| 221 | static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10); |
| 222 | |
| 223 | if (!print_fatal_signals) |
| 224 | return; |
| 225 | |
| 226 | if (!__ratelimit(&ratelimit_state)) |
| 227 | return; |
| 228 | |
Wang Xiaoqiang | 747800e | 2016-05-23 16:23:59 -0700 | [diff] [blame] | 229 | pr_info("%s/%d: reached RLIMIT_SIGPENDING, dropped signal %d\n", |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 230 | current->comm, current->pid, sig); |
| 231 | } |
| 232 | |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 233 | /** |
Tejun Heo | 7dd3db5 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 234 | * task_set_jobctl_pending - set jobctl pending bits |
| 235 | * @task: target task |
| 236 | * @mask: pending bits to set |
| 237 | * |
| 238 | * Clear @mask from @task->jobctl. @mask must be subset of |
| 239 | * %JOBCTL_PENDING_MASK | %JOBCTL_STOP_CONSUME | %JOBCTL_STOP_SIGMASK | |
| 240 | * %JOBCTL_TRAPPING. If stop signo is being set, the existing signo is |
| 241 | * cleared. If @task is already being killed or exiting, this function |
| 242 | * becomes noop. |
| 243 | * |
| 244 | * CONTEXT: |
| 245 | * Must be called with @task->sighand->siglock held. |
| 246 | * |
| 247 | * RETURNS: |
| 248 | * %true if @mask is set, %false if made noop because @task was dying. |
| 249 | */ |
Palmer Dabbelt | b76808e | 2015-04-30 21:19:57 -0700 | [diff] [blame] | 250 | bool task_set_jobctl_pending(struct task_struct *task, unsigned long mask) |
Tejun Heo | 7dd3db5 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 251 | { |
| 252 | BUG_ON(mask & ~(JOBCTL_PENDING_MASK | JOBCTL_STOP_CONSUME | |
| 253 | JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING)); |
| 254 | BUG_ON((mask & JOBCTL_TRAPPING) && !(mask & JOBCTL_PENDING_MASK)); |
| 255 | |
| 256 | if (unlikely(fatal_signal_pending(task) || (task->flags & PF_EXITING))) |
| 257 | return false; |
| 258 | |
| 259 | if (mask & JOBCTL_STOP_SIGMASK) |
| 260 | task->jobctl &= ~JOBCTL_STOP_SIGMASK; |
| 261 | |
| 262 | task->jobctl |= mask; |
| 263 | return true; |
| 264 | } |
| 265 | |
| 266 | /** |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 267 | * task_clear_jobctl_trapping - clear jobctl trapping bit |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 268 | * @task: target task |
| 269 | * |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 270 | * If JOBCTL_TRAPPING is set, a ptracer is waiting for us to enter TRACED. |
| 271 | * Clear it and wake up the ptracer. Note that we don't need any further |
| 272 | * locking. @task->siglock guarantees that @task->parent points to the |
| 273 | * ptracer. |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 274 | * |
| 275 | * CONTEXT: |
| 276 | * Must be called with @task->sighand->siglock held. |
| 277 | */ |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 278 | void task_clear_jobctl_trapping(struct task_struct *task) |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 279 | { |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 280 | if (unlikely(task->jobctl & JOBCTL_TRAPPING)) { |
| 281 | task->jobctl &= ~JOBCTL_TRAPPING; |
Oleg Nesterov | 650226b | 2014-06-06 14:36:44 -0700 | [diff] [blame] | 282 | smp_mb(); /* advised by wake_up_bit() */ |
Tejun Heo | 62c124f | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 283 | wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT); |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 284 | } |
| 285 | } |
| 286 | |
| 287 | /** |
Tejun Heo | 3759a0d | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 288 | * task_clear_jobctl_pending - clear jobctl pending bits |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 289 | * @task: target task |
Tejun Heo | 3759a0d | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 290 | * @mask: pending bits to clear |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 291 | * |
Tejun Heo | 3759a0d | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 292 | * Clear @mask from @task->jobctl. @mask must be subset of |
| 293 | * %JOBCTL_PENDING_MASK. If %JOBCTL_STOP_PENDING is being cleared, other |
| 294 | * STOP bits are cleared together. |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 295 | * |
Tejun Heo | 6dfca32 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 296 | * If clearing of @mask leaves no stop or trap pending, this function calls |
| 297 | * task_clear_jobctl_trapping(). |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 298 | * |
| 299 | * CONTEXT: |
| 300 | * Must be called with @task->sighand->siglock held. |
| 301 | */ |
Palmer Dabbelt | b76808e | 2015-04-30 21:19:57 -0700 | [diff] [blame] | 302 | void task_clear_jobctl_pending(struct task_struct *task, unsigned long mask) |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 303 | { |
Tejun Heo | 3759a0d | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 304 | BUG_ON(mask & ~JOBCTL_PENDING_MASK); |
| 305 | |
| 306 | if (mask & JOBCTL_STOP_PENDING) |
| 307 | mask |= JOBCTL_STOP_CONSUME | JOBCTL_STOP_DEQUEUED; |
| 308 | |
| 309 | task->jobctl &= ~mask; |
Tejun Heo | 6dfca32 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 310 | |
| 311 | if (!(task->jobctl & JOBCTL_PENDING_MASK)) |
| 312 | task_clear_jobctl_trapping(task); |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 313 | } |
| 314 | |
| 315 | /** |
| 316 | * task_participate_group_stop - participate in a group stop |
| 317 | * @task: task participating in a group stop |
| 318 | * |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 319 | * @task has %JOBCTL_STOP_PENDING set and is participating in a group stop. |
Tejun Heo | 39efa3e | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 320 | * Group stop states are cleared and the group stop count is consumed if |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 321 | * %JOBCTL_STOP_CONSUME was set. If the consumption completes the group |
Tejun Heo | 39efa3e | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 322 | * stop, the appropriate %SIGNAL_* flags are set. |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 323 | * |
| 324 | * CONTEXT: |
| 325 | * Must be called with @task->sighand->siglock held. |
Tejun Heo | 244056f | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 326 | * |
| 327 | * RETURNS: |
| 328 | * %true if group stop completion should be notified to the parent, %false |
| 329 | * otherwise. |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 330 | */ |
| 331 | static bool task_participate_group_stop(struct task_struct *task) |
| 332 | { |
| 333 | struct signal_struct *sig = task->signal; |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 334 | bool consume = task->jobctl & JOBCTL_STOP_CONSUME; |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 335 | |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 336 | WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)); |
Tejun Heo | 39efa3e | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 337 | |
Tejun Heo | 3759a0d | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 338 | task_clear_jobctl_pending(task, JOBCTL_STOP_PENDING); |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 339 | |
| 340 | if (!consume) |
| 341 | return false; |
| 342 | |
| 343 | if (!WARN_ON_ONCE(sig->group_stop_count == 0)) |
| 344 | sig->group_stop_count--; |
| 345 | |
Tejun Heo | 244056f | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 346 | /* |
| 347 | * Tell the caller to notify completion iff we are entering into a |
| 348 | * fresh group stop. Read comment in do_signal_stop() for details. |
| 349 | */ |
| 350 | if (!sig->group_stop_count && !(sig->flags & SIGNAL_STOP_STOPPED)) { |
Jamie Iles | 916a05b | 2017-01-10 16:57:54 -0800 | [diff] [blame] | 351 | signal_set_stop_flags(sig, SIGNAL_STOP_STOPPED); |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 352 | return true; |
| 353 | } |
| 354 | return false; |
| 355 | } |
| 356 | |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 357 | /* |
| 358 | * allocate a new signal queue record |
| 359 | * - this may be called without locks if and only if t == current, otherwise an |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 360 | * appropriate lock must be held to stop the target task from exiting |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 361 | */ |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 362 | static struct sigqueue * |
| 363 | __sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | { |
| 365 | struct sigqueue *q = NULL; |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 366 | struct user_struct *user; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 368 | /* |
Thomas Gleixner | 7cf7db8 | 2009-12-10 00:53:21 +0000 | [diff] [blame] | 369 | * Protect access to @t credentials. This can go away when all |
| 370 | * callers hold rcu read lock. |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 371 | */ |
Thomas Gleixner | 7cf7db8 | 2009-12-10 00:53:21 +0000 | [diff] [blame] | 372 | rcu_read_lock(); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 373 | user = get_uid(__task_cred(t)->user); |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 374 | atomic_inc(&user->sigpending); |
Thomas Gleixner | 7cf7db8 | 2009-12-10 00:53:21 +0000 | [diff] [blame] | 375 | rcu_read_unlock(); |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 376 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | if (override_rlimit || |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 378 | atomic_read(&user->sigpending) <= |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 379 | task_rlimit(t, RLIMIT_SIGPENDING)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | q = kmem_cache_alloc(sigqueue_cachep, flags); |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 381 | } else { |
| 382 | print_dropped_signal(sig); |
| 383 | } |
| 384 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | if (unlikely(q == NULL)) { |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 386 | atomic_dec(&user->sigpending); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 387 | free_uid(user); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | } else { |
| 389 | INIT_LIST_HEAD(&q->list); |
| 390 | q->flags = 0; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 391 | q->user = user; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | } |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 393 | |
| 394 | return q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | } |
| 396 | |
Andrew Morton | 514a01b | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 397 | static void __sigqueue_free(struct sigqueue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | { |
| 399 | if (q->flags & SIGQUEUE_PREALLOC) |
| 400 | return; |
| 401 | atomic_dec(&q->user->sigpending); |
| 402 | free_uid(q->user); |
| 403 | kmem_cache_free(sigqueue_cachep, q); |
| 404 | } |
| 405 | |
Oleg Nesterov | 6a14c5c | 2006-03-28 16:11:18 -0800 | [diff] [blame] | 406 | void flush_sigqueue(struct sigpending *queue) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | { |
| 408 | struct sigqueue *q; |
| 409 | |
| 410 | sigemptyset(&queue->signal); |
| 411 | while (!list_empty(&queue->list)) { |
| 412 | q = list_entry(queue->list.next, struct sigqueue , list); |
| 413 | list_del_init(&q->list); |
| 414 | __sigqueue_free(q); |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | /* |
Oleg Nesterov | 9e7c8f8 | 2015-06-04 16:22:16 -0400 | [diff] [blame] | 419 | * Flush all pending signals for this kthread. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | */ |
Oleg Nesterov | c81addc | 2006-03-28 16:11:17 -0800 | [diff] [blame] | 421 | void flush_signals(struct task_struct *t) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | { |
| 423 | unsigned long flags; |
| 424 | |
| 425 | spin_lock_irqsave(&t->sighand->siglock, flags); |
Oleg Nesterov | 9e7c8f8 | 2015-06-04 16:22:16 -0400 | [diff] [blame] | 426 | clear_tsk_thread_flag(t, TIF_SIGPENDING); |
| 427 | flush_sigqueue(&t->pending); |
| 428 | flush_sigqueue(&t->signal->shared_pending); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
| 430 | } |
| 431 | |
Oleg Nesterov | cbaffba | 2008-05-26 20:55:42 +0400 | [diff] [blame] | 432 | static void __flush_itimer_signals(struct sigpending *pending) |
| 433 | { |
| 434 | sigset_t signal, retain; |
| 435 | struct sigqueue *q, *n; |
| 436 | |
| 437 | signal = pending->signal; |
| 438 | sigemptyset(&retain); |
| 439 | |
| 440 | list_for_each_entry_safe(q, n, &pending->list, list) { |
| 441 | int sig = q->info.si_signo; |
| 442 | |
| 443 | if (likely(q->info.si_code != SI_TIMER)) { |
| 444 | sigaddset(&retain, sig); |
| 445 | } else { |
| 446 | sigdelset(&signal, sig); |
| 447 | list_del_init(&q->list); |
| 448 | __sigqueue_free(q); |
| 449 | } |
| 450 | } |
| 451 | |
| 452 | sigorsets(&pending->signal, &signal, &retain); |
| 453 | } |
| 454 | |
| 455 | void flush_itimer_signals(void) |
| 456 | { |
| 457 | struct task_struct *tsk = current; |
| 458 | unsigned long flags; |
| 459 | |
| 460 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
| 461 | __flush_itimer_signals(&tsk->pending); |
| 462 | __flush_itimer_signals(&tsk->signal->shared_pending); |
| 463 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
| 464 | } |
| 465 | |
Oleg Nesterov | 10ab825 | 2007-05-09 02:34:37 -0700 | [diff] [blame] | 466 | void ignore_signals(struct task_struct *t) |
| 467 | { |
| 468 | int i; |
| 469 | |
| 470 | for (i = 0; i < _NSIG; ++i) |
| 471 | t->sighand->action[i].sa.sa_handler = SIG_IGN; |
| 472 | |
| 473 | flush_signals(t); |
| 474 | } |
| 475 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | * Flush all handlers for a task. |
| 478 | */ |
| 479 | |
| 480 | void |
| 481 | flush_signal_handlers(struct task_struct *t, int force_default) |
| 482 | { |
| 483 | int i; |
| 484 | struct k_sigaction *ka = &t->sighand->action[0]; |
| 485 | for (i = _NSIG ; i != 0 ; i--) { |
| 486 | if (force_default || ka->sa.sa_handler != SIG_IGN) |
| 487 | ka->sa.sa_handler = SIG_DFL; |
| 488 | ka->sa.sa_flags = 0; |
Andrew Morton | 522cff1 | 2013-03-13 14:59:34 -0700 | [diff] [blame] | 489 | #ifdef __ARCH_HAS_SA_RESTORER |
Kees Cook | 2ca3952 | 2013-03-13 14:59:33 -0700 | [diff] [blame] | 490 | ka->sa.sa_restorer = NULL; |
| 491 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | sigemptyset(&ka->sa.sa_mask); |
| 493 | ka++; |
| 494 | } |
| 495 | } |
| 496 | |
Masoud Asgharifard Sharbiani | abd4f75 | 2007-07-22 11:12:28 +0200 | [diff] [blame] | 497 | int unhandled_signal(struct task_struct *tsk, int sig) |
| 498 | { |
Roland McGrath | 445a91d | 2008-07-25 19:45:52 -0700 | [diff] [blame] | 499 | void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; |
Serge E. Hallyn | b460cbc | 2007-10-18 23:39:52 -0700 | [diff] [blame] | 500 | if (is_global_init(tsk)) |
Masoud Asgharifard Sharbiani | abd4f75 | 2007-07-22 11:12:28 +0200 | [diff] [blame] | 501 | return 1; |
Roland McGrath | 445a91d | 2008-07-25 19:45:52 -0700 | [diff] [blame] | 502 | if (handler != SIG_IGN && handler != SIG_DFL) |
Masoud Asgharifard Sharbiani | abd4f75 | 2007-07-22 11:12:28 +0200 | [diff] [blame] | 503 | return 0; |
Tejun Heo | a288eec | 2011-06-17 16:50:37 +0200 | [diff] [blame] | 504 | /* if ptraced, let the tracer determine */ |
| 505 | return !tsk->ptrace; |
Masoud Asgharifard Sharbiani | abd4f75 | 2007-07-22 11:12:28 +0200 | [diff] [blame] | 506 | } |
| 507 | |
Eric W. Biederman | f719f20 | 2017-06-13 04:31:16 -0500 | [diff] [blame] | 508 | static void collect_signal(int sig, struct sigpending *list, siginfo_t *info, |
| 509 | bool *resched_timer) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | { |
| 511 | struct sigqueue *q, *first = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | /* |
| 514 | * Collect the siginfo appropriate to this signal. Check if |
| 515 | * there is another siginfo for the same signal. |
| 516 | */ |
| 517 | list_for_each_entry(q, &list->list, list) { |
| 518 | if (q->info.si_signo == sig) { |
Oleg Nesterov | d443420 | 2008-07-25 01:47:28 -0700 | [diff] [blame] | 519 | if (first) |
| 520 | goto still_pending; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | first = q; |
| 522 | } |
| 523 | } |
Oleg Nesterov | d443420 | 2008-07-25 01:47:28 -0700 | [diff] [blame] | 524 | |
| 525 | sigdelset(&list->signal, sig); |
| 526 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | if (first) { |
Oleg Nesterov | d443420 | 2008-07-25 01:47:28 -0700 | [diff] [blame] | 528 | still_pending: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | list_del_init(&first->list); |
| 530 | copy_siginfo(info, &first->info); |
Eric W. Biederman | f719f20 | 2017-06-13 04:31:16 -0500 | [diff] [blame] | 531 | |
| 532 | *resched_timer = |
| 533 | (first->flags & SIGQUEUE_PREALLOC) && |
| 534 | (info->si_code == SI_TIMER) && |
| 535 | (info->si_sys_private); |
| 536 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | __sigqueue_free(first); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | } else { |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 539 | /* |
| 540 | * Ok, it wasn't in the queue. This must be |
| 541 | * a fast-pathed signal or we must have been |
| 542 | * out of queue space. So zero out the info. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | info->si_signo = sig; |
| 545 | info->si_errno = 0; |
Oleg Nesterov | 7486e5d | 2009-12-15 16:47:24 -0800 | [diff] [blame] | 546 | info->si_code = SI_USER; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | info->si_pid = 0; |
| 548 | info->si_uid = 0; |
| 549 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | } |
| 551 | |
| 552 | static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, |
Eric W. Biederman | f719f20 | 2017-06-13 04:31:16 -0500 | [diff] [blame] | 553 | siginfo_t *info, bool *resched_timer) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | { |
Roland McGrath | 27d91e0 | 2006-09-29 02:00:31 -0700 | [diff] [blame] | 555 | int sig = next_signal(pending, mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | |
Oleg Nesterov | 2e01fab | 2015-11-06 16:32:19 -0800 | [diff] [blame] | 557 | if (sig) |
Eric W. Biederman | f719f20 | 2017-06-13 04:31:16 -0500 | [diff] [blame] | 558 | collect_signal(sig, pending, info, resched_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | return sig; |
| 560 | } |
| 561 | |
| 562 | /* |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 563 | * Dequeue a signal and return the element to the caller, which is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | * expected to free it. |
| 565 | * |
| 566 | * All callers have to hold the siglock. |
| 567 | */ |
| 568 | int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) |
| 569 | { |
Eric W. Biederman | f719f20 | 2017-06-13 04:31:16 -0500 | [diff] [blame] | 570 | bool resched_timer = false; |
Pavel Emelyanov | c5363d0 | 2008-04-30 00:52:40 -0700 | [diff] [blame] | 571 | int signr; |
Benjamin Herrenschmidt | caec4e8 | 2007-06-12 08:16:18 +1000 | [diff] [blame] | 572 | |
| 573 | /* We only dequeue private signals from ourselves, we don't let |
| 574 | * signalfd steal them |
| 575 | */ |
Eric W. Biederman | f719f20 | 2017-06-13 04:31:16 -0500 | [diff] [blame] | 576 | signr = __dequeue_signal(&tsk->pending, mask, info, &resched_timer); |
Thomas Gleixner | 8bfd9a7 | 2007-02-16 01:28:12 -0800 | [diff] [blame] | 577 | if (!signr) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | signr = __dequeue_signal(&tsk->signal->shared_pending, |
Eric W. Biederman | f719f20 | 2017-06-13 04:31:16 -0500 | [diff] [blame] | 579 | mask, info, &resched_timer); |
Thomas Gleixner | 8bfd9a7 | 2007-02-16 01:28:12 -0800 | [diff] [blame] | 580 | /* |
| 581 | * itimer signal ? |
| 582 | * |
| 583 | * itimers are process shared and we restart periodic |
| 584 | * itimers in the signal delivery path to prevent DoS |
| 585 | * attacks in the high resolution timer case. This is |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 586 | * compliant with the old way of self-restarting |
Thomas Gleixner | 8bfd9a7 | 2007-02-16 01:28:12 -0800 | [diff] [blame] | 587 | * itimers, as the SIGALRM is a legacy signal and only |
| 588 | * queued once. Changing the restart behaviour to |
| 589 | * restart the timer in the signal dequeue path is |
| 590 | * reducing the timer noise on heavy loaded !highres |
| 591 | * systems too. |
| 592 | */ |
| 593 | if (unlikely(signr == SIGALRM)) { |
| 594 | struct hrtimer *tmr = &tsk->signal->real_timer; |
| 595 | |
| 596 | if (!hrtimer_is_queued(tmr) && |
| 597 | tsk->signal->it_real_incr.tv64 != 0) { |
| 598 | hrtimer_forward(tmr, tmr->base->get_time(), |
| 599 | tsk->signal->it_real_incr); |
| 600 | hrtimer_restart(tmr); |
| 601 | } |
| 602 | } |
| 603 | } |
Pavel Emelyanov | c5363d0 | 2008-04-30 00:52:40 -0700 | [diff] [blame] | 604 | |
Davide Libenzi | b8fceee | 2007-09-20 12:40:16 -0700 | [diff] [blame] | 605 | recalc_sigpending(); |
Pavel Emelyanov | c5363d0 | 2008-04-30 00:52:40 -0700 | [diff] [blame] | 606 | if (!signr) |
| 607 | return 0; |
| 608 | |
| 609 | if (unlikely(sig_kernel_stop(signr))) { |
Thomas Gleixner | 8bfd9a7 | 2007-02-16 01:28:12 -0800 | [diff] [blame] | 610 | /* |
| 611 | * Set a marker that we have dequeued a stop signal. Our |
| 612 | * caller might release the siglock and then the pending |
| 613 | * stop signal it is about to process is no longer in the |
| 614 | * pending bitmasks, but must still be cleared by a SIGCONT |
| 615 | * (and overruled by a SIGKILL). So those cases clear this |
| 616 | * shared flag after we've set it. Note that this flag may |
| 617 | * remain set after the signal we return is ignored or |
| 618 | * handled. That doesn't matter because its only purpose |
| 619 | * is to alert stop-signal processing code when another |
| 620 | * processor has come along and cleared the flag. |
| 621 | */ |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 622 | current->jobctl |= JOBCTL_STOP_DEQUEUED; |
Thomas Gleixner | 8bfd9a7 | 2007-02-16 01:28:12 -0800 | [diff] [blame] | 623 | } |
Eric W. Biederman | f719f20 | 2017-06-13 04:31:16 -0500 | [diff] [blame] | 624 | if (resched_timer) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | /* |
| 626 | * Release the siglock to ensure proper locking order |
| 627 | * of timer locks outside of siglocks. Note, we leave |
| 628 | * irqs disabled here, since the posix-timers code is |
| 629 | * about to disable them again anyway. |
| 630 | */ |
| 631 | spin_unlock(&tsk->sighand->siglock); |
| 632 | do_schedule_next_timer(info); |
| 633 | spin_lock(&tsk->sighand->siglock); |
| 634 | } |
| 635 | return signr; |
| 636 | } |
| 637 | |
| 638 | /* |
| 639 | * Tell a process that it has a new active signal.. |
| 640 | * |
| 641 | * NOTE! we rely on the previous spin_lock to |
| 642 | * lock interrupts for us! We can only be called with |
| 643 | * "siglock" held, and the local interrupt must |
| 644 | * have been disabled when that got acquired! |
| 645 | * |
| 646 | * No need to set need_resched since signal event passing |
| 647 | * goes through ->blocked |
| 648 | */ |
Oleg Nesterov | 910ffdb | 2013-01-21 20:47:41 +0100 | [diff] [blame] | 649 | void signal_wake_up_state(struct task_struct *t, unsigned int state) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | /* |
Oleg Nesterov | 910ffdb | 2013-01-21 20:47:41 +0100 | [diff] [blame] | 653 | * TASK_WAKEKILL also means wake it up in the stopped/traced/killable |
Matthew Wilcox | f021a3c | 2007-12-06 11:13:16 -0500 | [diff] [blame] | 654 | * case. We don't check t->state here because there is a race with it |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | * executing another processor and just now entering stopped state. |
| 656 | * By using wake_up_state, we ensure the process will wake up and |
| 657 | * handle its death signal. |
| 658 | */ |
Oleg Nesterov | 910ffdb | 2013-01-21 20:47:41 +0100 | [diff] [blame] | 659 | if (!wake_up_state(t, state | TASK_INTERRUPTIBLE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | kick_process(t); |
| 661 | } |
| 662 | |
| 663 | /* |
| 664 | * Remove signals in mask from the pending set and queue. |
| 665 | * Returns 1 if any signals were found. |
| 666 | * |
| 667 | * All callers must be holding the siglock. |
George Anzinger | 71fabd5 | 2006-01-08 01:02:48 -0800 | [diff] [blame] | 668 | */ |
Oleg Nesterov | c09c144 | 2014-06-06 14:36:50 -0700 | [diff] [blame] | 669 | static int flush_sigqueue_mask(sigset_t *mask, struct sigpending *s) |
George Anzinger | 71fabd5 | 2006-01-08 01:02:48 -0800 | [diff] [blame] | 670 | { |
| 671 | struct sigqueue *q, *n; |
| 672 | sigset_t m; |
| 673 | |
| 674 | sigandsets(&m, mask, &s->signal); |
| 675 | if (sigisemptyset(&m)) |
| 676 | return 0; |
| 677 | |
Oleg Nesterov | 702a507 | 2011-04-27 22:01:27 +0200 | [diff] [blame] | 678 | sigandnsets(&s->signal, &s->signal, mask); |
George Anzinger | 71fabd5 | 2006-01-08 01:02:48 -0800 | [diff] [blame] | 679 | list_for_each_entry_safe(q, n, &s->list, list) { |
| 680 | if (sigismember(mask, q->info.si_signo)) { |
| 681 | list_del_init(&q->list); |
| 682 | __sigqueue_free(q); |
| 683 | } |
| 684 | } |
| 685 | return 1; |
| 686 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | |
Oleg Nesterov | 614c517 | 2009-12-15 16:47:22 -0800 | [diff] [blame] | 688 | static inline int is_si_special(const struct siginfo *info) |
| 689 | { |
| 690 | return info <= SEND_SIG_FORCED; |
| 691 | } |
| 692 | |
| 693 | static inline bool si_fromuser(const struct siginfo *info) |
| 694 | { |
| 695 | return info == SEND_SIG_NOINFO || |
| 696 | (!is_si_special(info) && SI_FROMUSER(info)); |
| 697 | } |
| 698 | |
Eric W. Biederman | 181f1f0d | 2019-02-06 17:51:47 -0600 | [diff] [blame] | 699 | static int dequeue_synchronous_signal(siginfo_t *info) |
| 700 | { |
| 701 | struct task_struct *tsk = current; |
| 702 | struct sigpending *pending = &tsk->pending; |
| 703 | struct sigqueue *q, *sync = NULL; |
| 704 | |
| 705 | /* |
| 706 | * Might a synchronous signal be in the queue? |
| 707 | */ |
| 708 | if (!((pending->signal.sig[0] & ~tsk->blocked.sig[0]) & SYNCHRONOUS_MASK)) |
| 709 | return 0; |
| 710 | |
| 711 | /* |
| 712 | * Return the first synchronous signal in the queue. |
| 713 | */ |
| 714 | list_for_each_entry(q, &pending->list, list) { |
| 715 | /* Synchronous signals have a postive si_code */ |
| 716 | if ((q->info.si_code > SI_USER) && |
| 717 | (sigmask(q->info.si_signo) & SYNCHRONOUS_MASK)) { |
| 718 | sync = q; |
| 719 | goto next; |
| 720 | } |
| 721 | } |
| 722 | return 0; |
| 723 | next: |
| 724 | /* |
| 725 | * Check if there is another siginfo for the same signal. |
| 726 | */ |
| 727 | list_for_each_entry_continue(q, &pending->list, list) { |
| 728 | if (q->info.si_signo == sync->info.si_signo) |
| 729 | goto still_pending; |
| 730 | } |
| 731 | |
| 732 | sigdelset(&pending->signal, sync->info.si_signo); |
| 733 | recalc_sigpending(); |
| 734 | still_pending: |
| 735 | list_del_init(&sync->list); |
| 736 | copy_siginfo(info, &sync->info); |
| 737 | __sigqueue_free(sync); |
| 738 | return info->si_signo; |
| 739 | } |
| 740 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 741 | /* |
Serge E. Hallyn | 39fd339 | 2011-03-23 16:43:19 -0700 | [diff] [blame] | 742 | * called with RCU read lock from check_kill_permission() |
| 743 | */ |
| 744 | static int kill_ok_by_cred(struct task_struct *t) |
| 745 | { |
| 746 | const struct cred *cred = current_cred(); |
| 747 | const struct cred *tcred = __task_cred(t); |
| 748 | |
Eric W. Biederman | 5af6620 | 2012-03-03 20:21:47 -0800 | [diff] [blame] | 749 | if (uid_eq(cred->euid, tcred->suid) || |
| 750 | uid_eq(cred->euid, tcred->uid) || |
| 751 | uid_eq(cred->uid, tcred->suid) || |
| 752 | uid_eq(cred->uid, tcred->uid)) |
Serge E. Hallyn | 39fd339 | 2011-03-23 16:43:19 -0700 | [diff] [blame] | 753 | return 1; |
| 754 | |
Eric W. Biederman | c4a4d60 | 2011-11-16 23:15:31 -0800 | [diff] [blame] | 755 | if (ns_capable(tcred->user_ns, CAP_KILL)) |
Serge E. Hallyn | 39fd339 | 2011-03-23 16:43:19 -0700 | [diff] [blame] | 756 | return 1; |
| 757 | |
| 758 | return 0; |
| 759 | } |
| 760 | |
| 761 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | * Bad permissions for sending the signal |
David Howells | 694f690 | 2010-08-04 16:59:14 +0100 | [diff] [blame] | 763 | * - the caller must hold the RCU read lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | */ |
| 765 | static int check_kill_permission(int sig, struct siginfo *info, |
| 766 | struct task_struct *t) |
| 767 | { |
Oleg Nesterov | 2e2ba22 | 2008-04-30 00:53:01 -0700 | [diff] [blame] | 768 | struct pid *sid; |
Oleg Nesterov | 3b5e9e5 | 2008-04-30 00:52:42 -0700 | [diff] [blame] | 769 | int error; |
| 770 | |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 771 | if (!valid_signal(sig)) |
Oleg Nesterov | 3b5e9e5 | 2008-04-30 00:52:42 -0700 | [diff] [blame] | 772 | return -EINVAL; |
| 773 | |
Oleg Nesterov | 614c517 | 2009-12-15 16:47:22 -0800 | [diff] [blame] | 774 | if (!si_fromuser(info)) |
Oleg Nesterov | 3b5e9e5 | 2008-04-30 00:52:42 -0700 | [diff] [blame] | 775 | return 0; |
| 776 | |
| 777 | error = audit_signal_info(sig, t); /* Let audit system see the signal */ |
| 778 | if (error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | return error; |
Amy Griffis | e54dc24 | 2007-03-29 18:01:04 -0400 | [diff] [blame] | 780 | |
Oleg Nesterov | 065add3 | 2010-05-26 14:42:54 -0700 | [diff] [blame] | 781 | if (!same_thread_group(current, t) && |
Serge E. Hallyn | 39fd339 | 2011-03-23 16:43:19 -0700 | [diff] [blame] | 782 | !kill_ok_by_cred(t)) { |
Oleg Nesterov | 2e2ba22 | 2008-04-30 00:53:01 -0700 | [diff] [blame] | 783 | switch (sig) { |
| 784 | case SIGCONT: |
Oleg Nesterov | 2e2ba22 | 2008-04-30 00:53:01 -0700 | [diff] [blame] | 785 | sid = task_session(t); |
Oleg Nesterov | 2e2ba22 | 2008-04-30 00:53:01 -0700 | [diff] [blame] | 786 | /* |
| 787 | * We don't return the error if sid == NULL. The |
| 788 | * task was unhashed, the caller must notice this. |
| 789 | */ |
| 790 | if (!sid || sid == task_session(current)) |
| 791 | break; |
| 792 | default: |
| 793 | return -EPERM; |
| 794 | } |
| 795 | } |
Steve Grubb | c2f0c7c | 2005-05-06 12:38:39 +0100 | [diff] [blame] | 796 | |
Amy Griffis | e54dc24 | 2007-03-29 18:01:04 -0400 | [diff] [blame] | 797 | return security_task_kill(t, info, sig, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | } |
| 799 | |
Tejun Heo | fb1d910 | 2011-06-14 11:20:17 +0200 | [diff] [blame] | 800 | /** |
| 801 | * ptrace_trap_notify - schedule trap to notify ptracer |
| 802 | * @t: tracee wanting to notify tracer |
| 803 | * |
| 804 | * This function schedules sticky ptrace trap which is cleared on the next |
| 805 | * TRAP_STOP to notify ptracer of an event. @t must have been seized by |
| 806 | * ptracer. |
| 807 | * |
Tejun Heo | 544b2c9 | 2011-06-14 11:20:18 +0200 | [diff] [blame] | 808 | * If @t is running, STOP trap will be taken. If trapped for STOP and |
| 809 | * ptracer is listening for events, tracee is woken up so that it can |
| 810 | * re-trap for the new event. If trapped otherwise, STOP trap will be |
| 811 | * eventually taken without returning to userland after the existing traps |
| 812 | * are finished by PTRACE_CONT. |
Tejun Heo | fb1d910 | 2011-06-14 11:20:17 +0200 | [diff] [blame] | 813 | * |
| 814 | * CONTEXT: |
| 815 | * Must be called with @task->sighand->siglock held. |
| 816 | */ |
| 817 | static void ptrace_trap_notify(struct task_struct *t) |
| 818 | { |
| 819 | WARN_ON_ONCE(!(t->ptrace & PT_SEIZED)); |
| 820 | assert_spin_locked(&t->sighand->siglock); |
| 821 | |
| 822 | task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY); |
Oleg Nesterov | 910ffdb | 2013-01-21 20:47:41 +0100 | [diff] [blame] | 823 | ptrace_signal_wake_up(t, t->jobctl & JOBCTL_LISTENING); |
Tejun Heo | fb1d910 | 2011-06-14 11:20:17 +0200 | [diff] [blame] | 824 | } |
| 825 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | /* |
Oleg Nesterov | 7e695a5 | 2008-04-30 00:52:59 -0700 | [diff] [blame] | 827 | * Handle magic process-wide effects of stop/continue signals. Unlike |
| 828 | * the signal actions, these happen immediately at signal-generation |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | * time regardless of blocking, ignoring, or handling. This does the |
| 830 | * actual continuing for SIGCONT, but not the actual stopping for stop |
Oleg Nesterov | 7e695a5 | 2008-04-30 00:52:59 -0700 | [diff] [blame] | 831 | * signals. The process stop is done as a signal action for SIG_DFL. |
| 832 | * |
| 833 | * Returns true if the signal should be actually delivered, otherwise |
| 834 | * it should be dropped. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | */ |
Oleg Nesterov | 403bad7 | 2013-04-30 15:28:10 -0700 | [diff] [blame] | 836 | static bool prepare_signal(int sig, struct task_struct *p, bool force) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | { |
Oleg Nesterov | ad16a460 | 2008-04-30 00:52:46 -0700 | [diff] [blame] | 838 | struct signal_struct *signal = p->signal; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 839 | struct task_struct *t; |
Oleg Nesterov | 9490592f | 2014-06-06 14:36:48 -0700 | [diff] [blame] | 840 | sigset_t flush; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | |
Oleg Nesterov | 403bad7 | 2013-04-30 15:28:10 -0700 | [diff] [blame] | 842 | if (signal->flags & (SIGNAL_GROUP_EXIT | SIGNAL_GROUP_COREDUMP)) { |
Oleg Nesterov | 5fa534c | 2015-11-06 16:32:31 -0800 | [diff] [blame] | 843 | if (!(signal->flags & SIGNAL_GROUP_EXIT)) |
Oleg Nesterov | 403bad7 | 2013-04-30 15:28:10 -0700 | [diff] [blame] | 844 | return sig == SIGKILL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | /* |
Oleg Nesterov | 7e695a5 | 2008-04-30 00:52:59 -0700 | [diff] [blame] | 846 | * The process is in the middle of dying, nothing to do. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 847 | */ |
Oleg Nesterov | 7e695a5 | 2008-04-30 00:52:59 -0700 | [diff] [blame] | 848 | } else if (sig_kernel_stop(sig)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 849 | /* |
| 850 | * This is a stop signal. Remove SIGCONT from all queues. |
| 851 | */ |
Oleg Nesterov | 9490592f | 2014-06-06 14:36:48 -0700 | [diff] [blame] | 852 | siginitset(&flush, sigmask(SIGCONT)); |
Oleg Nesterov | c09c144 | 2014-06-06 14:36:50 -0700 | [diff] [blame] | 853 | flush_sigqueue_mask(&flush, &signal->shared_pending); |
Oleg Nesterov | 9490592f | 2014-06-06 14:36:48 -0700 | [diff] [blame] | 854 | for_each_thread(p, t) |
Oleg Nesterov | c09c144 | 2014-06-06 14:36:50 -0700 | [diff] [blame] | 855 | flush_sigqueue_mask(&flush, &t->pending); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | } else if (sig == SIGCONT) { |
Oleg Nesterov | fc321d2 | 2008-04-30 00:52:46 -0700 | [diff] [blame] | 857 | unsigned int why; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | /* |
Oleg Nesterov | 1deac63 | 2011-04-01 20:11:50 +0200 | [diff] [blame] | 859 | * Remove all stop signals from all queues, wake all threads. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 860 | */ |
Oleg Nesterov | 9490592f | 2014-06-06 14:36:48 -0700 | [diff] [blame] | 861 | siginitset(&flush, SIG_KERNEL_STOP_MASK); |
Oleg Nesterov | c09c144 | 2014-06-06 14:36:50 -0700 | [diff] [blame] | 862 | flush_sigqueue_mask(&flush, &signal->shared_pending); |
Oleg Nesterov | 9490592f | 2014-06-06 14:36:48 -0700 | [diff] [blame] | 863 | for_each_thread(p, t) { |
Oleg Nesterov | c09c144 | 2014-06-06 14:36:50 -0700 | [diff] [blame] | 864 | flush_sigqueue_mask(&flush, &t->pending); |
Tejun Heo | 3759a0d | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 865 | task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING); |
Tejun Heo | fb1d910 | 2011-06-14 11:20:17 +0200 | [diff] [blame] | 866 | if (likely(!(t->ptrace & PT_SEIZED))) |
| 867 | wake_up_state(t, __TASK_STOPPED); |
| 868 | else |
| 869 | ptrace_trap_notify(t); |
Oleg Nesterov | 9490592f | 2014-06-06 14:36:48 -0700 | [diff] [blame] | 870 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | |
Oleg Nesterov | fc321d2 | 2008-04-30 00:52:46 -0700 | [diff] [blame] | 872 | /* |
| 873 | * Notify the parent with CLD_CONTINUED if we were stopped. |
| 874 | * |
| 875 | * If we were in the middle of a group stop, we pretend it |
| 876 | * was already finished, and then continued. Since SIGCHLD |
| 877 | * doesn't queue we report only CLD_STOPPED, as if the next |
| 878 | * CLD_CONTINUED was dropped. |
| 879 | */ |
| 880 | why = 0; |
Oleg Nesterov | ad16a460 | 2008-04-30 00:52:46 -0700 | [diff] [blame] | 881 | if (signal->flags & SIGNAL_STOP_STOPPED) |
Oleg Nesterov | fc321d2 | 2008-04-30 00:52:46 -0700 | [diff] [blame] | 882 | why |= SIGNAL_CLD_CONTINUED; |
Oleg Nesterov | ad16a460 | 2008-04-30 00:52:46 -0700 | [diff] [blame] | 883 | else if (signal->group_stop_count) |
Oleg Nesterov | fc321d2 | 2008-04-30 00:52:46 -0700 | [diff] [blame] | 884 | why |= SIGNAL_CLD_STOPPED; |
| 885 | |
| 886 | if (why) { |
Oleg Nesterov | 021e1ae | 2008-04-30 00:53:00 -0700 | [diff] [blame] | 887 | /* |
Roland McGrath | ae6d2ed | 2009-09-23 15:56:53 -0700 | [diff] [blame] | 888 | * The first thread which returns from do_signal_stop() |
Oleg Nesterov | 021e1ae | 2008-04-30 00:53:00 -0700 | [diff] [blame] | 889 | * will take ->siglock, notice SIGNAL_CLD_MASK, and |
| 890 | * notify its parent. See get_signal_to_deliver(). |
| 891 | */ |
Jamie Iles | 916a05b | 2017-01-10 16:57:54 -0800 | [diff] [blame] | 892 | signal_set_stop_flags(signal, why | SIGNAL_STOP_CONTINUED); |
Oleg Nesterov | ad16a460 | 2008-04-30 00:52:46 -0700 | [diff] [blame] | 893 | signal->group_stop_count = 0; |
| 894 | signal->group_exit_code = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 895 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 896 | } |
Oleg Nesterov | 7e695a5 | 2008-04-30 00:52:59 -0700 | [diff] [blame] | 897 | |
Oleg Nesterov | def8cf7 | 2012-03-23 15:02:45 -0700 | [diff] [blame] | 898 | return !sig_ignored(p, sig, force); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | } |
| 900 | |
Oleg Nesterov | 71f11dc | 2008-04-30 00:52:53 -0700 | [diff] [blame] | 901 | /* |
| 902 | * Test if P wants to take SIG. After we've checked all threads with this, |
| 903 | * it's equivalent to finding no threads not blocking SIG. Any threads not |
| 904 | * blocking SIG were ruled out because they are not running and already |
| 905 | * have pending signals. Such threads will dequeue from the shared queue |
| 906 | * as soon as they're available, so putting the signal on the shared queue |
| 907 | * will be equivalent to sending it to one such thread. |
| 908 | */ |
| 909 | static inline int wants_signal(int sig, struct task_struct *p) |
| 910 | { |
| 911 | if (sigismember(&p->blocked, sig)) |
| 912 | return 0; |
| 913 | if (p->flags & PF_EXITING) |
| 914 | return 0; |
| 915 | if (sig == SIGKILL) |
| 916 | return 1; |
| 917 | if (task_is_stopped_or_traced(p)) |
| 918 | return 0; |
| 919 | return task_curr(p) || !signal_pending(p); |
| 920 | } |
| 921 | |
Oleg Nesterov | 5fcd835 | 2008-04-30 00:52:55 -0700 | [diff] [blame] | 922 | static void complete_signal(int sig, struct task_struct *p, int group) |
Oleg Nesterov | 71f11dc | 2008-04-30 00:52:53 -0700 | [diff] [blame] | 923 | { |
| 924 | struct signal_struct *signal = p->signal; |
| 925 | struct task_struct *t; |
| 926 | |
| 927 | /* |
| 928 | * Now find a thread we can wake up to take the signal off the queue. |
| 929 | * |
| 930 | * If the main thread wants the signal, it gets first crack. |
| 931 | * Probably the least surprising to the average bear. |
| 932 | */ |
| 933 | if (wants_signal(sig, p)) |
| 934 | t = p; |
Oleg Nesterov | 5fcd835 | 2008-04-30 00:52:55 -0700 | [diff] [blame] | 935 | else if (!group || thread_group_empty(p)) |
Oleg Nesterov | 71f11dc | 2008-04-30 00:52:53 -0700 | [diff] [blame] | 936 | /* |
| 937 | * There is just one thread and it does not need to be woken. |
| 938 | * It will dequeue unblocked signals before it runs again. |
| 939 | */ |
| 940 | return; |
| 941 | else { |
| 942 | /* |
| 943 | * Otherwise try to find a suitable thread. |
| 944 | */ |
| 945 | t = signal->curr_target; |
| 946 | while (!wants_signal(sig, t)) { |
| 947 | t = next_thread(t); |
| 948 | if (t == signal->curr_target) |
| 949 | /* |
| 950 | * No thread needs to be woken. |
| 951 | * Any eligible threads will see |
| 952 | * the signal in the queue soon. |
| 953 | */ |
| 954 | return; |
| 955 | } |
| 956 | signal->curr_target = t; |
| 957 | } |
| 958 | |
| 959 | /* |
| 960 | * Found a killable thread. If the signal will be fatal, |
| 961 | * then start taking the whole group down immediately. |
| 962 | */ |
Oleg Nesterov | fae5fa4 | 2008-04-30 00:53:03 -0700 | [diff] [blame] | 963 | if (sig_fatal(p, sig) && |
Oleg Nesterov | 4d53eb4 | 2017-11-17 15:30:08 -0800 | [diff] [blame] | 964 | !(signal->flags & SIGNAL_GROUP_EXIT) && |
Oleg Nesterov | 71f11dc | 2008-04-30 00:52:53 -0700 | [diff] [blame] | 965 | !sigismember(&t->real_blocked, sig) && |
Oleg Nesterov | 4d53eb4 | 2017-11-17 15:30:08 -0800 | [diff] [blame] | 966 | (sig == SIGKILL || !p->ptrace)) { |
Oleg Nesterov | 71f11dc | 2008-04-30 00:52:53 -0700 | [diff] [blame] | 967 | /* |
| 968 | * This signal will be fatal to the whole group. |
| 969 | */ |
| 970 | if (!sig_kernel_coredump(sig)) { |
| 971 | /* |
| 972 | * Start a group exit and wake everybody up. |
| 973 | * This way we don't have other threads |
| 974 | * running and doing things after a slower |
| 975 | * thread has the fatal signal pending. |
| 976 | */ |
| 977 | signal->flags = SIGNAL_GROUP_EXIT; |
| 978 | signal->group_exit_code = sig; |
| 979 | signal->group_stop_count = 0; |
| 980 | t = p; |
| 981 | do { |
Tejun Heo | 6dfca32 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 982 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); |
Oleg Nesterov | 71f11dc | 2008-04-30 00:52:53 -0700 | [diff] [blame] | 983 | sigaddset(&t->pending.signal, SIGKILL); |
| 984 | signal_wake_up(t, 1); |
| 985 | } while_each_thread(p, t); |
| 986 | return; |
| 987 | } |
| 988 | } |
| 989 | |
| 990 | /* |
| 991 | * The signal is already in the shared-pending queue. |
| 992 | * Tell the chosen thread to wake up and dequeue it. |
| 993 | */ |
| 994 | signal_wake_up(t, sig == SIGKILL); |
| 995 | return; |
| 996 | } |
| 997 | |
Pavel Emelyanov | af7fff9 | 2008-04-30 00:52:34 -0700 | [diff] [blame] | 998 | static inline int legacy_queue(struct sigpending *signals, int sig) |
| 999 | { |
| 1000 | return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); |
| 1001 | } |
| 1002 | |
Serge E. Hallyn | 6b550f9 | 2012-01-10 15:11:37 -0800 | [diff] [blame] | 1003 | #ifdef CONFIG_USER_NS |
| 1004 | static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t) |
| 1005 | { |
| 1006 | if (current_user_ns() == task_cred_xxx(t, user_ns)) |
| 1007 | return; |
| 1008 | |
| 1009 | if (SI_FROMKERNEL(info)) |
| 1010 | return; |
| 1011 | |
Eric W. Biederman | 078de5f | 2012-02-08 07:00:08 -0800 | [diff] [blame] | 1012 | rcu_read_lock(); |
| 1013 | info->si_uid = from_kuid_munged(task_cred_xxx(t, user_ns), |
| 1014 | make_kuid(current_user_ns(), info->si_uid)); |
| 1015 | rcu_read_unlock(); |
Serge E. Hallyn | 6b550f9 | 2012-01-10 15:11:37 -0800 | [diff] [blame] | 1016 | } |
| 1017 | #else |
| 1018 | static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t) |
| 1019 | { |
| 1020 | return; |
| 1021 | } |
| 1022 | #endif |
| 1023 | |
Sukadev Bhattiprolu | 7978b56 | 2009-04-02 16:58:04 -0700 | [diff] [blame] | 1024 | static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, |
| 1025 | int group, int from_ancestor_ns) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1026 | { |
Oleg Nesterov | 2ca3515 | 2008-04-30 00:52:54 -0700 | [diff] [blame] | 1027 | struct sigpending *pending; |
Oleg Nesterov | 6e65acb | 2008-04-30 00:52:50 -0700 | [diff] [blame] | 1028 | struct sigqueue *q; |
Vegard Nossum | 7a0aeb1 | 2009-05-16 11:28:33 +0200 | [diff] [blame] | 1029 | int override_rlimit; |
Oleg Nesterov | 6c303d3 | 2011-11-22 21:13:48 +0100 | [diff] [blame] | 1030 | int ret = 0, result; |
Mathieu Desnoyers | 0a16b60 | 2008-07-18 12:16:17 -0400 | [diff] [blame] | 1031 | |
Oleg Nesterov | 6e65acb | 2008-04-30 00:52:50 -0700 | [diff] [blame] | 1032 | assert_spin_locked(&t->sighand->siglock); |
Sukadev Bhattiprolu | 921cf9f | 2009-04-02 16:58:05 -0700 | [diff] [blame] | 1033 | |
Oleg Nesterov | 6c303d3 | 2011-11-22 21:13:48 +0100 | [diff] [blame] | 1034 | result = TRACE_SIGNAL_IGNORED; |
Oleg Nesterov | 629d362 | 2012-03-23 15:02:44 -0700 | [diff] [blame] | 1035 | if (!prepare_signal(sig, t, |
Eric W. Biederman | ba277fe | 2018-09-03 20:02:46 +0200 | [diff] [blame] | 1036 | from_ancestor_ns || (info == SEND_SIG_PRIV) || (info == SEND_SIG_FORCED))) |
Oleg Nesterov | 6c303d3 | 2011-11-22 21:13:48 +0100 | [diff] [blame] | 1037 | goto ret; |
Oleg Nesterov | 2ca3515 | 2008-04-30 00:52:54 -0700 | [diff] [blame] | 1038 | |
| 1039 | pending = group ? &t->signal->shared_pending : &t->pending; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1040 | /* |
Pavel Emelyanov | 2acb024 | 2008-04-30 00:52:35 -0700 | [diff] [blame] | 1041 | * Short-circuit ignored signals and support queuing |
| 1042 | * exactly one non-rt signal, so that we can get more |
| 1043 | * detailed information about the cause of the signal. |
| 1044 | */ |
Oleg Nesterov | 6c303d3 | 2011-11-22 21:13:48 +0100 | [diff] [blame] | 1045 | result = TRACE_SIGNAL_ALREADY_PENDING; |
Oleg Nesterov | 7e695a5 | 2008-04-30 00:52:59 -0700 | [diff] [blame] | 1046 | if (legacy_queue(pending, sig)) |
Oleg Nesterov | 6c303d3 | 2011-11-22 21:13:48 +0100 | [diff] [blame] | 1047 | goto ret; |
| 1048 | |
| 1049 | result = TRACE_SIGNAL_DELIVERED; |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 1050 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1051 | * fast-pathed signals for kernel-internal things like SIGSTOP |
| 1052 | * or SIGKILL. |
| 1053 | */ |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1054 | if (info == SEND_SIG_FORCED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1055 | goto out_set; |
| 1056 | |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 1057 | /* |
| 1058 | * Real-time signals must be queued if sent by sigqueue, or |
| 1059 | * some other real-time mechanism. It is implementation |
| 1060 | * defined whether kill() does so. We attempt to do so, on |
| 1061 | * the principle of least surprise, but since kill is not |
| 1062 | * allowed to fail with EAGAIN when low on memory we just |
| 1063 | * make sure at least one signal gets delivered and don't |
| 1064 | * pass on the info struct. |
| 1065 | */ |
Vegard Nossum | 7a0aeb1 | 2009-05-16 11:28:33 +0200 | [diff] [blame] | 1066 | if (sig < SIGRTMIN) |
| 1067 | override_rlimit = (is_si_special(info) || info->si_code >= 0); |
| 1068 | else |
| 1069 | override_rlimit = 0; |
| 1070 | |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 1071 | q = __sigqueue_alloc(sig, t, GFP_ATOMIC | __GFP_NOTRACK_FALSE_POSITIVE, |
Vegard Nossum | 7a0aeb1 | 2009-05-16 11:28:33 +0200 | [diff] [blame] | 1072 | override_rlimit); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1073 | if (q) { |
Oleg Nesterov | 2ca3515 | 2008-04-30 00:52:54 -0700 | [diff] [blame] | 1074 | list_add_tail(&q->list, &pending->list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1075 | switch ((unsigned long) info) { |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1076 | case (unsigned long) SEND_SIG_NOINFO: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | q->info.si_signo = sig; |
| 1078 | q->info.si_errno = 0; |
| 1079 | q->info.si_code = SI_USER; |
Sukadev Bhattiprolu | 9cd4fd1 | 2009-01-06 14:42:46 -0800 | [diff] [blame] | 1080 | q->info.si_pid = task_tgid_nr_ns(current, |
Sukadev Bhattiprolu | 09bca05 | 2009-01-06 14:42:45 -0800 | [diff] [blame] | 1081 | task_active_pid_ns(t)); |
Eric W. Biederman | 078de5f | 2012-02-08 07:00:08 -0800 | [diff] [blame] | 1082 | q->info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1083 | break; |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1084 | case (unsigned long) SEND_SIG_PRIV: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | q->info.si_signo = sig; |
| 1086 | q->info.si_errno = 0; |
| 1087 | q->info.si_code = SI_KERNEL; |
| 1088 | q->info.si_pid = 0; |
| 1089 | q->info.si_uid = 0; |
| 1090 | break; |
| 1091 | default: |
| 1092 | copy_siginfo(&q->info, info); |
Sukadev Bhattiprolu | 6588c1e | 2009-04-02 16:58:09 -0700 | [diff] [blame] | 1093 | if (from_ancestor_ns) |
| 1094 | q->info.si_pid = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1095 | break; |
| 1096 | } |
Serge E. Hallyn | 6b550f9 | 2012-01-10 15:11:37 -0800 | [diff] [blame] | 1097 | |
| 1098 | userns_fixup_signal_uid(&q->info, t); |
| 1099 | |
Oleg Nesterov | 621d312 | 2005-10-30 15:03:45 -0800 | [diff] [blame] | 1100 | } else if (!is_si_special(info)) { |
Masami Hiramatsu | ba005e1 | 2009-11-24 16:56:58 -0500 | [diff] [blame] | 1101 | if (sig >= SIGRTMIN && info->si_code != SI_USER) { |
| 1102 | /* |
| 1103 | * Queue overflow, abort. We may abort if the |
| 1104 | * signal was rt and sent by user using something |
| 1105 | * other than kill(). |
| 1106 | */ |
Oleg Nesterov | 6c303d3 | 2011-11-22 21:13:48 +0100 | [diff] [blame] | 1107 | result = TRACE_SIGNAL_OVERFLOW_FAIL; |
| 1108 | ret = -EAGAIN; |
| 1109 | goto ret; |
Masami Hiramatsu | ba005e1 | 2009-11-24 16:56:58 -0500 | [diff] [blame] | 1110 | } else { |
| 1111 | /* |
| 1112 | * This is a silent loss of information. We still |
| 1113 | * send the signal, but the *info bits are lost. |
| 1114 | */ |
Oleg Nesterov | 6c303d3 | 2011-11-22 21:13:48 +0100 | [diff] [blame] | 1115 | result = TRACE_SIGNAL_LOSE_INFO; |
Masami Hiramatsu | ba005e1 | 2009-11-24 16:56:58 -0500 | [diff] [blame] | 1116 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1117 | } |
| 1118 | |
| 1119 | out_set: |
Oleg Nesterov | 53c3033 | 2008-04-30 00:53:00 -0700 | [diff] [blame] | 1120 | signalfd_notify(t, sig); |
Oleg Nesterov | 2ca3515 | 2008-04-30 00:52:54 -0700 | [diff] [blame] | 1121 | sigaddset(&pending->signal, sig); |
Pavel Emelyanov | 4cd4b6d | 2008-04-30 00:52:55 -0700 | [diff] [blame] | 1122 | complete_signal(sig, t, group); |
Oleg Nesterov | 6c303d3 | 2011-11-22 21:13:48 +0100 | [diff] [blame] | 1123 | ret: |
| 1124 | trace_signal_generate(sig, info, t, group, result); |
| 1125 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | } |
| 1127 | |
Sukadev Bhattiprolu | 7978b56 | 2009-04-02 16:58:04 -0700 | [diff] [blame] | 1128 | static int send_signal(int sig, struct siginfo *info, struct task_struct *t, |
| 1129 | int group) |
| 1130 | { |
Sukadev Bhattiprolu | 921cf9f | 2009-04-02 16:58:05 -0700 | [diff] [blame] | 1131 | int from_ancestor_ns = 0; |
| 1132 | |
| 1133 | #ifdef CONFIG_PID_NS |
Oleg Nesterov | dd34200 | 2009-12-15 16:47:24 -0800 | [diff] [blame] | 1134 | from_ancestor_ns = si_fromuser(info) && |
| 1135 | !task_pid_nr_ns(current, task_active_pid_ns(t)); |
Sukadev Bhattiprolu | 921cf9f | 2009-04-02 16:58:05 -0700 | [diff] [blame] | 1136 | #endif |
| 1137 | |
| 1138 | return __send_signal(sig, info, t, group, from_ancestor_ns); |
Sukadev Bhattiprolu | 7978b56 | 2009-04-02 16:58:04 -0700 | [diff] [blame] | 1139 | } |
| 1140 | |
Al Viro | 4aaefee | 2012-11-05 13:09:56 -0500 | [diff] [blame] | 1141 | static void print_fatal_signal(int signr) |
Ingo Molnar | 45807a1 | 2007-07-15 23:40:10 -0700 | [diff] [blame] | 1142 | { |
Al Viro | 4aaefee | 2012-11-05 13:09:56 -0500 | [diff] [blame] | 1143 | struct pt_regs *regs = signal_pt_regs(); |
Wang Xiaoqiang | 747800e | 2016-05-23 16:23:59 -0700 | [diff] [blame] | 1144 | pr_info("potentially unexpected fatal signal %d.\n", signr); |
Ingo Molnar | 45807a1 | 2007-07-15 23:40:10 -0700 | [diff] [blame] | 1145 | |
Al Viro | ca5cd87 | 2007-10-29 04:31:16 +0000 | [diff] [blame] | 1146 | #if defined(__i386__) && !defined(__arch_um__) |
Wang Xiaoqiang | 747800e | 2016-05-23 16:23:59 -0700 | [diff] [blame] | 1147 | pr_info("code at %08lx: ", regs->ip); |
Ingo Molnar | 45807a1 | 2007-07-15 23:40:10 -0700 | [diff] [blame] | 1148 | { |
| 1149 | int i; |
| 1150 | for (i = 0; i < 16; i++) { |
| 1151 | unsigned char insn; |
| 1152 | |
Andi Kleen | b45c6e7 | 2010-01-08 14:42:52 -0800 | [diff] [blame] | 1153 | if (get_user(insn, (unsigned char *)(regs->ip + i))) |
| 1154 | break; |
Wang Xiaoqiang | 747800e | 2016-05-23 16:23:59 -0700 | [diff] [blame] | 1155 | pr_cont("%02x ", insn); |
Ingo Molnar | 45807a1 | 2007-07-15 23:40:10 -0700 | [diff] [blame] | 1156 | } |
| 1157 | } |
Wang Xiaoqiang | 747800e | 2016-05-23 16:23:59 -0700 | [diff] [blame] | 1158 | pr_cont("\n"); |
Ingo Molnar | 45807a1 | 2007-07-15 23:40:10 -0700 | [diff] [blame] | 1159 | #endif |
Ed Swierk | 3a9f84d | 2009-01-26 15:33:31 -0800 | [diff] [blame] | 1160 | preempt_disable(); |
Ingo Molnar | 45807a1 | 2007-07-15 23:40:10 -0700 | [diff] [blame] | 1161 | show_regs(regs); |
Ed Swierk | 3a9f84d | 2009-01-26 15:33:31 -0800 | [diff] [blame] | 1162 | preempt_enable(); |
Ingo Molnar | 45807a1 | 2007-07-15 23:40:10 -0700 | [diff] [blame] | 1163 | } |
| 1164 | |
| 1165 | static int __init setup_print_fatal_signals(char *str) |
| 1166 | { |
| 1167 | get_option (&str, &print_fatal_signals); |
| 1168 | |
| 1169 | return 1; |
| 1170 | } |
| 1171 | |
| 1172 | __setup("print-fatal-signals=", setup_print_fatal_signals); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1173 | |
Pavel Emelyanov | 4cd4b6d | 2008-04-30 00:52:55 -0700 | [diff] [blame] | 1174 | int |
| 1175 | __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
| 1176 | { |
| 1177 | return send_signal(sig, info, p, 1); |
| 1178 | } |
| 1179 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1180 | static int |
| 1181 | specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) |
| 1182 | { |
Pavel Emelyanov | 4cd4b6d | 2008-04-30 00:52:55 -0700 | [diff] [blame] | 1183 | return send_signal(sig, info, t, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1184 | } |
| 1185 | |
Oleg Nesterov | 4a30deb | 2009-09-23 15:57:00 -0700 | [diff] [blame] | 1186 | int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, |
| 1187 | bool group) |
| 1188 | { |
| 1189 | unsigned long flags; |
| 1190 | int ret = -ESRCH; |
| 1191 | |
| 1192 | if (lock_task_sighand(p, &flags)) { |
| 1193 | ret = send_signal(sig, info, p, group); |
| 1194 | unlock_task_sighand(p, &flags); |
| 1195 | } |
| 1196 | |
| 1197 | return ret; |
| 1198 | } |
| 1199 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1200 | /* |
| 1201 | * Force a signal that the process can't ignore: if necessary |
| 1202 | * we unblock the signal and change any SIG_IGN to SIG_DFL. |
Linus Torvalds | ae74c3b | 2006-08-02 20:17:49 -0700 | [diff] [blame] | 1203 | * |
| 1204 | * Note: If we unblock the signal, we always reset it to SIG_DFL, |
| 1205 | * since we do not want to have a signal handler that was blocked |
| 1206 | * be invoked when user space had explicitly blocked it. |
| 1207 | * |
Oleg Nesterov | 80fe728 | 2008-04-30 00:53:05 -0700 | [diff] [blame] | 1208 | * We don't want to have recursive SIGSEGV's etc, for example, |
| 1209 | * that is why we also clear SIGNAL_UNKILLABLE. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1210 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1211 | int |
| 1212 | force_sig_info(int sig, struct siginfo *info, struct task_struct *t) |
| 1213 | { |
| 1214 | unsigned long int flags; |
Linus Torvalds | ae74c3b | 2006-08-02 20:17:49 -0700 | [diff] [blame] | 1215 | int ret, blocked, ignored; |
| 1216 | struct k_sigaction *action; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1217 | |
| 1218 | spin_lock_irqsave(&t->sighand->siglock, flags); |
Linus Torvalds | ae74c3b | 2006-08-02 20:17:49 -0700 | [diff] [blame] | 1219 | action = &t->sighand->action[sig-1]; |
| 1220 | ignored = action->sa.sa_handler == SIG_IGN; |
| 1221 | blocked = sigismember(&t->blocked, sig); |
| 1222 | if (blocked || ignored) { |
| 1223 | action->sa.sa_handler = SIG_DFL; |
| 1224 | if (blocked) { |
| 1225 | sigdelset(&t->blocked, sig); |
Roland McGrath | 7bb44ad | 2007-05-23 13:57:44 -0700 | [diff] [blame] | 1226 | recalc_sigpending_and_wake(t); |
Linus Torvalds | ae74c3b | 2006-08-02 20:17:49 -0700 | [diff] [blame] | 1227 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1228 | } |
Oleg Nesterov | 80fe728 | 2008-04-30 00:53:05 -0700 | [diff] [blame] | 1229 | if (action->sa.sa_handler == SIG_DFL) |
| 1230 | t->signal->flags &= ~SIGNAL_UNKILLABLE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1231 | ret = specific_send_sig_info(sig, info, t); |
| 1232 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
| 1233 | |
| 1234 | return ret; |
| 1235 | } |
| 1236 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1237 | /* |
| 1238 | * Nuke all other threads in the group. |
| 1239 | */ |
Oleg Nesterov | 09faef1 | 2010-05-26 14:43:11 -0700 | [diff] [blame] | 1240 | int zap_other_threads(struct task_struct *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1241 | { |
Oleg Nesterov | 09faef1 | 2010-05-26 14:43:11 -0700 | [diff] [blame] | 1242 | struct task_struct *t = p; |
| 1243 | int count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1245 | p->signal->group_stop_count = 0; |
| 1246 | |
Oleg Nesterov | 09faef1 | 2010-05-26 14:43:11 -0700 | [diff] [blame] | 1247 | while_each_thread(p, t) { |
Tejun Heo | 6dfca32 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 1248 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); |
Oleg Nesterov | 09faef1 | 2010-05-26 14:43:11 -0700 | [diff] [blame] | 1249 | count++; |
| 1250 | |
| 1251 | /* Don't bother with already dead threads */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1252 | if (t->exit_state) |
| 1253 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1254 | sigaddset(&t->pending.signal, SIGKILL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1255 | signal_wake_up(t, 1); |
| 1256 | } |
Oleg Nesterov | 09faef1 | 2010-05-26 14:43:11 -0700 | [diff] [blame] | 1257 | |
| 1258 | return count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | } |
| 1260 | |
Namhyung Kim | b8ed374 | 2010-10-27 15:34:06 -0700 | [diff] [blame] | 1261 | struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, |
| 1262 | unsigned long *flags) |
Oleg Nesterov | f63ee72 | 2006-03-28 16:11:13 -0800 | [diff] [blame] | 1263 | { |
| 1264 | struct sighand_struct *sighand; |
| 1265 | |
| 1266 | for (;;) { |
Paul E. McKenney | c41247e | 2014-05-05 08:18:30 -0700 | [diff] [blame] | 1267 | /* |
| 1268 | * Disable interrupts early to avoid deadlocks. |
| 1269 | * See rcu_read_unlock() comment header for details. |
| 1270 | */ |
Paul E. McKenney | a841796 | 2011-07-19 03:25:36 -0700 | [diff] [blame] | 1271 | local_irq_save(*flags); |
| 1272 | rcu_read_lock(); |
Oleg Nesterov | f63ee72 | 2006-03-28 16:11:13 -0800 | [diff] [blame] | 1273 | sighand = rcu_dereference(tsk->sighand); |
Paul E. McKenney | a841796 | 2011-07-19 03:25:36 -0700 | [diff] [blame] | 1274 | if (unlikely(sighand == NULL)) { |
| 1275 | rcu_read_unlock(); |
| 1276 | local_irq_restore(*flags); |
Oleg Nesterov | f63ee72 | 2006-03-28 16:11:13 -0800 | [diff] [blame] | 1277 | break; |
Paul E. McKenney | a841796 | 2011-07-19 03:25:36 -0700 | [diff] [blame] | 1278 | } |
Oleg Nesterov | 392809b | 2014-09-28 23:44:18 +0200 | [diff] [blame] | 1279 | /* |
| 1280 | * This sighand can be already freed and even reused, but |
| 1281 | * we rely on SLAB_DESTROY_BY_RCU and sighand_ctor() which |
| 1282 | * initializes ->siglock: this slab can't go away, it has |
| 1283 | * the same object type, ->siglock can't be reinitialized. |
| 1284 | * |
| 1285 | * We need to ensure that tsk->sighand is still the same |
| 1286 | * after we take the lock, we can race with de_thread() or |
| 1287 | * __exit_signal(). In the latter case the next iteration |
| 1288 | * must see ->sighand == NULL. |
| 1289 | */ |
Paul E. McKenney | a841796 | 2011-07-19 03:25:36 -0700 | [diff] [blame] | 1290 | spin_lock(&sighand->siglock); |
| 1291 | if (likely(sighand == tsk->sighand)) { |
| 1292 | rcu_read_unlock(); |
Oleg Nesterov | f63ee72 | 2006-03-28 16:11:13 -0800 | [diff] [blame] | 1293 | break; |
Paul E. McKenney | a841796 | 2011-07-19 03:25:36 -0700 | [diff] [blame] | 1294 | } |
| 1295 | spin_unlock(&sighand->siglock); |
| 1296 | rcu_read_unlock(); |
| 1297 | local_irq_restore(*flags); |
Oleg Nesterov | f63ee72 | 2006-03-28 16:11:13 -0800 | [diff] [blame] | 1298 | } |
| 1299 | |
| 1300 | return sighand; |
| 1301 | } |
| 1302 | |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 1303 | /* |
| 1304 | * send signal info to all the members of a group |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 1305 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1306 | int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
| 1307 | { |
David Howells | 694f690 | 2010-08-04 16:59:14 +0100 | [diff] [blame] | 1308 | int ret; |
| 1309 | |
| 1310 | rcu_read_lock(); |
| 1311 | ret = check_kill_permission(sig, info, p); |
| 1312 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1313 | |
Oleg Nesterov | 4a30deb | 2009-09-23 15:57:00 -0700 | [diff] [blame] | 1314 | if (!ret && sig) |
| 1315 | ret = do_send_sig_info(sig, info, p, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1316 | |
| 1317 | return ret; |
| 1318 | } |
| 1319 | |
| 1320 | /* |
Pavel Emelyanov | 146a505 | 2008-02-08 04:19:22 -0800 | [diff] [blame] | 1321 | * __kill_pgrp_info() sends a signal to a process group: this is what the tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1322 | * control characters do (^C, ^Z etc) |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 1323 | * - the caller must hold at least a readlock on tasklist_lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1324 | */ |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1325 | int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1326 | { |
| 1327 | struct task_struct *p = NULL; |
| 1328 | int retval, success; |
| 1329 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1330 | success = 0; |
| 1331 | retval = -ESRCH; |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1332 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1333 | int err = group_send_sig_info(sig, info, p); |
| 1334 | success |= !err; |
| 1335 | retval = err; |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1336 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | return success ? 0 : retval; |
| 1338 | } |
| 1339 | |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1340 | int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1341 | { |
Oleg Nesterov | d36174b | 2008-02-08 04:19:18 -0800 | [diff] [blame] | 1342 | int error = -ESRCH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | struct task_struct *p; |
| 1344 | |
Paul E. McKenney | eca1a08 | 2014-10-23 11:41:22 -0700 | [diff] [blame] | 1345 | for (;;) { |
| 1346 | rcu_read_lock(); |
| 1347 | p = pid_task(pid, PIDTYPE_PID); |
| 1348 | if (p) |
| 1349 | error = group_send_sig_info(sig, info, p); |
| 1350 | rcu_read_unlock(); |
| 1351 | if (likely(!p || error != -ESRCH)) |
| 1352 | return error; |
Oleg Nesterov | 6ca25b5 | 2008-04-30 00:52:45 -0700 | [diff] [blame] | 1353 | |
Paul E. McKenney | eca1a08 | 2014-10-23 11:41:22 -0700 | [diff] [blame] | 1354 | /* |
| 1355 | * The task was unhashed in between, try again. If it |
| 1356 | * is dead, pid_task() will return NULL, if we race with |
| 1357 | * de_thread() it will find the new leader. |
| 1358 | */ |
| 1359 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1360 | } |
| 1361 | |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 1362 | int kill_proc_info(int sig, struct siginfo *info, pid_t pid) |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1363 | { |
| 1364 | int error; |
| 1365 | rcu_read_lock(); |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1366 | error = kill_pid_info(sig, info, find_vpid(pid)); |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1367 | rcu_read_unlock(); |
| 1368 | return error; |
| 1369 | } |
| 1370 | |
Serge Hallyn | d178bc3 | 2011-09-26 10:45:18 -0500 | [diff] [blame] | 1371 | static int kill_as_cred_perm(const struct cred *cred, |
| 1372 | struct task_struct *target) |
| 1373 | { |
| 1374 | const struct cred *pcred = __task_cred(target); |
Eric W. Biederman | 5af6620 | 2012-03-03 20:21:47 -0800 | [diff] [blame] | 1375 | if (!uid_eq(cred->euid, pcred->suid) && !uid_eq(cred->euid, pcred->uid) && |
| 1376 | !uid_eq(cred->uid, pcred->suid) && !uid_eq(cred->uid, pcred->uid)) |
Serge Hallyn | d178bc3 | 2011-09-26 10:45:18 -0500 | [diff] [blame] | 1377 | return 0; |
| 1378 | return 1; |
| 1379 | } |
| 1380 | |
Eric W. Biederman | 2425c08 | 2006-10-02 02:17:28 -0700 | [diff] [blame] | 1381 | /* like kill_pid_info(), but doesn't use uid/euid of "current" */ |
Serge Hallyn | d178bc3 | 2011-09-26 10:45:18 -0500 | [diff] [blame] | 1382 | int kill_pid_info_as_cred(int sig, struct siginfo *info, struct pid *pid, |
| 1383 | const struct cred *cred, u32 secid) |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1384 | { |
| 1385 | int ret = -EINVAL; |
| 1386 | struct task_struct *p; |
Thomas Gleixner | 14d8c9f | 2009-12-10 00:53:17 +0000 | [diff] [blame] | 1387 | unsigned long flags; |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1388 | |
| 1389 | if (!valid_signal(sig)) |
| 1390 | return ret; |
| 1391 | |
Thomas Gleixner | 14d8c9f | 2009-12-10 00:53:17 +0000 | [diff] [blame] | 1392 | rcu_read_lock(); |
Eric W. Biederman | 2425c08 | 2006-10-02 02:17:28 -0700 | [diff] [blame] | 1393 | p = pid_task(pid, PIDTYPE_PID); |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1394 | if (!p) { |
| 1395 | ret = -ESRCH; |
| 1396 | goto out_unlock; |
| 1397 | } |
Serge Hallyn | d178bc3 | 2011-09-26 10:45:18 -0500 | [diff] [blame] | 1398 | if (si_fromuser(info) && !kill_as_cred_perm(cred, p)) { |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1399 | ret = -EPERM; |
| 1400 | goto out_unlock; |
| 1401 | } |
David Quigley | 8f95dc5 | 2006-06-30 01:55:47 -0700 | [diff] [blame] | 1402 | ret = security_task_kill(p, info, sig, secid); |
| 1403 | if (ret) |
| 1404 | goto out_unlock; |
Thomas Gleixner | 14d8c9f | 2009-12-10 00:53:17 +0000 | [diff] [blame] | 1405 | |
| 1406 | if (sig) { |
| 1407 | if (lock_task_sighand(p, &flags)) { |
| 1408 | ret = __send_signal(sig, info, p, 1, 0); |
| 1409 | unlock_task_sighand(p, &flags); |
| 1410 | } else |
| 1411 | ret = -ESRCH; |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1412 | } |
| 1413 | out_unlock: |
Thomas Gleixner | 14d8c9f | 2009-12-10 00:53:17 +0000 | [diff] [blame] | 1414 | rcu_read_unlock(); |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1415 | return ret; |
| 1416 | } |
Serge Hallyn | d178bc3 | 2011-09-26 10:45:18 -0500 | [diff] [blame] | 1417 | EXPORT_SYMBOL_GPL(kill_pid_info_as_cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1418 | |
| 1419 | /* |
| 1420 | * kill_something_info() interprets pid in interesting ways just like kill(2). |
| 1421 | * |
| 1422 | * POSIX specifies that kill(-1,sig) is unspecified, but what we have |
| 1423 | * is probably wrong. Should make it like BSD or SYSV. |
| 1424 | */ |
| 1425 | |
Gustavo Fernando Padovan | bc64efd | 2008-07-25 01:47:33 -0700 | [diff] [blame] | 1426 | static int kill_something_info(int sig, struct siginfo *info, pid_t pid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1427 | { |
Eric W. Biederman | 8d42db18 | 2007-02-12 00:52:55 -0800 | [diff] [blame] | 1428 | int ret; |
Pavel Emelyanov | d5df763 | 2008-02-08 04:19:22 -0800 | [diff] [blame] | 1429 | |
| 1430 | if (pid > 0) { |
| 1431 | rcu_read_lock(); |
| 1432 | ret = kill_pid_info(sig, info, find_vpid(pid)); |
| 1433 | rcu_read_unlock(); |
| 1434 | return ret; |
| 1435 | } |
| 1436 | |
zhongjiang | ec1975a | 2017-07-10 15:52:57 -0700 | [diff] [blame] | 1437 | /* -INT_MIN is undefined. Exclude this case to avoid a UBSAN warning */ |
| 1438 | if (pid == INT_MIN) |
| 1439 | return -ESRCH; |
| 1440 | |
Pavel Emelyanov | d5df763 | 2008-02-08 04:19:22 -0800 | [diff] [blame] | 1441 | read_lock(&tasklist_lock); |
| 1442 | if (pid != -1) { |
| 1443 | ret = __kill_pgrp_info(sig, info, |
| 1444 | pid ? find_vpid(-pid) : task_pgrp(current)); |
| 1445 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1446 | int retval = 0, count = 0; |
| 1447 | struct task_struct * p; |
| 1448 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1449 | for_each_process(p) { |
Sukadev Bhattiprolu | d25141a | 2008-10-29 14:01:11 -0700 | [diff] [blame] | 1450 | if (task_pid_vnr(p) > 1 && |
| 1451 | !same_thread_group(p, current)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1452 | int err = group_send_sig_info(sig, info, p); |
| 1453 | ++count; |
| 1454 | if (err != -EPERM) |
| 1455 | retval = err; |
| 1456 | } |
| 1457 | } |
Eric W. Biederman | 8d42db18 | 2007-02-12 00:52:55 -0800 | [diff] [blame] | 1458 | ret = count ? retval : -ESRCH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1459 | } |
Pavel Emelyanov | d5df763 | 2008-02-08 04:19:22 -0800 | [diff] [blame] | 1460 | read_unlock(&tasklist_lock); |
| 1461 | |
Eric W. Biederman | 8d42db18 | 2007-02-12 00:52:55 -0800 | [diff] [blame] | 1462 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1463 | } |
| 1464 | |
| 1465 | /* |
| 1466 | * These are for backward compatibility with the rest of the kernel source. |
| 1467 | */ |
| 1468 | |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 1469 | int send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1471 | /* |
| 1472 | * Make sure legacy kernel users don't send in bad values |
| 1473 | * (normal paths check this in check_kill_permission). |
| 1474 | */ |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 1475 | if (!valid_signal(sig)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1476 | return -EINVAL; |
| 1477 | |
Oleg Nesterov | 4a30deb | 2009-09-23 15:57:00 -0700 | [diff] [blame] | 1478 | return do_send_sig_info(sig, info, p, false); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1479 | } |
| 1480 | |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1481 | #define __si_special(priv) \ |
| 1482 | ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) |
| 1483 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1484 | int |
| 1485 | send_sig(int sig, struct task_struct *p, int priv) |
| 1486 | { |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1487 | return send_sig_info(sig, __si_special(priv), p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1488 | } |
| 1489 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1490 | void |
| 1491 | force_sig(int sig, struct task_struct *p) |
| 1492 | { |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1493 | force_sig_info(sig, SEND_SIG_PRIV, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | } |
| 1495 | |
| 1496 | /* |
| 1497 | * When things go south during signal handling, we |
| 1498 | * will force a SIGSEGV. And if the signal that caused |
| 1499 | * the problem was already a SIGSEGV, we'll want to |
| 1500 | * make sure we don't even try to deliver the signal.. |
| 1501 | */ |
| 1502 | int |
| 1503 | force_sigsegv(int sig, struct task_struct *p) |
| 1504 | { |
| 1505 | if (sig == SIGSEGV) { |
| 1506 | unsigned long flags; |
| 1507 | spin_lock_irqsave(&p->sighand->siglock, flags); |
| 1508 | p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; |
| 1509 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
| 1510 | } |
| 1511 | force_sig(SIGSEGV, p); |
| 1512 | return 0; |
| 1513 | } |
| 1514 | |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1515 | int kill_pgrp(struct pid *pid, int sig, int priv) |
| 1516 | { |
Pavel Emelyanov | 146a505 | 2008-02-08 04:19:22 -0800 | [diff] [blame] | 1517 | int ret; |
| 1518 | |
| 1519 | read_lock(&tasklist_lock); |
| 1520 | ret = __kill_pgrp_info(sig, __si_special(priv), pid); |
| 1521 | read_unlock(&tasklist_lock); |
| 1522 | |
| 1523 | return ret; |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1524 | } |
| 1525 | EXPORT_SYMBOL(kill_pgrp); |
| 1526 | |
| 1527 | int kill_pid(struct pid *pid, int sig, int priv) |
| 1528 | { |
| 1529 | return kill_pid_info(sig, __si_special(priv), pid); |
| 1530 | } |
| 1531 | EXPORT_SYMBOL(kill_pid); |
| 1532 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1533 | /* |
| 1534 | * These functions support sending signals using preallocated sigqueue |
| 1535 | * structures. This is needed "because realtime applications cannot |
| 1536 | * afford to lose notifications of asynchronous events, like timer |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 1537 | * expirations or I/O completions". In the case of POSIX Timers |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1538 | * we allocate the sigqueue structure from the timer_create. If this |
| 1539 | * allocation fails we are able to report the failure to the application |
| 1540 | * with an EAGAIN error. |
| 1541 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1542 | struct sigqueue *sigqueue_alloc(void) |
| 1543 | { |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 1544 | struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1545 | |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 1546 | if (q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1547 | q->flags |= SIGQUEUE_PREALLOC; |
Naohiro Ooiwa | f84d49b | 2009-11-09 00:46:42 +0900 | [diff] [blame] | 1548 | |
| 1549 | return q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1550 | } |
| 1551 | |
| 1552 | void sigqueue_free(struct sigqueue *q) |
| 1553 | { |
| 1554 | unsigned long flags; |
Oleg Nesterov | 60187d2 | 2007-08-30 23:56:35 -0700 | [diff] [blame] | 1555 | spinlock_t *lock = ¤t->sighand->siglock; |
| 1556 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1557 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
| 1558 | /* |
Oleg Nesterov | c8e85b4f | 2008-05-26 20:55:42 +0400 | [diff] [blame] | 1559 | * We must hold ->siglock while testing q->list |
| 1560 | * to serialize with collect_signal() or with |
Oleg Nesterov | da7978b | 2008-05-23 13:04:41 -0700 | [diff] [blame] | 1561 | * __exit_signal()->flush_sigqueue(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1562 | */ |
Oleg Nesterov | 60187d2 | 2007-08-30 23:56:35 -0700 | [diff] [blame] | 1563 | spin_lock_irqsave(lock, flags); |
Oleg Nesterov | c8e85b4f | 2008-05-26 20:55:42 +0400 | [diff] [blame] | 1564 | q->flags &= ~SIGQUEUE_PREALLOC; |
| 1565 | /* |
| 1566 | * If it is queued it will be freed when dequeued, |
| 1567 | * like the "regular" sigqueue. |
| 1568 | */ |
Oleg Nesterov | 60187d2 | 2007-08-30 23:56:35 -0700 | [diff] [blame] | 1569 | if (!list_empty(&q->list)) |
Oleg Nesterov | c8e85b4f | 2008-05-26 20:55:42 +0400 | [diff] [blame] | 1570 | q = NULL; |
Oleg Nesterov | 60187d2 | 2007-08-30 23:56:35 -0700 | [diff] [blame] | 1571 | spin_unlock_irqrestore(lock, flags); |
| 1572 | |
Oleg Nesterov | c8e85b4f | 2008-05-26 20:55:42 +0400 | [diff] [blame] | 1573 | if (q) |
| 1574 | __sigqueue_free(q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1575 | } |
| 1576 | |
Oleg Nesterov | ac5c215 | 2008-04-30 00:52:57 -0700 | [diff] [blame] | 1577 | int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) |
Pavel Emelyanov | 9e3bd6c | 2008-04-30 00:52:41 -0700 | [diff] [blame] | 1578 | { |
Oleg Nesterov | e62e665 | 2008-04-30 00:52:56 -0700 | [diff] [blame] | 1579 | int sig = q->info.si_signo; |
Oleg Nesterov | 2ca3515 | 2008-04-30 00:52:54 -0700 | [diff] [blame] | 1580 | struct sigpending *pending; |
Oleg Nesterov | e62e665 | 2008-04-30 00:52:56 -0700 | [diff] [blame] | 1581 | unsigned long flags; |
Oleg Nesterov | 163566f | 2011-11-22 21:37:41 +0100 | [diff] [blame] | 1582 | int ret, result; |
Oleg Nesterov | 2ca3515 | 2008-04-30 00:52:54 -0700 | [diff] [blame] | 1583 | |
Pavel Emelyanov | 4cd4b6d | 2008-04-30 00:52:55 -0700 | [diff] [blame] | 1584 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
Oleg Nesterov | e62e665 | 2008-04-30 00:52:56 -0700 | [diff] [blame] | 1585 | |
| 1586 | ret = -1; |
| 1587 | if (!likely(lock_task_sighand(t, &flags))) |
| 1588 | goto ret; |
| 1589 | |
Oleg Nesterov | 7e695a5 | 2008-04-30 00:52:59 -0700 | [diff] [blame] | 1590 | ret = 1; /* the signal is ignored */ |
Oleg Nesterov | 163566f | 2011-11-22 21:37:41 +0100 | [diff] [blame] | 1591 | result = TRACE_SIGNAL_IGNORED; |
Oleg Nesterov | def8cf7 | 2012-03-23 15:02:45 -0700 | [diff] [blame] | 1592 | if (!prepare_signal(sig, t, false)) |
Oleg Nesterov | e62e665 | 2008-04-30 00:52:56 -0700 | [diff] [blame] | 1593 | goto out; |
| 1594 | |
| 1595 | ret = 0; |
Pavel Emelyanov | 9e3bd6c | 2008-04-30 00:52:41 -0700 | [diff] [blame] | 1596 | if (unlikely(!list_empty(&q->list))) { |
| 1597 | /* |
| 1598 | * If an SI_TIMER entry is already queue just increment |
| 1599 | * the overrun count. |
| 1600 | */ |
Pavel Emelyanov | 9e3bd6c | 2008-04-30 00:52:41 -0700 | [diff] [blame] | 1601 | BUG_ON(q->info.si_code != SI_TIMER); |
| 1602 | q->info.si_overrun++; |
Oleg Nesterov | 163566f | 2011-11-22 21:37:41 +0100 | [diff] [blame] | 1603 | result = TRACE_SIGNAL_ALREADY_PENDING; |
Oleg Nesterov | e62e665 | 2008-04-30 00:52:56 -0700 | [diff] [blame] | 1604 | goto out; |
Pavel Emelyanov | 9e3bd6c | 2008-04-30 00:52:41 -0700 | [diff] [blame] | 1605 | } |
Oleg Nesterov | ba66129 | 2008-07-23 20:52:05 +0400 | [diff] [blame] | 1606 | q->info.si_overrun = 0; |
Pavel Emelyanov | 9e3bd6c | 2008-04-30 00:52:41 -0700 | [diff] [blame] | 1607 | |
Pavel Emelyanov | 9e3bd6c | 2008-04-30 00:52:41 -0700 | [diff] [blame] | 1608 | signalfd_notify(t, sig); |
Oleg Nesterov | 2ca3515 | 2008-04-30 00:52:54 -0700 | [diff] [blame] | 1609 | pending = group ? &t->signal->shared_pending : &t->pending; |
Pavel Emelyanov | 9e3bd6c | 2008-04-30 00:52:41 -0700 | [diff] [blame] | 1610 | list_add_tail(&q->list, &pending->list); |
| 1611 | sigaddset(&pending->signal, sig); |
Pavel Emelyanov | 4cd4b6d | 2008-04-30 00:52:55 -0700 | [diff] [blame] | 1612 | complete_signal(sig, t, group); |
Oleg Nesterov | 163566f | 2011-11-22 21:37:41 +0100 | [diff] [blame] | 1613 | result = TRACE_SIGNAL_DELIVERED; |
Oleg Nesterov | e62e665 | 2008-04-30 00:52:56 -0700 | [diff] [blame] | 1614 | out: |
Oleg Nesterov | 163566f | 2011-11-22 21:37:41 +0100 | [diff] [blame] | 1615 | trace_signal_generate(sig, &q->info, t, group, result); |
Oleg Nesterov | e62e665 | 2008-04-30 00:52:56 -0700 | [diff] [blame] | 1616 | unlock_task_sighand(t, &flags); |
| 1617 | ret: |
| 1618 | return ret; |
Pavel Emelyanov | 9e3bd6c | 2008-04-30 00:52:41 -0700 | [diff] [blame] | 1619 | } |
| 1620 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1622 | * Let a parent know about the death of a child. |
| 1623 | * For a stopped/continued status change, use do_notify_parent_cldstop instead. |
Roland McGrath | 2b2a1ff | 2008-07-25 19:45:54 -0700 | [diff] [blame] | 1624 | * |
Oleg Nesterov | 53c8f9f | 2011-06-22 23:08:18 +0200 | [diff] [blame] | 1625 | * Returns true if our parent ignored us and so we've switched to |
| 1626 | * self-reaping. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1627 | */ |
Oleg Nesterov | 53c8f9f | 2011-06-22 23:08:18 +0200 | [diff] [blame] | 1628 | bool do_notify_parent(struct task_struct *tsk, int sig) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1629 | { |
| 1630 | struct siginfo info; |
| 1631 | unsigned long flags; |
| 1632 | struct sighand_struct *psig; |
Oleg Nesterov | 53c8f9f | 2011-06-22 23:08:18 +0200 | [diff] [blame] | 1633 | bool autoreap = false; |
Frederic Weisbecker | 6fac482 | 2012-11-13 14:20:55 +0100 | [diff] [blame] | 1634 | cputime_t utime, stime; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1635 | |
| 1636 | BUG_ON(sig == -1); |
| 1637 | |
| 1638 | /* do_notify_parent_cldstop should have been called instead. */ |
Matthew Wilcox | e1abb39 | 2007-12-06 11:07:35 -0500 | [diff] [blame] | 1639 | BUG_ON(task_is_stopped_or_traced(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1640 | |
Tejun Heo | d21142e | 2011-06-17 16:50:34 +0200 | [diff] [blame] | 1641 | BUG_ON(!tsk->ptrace && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1642 | (tsk->group_leader != tsk || !thread_group_empty(tsk))); |
| 1643 | |
Oleg Nesterov | b6e238d | 2012-03-19 17:03:41 +0100 | [diff] [blame] | 1644 | if (sig != SIGCHLD) { |
| 1645 | /* |
| 1646 | * This is only possible if parent == real_parent. |
| 1647 | * Check if it has changed security domain. |
| 1648 | */ |
| 1649 | if (tsk->parent_exec_id != tsk->parent->self_exec_id) |
| 1650 | sig = SIGCHLD; |
| 1651 | } |
| 1652 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1653 | info.si_signo = sig; |
| 1654 | info.si_errno = 0; |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1655 | /* |
Eric W. Biederman | 3208450 | 2012-05-31 16:26:39 -0700 | [diff] [blame] | 1656 | * We are under tasklist_lock here so our parent is tied to |
| 1657 | * us and cannot change. |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1658 | * |
Eric W. Biederman | 3208450 | 2012-05-31 16:26:39 -0700 | [diff] [blame] | 1659 | * task_active_pid_ns will always return the same pid namespace |
| 1660 | * until a task passes through release_task. |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1661 | * |
| 1662 | * write_lock() currently calls preempt_disable() which is the |
| 1663 | * same as rcu_read_lock(), but according to Oleg, this is not |
| 1664 | * correct to rely on this |
| 1665 | */ |
| 1666 | rcu_read_lock(); |
Eric W. Biederman | 3208450 | 2012-05-31 16:26:39 -0700 | [diff] [blame] | 1667 | info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(tsk->parent)); |
Eric W. Biederman | 54ba47e | 2012-03-13 16:04:35 -0700 | [diff] [blame] | 1668 | info.si_uid = from_kuid_munged(task_cred_xxx(tsk->parent, user_ns), |
| 1669 | task_uid(tsk)); |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1670 | rcu_read_unlock(); |
| 1671 | |
Frederic Weisbecker | 6fac482 | 2012-11-13 14:20:55 +0100 | [diff] [blame] | 1672 | task_cputime(tsk, &utime, &stime); |
| 1673 | info.si_utime = cputime_to_clock_t(utime + tsk->signal->utime); |
| 1674 | info.si_stime = cputime_to_clock_t(stime + tsk->signal->stime); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1675 | |
| 1676 | info.si_status = tsk->exit_code & 0x7f; |
| 1677 | if (tsk->exit_code & 0x80) |
| 1678 | info.si_code = CLD_DUMPED; |
| 1679 | else if (tsk->exit_code & 0x7f) |
| 1680 | info.si_code = CLD_KILLED; |
| 1681 | else { |
| 1682 | info.si_code = CLD_EXITED; |
| 1683 | info.si_status = tsk->exit_code >> 8; |
| 1684 | } |
| 1685 | |
| 1686 | psig = tsk->parent->sighand; |
| 1687 | spin_lock_irqsave(&psig->siglock, flags); |
Tejun Heo | d21142e | 2011-06-17 16:50:34 +0200 | [diff] [blame] | 1688 | if (!tsk->ptrace && sig == SIGCHLD && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1689 | (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || |
| 1690 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { |
| 1691 | /* |
| 1692 | * We are exiting and our parent doesn't care. POSIX.1 |
| 1693 | * defines special semantics for setting SIGCHLD to SIG_IGN |
| 1694 | * or setting the SA_NOCLDWAIT flag: we should be reaped |
| 1695 | * automatically and not left for our parent's wait4 call. |
| 1696 | * Rather than having the parent do it as a magic kind of |
| 1697 | * signal handler, we just set this to tell do_exit that we |
| 1698 | * can be cleaned up without becoming a zombie. Note that |
| 1699 | * we still call __wake_up_parent in this case, because a |
| 1700 | * blocked sys_wait4 might now return -ECHILD. |
| 1701 | * |
| 1702 | * Whether we send SIGCHLD or not for SA_NOCLDWAIT |
| 1703 | * is implementation-defined: we do (if you don't want |
| 1704 | * it, just use SIG_IGN instead). |
| 1705 | */ |
Oleg Nesterov | 53c8f9f | 2011-06-22 23:08:18 +0200 | [diff] [blame] | 1706 | autoreap = true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1707 | if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) |
Oleg Nesterov | 53c8f9f | 2011-06-22 23:08:18 +0200 | [diff] [blame] | 1708 | sig = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1709 | } |
Oleg Nesterov | 53c8f9f | 2011-06-22 23:08:18 +0200 | [diff] [blame] | 1710 | if (valid_signal(sig) && sig) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1711 | __group_send_sig_info(sig, &info, tsk->parent); |
| 1712 | __wake_up_parent(tsk, tsk->parent); |
| 1713 | spin_unlock_irqrestore(&psig->siglock, flags); |
Roland McGrath | 2b2a1ff | 2008-07-25 19:45:54 -0700 | [diff] [blame] | 1714 | |
Oleg Nesterov | 53c8f9f | 2011-06-22 23:08:18 +0200 | [diff] [blame] | 1715 | return autoreap; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1716 | } |
| 1717 | |
Tejun Heo | 75b9595 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 1718 | /** |
| 1719 | * do_notify_parent_cldstop - notify parent of stopped/continued state change |
| 1720 | * @tsk: task reporting the state change |
| 1721 | * @for_ptracer: the notification is for ptracer |
| 1722 | * @why: CLD_{CONTINUED|STOPPED|TRAPPED} to report |
| 1723 | * |
| 1724 | * Notify @tsk's parent that the stopped/continued state has changed. If |
| 1725 | * @for_ptracer is %false, @tsk's group leader notifies to its real parent. |
| 1726 | * If %true, @tsk reports to @tsk->parent which should be the ptracer. |
| 1727 | * |
| 1728 | * CONTEXT: |
| 1729 | * Must be called with tasklist_lock at least read locked. |
| 1730 | */ |
| 1731 | static void do_notify_parent_cldstop(struct task_struct *tsk, |
| 1732 | bool for_ptracer, int why) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1733 | { |
| 1734 | struct siginfo info; |
| 1735 | unsigned long flags; |
Oleg Nesterov | bc505a4 | 2005-09-06 15:17:32 -0700 | [diff] [blame] | 1736 | struct task_struct *parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1737 | struct sighand_struct *sighand; |
Frederic Weisbecker | 6fac482 | 2012-11-13 14:20:55 +0100 | [diff] [blame] | 1738 | cputime_t utime, stime; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1739 | |
Tejun Heo | 75b9595 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 1740 | if (for_ptracer) { |
Oleg Nesterov | bc505a4 | 2005-09-06 15:17:32 -0700 | [diff] [blame] | 1741 | parent = tsk->parent; |
Tejun Heo | 75b9595 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 1742 | } else { |
Oleg Nesterov | bc505a4 | 2005-09-06 15:17:32 -0700 | [diff] [blame] | 1743 | tsk = tsk->group_leader; |
| 1744 | parent = tsk->real_parent; |
| 1745 | } |
| 1746 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1747 | info.si_signo = SIGCHLD; |
| 1748 | info.si_errno = 0; |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1749 | /* |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 1750 | * see comment in do_notify_parent() about the following 4 lines |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1751 | */ |
| 1752 | rcu_read_lock(); |
Eric W. Biederman | 17cf22c | 2010-03-02 14:51:53 -0800 | [diff] [blame] | 1753 | info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(parent)); |
Eric W. Biederman | 54ba47e | 2012-03-13 16:04:35 -0700 | [diff] [blame] | 1754 | info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk)); |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1755 | rcu_read_unlock(); |
| 1756 | |
Frederic Weisbecker | 6fac482 | 2012-11-13 14:20:55 +0100 | [diff] [blame] | 1757 | task_cputime(tsk, &utime, &stime); |
| 1758 | info.si_utime = cputime_to_clock_t(utime); |
| 1759 | info.si_stime = cputime_to_clock_t(stime); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1760 | |
| 1761 | info.si_code = why; |
| 1762 | switch (why) { |
| 1763 | case CLD_CONTINUED: |
| 1764 | info.si_status = SIGCONT; |
| 1765 | break; |
| 1766 | case CLD_STOPPED: |
| 1767 | info.si_status = tsk->signal->group_exit_code & 0x7f; |
| 1768 | break; |
| 1769 | case CLD_TRAPPED: |
| 1770 | info.si_status = tsk->exit_code & 0x7f; |
| 1771 | break; |
| 1772 | default: |
| 1773 | BUG(); |
| 1774 | } |
| 1775 | |
| 1776 | sighand = parent->sighand; |
| 1777 | spin_lock_irqsave(&sighand->siglock, flags); |
| 1778 | if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && |
| 1779 | !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) |
| 1780 | __group_send_sig_info(SIGCHLD, &info, parent); |
| 1781 | /* |
| 1782 | * Even if SIGCHLD is not generated, we must wake up wait4 calls. |
| 1783 | */ |
| 1784 | __wake_up_parent(tsk, parent); |
| 1785 | spin_unlock_irqrestore(&sighand->siglock, flags); |
| 1786 | } |
| 1787 | |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1788 | static inline int may_ptrace_stop(void) |
| 1789 | { |
Tejun Heo | d21142e | 2011-06-17 16:50:34 +0200 | [diff] [blame] | 1790 | if (!likely(current->ptrace)) |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1791 | return 0; |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1792 | /* |
| 1793 | * Are we in the middle of do_coredump? |
| 1794 | * If so and our tracer is also part of the coredump stopping |
| 1795 | * is a deadlock situation, and pointless because our tracer |
| 1796 | * is dead so don't allow us to stop. |
| 1797 | * If SIGKILL was already sent before the caller unlocked |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 1798 | * ->siglock we must see ->core_state != NULL. Otherwise it |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1799 | * is safe to enter schedule(). |
Oleg Nesterov | 9899d11 | 2013-01-21 20:48:00 +0100 | [diff] [blame] | 1800 | * |
| 1801 | * This is almost outdated, a task with the pending SIGKILL can't |
| 1802 | * block in TASK_TRACED. But PTRACE_EVENT_EXIT can be reported |
| 1803 | * after SIGKILL was already dequeued. |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1804 | */ |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 1805 | if (unlikely(current->mm->core_state) && |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1806 | unlikely(current->mm == current->parent->mm)) |
| 1807 | return 0; |
| 1808 | |
| 1809 | return 1; |
| 1810 | } |
| 1811 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1812 | /* |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 1813 | * Return non-zero if there is a SIGKILL that should be waking us up. |
Roland McGrath | 1a669c2 | 2008-02-06 01:37:37 -0800 | [diff] [blame] | 1814 | * Called with the siglock held. |
| 1815 | */ |
| 1816 | static int sigkill_pending(struct task_struct *tsk) |
| 1817 | { |
Oleg Nesterov | 3d749b9 | 2008-07-25 01:47:37 -0700 | [diff] [blame] | 1818 | return sigismember(&tsk->pending.signal, SIGKILL) || |
| 1819 | sigismember(&tsk->signal->shared_pending.signal, SIGKILL); |
Roland McGrath | 1a669c2 | 2008-02-06 01:37:37 -0800 | [diff] [blame] | 1820 | } |
| 1821 | |
| 1822 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1823 | * This must be called with current->sighand->siglock held. |
| 1824 | * |
| 1825 | * This should be the path for all ptrace stops. |
| 1826 | * We always set current->last_siginfo while stopped here. |
| 1827 | * That makes it a way to test a stopped process for |
| 1828 | * being ptrace-stopped vs being job-control-stopped. |
| 1829 | * |
Oleg Nesterov | 20686a3 | 2008-02-08 04:19:03 -0800 | [diff] [blame] | 1830 | * If we actually decide not to stop at all because the tracer |
| 1831 | * is gone, we keep current->exit_code unless clear_code. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1832 | */ |
Tejun Heo | fe1bc6a | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 1833 | static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) |
Namhyung Kim | b840115 | 2010-10-27 15:34:07 -0700 | [diff] [blame] | 1834 | __releases(¤t->sighand->siglock) |
| 1835 | __acquires(¤t->sighand->siglock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1836 | { |
Tejun Heo | ceb6bd6 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 1837 | bool gstop_done = false; |
| 1838 | |
Roland McGrath | 1a669c2 | 2008-02-06 01:37:37 -0800 | [diff] [blame] | 1839 | if (arch_ptrace_stop_needed(exit_code, info)) { |
| 1840 | /* |
| 1841 | * The arch code has something special to do before a |
| 1842 | * ptrace stop. This is allowed to block, e.g. for faults |
| 1843 | * on user stack pages. We can't keep the siglock while |
| 1844 | * calling arch_ptrace_stop, so we must release it now. |
| 1845 | * To preserve proper semantics, we must do this before |
| 1846 | * any signal bookkeeping like checking group_stop_count. |
| 1847 | * Meanwhile, a SIGKILL could come in before we retake the |
| 1848 | * siglock. That must prevent us from sleeping in TASK_TRACED. |
| 1849 | * So after regaining the lock, we must check for SIGKILL. |
| 1850 | */ |
| 1851 | spin_unlock_irq(¤t->sighand->siglock); |
| 1852 | arch_ptrace_stop(exit_code, info); |
| 1853 | spin_lock_irq(¤t->sighand->siglock); |
Oleg Nesterov | 3d749b9 | 2008-07-25 01:47:37 -0700 | [diff] [blame] | 1854 | if (sigkill_pending(current)) |
| 1855 | return; |
Roland McGrath | 1a669c2 | 2008-02-06 01:37:37 -0800 | [diff] [blame] | 1856 | } |
| 1857 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1858 | /* |
Tejun Heo | 81be24b | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 1859 | * We're committing to trapping. TRACED should be visible before |
| 1860 | * TRAPPING is cleared; otherwise, the tracer might fail do_wait(). |
| 1861 | * Also, transition to TRACED and updates to ->jobctl should be |
| 1862 | * atomic with respect to siglock and should be done after the arch |
| 1863 | * hook as siglock is released and regrabbed across it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1864 | */ |
Tejun Heo | 81be24b | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 1865 | set_current_state(TASK_TRACED); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1866 | |
| 1867 | current->last_siginfo = info; |
| 1868 | current->exit_code = exit_code; |
| 1869 | |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 1870 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1871 | * If @why is CLD_STOPPED, we're trapping to participate in a group |
| 1872 | * stop. Do the bookkeeping. Note that if SIGCONT was delievered |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 1873 | * across siglock relocks since INTERRUPT was scheduled, PENDING |
| 1874 | * could be clear now. We act as if SIGCONT is received after |
| 1875 | * TASK_TRACED is entered - ignore it. |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 1876 | */ |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 1877 | if (why == CLD_STOPPED && (current->jobctl & JOBCTL_STOP_PENDING)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1878 | gstop_done = task_participate_group_stop(current); |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 1879 | |
Tejun Heo | fb1d910 | 2011-06-14 11:20:17 +0200 | [diff] [blame] | 1880 | /* any trap clears pending STOP trap, STOP trap clears NOTIFY */ |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 1881 | task_clear_jobctl_pending(current, JOBCTL_TRAP_STOP); |
Tejun Heo | fb1d910 | 2011-06-14 11:20:17 +0200 | [diff] [blame] | 1882 | if (info && info->si_code >> 8 == PTRACE_EVENT_STOP) |
| 1883 | task_clear_jobctl_pending(current, JOBCTL_TRAP_NOTIFY); |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 1884 | |
Tejun Heo | 81be24b | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 1885 | /* entering a trap, clear TRAPPING */ |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 1886 | task_clear_jobctl_trapping(current); |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 1887 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1888 | spin_unlock_irq(¤t->sighand->siglock); |
| 1889 | read_lock(&tasklist_lock); |
Oleg Nesterov | 3d749b9 | 2008-07-25 01:47:37 -0700 | [diff] [blame] | 1890 | if (may_ptrace_stop()) { |
Tejun Heo | ceb6bd6 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 1891 | /* |
| 1892 | * Notify parents of the stop. |
| 1893 | * |
| 1894 | * While ptraced, there are two parents - the ptracer and |
| 1895 | * the real_parent of the group_leader. The ptracer should |
| 1896 | * know about every stop while the real parent is only |
| 1897 | * interested in the completion of group stop. The states |
| 1898 | * for the two don't interact with each other. Notify |
| 1899 | * separately unless they're gonna be duplicates. |
| 1900 | */ |
| 1901 | do_notify_parent_cldstop(current, true, why); |
Oleg Nesterov | bb3696d | 2011-06-24 17:34:23 +0200 | [diff] [blame] | 1902 | if (gstop_done && ptrace_reparented(current)) |
Tejun Heo | ceb6bd6 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 1903 | do_notify_parent_cldstop(current, false, why); |
| 1904 | |
Miklos Szeredi | 53da1d9 | 2009-03-23 16:07:24 +0100 | [diff] [blame] | 1905 | /* |
| 1906 | * Don't want to allow preemption here, because |
| 1907 | * sys_ptrace() needs this task to be inactive. |
| 1908 | * |
| 1909 | * XXX: implement read_unlock_no_resched(). |
| 1910 | */ |
| 1911 | preempt_disable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1912 | read_unlock(&tasklist_lock); |
Miklos Szeredi | 53da1d9 | 2009-03-23 16:07:24 +0100 | [diff] [blame] | 1913 | preempt_enable_no_resched(); |
Oleg Nesterov | 5d8f72b | 2012-10-26 19:46:06 +0200 | [diff] [blame] | 1914 | freezable_schedule(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1915 | } else { |
| 1916 | /* |
| 1917 | * By the time we got the lock, our tracer went away. |
Oleg Nesterov | 6405f7f | 2008-02-08 04:19:00 -0800 | [diff] [blame] | 1918 | * Don't drop the lock yet, another tracer may come. |
Tejun Heo | ceb6bd6 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 1919 | * |
| 1920 | * If @gstop_done, the ptracer went away between group stop |
| 1921 | * completion and here. During detach, it would have set |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 1922 | * JOBCTL_STOP_PENDING on us and we'll re-enter |
| 1923 | * TASK_STOPPED in do_signal_stop() on return, so notifying |
| 1924 | * the real parent of the group stop completion is enough. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1925 | */ |
Tejun Heo | ceb6bd6 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 1926 | if (gstop_done) |
| 1927 | do_notify_parent_cldstop(current, false, why); |
| 1928 | |
Oleg Nesterov | 9899d11 | 2013-01-21 20:48:00 +0100 | [diff] [blame] | 1929 | /* tasklist protects us from ptrace_freeze_traced() */ |
Oleg Nesterov | 6405f7f | 2008-02-08 04:19:00 -0800 | [diff] [blame] | 1930 | __set_current_state(TASK_RUNNING); |
Oleg Nesterov | 20686a3 | 2008-02-08 04:19:03 -0800 | [diff] [blame] | 1931 | if (clear_code) |
| 1932 | current->exit_code = 0; |
Oleg Nesterov | 6405f7f | 2008-02-08 04:19:00 -0800 | [diff] [blame] | 1933 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1934 | } |
| 1935 | |
| 1936 | /* |
| 1937 | * We are back. Now reacquire the siglock before touching |
| 1938 | * last_siginfo, so that we are sure to have synchronized with |
| 1939 | * any signal-sending on another CPU that wants to examine it. |
| 1940 | */ |
| 1941 | spin_lock_irq(¤t->sighand->siglock); |
| 1942 | current->last_siginfo = NULL; |
| 1943 | |
Tejun Heo | 544b2c9 | 2011-06-14 11:20:18 +0200 | [diff] [blame] | 1944 | /* LISTENING can be set only during STOP traps, clear it */ |
| 1945 | current->jobctl &= ~JOBCTL_LISTENING; |
| 1946 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1947 | /* |
| 1948 | * Queued signals ignored us while we were stopped for tracing. |
| 1949 | * So check for any that we should take before resuming user mode. |
Roland McGrath | b74d0de | 2007-06-06 03:59:00 -0700 | [diff] [blame] | 1950 | * This sets TIF_SIGPENDING, but never clears it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1951 | */ |
Roland McGrath | b74d0de | 2007-06-06 03:59:00 -0700 | [diff] [blame] | 1952 | recalc_sigpending_tsk(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1953 | } |
| 1954 | |
Tejun Heo | 3544d72 | 2011-06-14 11:20:15 +0200 | [diff] [blame] | 1955 | static void ptrace_do_notify(int signr, int exit_code, int why) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1956 | { |
| 1957 | siginfo_t info; |
| 1958 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1959 | memset(&info, 0, sizeof info); |
Tejun Heo | 3544d72 | 2011-06-14 11:20:15 +0200 | [diff] [blame] | 1960 | info.si_signo = signr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1961 | info.si_code = exit_code; |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1962 | info.si_pid = task_pid_vnr(current); |
Eric W. Biederman | 078de5f | 2012-02-08 07:00:08 -0800 | [diff] [blame] | 1963 | info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1964 | |
| 1965 | /* Let the debugger run. */ |
Tejun Heo | 3544d72 | 2011-06-14 11:20:15 +0200 | [diff] [blame] | 1966 | ptrace_stop(exit_code, why, 1, &info); |
| 1967 | } |
| 1968 | |
| 1969 | void ptrace_notify(int exit_code) |
| 1970 | { |
| 1971 | BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); |
Oleg Nesterov | f784e8a | 2012-08-26 21:12:17 +0200 | [diff] [blame] | 1972 | if (unlikely(current->task_works)) |
| 1973 | task_work_run(); |
Tejun Heo | 3544d72 | 2011-06-14 11:20:15 +0200 | [diff] [blame] | 1974 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1975 | spin_lock_irq(¤t->sighand->siglock); |
Tejun Heo | 3544d72 | 2011-06-14 11:20:15 +0200 | [diff] [blame] | 1976 | ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1977 | spin_unlock_irq(¤t->sighand->siglock); |
| 1978 | } |
| 1979 | |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 1980 | /** |
| 1981 | * do_signal_stop - handle group stop for SIGSTOP and other stop signals |
| 1982 | * @signr: signr causing group stop if initiating |
| 1983 | * |
| 1984 | * If %JOBCTL_STOP_PENDING is not set yet, initiate group stop with @signr |
| 1985 | * and participate in it. If already set, participate in the existing |
| 1986 | * group stop. If participated in a group stop (and thus slept), %true is |
| 1987 | * returned with siglock released. |
| 1988 | * |
| 1989 | * If ptraced, this function doesn't handle stop itself. Instead, |
| 1990 | * %JOBCTL_TRAP_STOP is scheduled and %false is returned with siglock |
| 1991 | * untouched. The caller must ensure that INTERRUPT trap handling takes |
| 1992 | * places afterwards. |
| 1993 | * |
| 1994 | * CONTEXT: |
| 1995 | * Must be called with @current->sighand->siglock held, which is released |
| 1996 | * on %true return. |
| 1997 | * |
| 1998 | * RETURNS: |
| 1999 | * %false if group stop is already cancelled or ptrace trap is scheduled. |
| 2000 | * %true if participated in group stop. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2001 | */ |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2002 | static bool do_signal_stop(int signr) |
| 2003 | __releases(¤t->sighand->siglock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2004 | { |
| 2005 | struct signal_struct *sig = current->signal; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2006 | |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 2007 | if (!(current->jobctl & JOBCTL_STOP_PENDING)) { |
Palmer Dabbelt | b76808e | 2015-04-30 21:19:57 -0700 | [diff] [blame] | 2008 | unsigned long gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME; |
Oleg Nesterov | f558b7e | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 2009 | struct task_struct *t; |
| 2010 | |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 2011 | /* signr will be recorded in task->jobctl for retries */ |
| 2012 | WARN_ON_ONCE(signr & ~JOBCTL_STOP_SIGMASK); |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2013 | |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 2014 | if (!likely(current->jobctl & JOBCTL_STOP_DEQUEUED) || |
Oleg Nesterov | 573cf9a | 2008-04-30 00:52:36 -0700 | [diff] [blame] | 2015 | unlikely(signal_group_exit(sig))) |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2016 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2017 | /* |
Tejun Heo | 408a37d | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2018 | * There is no group stop already in progress. We must |
| 2019 | * initiate one now. |
| 2020 | * |
| 2021 | * While ptraced, a task may be resumed while group stop is |
| 2022 | * still in effect and then receive a stop signal and |
| 2023 | * initiate another group stop. This deviates from the |
| 2024 | * usual behavior as two consecutive stop signals can't |
Oleg Nesterov | 780006eac | 2011-04-01 20:12:16 +0200 | [diff] [blame] | 2025 | * cause two group stops when !ptraced. That is why we |
| 2026 | * also check !task_is_stopped(t) below. |
Tejun Heo | 408a37d | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2027 | * |
| 2028 | * The condition can be distinguished by testing whether |
| 2029 | * SIGNAL_STOP_STOPPED is already set. Don't generate |
| 2030 | * group_exit_code in such case. |
| 2031 | * |
| 2032 | * This is not necessary for SIGNAL_STOP_CONTINUED because |
| 2033 | * an intervening stop signal is required to cause two |
| 2034 | * continued events regardless of ptrace. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2035 | */ |
Tejun Heo | 408a37d | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2036 | if (!(sig->flags & SIGNAL_STOP_STOPPED)) |
| 2037 | sig->group_exit_code = signr; |
Oleg Nesterov | a122b34 | 2006-03-28 16:11:22 -0800 | [diff] [blame] | 2038 | |
Tejun Heo | 7dd3db5 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 2039 | sig->group_stop_count = 0; |
| 2040 | |
| 2041 | if (task_set_jobctl_pending(current, signr | gstop)) |
| 2042 | sig->group_stop_count++; |
| 2043 | |
Oleg Nesterov | 8d38f20 | 2014-01-23 15:55:56 -0800 | [diff] [blame] | 2044 | t = current; |
| 2045 | while_each_thread(current, t) { |
Oleg Nesterov | a122b34 | 2006-03-28 16:11:22 -0800 | [diff] [blame] | 2046 | /* |
| 2047 | * Setting state to TASK_STOPPED for a group |
| 2048 | * stop is always done with the siglock held, |
| 2049 | * so this check has no races. |
| 2050 | */ |
Tejun Heo | 7dd3db5 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 2051 | if (!task_is_stopped(t) && |
| 2052 | task_set_jobctl_pending(t, signr | gstop)) { |
Roland McGrath | ae6d2ed | 2009-09-23 15:56:53 -0700 | [diff] [blame] | 2053 | sig->group_stop_count++; |
Tejun Heo | fb1d910 | 2011-06-14 11:20:17 +0200 | [diff] [blame] | 2054 | if (likely(!(t->ptrace & PT_SEIZED))) |
| 2055 | signal_wake_up(t, 0); |
| 2056 | else |
| 2057 | ptrace_trap_notify(t); |
Oleg Nesterov | a122b34 | 2006-03-28 16:11:22 -0800 | [diff] [blame] | 2058 | } |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2059 | } |
Roland McGrath | ae6d2ed | 2009-09-23 15:56:53 -0700 | [diff] [blame] | 2060 | } |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2061 | |
Tejun Heo | d21142e | 2011-06-17 16:50:34 +0200 | [diff] [blame] | 2062 | if (likely(!current->ptrace)) { |
Tejun Heo | 5224fa3 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2063 | int notify = 0; |
| 2064 | |
| 2065 | /* |
| 2066 | * If there are no other threads in the group, or if there |
| 2067 | * is a group stop in progress and we are the last to stop, |
| 2068 | * report to the parent. |
| 2069 | */ |
| 2070 | if (task_participate_group_stop(current)) |
| 2071 | notify = CLD_STOPPED; |
| 2072 | |
Roland McGrath | ae6d2ed | 2009-09-23 15:56:53 -0700 | [diff] [blame] | 2073 | __set_current_state(TASK_STOPPED); |
Tejun Heo | 5224fa3 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2074 | spin_unlock_irq(¤t->sighand->siglock); |
| 2075 | |
Tejun Heo | 62bcf9d | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2076 | /* |
| 2077 | * Notify the parent of the group stop completion. Because |
| 2078 | * we're not holding either the siglock or tasklist_lock |
| 2079 | * here, ptracer may attach inbetween; however, this is for |
| 2080 | * group stop and should always be delivered to the real |
| 2081 | * parent of the group leader. The new ptracer will get |
| 2082 | * its notification when this task transitions into |
| 2083 | * TASK_TRACED. |
| 2084 | */ |
Tejun Heo | 5224fa3 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2085 | if (notify) { |
| 2086 | read_lock(&tasklist_lock); |
Tejun Heo | 62bcf9d | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2087 | do_notify_parent_cldstop(current, false, notify); |
Tejun Heo | 5224fa3 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2088 | read_unlock(&tasklist_lock); |
| 2089 | } |
| 2090 | |
| 2091 | /* Now we don't run again until woken by SIGCONT or SIGKILL */ |
Oleg Nesterov | 5d8f72b | 2012-10-26 19:46:06 +0200 | [diff] [blame] | 2092 | freezable_schedule(); |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2093 | return true; |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2094 | } else { |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2095 | /* |
| 2096 | * While ptraced, group stop is handled by STOP trap. |
| 2097 | * Schedule it and let the caller deal with it. |
| 2098 | */ |
| 2099 | task_set_jobctl_pending(current, JOBCTL_TRAP_STOP); |
| 2100 | return false; |
Roland McGrath | ae6d2ed | 2009-09-23 15:56:53 -0700 | [diff] [blame] | 2101 | } |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2102 | } |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2103 | |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2104 | /** |
| 2105 | * do_jobctl_trap - take care of ptrace jobctl traps |
| 2106 | * |
Tejun Heo | 3544d72 | 2011-06-14 11:20:15 +0200 | [diff] [blame] | 2107 | * When PT_SEIZED, it's used for both group stop and explicit |
| 2108 | * SEIZE/INTERRUPT traps. Both generate PTRACE_EVENT_STOP trap with |
| 2109 | * accompanying siginfo. If stopped, lower eight bits of exit_code contain |
| 2110 | * the stop signal; otherwise, %SIGTRAP. |
| 2111 | * |
| 2112 | * When !PT_SEIZED, it's used only for group stop trap with stop signal |
| 2113 | * number as exit_code and no siginfo. |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2114 | * |
| 2115 | * CONTEXT: |
| 2116 | * Must be called with @current->sighand->siglock held, which may be |
| 2117 | * released and re-acquired before returning with intervening sleep. |
| 2118 | */ |
| 2119 | static void do_jobctl_trap(void) |
| 2120 | { |
Tejun Heo | 3544d72 | 2011-06-14 11:20:15 +0200 | [diff] [blame] | 2121 | struct signal_struct *signal = current->signal; |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2122 | int signr = current->jobctl & JOBCTL_STOP_SIGMASK; |
Tejun Heo | d79fdd6 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2123 | |
Tejun Heo | 3544d72 | 2011-06-14 11:20:15 +0200 | [diff] [blame] | 2124 | if (current->ptrace & PT_SEIZED) { |
| 2125 | if (!signal->group_stop_count && |
| 2126 | !(signal->flags & SIGNAL_STOP_STOPPED)) |
| 2127 | signr = SIGTRAP; |
| 2128 | WARN_ON_ONCE(!signr); |
| 2129 | ptrace_do_notify(signr, signr | (PTRACE_EVENT_STOP << 8), |
| 2130 | CLD_STOPPED); |
| 2131 | } else { |
| 2132 | WARN_ON_ONCE(!signr); |
| 2133 | ptrace_stop(signr, CLD_STOPPED, 0, NULL); |
Roland McGrath | ae6d2ed | 2009-09-23 15:56:53 -0700 | [diff] [blame] | 2134 | current->exit_code = 0; |
| 2135 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2136 | } |
| 2137 | |
Al Viro | 94eb22d | 2012-11-05 13:08:06 -0500 | [diff] [blame] | 2138 | static int ptrace_signal(int signr, siginfo_t *info) |
Roland McGrath | 18c98b6 | 2008-04-17 18:44:38 -0700 | [diff] [blame] | 2139 | { |
Al Viro | b7f9591 | 2012-11-05 13:06:22 -0500 | [diff] [blame] | 2140 | ptrace_signal_deliver(); |
Oleg Nesterov | 8a35241 | 2011-07-21 17:06:53 +0200 | [diff] [blame] | 2141 | /* |
| 2142 | * We do not check sig_kernel_stop(signr) but set this marker |
| 2143 | * unconditionally because we do not know whether debugger will |
| 2144 | * change signr. This flag has no meaning unless we are going |
| 2145 | * to stop after return from ptrace_stop(). In this case it will |
| 2146 | * be checked in do_signal_stop(), we should only stop if it was |
| 2147 | * not cleared by SIGCONT while we were sleeping. See also the |
| 2148 | * comment in dequeue_signal(). |
| 2149 | */ |
| 2150 | current->jobctl |= JOBCTL_STOP_DEQUEUED; |
Tejun Heo | fe1bc6a | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2151 | ptrace_stop(signr, CLD_TRAPPED, 0, info); |
Roland McGrath | 18c98b6 | 2008-04-17 18:44:38 -0700 | [diff] [blame] | 2152 | |
| 2153 | /* We're back. Did the debugger cancel the sig? */ |
| 2154 | signr = current->exit_code; |
| 2155 | if (signr == 0) |
| 2156 | return signr; |
| 2157 | |
| 2158 | current->exit_code = 0; |
| 2159 | |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 2160 | /* |
| 2161 | * Update the siginfo structure if the signal has |
| 2162 | * changed. If the debugger wanted something |
| 2163 | * specific in the siginfo structure then it should |
| 2164 | * have updated *info via PTRACE_SETSIGINFO. |
| 2165 | */ |
Roland McGrath | 18c98b6 | 2008-04-17 18:44:38 -0700 | [diff] [blame] | 2166 | if (signr != info->si_signo) { |
| 2167 | info->si_signo = signr; |
| 2168 | info->si_errno = 0; |
| 2169 | info->si_code = SI_USER; |
Serge E. Hallyn | 6b550f9 | 2012-01-10 15:11:37 -0800 | [diff] [blame] | 2170 | rcu_read_lock(); |
Roland McGrath | 18c98b6 | 2008-04-17 18:44:38 -0700 | [diff] [blame] | 2171 | info->si_pid = task_pid_vnr(current->parent); |
Eric W. Biederman | 54ba47e | 2012-03-13 16:04:35 -0700 | [diff] [blame] | 2172 | info->si_uid = from_kuid_munged(current_user_ns(), |
| 2173 | task_uid(current->parent)); |
Serge E. Hallyn | 6b550f9 | 2012-01-10 15:11:37 -0800 | [diff] [blame] | 2174 | rcu_read_unlock(); |
Roland McGrath | 18c98b6 | 2008-04-17 18:44:38 -0700 | [diff] [blame] | 2175 | } |
| 2176 | |
| 2177 | /* If the (new) signal is now blocked, requeue it. */ |
| 2178 | if (sigismember(¤t->blocked, signr)) { |
| 2179 | specific_send_sig_info(signr, info, current); |
| 2180 | signr = 0; |
| 2181 | } |
| 2182 | |
| 2183 | return signr; |
| 2184 | } |
| 2185 | |
Richard Weinberger | 828b1f6 | 2013-10-07 15:26:57 +0200 | [diff] [blame] | 2186 | int get_signal(struct ksignal *ksig) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2187 | { |
Oleg Nesterov | f6b76d4 | 2008-04-30 00:52:47 -0700 | [diff] [blame] | 2188 | struct sighand_struct *sighand = current->sighand; |
| 2189 | struct signal_struct *signal = current->signal; |
| 2190 | int signr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2191 | |
Oleg Nesterov | f784e8a | 2012-08-26 21:12:17 +0200 | [diff] [blame] | 2192 | if (unlikely(current->task_works)) |
| 2193 | task_work_run(); |
Al Viro | 7266702 | 2012-07-15 14:10:52 +0400 | [diff] [blame] | 2194 | |
Srikar Dronamraju | 0326f5a | 2012-03-13 23:30:11 +0530 | [diff] [blame] | 2195 | if (unlikely(uprobe_deny_signal())) |
| 2196 | return 0; |
| 2197 | |
Roland McGrath | 13b1c3d | 2008-03-03 20:22:05 -0800 | [diff] [blame] | 2198 | /* |
Oleg Nesterov | 5d8f72b | 2012-10-26 19:46:06 +0200 | [diff] [blame] | 2199 | * Do this once, we can't return to user-mode if freezing() == T. |
| 2200 | * do_signal_stop() and ptrace_stop() do freezable_schedule() and |
| 2201 | * thus do not need another check after return. |
Roland McGrath | 13b1c3d | 2008-03-03 20:22:05 -0800 | [diff] [blame] | 2202 | */ |
Rafael J. Wysocki | fc558a7 | 2006-03-23 03:00:05 -0800 | [diff] [blame] | 2203 | try_to_freeze(); |
| 2204 | |
Oleg Nesterov | 5d8f72b | 2012-10-26 19:46:06 +0200 | [diff] [blame] | 2205 | relock: |
Oleg Nesterov | f6b76d4 | 2008-04-30 00:52:47 -0700 | [diff] [blame] | 2206 | spin_lock_irq(&sighand->siglock); |
Oleg Nesterov | 021e1ae | 2008-04-30 00:53:00 -0700 | [diff] [blame] | 2207 | /* |
| 2208 | * Every stopped thread goes here after wakeup. Check to see if |
| 2209 | * we should notify the parent, prepare_signal(SIGCONT) encodes |
| 2210 | * the CLD_ si_code into SIGNAL_CLD_MASK bits. |
| 2211 | */ |
Oleg Nesterov | f6b76d4 | 2008-04-30 00:52:47 -0700 | [diff] [blame] | 2212 | if (unlikely(signal->flags & SIGNAL_CLD_MASK)) { |
Tejun Heo | c672af3 | 2011-03-23 10:36:59 +0100 | [diff] [blame] | 2213 | int why; |
| 2214 | |
| 2215 | if (signal->flags & SIGNAL_CLD_CONTINUED) |
| 2216 | why = CLD_CONTINUED; |
| 2217 | else |
| 2218 | why = CLD_STOPPED; |
| 2219 | |
Oleg Nesterov | f6b76d4 | 2008-04-30 00:52:47 -0700 | [diff] [blame] | 2220 | signal->flags &= ~SIGNAL_CLD_MASK; |
Roland McGrath | ae6d2ed | 2009-09-23 15:56:53 -0700 | [diff] [blame] | 2221 | |
Oleg Nesterov | f6b76d4 | 2008-04-30 00:52:47 -0700 | [diff] [blame] | 2222 | spin_unlock_irq(&sighand->siglock); |
Oleg Nesterov | e442055 | 2008-04-30 00:52:44 -0700 | [diff] [blame] | 2223 | |
Tejun Heo | ceb6bd6 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2224 | /* |
| 2225 | * Notify the parent that we're continuing. This event is |
| 2226 | * always per-process and doesn't make whole lot of sense |
| 2227 | * for ptracers, who shouldn't consume the state via |
| 2228 | * wait(2) either, but, for backward compatibility, notify |
| 2229 | * the ptracer of the group leader too unless it's gonna be |
| 2230 | * a duplicate. |
| 2231 | */ |
Tejun Heo | edf2ed1 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2232 | read_lock(&tasklist_lock); |
Tejun Heo | ceb6bd6 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2233 | do_notify_parent_cldstop(current, false, why); |
| 2234 | |
Oleg Nesterov | bb3696d | 2011-06-24 17:34:23 +0200 | [diff] [blame] | 2235 | if (ptrace_reparented(current->group_leader)) |
| 2236 | do_notify_parent_cldstop(current->group_leader, |
| 2237 | true, why); |
Tejun Heo | edf2ed1 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2238 | read_unlock(&tasklist_lock); |
Tejun Heo | ceb6bd6 | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2239 | |
Oleg Nesterov | e442055 | 2008-04-30 00:52:44 -0700 | [diff] [blame] | 2240 | goto relock; |
| 2241 | } |
| 2242 | |
Eric W. Biederman | 39beaea | 2019-02-06 18:39:40 -0600 | [diff] [blame] | 2243 | /* Has this task already been marked for death? */ |
Eric W. Biederman | aa74f26 | 2019-02-11 23:27:42 -0600 | [diff] [blame] | 2244 | if (signal_group_exit(signal)) { |
| 2245 | ksig->info.si_signo = signr = SIGKILL; |
| 2246 | sigdelset(¤t->pending.signal, SIGKILL); |
| 2247 | recalc_sigpending(); |
Eric W. Biederman | 39beaea | 2019-02-06 18:39:40 -0600 | [diff] [blame] | 2248 | goto fatal; |
Eric W. Biederman | aa74f26 | 2019-02-11 23:27:42 -0600 | [diff] [blame] | 2249 | } |
Eric W. Biederman | 39beaea | 2019-02-06 18:39:40 -0600 | [diff] [blame] | 2250 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2251 | for (;;) { |
| 2252 | struct k_sigaction *ka; |
Tejun Heo | dd1d677 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 2253 | |
| 2254 | if (unlikely(current->jobctl & JOBCTL_STOP_PENDING) && |
| 2255 | do_signal_stop(0)) |
Roland McGrath | 7bcf6a2 | 2008-07-25 19:45:53 -0700 | [diff] [blame] | 2256 | goto relock; |
Oleg Nesterov | 1be5396 | 2009-12-15 16:47:26 -0800 | [diff] [blame] | 2257 | |
Tejun Heo | 73ddff2 | 2011-06-14 11:20:14 +0200 | [diff] [blame] | 2258 | if (unlikely(current->jobctl & JOBCTL_TRAP_MASK)) { |
| 2259 | do_jobctl_trap(); |
| 2260 | spin_unlock_irq(&sighand->siglock); |
| 2261 | goto relock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2262 | } |
| 2263 | |
Eric W. Biederman | 181f1f0d | 2019-02-06 17:51:47 -0600 | [diff] [blame] | 2264 | /* |
| 2265 | * Signals generated by the execution of an instruction |
| 2266 | * need to be delivered before any other pending signals |
| 2267 | * so that the instruction pointer in the signal stack |
| 2268 | * frame points to the faulting instruction. |
| 2269 | */ |
| 2270 | signr = dequeue_synchronous_signal(&ksig->info); |
| 2271 | if (!signr) |
| 2272 | signr = dequeue_signal(current, ¤t->blocked, &ksig->info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2273 | |
Tejun Heo | dd1d677 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 2274 | if (!signr) |
| 2275 | break; /* will return 0 */ |
| 2276 | |
Oleg Nesterov | 8a35241 | 2011-07-21 17:06:53 +0200 | [diff] [blame] | 2277 | if (unlikely(current->ptrace) && signr != SIGKILL) { |
Richard Weinberger | 828b1f6 | 2013-10-07 15:26:57 +0200 | [diff] [blame] | 2278 | signr = ptrace_signal(signr, &ksig->info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2279 | if (!signr) |
Tejun Heo | dd1d677 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 2280 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2281 | } |
| 2282 | |
Tejun Heo | dd1d677 | 2011-06-02 11:14:00 +0200 | [diff] [blame] | 2283 | ka = &sighand->action[signr-1]; |
| 2284 | |
Masami Hiramatsu | f9d4257 | 2009-11-24 16:56:51 -0500 | [diff] [blame] | 2285 | /* Trace actually delivered signals. */ |
Richard Weinberger | 828b1f6 | 2013-10-07 15:26:57 +0200 | [diff] [blame] | 2286 | trace_signal_deliver(signr, &ksig->info, ka); |
Masami Hiramatsu | f9d4257 | 2009-11-24 16:56:51 -0500 | [diff] [blame] | 2287 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2288 | if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ |
| 2289 | continue; |
| 2290 | if (ka->sa.sa_handler != SIG_DFL) { |
| 2291 | /* Run the handler. */ |
Richard Weinberger | 828b1f6 | 2013-10-07 15:26:57 +0200 | [diff] [blame] | 2292 | ksig->ka = *ka; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2293 | |
| 2294 | if (ka->sa.sa_flags & SA_ONESHOT) |
| 2295 | ka->sa.sa_handler = SIG_DFL; |
| 2296 | |
| 2297 | break; /* will return non-zero "signr" value */ |
| 2298 | } |
| 2299 | |
| 2300 | /* |
| 2301 | * Now we are doing the default action for this signal. |
| 2302 | */ |
| 2303 | if (sig_kernel_ignore(signr)) /* Default is nothing. */ |
| 2304 | continue; |
| 2305 | |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 2306 | /* |
Sukadev Bhattiprolu | 0fbc26a | 2007-10-18 23:40:13 -0700 | [diff] [blame] | 2307 | * Global init gets no signals it doesn't want. |
Sukadev Bhattiprolu | b3bfa0c | 2009-04-02 16:58:08 -0700 | [diff] [blame] | 2308 | * Container-init gets no signals it doesn't want from same |
| 2309 | * container. |
| 2310 | * |
| 2311 | * Note that if global/container-init sees a sig_kernel_only() |
| 2312 | * signal here, the signal must have been generated internally |
| 2313 | * or must have come from an ancestor namespace. In either |
| 2314 | * case, the signal cannot be dropped. |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 2315 | */ |
Oleg Nesterov | fae5fa4 | 2008-04-30 00:53:03 -0700 | [diff] [blame] | 2316 | if (unlikely(signal->flags & SIGNAL_UNKILLABLE) && |
Sukadev Bhattiprolu | b3bfa0c | 2009-04-02 16:58:08 -0700 | [diff] [blame] | 2317 | !sig_kernel_only(signr)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2318 | continue; |
| 2319 | |
| 2320 | if (sig_kernel_stop(signr)) { |
| 2321 | /* |
| 2322 | * The default action is to stop all threads in |
| 2323 | * the thread group. The job control signals |
| 2324 | * do nothing in an orphaned pgrp, but SIGSTOP |
| 2325 | * always works. Note that siglock needs to be |
| 2326 | * dropped during the call to is_orphaned_pgrp() |
| 2327 | * because of lock ordering with tasklist_lock. |
| 2328 | * This allows an intervening SIGCONT to be posted. |
| 2329 | * We need to check for that and bail out if necessary. |
| 2330 | */ |
| 2331 | if (signr != SIGSTOP) { |
Oleg Nesterov | f6b76d4 | 2008-04-30 00:52:47 -0700 | [diff] [blame] | 2332 | spin_unlock_irq(&sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2333 | |
| 2334 | /* signals can be posted during this window */ |
| 2335 | |
Eric W. Biederman | 3e7cd6c | 2007-02-12 00:52:58 -0800 | [diff] [blame] | 2336 | if (is_current_pgrp_orphaned()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2337 | goto relock; |
| 2338 | |
Oleg Nesterov | f6b76d4 | 2008-04-30 00:52:47 -0700 | [diff] [blame] | 2339 | spin_lock_irq(&sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2340 | } |
| 2341 | |
Richard Weinberger | 828b1f6 | 2013-10-07 15:26:57 +0200 | [diff] [blame] | 2342 | if (likely(do_signal_stop(ksig->info.si_signo))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2343 | /* It released the siglock. */ |
| 2344 | goto relock; |
| 2345 | } |
| 2346 | |
| 2347 | /* |
| 2348 | * We didn't actually stop, due to a race |
| 2349 | * with SIGCONT or something like that. |
| 2350 | */ |
| 2351 | continue; |
| 2352 | } |
| 2353 | |
Eric W. Biederman | 39beaea | 2019-02-06 18:39:40 -0600 | [diff] [blame] | 2354 | fatal: |
Oleg Nesterov | f6b76d4 | 2008-04-30 00:52:47 -0700 | [diff] [blame] | 2355 | spin_unlock_irq(&sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2356 | |
| 2357 | /* |
| 2358 | * Anything else is fatal, maybe with a core dump. |
| 2359 | */ |
| 2360 | current->flags |= PF_SIGNALED; |
Oleg Nesterov | 2dce81b | 2008-04-30 00:52:58 -0700 | [diff] [blame] | 2361 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2362 | if (sig_kernel_coredump(signr)) { |
Oleg Nesterov | 2dce81b | 2008-04-30 00:52:58 -0700 | [diff] [blame] | 2363 | if (print_fatal_signals) |
Richard Weinberger | 828b1f6 | 2013-10-07 15:26:57 +0200 | [diff] [blame] | 2364 | print_fatal_signal(ksig->info.si_signo); |
Jesper Derehag | 2b5faa4 | 2013-03-19 20:50:05 +0000 | [diff] [blame] | 2365 | proc_coredump_connector(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2366 | /* |
| 2367 | * If it was able to dump core, this kills all |
| 2368 | * other threads in the group and synchronizes with |
| 2369 | * their demise. If we lost the race with another |
| 2370 | * thread getting here, it set group_exit_code |
| 2371 | * first and our do_group_exit call below will use |
| 2372 | * that value and ignore the one we pass it. |
| 2373 | */ |
Richard Weinberger | 828b1f6 | 2013-10-07 15:26:57 +0200 | [diff] [blame] | 2374 | do_coredump(&ksig->info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2375 | } |
| 2376 | |
| 2377 | /* |
| 2378 | * Death signals, no core dump. |
| 2379 | */ |
Richard Weinberger | 828b1f6 | 2013-10-07 15:26:57 +0200 | [diff] [blame] | 2380 | do_group_exit(ksig->info.si_signo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2381 | /* NOTREACHED */ |
| 2382 | } |
Oleg Nesterov | f6b76d4 | 2008-04-30 00:52:47 -0700 | [diff] [blame] | 2383 | spin_unlock_irq(&sighand->siglock); |
Richard Weinberger | 828b1f6 | 2013-10-07 15:26:57 +0200 | [diff] [blame] | 2384 | |
| 2385 | ksig->sig = signr; |
| 2386 | return ksig->sig > 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2387 | } |
| 2388 | |
Matt Fleming | 5e6292c | 2012-01-10 15:11:17 -0800 | [diff] [blame] | 2389 | /** |
Al Viro | efee984 | 2012-04-28 02:04:15 -0400 | [diff] [blame] | 2390 | * signal_delivered - |
Richard Weinberger | 10b1c7a | 2014-07-13 13:36:04 +0200 | [diff] [blame] | 2391 | * @ksig: kernel signal struct |
Al Viro | efee984 | 2012-04-28 02:04:15 -0400 | [diff] [blame] | 2392 | * @stepping: nonzero if debugger single-step or block-step in use |
Matt Fleming | 5e6292c | 2012-01-10 15:11:17 -0800 | [diff] [blame] | 2393 | * |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 2394 | * This function should be called when a signal has successfully been |
Richard Weinberger | 10b1c7a | 2014-07-13 13:36:04 +0200 | [diff] [blame] | 2395 | * delivered. It updates the blocked signals accordingly (@ksig->ka.sa.sa_mask |
Al Viro | efee984 | 2012-04-28 02:04:15 -0400 | [diff] [blame] | 2396 | * is always blocked, and the signal itself is blocked unless %SA_NODEFER |
Richard Weinberger | 10b1c7a | 2014-07-13 13:36:04 +0200 | [diff] [blame] | 2397 | * is set in @ksig->ka.sa.sa_flags. Tracing is notified. |
Matt Fleming | 5e6292c | 2012-01-10 15:11:17 -0800 | [diff] [blame] | 2398 | */ |
Richard Weinberger | 10b1c7a | 2014-07-13 13:36:04 +0200 | [diff] [blame] | 2399 | static void signal_delivered(struct ksignal *ksig, int stepping) |
Matt Fleming | 5e6292c | 2012-01-10 15:11:17 -0800 | [diff] [blame] | 2400 | { |
| 2401 | sigset_t blocked; |
| 2402 | |
Al Viro | a610d6e | 2012-05-21 23:42:15 -0400 | [diff] [blame] | 2403 | /* A signal was successfully delivered, and the |
| 2404 | saved sigmask was stored on the signal frame, |
| 2405 | and will be restored by sigreturn. So we can |
| 2406 | simply clear the restore sigmask flag. */ |
| 2407 | clear_restore_sigmask(); |
| 2408 | |
Richard Weinberger | 10b1c7a | 2014-07-13 13:36:04 +0200 | [diff] [blame] | 2409 | sigorsets(&blocked, ¤t->blocked, &ksig->ka.sa.sa_mask); |
| 2410 | if (!(ksig->ka.sa.sa_flags & SA_NODEFER)) |
| 2411 | sigaddset(&blocked, ksig->sig); |
Matt Fleming | 5e6292c | 2012-01-10 15:11:17 -0800 | [diff] [blame] | 2412 | set_current_blocked(&blocked); |
Richard Weinberger | df5601f | 2013-10-07 15:37:19 +0200 | [diff] [blame] | 2413 | tracehook_signal_handler(stepping); |
Matt Fleming | 5e6292c | 2012-01-10 15:11:17 -0800 | [diff] [blame] | 2414 | } |
| 2415 | |
Al Viro | 2ce5da1 | 2012-11-07 15:11:25 -0500 | [diff] [blame] | 2416 | void signal_setup_done(int failed, struct ksignal *ksig, int stepping) |
| 2417 | { |
| 2418 | if (failed) |
| 2419 | force_sigsegv(ksig->sig, current); |
| 2420 | else |
Richard Weinberger | 10b1c7a | 2014-07-13 13:36:04 +0200 | [diff] [blame] | 2421 | signal_delivered(ksig, stepping); |
Al Viro | 2ce5da1 | 2012-11-07 15:11:25 -0500 | [diff] [blame] | 2422 | } |
| 2423 | |
Oleg Nesterov | 0edceb7bc | 2011-04-27 19:17:37 +0200 | [diff] [blame] | 2424 | /* |
| 2425 | * It could be that complete_signal() picked us to notify about the |
Oleg Nesterov | fec9993 | 2011-04-27 19:50:21 +0200 | [diff] [blame] | 2426 | * group-wide signal. Other threads should be notified now to take |
| 2427 | * the shared signals in @which since we will not. |
Oleg Nesterov | 0edceb7bc | 2011-04-27 19:17:37 +0200 | [diff] [blame] | 2428 | */ |
Oleg Nesterov | f646e22 | 2011-04-27 19:18:39 +0200 | [diff] [blame] | 2429 | static void retarget_shared_pending(struct task_struct *tsk, sigset_t *which) |
Oleg Nesterov | 0edceb7bc | 2011-04-27 19:17:37 +0200 | [diff] [blame] | 2430 | { |
Oleg Nesterov | f646e22 | 2011-04-27 19:18:39 +0200 | [diff] [blame] | 2431 | sigset_t retarget; |
Oleg Nesterov | 0edceb7bc | 2011-04-27 19:17:37 +0200 | [diff] [blame] | 2432 | struct task_struct *t; |
| 2433 | |
Oleg Nesterov | f646e22 | 2011-04-27 19:18:39 +0200 | [diff] [blame] | 2434 | sigandsets(&retarget, &tsk->signal->shared_pending.signal, which); |
| 2435 | if (sigisemptyset(&retarget)) |
| 2436 | return; |
| 2437 | |
Oleg Nesterov | 0edceb7bc | 2011-04-27 19:17:37 +0200 | [diff] [blame] | 2438 | t = tsk; |
| 2439 | while_each_thread(tsk, t) { |
Oleg Nesterov | fec9993 | 2011-04-27 19:50:21 +0200 | [diff] [blame] | 2440 | if (t->flags & PF_EXITING) |
| 2441 | continue; |
| 2442 | |
| 2443 | if (!has_pending_signals(&retarget, &t->blocked)) |
| 2444 | continue; |
| 2445 | /* Remove the signals this thread can handle. */ |
| 2446 | sigandsets(&retarget, &retarget, &t->blocked); |
| 2447 | |
| 2448 | if (!signal_pending(t)) |
| 2449 | signal_wake_up(t, 0); |
| 2450 | |
| 2451 | if (sigisemptyset(&retarget)) |
| 2452 | break; |
Oleg Nesterov | 0edceb7bc | 2011-04-27 19:17:37 +0200 | [diff] [blame] | 2453 | } |
| 2454 | } |
| 2455 | |
Oleg Nesterov | d12619b | 2008-02-08 04:19:12 -0800 | [diff] [blame] | 2456 | void exit_signals(struct task_struct *tsk) |
| 2457 | { |
| 2458 | int group_stop = 0; |
Oleg Nesterov | f646e22 | 2011-04-27 19:18:39 +0200 | [diff] [blame] | 2459 | sigset_t unblocked; |
Oleg Nesterov | d12619b | 2008-02-08 04:19:12 -0800 | [diff] [blame] | 2460 | |
Tejun Heo | 77e4ef9 | 2011-12-12 18:12:21 -0800 | [diff] [blame] | 2461 | /* |
| 2462 | * @tsk is about to have PF_EXITING set - lock out users which |
| 2463 | * expect stable threadgroup. |
| 2464 | */ |
| 2465 | threadgroup_change_begin(tsk); |
| 2466 | |
Oleg Nesterov | 5dee170 | 2008-02-08 04:19:13 -0800 | [diff] [blame] | 2467 | if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { |
| 2468 | tsk->flags |= PF_EXITING; |
Tejun Heo | 77e4ef9 | 2011-12-12 18:12:21 -0800 | [diff] [blame] | 2469 | threadgroup_change_end(tsk); |
Oleg Nesterov | 5dee170 | 2008-02-08 04:19:13 -0800 | [diff] [blame] | 2470 | return; |
Oleg Nesterov | d12619b | 2008-02-08 04:19:12 -0800 | [diff] [blame] | 2471 | } |
| 2472 | |
Oleg Nesterov | 5dee170 | 2008-02-08 04:19:13 -0800 | [diff] [blame] | 2473 | spin_lock_irq(&tsk->sighand->siglock); |
Oleg Nesterov | d12619b | 2008-02-08 04:19:12 -0800 | [diff] [blame] | 2474 | /* |
| 2475 | * From now this task is not visible for group-wide signals, |
| 2476 | * see wants_signal(), do_signal_stop(). |
| 2477 | */ |
| 2478 | tsk->flags |= PF_EXITING; |
Tejun Heo | 77e4ef9 | 2011-12-12 18:12:21 -0800 | [diff] [blame] | 2479 | |
| 2480 | threadgroup_change_end(tsk); |
| 2481 | |
Oleg Nesterov | 5dee170 | 2008-02-08 04:19:13 -0800 | [diff] [blame] | 2482 | if (!signal_pending(tsk)) |
| 2483 | goto out; |
| 2484 | |
Oleg Nesterov | f646e22 | 2011-04-27 19:18:39 +0200 | [diff] [blame] | 2485 | unblocked = tsk->blocked; |
| 2486 | signotset(&unblocked); |
| 2487 | retarget_shared_pending(tsk, &unblocked); |
Oleg Nesterov | 5dee170 | 2008-02-08 04:19:13 -0800 | [diff] [blame] | 2488 | |
Tejun Heo | a8f072c | 2011-06-02 11:13:59 +0200 | [diff] [blame] | 2489 | if (unlikely(tsk->jobctl & JOBCTL_STOP_PENDING) && |
Tejun Heo | e5c1902 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2490 | task_participate_group_stop(tsk)) |
Tejun Heo | edf2ed1 | 2011-03-23 10:37:00 +0100 | [diff] [blame] | 2491 | group_stop = CLD_STOPPED; |
Oleg Nesterov | 5dee170 | 2008-02-08 04:19:13 -0800 | [diff] [blame] | 2492 | out: |
Oleg Nesterov | d12619b | 2008-02-08 04:19:12 -0800 | [diff] [blame] | 2493 | spin_unlock_irq(&tsk->sighand->siglock); |
| 2494 | |
Tejun Heo | 62bcf9d | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2495 | /* |
| 2496 | * If group stop has completed, deliver the notification. This |
| 2497 | * should always go to the real parent of the group leader. |
| 2498 | */ |
Roland McGrath | ae6d2ed | 2009-09-23 15:56:53 -0700 | [diff] [blame] | 2499 | if (unlikely(group_stop)) { |
Oleg Nesterov | d12619b | 2008-02-08 04:19:12 -0800 | [diff] [blame] | 2500 | read_lock(&tasklist_lock); |
Tejun Heo | 62bcf9d | 2011-03-23 10:37:01 +0100 | [diff] [blame] | 2501 | do_notify_parent_cldstop(tsk, false, group_stop); |
Oleg Nesterov | d12619b | 2008-02-08 04:19:12 -0800 | [diff] [blame] | 2502 | read_unlock(&tasklist_lock); |
| 2503 | } |
| 2504 | } |
| 2505 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2506 | EXPORT_SYMBOL(recalc_sigpending); |
| 2507 | EXPORT_SYMBOL_GPL(dequeue_signal); |
| 2508 | EXPORT_SYMBOL(flush_signals); |
| 2509 | EXPORT_SYMBOL(force_sig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2510 | EXPORT_SYMBOL(send_sig); |
| 2511 | EXPORT_SYMBOL(send_sig_info); |
| 2512 | EXPORT_SYMBOL(sigprocmask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2513 | |
| 2514 | /* |
| 2515 | * System call entry points. |
| 2516 | */ |
| 2517 | |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 2518 | /** |
| 2519 | * sys_restart_syscall - restart a system call |
| 2520 | */ |
Heiko Carstens | 754fe8d | 2009-01-14 14:14:09 +0100 | [diff] [blame] | 2521 | SYSCALL_DEFINE0(restart_syscall) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2522 | { |
Andy Lutomirski | f56141e | 2015-02-12 15:01:14 -0800 | [diff] [blame] | 2523 | struct restart_block *restart = ¤t->restart_block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2524 | return restart->fn(restart); |
| 2525 | } |
| 2526 | |
| 2527 | long do_no_restart_syscall(struct restart_block *param) |
| 2528 | { |
| 2529 | return -EINTR; |
| 2530 | } |
| 2531 | |
Oleg Nesterov | b182801 | 2011-04-27 21:56:14 +0200 | [diff] [blame] | 2532 | static void __set_task_blocked(struct task_struct *tsk, const sigset_t *newset) |
| 2533 | { |
| 2534 | if (signal_pending(tsk) && !thread_group_empty(tsk)) { |
| 2535 | sigset_t newblocked; |
| 2536 | /* A set of now blocked but previously unblocked signals. */ |
Oleg Nesterov | 702a507 | 2011-04-27 22:01:27 +0200 | [diff] [blame] | 2537 | sigandnsets(&newblocked, newset, ¤t->blocked); |
Oleg Nesterov | b182801 | 2011-04-27 21:56:14 +0200 | [diff] [blame] | 2538 | retarget_shared_pending(tsk, &newblocked); |
| 2539 | } |
| 2540 | tsk->blocked = *newset; |
| 2541 | recalc_sigpending(); |
| 2542 | } |
| 2543 | |
Oleg Nesterov | e6fa16a | 2011-04-27 20:59:41 +0200 | [diff] [blame] | 2544 | /** |
| 2545 | * set_current_blocked - change current->blocked mask |
| 2546 | * @newset: new mask |
| 2547 | * |
| 2548 | * It is wrong to change ->blocked directly, this helper should be used |
| 2549 | * to ensure the process can't miss a shared signal we are going to block. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2550 | */ |
Al Viro | 77097ae | 2012-04-27 13:58:59 -0400 | [diff] [blame] | 2551 | void set_current_blocked(sigset_t *newset) |
| 2552 | { |
Al Viro | 77097ae | 2012-04-27 13:58:59 -0400 | [diff] [blame] | 2553 | sigdelsetmask(newset, sigmask(SIGKILL) | sigmask(SIGSTOP)); |
Oleg Nesterov | 0c4a842 | 2013-01-05 19:13:29 +0100 | [diff] [blame] | 2554 | __set_current_blocked(newset); |
Al Viro | 77097ae | 2012-04-27 13:58:59 -0400 | [diff] [blame] | 2555 | } |
| 2556 | |
| 2557 | void __set_current_blocked(const sigset_t *newset) |
Oleg Nesterov | e6fa16a | 2011-04-27 20:59:41 +0200 | [diff] [blame] | 2558 | { |
| 2559 | struct task_struct *tsk = current; |
| 2560 | |
Waiman Long | 20a3061 | 2016-12-14 15:04:10 -0800 | [diff] [blame] | 2561 | /* |
| 2562 | * In case the signal mask hasn't changed, there is nothing we need |
| 2563 | * to do. The current->blocked shouldn't be modified by other task. |
| 2564 | */ |
| 2565 | if (sigequalsets(&tsk->blocked, newset)) |
| 2566 | return; |
| 2567 | |
Oleg Nesterov | e6fa16a | 2011-04-27 20:59:41 +0200 | [diff] [blame] | 2568 | spin_lock_irq(&tsk->sighand->siglock); |
Oleg Nesterov | b182801 | 2011-04-27 21:56:14 +0200 | [diff] [blame] | 2569 | __set_task_blocked(tsk, newset); |
Oleg Nesterov | e6fa16a | 2011-04-27 20:59:41 +0200 | [diff] [blame] | 2570 | spin_unlock_irq(&tsk->sighand->siglock); |
| 2571 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2572 | |
| 2573 | /* |
| 2574 | * This is also useful for kernel threads that want to temporarily |
| 2575 | * (or permanently) block certain signals. |
| 2576 | * |
| 2577 | * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel |
| 2578 | * interface happily blocks "unblockable" signals like SIGKILL |
| 2579 | * and friends. |
| 2580 | */ |
| 2581 | int sigprocmask(int how, sigset_t *set, sigset_t *oldset) |
| 2582 | { |
Oleg Nesterov | 73ef4ae | 2011-04-27 19:54:20 +0200 | [diff] [blame] | 2583 | struct task_struct *tsk = current; |
| 2584 | sigset_t newset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2585 | |
Oleg Nesterov | 73ef4ae | 2011-04-27 19:54:20 +0200 | [diff] [blame] | 2586 | /* Lockless, only current can change ->blocked, never from irq */ |
Oleg Nesterov | a26fd33 | 2006-03-23 03:00:49 -0800 | [diff] [blame] | 2587 | if (oldset) |
Oleg Nesterov | 73ef4ae | 2011-04-27 19:54:20 +0200 | [diff] [blame] | 2588 | *oldset = tsk->blocked; |
Oleg Nesterov | a26fd33 | 2006-03-23 03:00:49 -0800 | [diff] [blame] | 2589 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2590 | switch (how) { |
| 2591 | case SIG_BLOCK: |
Oleg Nesterov | 73ef4ae | 2011-04-27 19:54:20 +0200 | [diff] [blame] | 2592 | sigorsets(&newset, &tsk->blocked, set); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2593 | break; |
| 2594 | case SIG_UNBLOCK: |
Oleg Nesterov | 702a507 | 2011-04-27 22:01:27 +0200 | [diff] [blame] | 2595 | sigandnsets(&newset, &tsk->blocked, set); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2596 | break; |
| 2597 | case SIG_SETMASK: |
Oleg Nesterov | 73ef4ae | 2011-04-27 19:54:20 +0200 | [diff] [blame] | 2598 | newset = *set; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2599 | break; |
| 2600 | default: |
Oleg Nesterov | 73ef4ae | 2011-04-27 19:54:20 +0200 | [diff] [blame] | 2601 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2602 | } |
Oleg Nesterov | a26fd33 | 2006-03-23 03:00:49 -0800 | [diff] [blame] | 2603 | |
Al Viro | 77097ae | 2012-04-27 13:58:59 -0400 | [diff] [blame] | 2604 | __set_current_blocked(&newset); |
Oleg Nesterov | 73ef4ae | 2011-04-27 19:54:20 +0200 | [diff] [blame] | 2605 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2606 | } |
| 2607 | |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 2608 | /** |
| 2609 | * sys_rt_sigprocmask - change the list of currently blocked signals |
| 2610 | * @how: whether to add, remove, or set signals |
Randy Dunlap | ada9c93 | 2011-06-14 15:50:11 -0700 | [diff] [blame] | 2611 | * @nset: stores pending signals |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 2612 | * @oset: previous value of signal mask if non-null |
| 2613 | * @sigsetsize: size of sigset_t type |
| 2614 | */ |
Oleg Nesterov | bb7efee | 2011-04-27 21:18:10 +0200 | [diff] [blame] | 2615 | SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset, |
Heiko Carstens | 17da2bd | 2009-01-14 14:14:10 +0100 | [diff] [blame] | 2616 | sigset_t __user *, oset, size_t, sigsetsize) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2617 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2618 | sigset_t old_set, new_set; |
Oleg Nesterov | bb7efee | 2011-04-27 21:18:10 +0200 | [diff] [blame] | 2619 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2620 | |
| 2621 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 2622 | if (sigsetsize != sizeof(sigset_t)) |
Oleg Nesterov | bb7efee | 2011-04-27 21:18:10 +0200 | [diff] [blame] | 2623 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2624 | |
Oleg Nesterov | bb7efee | 2011-04-27 21:18:10 +0200 | [diff] [blame] | 2625 | old_set = current->blocked; |
| 2626 | |
| 2627 | if (nset) { |
| 2628 | if (copy_from_user(&new_set, nset, sizeof(sigset_t))) |
| 2629 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2630 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
| 2631 | |
Oleg Nesterov | bb7efee | 2011-04-27 21:18:10 +0200 | [diff] [blame] | 2632 | error = sigprocmask(how, &new_set, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2633 | if (error) |
Oleg Nesterov | bb7efee | 2011-04-27 21:18:10 +0200 | [diff] [blame] | 2634 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2635 | } |
Oleg Nesterov | bb7efee | 2011-04-27 21:18:10 +0200 | [diff] [blame] | 2636 | |
| 2637 | if (oset) { |
| 2638 | if (copy_to_user(oset, &old_set, sizeof(sigset_t))) |
| 2639 | return -EFAULT; |
| 2640 | } |
| 2641 | |
| 2642 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2643 | } |
| 2644 | |
Al Viro | 322a56c | 2012-12-25 13:32:58 -0500 | [diff] [blame] | 2645 | #ifdef CONFIG_COMPAT |
Al Viro | 322a56c | 2012-12-25 13:32:58 -0500 | [diff] [blame] | 2646 | COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset, |
| 2647 | compat_sigset_t __user *, oset, compat_size_t, sigsetsize) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2648 | { |
Al Viro | 322a56c | 2012-12-25 13:32:58 -0500 | [diff] [blame] | 2649 | #ifdef __BIG_ENDIAN |
| 2650 | sigset_t old_set = current->blocked; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2651 | |
Al Viro | 322a56c | 2012-12-25 13:32:58 -0500 | [diff] [blame] | 2652 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 2653 | if (sigsetsize != sizeof(sigset_t)) |
| 2654 | return -EINVAL; |
| 2655 | |
| 2656 | if (nset) { |
| 2657 | compat_sigset_t new32; |
| 2658 | sigset_t new_set; |
| 2659 | int error; |
| 2660 | if (copy_from_user(&new32, nset, sizeof(compat_sigset_t))) |
| 2661 | return -EFAULT; |
| 2662 | |
| 2663 | sigset_from_compat(&new_set, &new32); |
| 2664 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
| 2665 | |
| 2666 | error = sigprocmask(how, &new_set, NULL); |
| 2667 | if (error) |
| 2668 | return error; |
| 2669 | } |
| 2670 | if (oset) { |
| 2671 | compat_sigset_t old32; |
| 2672 | sigset_to_compat(&old32, &old_set); |
Al Viro | db61ec2 | 2013-03-02 20:39:15 -0500 | [diff] [blame] | 2673 | if (copy_to_user(oset, &old32, sizeof(compat_sigset_t))) |
Al Viro | 322a56c | 2012-12-25 13:32:58 -0500 | [diff] [blame] | 2674 | return -EFAULT; |
| 2675 | } |
| 2676 | return 0; |
| 2677 | #else |
| 2678 | return sys_rt_sigprocmask(how, (sigset_t __user *)nset, |
| 2679 | (sigset_t __user *)oset, sigsetsize); |
| 2680 | #endif |
| 2681 | } |
| 2682 | #endif |
Al Viro | 322a56c | 2012-12-25 13:32:58 -0500 | [diff] [blame] | 2683 | |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 2684 | static int do_sigpending(void *set, unsigned long sigsetsize) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2685 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2686 | if (sigsetsize > sizeof(sigset_t)) |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 2687 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2688 | |
| 2689 | spin_lock_irq(¤t->sighand->siglock); |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 2690 | sigorsets(set, ¤t->pending.signal, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2691 | ¤t->signal->shared_pending.signal); |
| 2692 | spin_unlock_irq(¤t->sighand->siglock); |
| 2693 | |
| 2694 | /* Outside the lock because only this thread touches it. */ |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 2695 | sigandsets(set, ¤t->blocked, set); |
| 2696 | return 0; |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 2697 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2698 | |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 2699 | /** |
| 2700 | * sys_rt_sigpending - examine a pending signal that has been raised |
| 2701 | * while blocked |
Randy Dunlap | 20f22ab | 2013-03-04 14:32:59 -0800 | [diff] [blame] | 2702 | * @uset: stores pending signals |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 2703 | * @sigsetsize: size of sigset_t type or larger |
| 2704 | */ |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 2705 | SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, uset, size_t, sigsetsize) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2706 | { |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 2707 | sigset_t set; |
| 2708 | int err = do_sigpending(&set, sigsetsize); |
| 2709 | if (!err && copy_to_user(uset, &set, sigsetsize)) |
| 2710 | err = -EFAULT; |
| 2711 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2712 | } |
| 2713 | |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 2714 | #ifdef CONFIG_COMPAT |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 2715 | COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset, |
| 2716 | compat_size_t, sigsetsize) |
| 2717 | { |
| 2718 | #ifdef __BIG_ENDIAN |
| 2719 | sigset_t set; |
| 2720 | int err = do_sigpending(&set, sigsetsize); |
| 2721 | if (!err) { |
| 2722 | compat_sigset_t set32; |
| 2723 | sigset_to_compat(&set32, &set); |
| 2724 | /* we can get here only if sigsetsize <= sizeof(set) */ |
| 2725 | if (copy_to_user(uset, &set32, sigsetsize)) |
| 2726 | err = -EFAULT; |
| 2727 | } |
| 2728 | return err; |
| 2729 | #else |
| 2730 | return sys_rt_sigpending((sigset_t __user *)uset, sigsetsize); |
| 2731 | #endif |
| 2732 | } |
| 2733 | #endif |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 2734 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2735 | #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER |
| 2736 | |
Al Viro | ce39596 | 2013-10-13 17:23:53 -0400 | [diff] [blame] | 2737 | int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2738 | { |
| 2739 | int err; |
| 2740 | |
| 2741 | if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) |
| 2742 | return -EFAULT; |
| 2743 | if (from->si_code < 0) |
| 2744 | return __copy_to_user(to, from, sizeof(siginfo_t)) |
| 2745 | ? -EFAULT : 0; |
| 2746 | /* |
| 2747 | * If you change siginfo_t structure, please be sure |
| 2748 | * this code is fixed accordingly. |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 2749 | * Please remember to update the signalfd_copyinfo() function |
| 2750 | * inside fs/signalfd.c too, in case siginfo_t changes. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2751 | * It should never copy any pad contained in the structure |
| 2752 | * to avoid security leaks, but must copy the generic |
| 2753 | * 3 ints plus the relevant union member. |
| 2754 | */ |
| 2755 | err = __put_user(from->si_signo, &to->si_signo); |
| 2756 | err |= __put_user(from->si_errno, &to->si_errno); |
| 2757 | err |= __put_user((short)from->si_code, &to->si_code); |
| 2758 | switch (from->si_code & __SI_MASK) { |
| 2759 | case __SI_KILL: |
| 2760 | err |= __put_user(from->si_pid, &to->si_pid); |
| 2761 | err |= __put_user(from->si_uid, &to->si_uid); |
| 2762 | break; |
| 2763 | case __SI_TIMER: |
| 2764 | err |= __put_user(from->si_tid, &to->si_tid); |
| 2765 | err |= __put_user(from->si_overrun, &to->si_overrun); |
| 2766 | err |= __put_user(from->si_ptr, &to->si_ptr); |
| 2767 | break; |
| 2768 | case __SI_POLL: |
| 2769 | err |= __put_user(from->si_band, &to->si_band); |
| 2770 | err |= __put_user(from->si_fd, &to->si_fd); |
| 2771 | break; |
| 2772 | case __SI_FAULT: |
| 2773 | err |= __put_user(from->si_addr, &to->si_addr); |
| 2774 | #ifdef __ARCH_SI_TRAPNO |
| 2775 | err |= __put_user(from->si_trapno, &to->si_trapno); |
| 2776 | #endif |
Andi Kleen | a337fda | 2010-09-27 20:32:19 +0200 | [diff] [blame] | 2777 | #ifdef BUS_MCEERR_AO |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 2778 | /* |
Andi Kleen | a337fda | 2010-09-27 20:32:19 +0200 | [diff] [blame] | 2779 | * Other callers might not initialize the si_lsb field, |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 2780 | * so check explicitly for the right codes here. |
Andi Kleen | a337fda | 2010-09-27 20:32:19 +0200 | [diff] [blame] | 2781 | */ |
Amanieu d'Antras | 2613502 | 2015-08-06 15:46:29 -0700 | [diff] [blame] | 2782 | if (from->si_signo == SIGBUS && |
| 2783 | (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)) |
Andi Kleen | a337fda | 2010-09-27 20:32:19 +0200 | [diff] [blame] | 2784 | err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb); |
| 2785 | #endif |
Qiaowei Ren | ee1b58d | 2014-11-14 07:18:19 -0800 | [diff] [blame] | 2786 | #ifdef SEGV_BNDERR |
Amanieu d'Antras | 2613502 | 2015-08-06 15:46:29 -0700 | [diff] [blame] | 2787 | if (from->si_signo == SIGSEGV && from->si_code == SEGV_BNDERR) { |
| 2788 | err |= __put_user(from->si_lower, &to->si_lower); |
| 2789 | err |= __put_user(from->si_upper, &to->si_upper); |
| 2790 | } |
Qiaowei Ren | ee1b58d | 2014-11-14 07:18:19 -0800 | [diff] [blame] | 2791 | #endif |
Dave Hansen | cd0ea35 | 2016-02-12 13:02:12 -0800 | [diff] [blame] | 2792 | #ifdef SEGV_PKUERR |
| 2793 | if (from->si_signo == SIGSEGV && from->si_code == SEGV_PKUERR) |
| 2794 | err |= __put_user(from->si_pkey, &to->si_pkey); |
| 2795 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2796 | break; |
| 2797 | case __SI_CHLD: |
| 2798 | err |= __put_user(from->si_pid, &to->si_pid); |
| 2799 | err |= __put_user(from->si_uid, &to->si_uid); |
| 2800 | err |= __put_user(from->si_status, &to->si_status); |
| 2801 | err |= __put_user(from->si_utime, &to->si_utime); |
| 2802 | err |= __put_user(from->si_stime, &to->si_stime); |
| 2803 | break; |
| 2804 | case __SI_RT: /* This is not generated by the kernel as of now. */ |
| 2805 | case __SI_MESGQ: /* But this is */ |
| 2806 | err |= __put_user(from->si_pid, &to->si_pid); |
| 2807 | err |= __put_user(from->si_uid, &to->si_uid); |
| 2808 | err |= __put_user(from->si_ptr, &to->si_ptr); |
| 2809 | break; |
Will Drewry | a0727e8 | 2012-04-12 16:48:00 -0500 | [diff] [blame] | 2810 | #ifdef __ARCH_SIGSYS |
| 2811 | case __SI_SYS: |
| 2812 | err |= __put_user(from->si_call_addr, &to->si_call_addr); |
| 2813 | err |= __put_user(from->si_syscall, &to->si_syscall); |
| 2814 | err |= __put_user(from->si_arch, &to->si_arch); |
| 2815 | break; |
| 2816 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2817 | default: /* this is just in case for now ... */ |
| 2818 | err |= __put_user(from->si_pid, &to->si_pid); |
| 2819 | err |= __put_user(from->si_uid, &to->si_uid); |
| 2820 | break; |
| 2821 | } |
| 2822 | return err; |
| 2823 | } |
| 2824 | |
| 2825 | #endif |
| 2826 | |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 2827 | /** |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2828 | * do_sigtimedwait - wait for queued signals specified in @which |
| 2829 | * @which: queued signals to wait for |
| 2830 | * @info: if non-null, the signal's siginfo is returned here |
| 2831 | * @ts: upper bound on process time suspension |
| 2832 | */ |
| 2833 | int do_sigtimedwait(const sigset_t *which, siginfo_t *info, |
Thomas Gleixner | 2b1ecc3 | 2016-07-04 09:50:25 +0000 | [diff] [blame] | 2834 | const struct timespec *ts) |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2835 | { |
Thomas Gleixner | 2b1ecc3 | 2016-07-04 09:50:25 +0000 | [diff] [blame] | 2836 | ktime_t *to = NULL, timeout = { .tv64 = KTIME_MAX }; |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2837 | struct task_struct *tsk = current; |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2838 | sigset_t mask = *which; |
Thomas Gleixner | 2b1ecc3 | 2016-07-04 09:50:25 +0000 | [diff] [blame] | 2839 | int sig, ret = 0; |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2840 | |
| 2841 | if (ts) { |
| 2842 | if (!timespec_valid(ts)) |
| 2843 | return -EINVAL; |
Thomas Gleixner | 2b1ecc3 | 2016-07-04 09:50:25 +0000 | [diff] [blame] | 2844 | timeout = timespec_to_ktime(*ts); |
| 2845 | to = &timeout; |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2846 | } |
| 2847 | |
| 2848 | /* |
| 2849 | * Invert the set of allowed signals to get those we want to block. |
| 2850 | */ |
| 2851 | sigdelsetmask(&mask, sigmask(SIGKILL) | sigmask(SIGSTOP)); |
| 2852 | signotset(&mask); |
| 2853 | |
| 2854 | spin_lock_irq(&tsk->sighand->siglock); |
| 2855 | sig = dequeue_signal(tsk, &mask, info); |
Thomas Gleixner | 2b1ecc3 | 2016-07-04 09:50:25 +0000 | [diff] [blame] | 2856 | if (!sig && timeout.tv64) { |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2857 | /* |
| 2858 | * None ready, temporarily unblock those we're interested |
| 2859 | * while we are sleeping in so that we'll be awakened when |
Oleg Nesterov | b182801 | 2011-04-27 21:56:14 +0200 | [diff] [blame] | 2860 | * they arrive. Unblocking is always fine, we can avoid |
| 2861 | * set_current_blocked(). |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2862 | */ |
| 2863 | tsk->real_blocked = tsk->blocked; |
| 2864 | sigandsets(&tsk->blocked, &tsk->blocked, &mask); |
| 2865 | recalc_sigpending(); |
| 2866 | spin_unlock_irq(&tsk->sighand->siglock); |
| 2867 | |
Thomas Gleixner | 2b1ecc3 | 2016-07-04 09:50:25 +0000 | [diff] [blame] | 2868 | __set_current_state(TASK_INTERRUPTIBLE); |
| 2869 | ret = freezable_schedule_hrtimeout_range(to, tsk->timer_slack_ns, |
| 2870 | HRTIMER_MODE_REL); |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2871 | spin_lock_irq(&tsk->sighand->siglock); |
Oleg Nesterov | b182801 | 2011-04-27 21:56:14 +0200 | [diff] [blame] | 2872 | __set_task_blocked(tsk, &tsk->real_blocked); |
Oleg Nesterov | 6114041 | 2014-06-06 14:36:46 -0700 | [diff] [blame] | 2873 | sigemptyset(&tsk->real_blocked); |
Oleg Nesterov | b182801 | 2011-04-27 21:56:14 +0200 | [diff] [blame] | 2874 | sig = dequeue_signal(tsk, &mask, info); |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2875 | } |
| 2876 | spin_unlock_irq(&tsk->sighand->siglock); |
| 2877 | |
| 2878 | if (sig) |
| 2879 | return sig; |
Thomas Gleixner | 2b1ecc3 | 2016-07-04 09:50:25 +0000 | [diff] [blame] | 2880 | return ret ? -EINTR : -EAGAIN; |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2881 | } |
| 2882 | |
| 2883 | /** |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 2884 | * sys_rt_sigtimedwait - synchronously wait for queued signals specified |
| 2885 | * in @uthese |
| 2886 | * @uthese: queued signals to wait for |
| 2887 | * @uinfo: if non-null, the signal's siginfo is returned here |
| 2888 | * @uts: upper bound on process time suspension |
| 2889 | * @sigsetsize: size of sigset_t type |
| 2890 | */ |
Heiko Carstens | 17da2bd | 2009-01-14 14:14:10 +0100 | [diff] [blame] | 2891 | SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, |
| 2892 | siginfo_t __user *, uinfo, const struct timespec __user *, uts, |
| 2893 | size_t, sigsetsize) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2894 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2895 | sigset_t these; |
| 2896 | struct timespec ts; |
| 2897 | siginfo_t info; |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2898 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2899 | |
| 2900 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 2901 | if (sigsetsize != sizeof(sigset_t)) |
| 2902 | return -EINVAL; |
| 2903 | |
| 2904 | if (copy_from_user(&these, uthese, sizeof(these))) |
| 2905 | return -EFAULT; |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 2906 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2907 | if (uts) { |
| 2908 | if (copy_from_user(&ts, uts, sizeof(ts))) |
| 2909 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2910 | } |
| 2911 | |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2912 | ret = do_sigtimedwait(&these, &info, uts ? &ts : NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2913 | |
Oleg Nesterov | 943df14 | 2011-04-27 21:44:14 +0200 | [diff] [blame] | 2914 | if (ret > 0 && uinfo) { |
| 2915 | if (copy_siginfo_to_user(uinfo, &info)) |
| 2916 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2917 | } |
| 2918 | |
| 2919 | return ret; |
| 2920 | } |
| 2921 | |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 2922 | /** |
| 2923 | * sys_kill - send a signal to a process |
| 2924 | * @pid: the PID of the process |
| 2925 | * @sig: signal to be sent |
| 2926 | */ |
Heiko Carstens | 17da2bd | 2009-01-14 14:14:10 +0100 | [diff] [blame] | 2927 | SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2928 | { |
| 2929 | struct siginfo info; |
| 2930 | |
| 2931 | info.si_signo = sig; |
| 2932 | info.si_errno = 0; |
| 2933 | info.si_code = SI_USER; |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 2934 | info.si_pid = task_tgid_vnr(current); |
Eric W. Biederman | 078de5f | 2012-02-08 07:00:08 -0800 | [diff] [blame] | 2935 | info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2936 | |
| 2937 | return kill_something_info(sig, &info, pid); |
| 2938 | } |
| 2939 | |
Thomas Gleixner | 30b4ae8 | 2009-04-04 21:01:01 +0000 | [diff] [blame] | 2940 | static int |
| 2941 | do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2942 | { |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2943 | struct task_struct *p; |
Thomas Gleixner | 30b4ae8 | 2009-04-04 21:01:01 +0000 | [diff] [blame] | 2944 | int error = -ESRCH; |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2945 | |
Oleg Nesterov | 3547ff3 | 2008-04-30 00:52:51 -0700 | [diff] [blame] | 2946 | rcu_read_lock(); |
Pavel Emelyanov | 228ebcb | 2007-10-18 23:40:16 -0700 | [diff] [blame] | 2947 | p = find_task_by_vpid(pid); |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 2948 | if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) { |
Thomas Gleixner | 30b4ae8 | 2009-04-04 21:01:01 +0000 | [diff] [blame] | 2949 | error = check_kill_permission(sig, info, p); |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2950 | /* |
| 2951 | * The null signal is a permissions and process existence |
| 2952 | * probe. No signal is actually delivered. |
| 2953 | */ |
Oleg Nesterov | 4a30deb | 2009-09-23 15:57:00 -0700 | [diff] [blame] | 2954 | if (!error && sig) { |
| 2955 | error = do_send_sig_info(sig, info, p, false); |
| 2956 | /* |
| 2957 | * If lock_task_sighand() failed we pretend the task |
| 2958 | * dies after receiving the signal. The window is tiny, |
| 2959 | * and the signal is private anyway. |
| 2960 | */ |
| 2961 | if (unlikely(error == -ESRCH)) |
| 2962 | error = 0; |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2963 | } |
| 2964 | } |
Oleg Nesterov | 3547ff3 | 2008-04-30 00:52:51 -0700 | [diff] [blame] | 2965 | rcu_read_unlock(); |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2966 | |
| 2967 | return error; |
| 2968 | } |
| 2969 | |
Thomas Gleixner | 30b4ae8 | 2009-04-04 21:01:01 +0000 | [diff] [blame] | 2970 | static int do_tkill(pid_t tgid, pid_t pid, int sig) |
| 2971 | { |
Emese Revfy | b9e146d | 2013-04-17 15:58:36 -0700 | [diff] [blame] | 2972 | struct siginfo info = {}; |
Thomas Gleixner | 30b4ae8 | 2009-04-04 21:01:01 +0000 | [diff] [blame] | 2973 | |
| 2974 | info.si_signo = sig; |
| 2975 | info.si_errno = 0; |
| 2976 | info.si_code = SI_TKILL; |
| 2977 | info.si_pid = task_tgid_vnr(current); |
Eric W. Biederman | 078de5f | 2012-02-08 07:00:08 -0800 | [diff] [blame] | 2978 | info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
Thomas Gleixner | 30b4ae8 | 2009-04-04 21:01:01 +0000 | [diff] [blame] | 2979 | |
| 2980 | return do_send_specific(tgid, pid, sig, &info); |
| 2981 | } |
| 2982 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2983 | /** |
| 2984 | * sys_tgkill - send signal to one specific thread |
| 2985 | * @tgid: the thread group ID of the thread |
| 2986 | * @pid: the PID of the thread |
| 2987 | * @sig: signal to be sent |
| 2988 | * |
Robert P. J. Day | 72fd4a3 | 2007-02-10 01:45:59 -0800 | [diff] [blame] | 2989 | * This syscall also checks the @tgid and returns -ESRCH even if the PID |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2990 | * exists but it's not belonging to the target process anymore. This |
| 2991 | * method solves the problem of threads exiting and PIDs getting reused. |
| 2992 | */ |
Heiko Carstens | a5f8fa9 | 2009-01-14 14:14:11 +0100 | [diff] [blame] | 2993 | SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2994 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2995 | /* This is only valid for single tasks */ |
| 2996 | if (pid <= 0 || tgid <= 0) |
| 2997 | return -EINVAL; |
| 2998 | |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2999 | return do_tkill(tgid, pid, sig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3000 | } |
| 3001 | |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 3002 | /** |
| 3003 | * sys_tkill - send signal to one specific task |
| 3004 | * @pid: the PID of the task |
| 3005 | * @sig: signal to be sent |
| 3006 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3007 | * Send a signal to only one task, even if it's a CLONE_THREAD task. |
| 3008 | */ |
Heiko Carstens | a5f8fa9 | 2009-01-14 14:14:11 +0100 | [diff] [blame] | 3009 | SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3010 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3011 | /* This is only valid for single tasks */ |
| 3012 | if (pid <= 0) |
| 3013 | return -EINVAL; |
| 3014 | |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 3015 | return do_tkill(0, pid, sig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3016 | } |
| 3017 | |
Al Viro | 75907d4 | 2012-12-25 15:19:12 -0500 | [diff] [blame] | 3018 | static int do_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t *info) |
| 3019 | { |
| 3020 | /* Not even root can pretend to send signals from the kernel. |
| 3021 | * Nor can they impersonate a kill()/tgkill(), which adds source info. |
| 3022 | */ |
Andrey Vagin | 66dd34a | 2013-02-27 17:03:12 -0800 | [diff] [blame] | 3023 | if ((info->si_code >= 0 || info->si_code == SI_TKILL) && |
Vladimir Davydov | 69828dc | 2015-04-16 12:47:35 -0700 | [diff] [blame] | 3024 | (task_pid_vnr(current) != pid)) |
Al Viro | 75907d4 | 2012-12-25 15:19:12 -0500 | [diff] [blame] | 3025 | return -EPERM; |
Vladimir Davydov | 69828dc | 2015-04-16 12:47:35 -0700 | [diff] [blame] | 3026 | |
Al Viro | 75907d4 | 2012-12-25 15:19:12 -0500 | [diff] [blame] | 3027 | info->si_signo = sig; |
| 3028 | |
| 3029 | /* POSIX.1b doesn't mention process groups. */ |
| 3030 | return kill_proc_info(sig, info, pid); |
| 3031 | } |
| 3032 | |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 3033 | /** |
| 3034 | * sys_rt_sigqueueinfo - send signal information to a signal |
| 3035 | * @pid: the PID of the thread |
| 3036 | * @sig: signal to be sent |
| 3037 | * @uinfo: signal info to be sent |
| 3038 | */ |
Heiko Carstens | a5f8fa9 | 2009-01-14 14:14:11 +0100 | [diff] [blame] | 3039 | SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, |
| 3040 | siginfo_t __user *, uinfo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3041 | { |
| 3042 | siginfo_t info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3043 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) |
| 3044 | return -EFAULT; |
Al Viro | 75907d4 | 2012-12-25 15:19:12 -0500 | [diff] [blame] | 3045 | return do_rt_sigqueueinfo(pid, sig, &info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3046 | } |
| 3047 | |
Al Viro | 75907d4 | 2012-12-25 15:19:12 -0500 | [diff] [blame] | 3048 | #ifdef CONFIG_COMPAT |
Al Viro | 75907d4 | 2012-12-25 15:19:12 -0500 | [diff] [blame] | 3049 | COMPAT_SYSCALL_DEFINE3(rt_sigqueueinfo, |
| 3050 | compat_pid_t, pid, |
| 3051 | int, sig, |
| 3052 | struct compat_siginfo __user *, uinfo) |
| 3053 | { |
Amanieu d'Antras | 3c00cb5 | 2015-08-06 15:46:26 -0700 | [diff] [blame] | 3054 | siginfo_t info = {}; |
Al Viro | 75907d4 | 2012-12-25 15:19:12 -0500 | [diff] [blame] | 3055 | int ret = copy_siginfo_from_user32(&info, uinfo); |
| 3056 | if (unlikely(ret)) |
| 3057 | return ret; |
| 3058 | return do_rt_sigqueueinfo(pid, sig, &info); |
| 3059 | } |
| 3060 | #endif |
Al Viro | 75907d4 | 2012-12-25 15:19:12 -0500 | [diff] [blame] | 3061 | |
Al Viro | 9aae8fc | 2012-12-24 23:12:04 -0500 | [diff] [blame] | 3062 | static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) |
Thomas Gleixner | 62ab450 | 2009-04-04 21:01:06 +0000 | [diff] [blame] | 3063 | { |
| 3064 | /* This is only valid for single tasks */ |
| 3065 | if (pid <= 0 || tgid <= 0) |
| 3066 | return -EINVAL; |
| 3067 | |
| 3068 | /* Not even root can pretend to send signals from the kernel. |
Julien Tinnes | da48524 | 2011-03-18 15:05:21 -0700 | [diff] [blame] | 3069 | * Nor can they impersonate a kill()/tgkill(), which adds source info. |
| 3070 | */ |
Vladimir Davydov | 69828dc | 2015-04-16 12:47:35 -0700 | [diff] [blame] | 3071 | if ((info->si_code >= 0 || info->si_code == SI_TKILL) && |
| 3072 | (task_pid_vnr(current) != pid)) |
Thomas Gleixner | 62ab450 | 2009-04-04 21:01:06 +0000 | [diff] [blame] | 3073 | return -EPERM; |
Vladimir Davydov | 69828dc | 2015-04-16 12:47:35 -0700 | [diff] [blame] | 3074 | |
Thomas Gleixner | 62ab450 | 2009-04-04 21:01:06 +0000 | [diff] [blame] | 3075 | info->si_signo = sig; |
| 3076 | |
| 3077 | return do_send_specific(tgid, pid, sig, info); |
| 3078 | } |
| 3079 | |
| 3080 | SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, |
| 3081 | siginfo_t __user *, uinfo) |
| 3082 | { |
| 3083 | siginfo_t info; |
| 3084 | |
| 3085 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) |
| 3086 | return -EFAULT; |
| 3087 | |
| 3088 | return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); |
| 3089 | } |
| 3090 | |
Al Viro | 9aae8fc | 2012-12-24 23:12:04 -0500 | [diff] [blame] | 3091 | #ifdef CONFIG_COMPAT |
| 3092 | COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo, |
| 3093 | compat_pid_t, tgid, |
| 3094 | compat_pid_t, pid, |
| 3095 | int, sig, |
| 3096 | struct compat_siginfo __user *, uinfo) |
| 3097 | { |
Amanieu d'Antras | 3c00cb5 | 2015-08-06 15:46:26 -0700 | [diff] [blame] | 3098 | siginfo_t info = {}; |
Al Viro | 9aae8fc | 2012-12-24 23:12:04 -0500 | [diff] [blame] | 3099 | |
| 3100 | if (copy_siginfo_from_user32(&info, uinfo)) |
| 3101 | return -EFAULT; |
| 3102 | return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); |
| 3103 | } |
| 3104 | #endif |
| 3105 | |
Oleg Nesterov | 0341729 | 2014-06-06 14:36:53 -0700 | [diff] [blame] | 3106 | /* |
Oleg Nesterov | b4e7426 | 2014-06-06 14:37:00 -0700 | [diff] [blame] | 3107 | * For kthreads only, must not be used if cloned with CLONE_SIGHAND |
Oleg Nesterov | 0341729 | 2014-06-06 14:36:53 -0700 | [diff] [blame] | 3108 | */ |
Oleg Nesterov | b4e7426 | 2014-06-06 14:37:00 -0700 | [diff] [blame] | 3109 | void kernel_sigaction(int sig, __sighandler_t action) |
Oleg Nesterov | 0341729 | 2014-06-06 14:36:53 -0700 | [diff] [blame] | 3110 | { |
Oleg Nesterov | ec5955b | 2014-06-06 14:36:57 -0700 | [diff] [blame] | 3111 | spin_lock_irq(¤t->sighand->siglock); |
Oleg Nesterov | b4e7426 | 2014-06-06 14:37:00 -0700 | [diff] [blame] | 3112 | current->sighand->action[sig - 1].sa.sa_handler = action; |
| 3113 | if (action == SIG_IGN) { |
| 3114 | sigset_t mask; |
| 3115 | |
| 3116 | sigemptyset(&mask); |
| 3117 | sigaddset(&mask, sig); |
| 3118 | |
| 3119 | flush_sigqueue_mask(&mask, ¤t->signal->shared_pending); |
| 3120 | flush_sigqueue_mask(&mask, ¤t->pending); |
| 3121 | recalc_sigpending(); |
| 3122 | } |
Oleg Nesterov | 0341729 | 2014-06-06 14:36:53 -0700 | [diff] [blame] | 3123 | spin_unlock_irq(¤t->sighand->siglock); |
| 3124 | } |
Oleg Nesterov | b4e7426 | 2014-06-06 14:37:00 -0700 | [diff] [blame] | 3125 | EXPORT_SYMBOL(kernel_sigaction); |
Oleg Nesterov | 0341729 | 2014-06-06 14:36:53 -0700 | [diff] [blame] | 3126 | |
Dmitry Safonov | 6846351 | 2016-09-05 16:33:08 +0300 | [diff] [blame] | 3127 | void __weak sigaction_compat_abi(struct k_sigaction *act, |
| 3128 | struct k_sigaction *oact) |
| 3129 | { |
| 3130 | } |
| 3131 | |
Oleg Nesterov | 88531f7 | 2006-03-28 16:11:24 -0800 | [diff] [blame] | 3132 | int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3133 | { |
Oleg Nesterov | afe2b03 | 2014-06-06 14:36:51 -0700 | [diff] [blame] | 3134 | struct task_struct *p = current, *t; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3135 | struct k_sigaction *k; |
George Anzinger | 71fabd5 | 2006-01-08 01:02:48 -0800 | [diff] [blame] | 3136 | sigset_t mask; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3137 | |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 3138 | if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3139 | return -EINVAL; |
| 3140 | |
Oleg Nesterov | afe2b03 | 2014-06-06 14:36:51 -0700 | [diff] [blame] | 3141 | k = &p->sighand->action[sig-1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3142 | |
Oleg Nesterov | afe2b03 | 2014-06-06 14:36:51 -0700 | [diff] [blame] | 3143 | spin_lock_irq(&p->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3144 | if (oact) |
| 3145 | *oact = *k; |
| 3146 | |
Dmitry Safonov | 6846351 | 2016-09-05 16:33:08 +0300 | [diff] [blame] | 3147 | sigaction_compat_abi(act, oact); |
| 3148 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3149 | if (act) { |
Oleg Nesterov | 9ac95f2 | 2006-02-09 22:41:50 +0300 | [diff] [blame] | 3150 | sigdelsetmask(&act->sa.sa_mask, |
| 3151 | sigmask(SIGKILL) | sigmask(SIGSTOP)); |
Oleg Nesterov | 88531f7 | 2006-03-28 16:11:24 -0800 | [diff] [blame] | 3152 | *k = *act; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3153 | /* |
| 3154 | * POSIX 3.3.1.3: |
| 3155 | * "Setting a signal action to SIG_IGN for a signal that is |
| 3156 | * pending shall cause the pending signal to be discarded, |
| 3157 | * whether or not it is blocked." |
| 3158 | * |
| 3159 | * "Setting a signal action to SIG_DFL for a signal that is |
| 3160 | * pending and whose default action is to ignore the signal |
| 3161 | * (for example, SIGCHLD), shall cause the pending signal to |
| 3162 | * be discarded, whether or not it is blocked" |
| 3163 | */ |
Oleg Nesterov | afe2b03 | 2014-06-06 14:36:51 -0700 | [diff] [blame] | 3164 | if (sig_handler_ignored(sig_handler(p, sig), sig)) { |
George Anzinger | 71fabd5 | 2006-01-08 01:02:48 -0800 | [diff] [blame] | 3165 | sigemptyset(&mask); |
| 3166 | sigaddset(&mask, sig); |
Oleg Nesterov | afe2b03 | 2014-06-06 14:36:51 -0700 | [diff] [blame] | 3167 | flush_sigqueue_mask(&mask, &p->signal->shared_pending); |
| 3168 | for_each_thread(p, t) |
Oleg Nesterov | c09c144 | 2014-06-06 14:36:50 -0700 | [diff] [blame] | 3169 | flush_sigqueue_mask(&mask, &t->pending); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3170 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3171 | } |
| 3172 | |
Oleg Nesterov | afe2b03 | 2014-06-06 14:36:51 -0700 | [diff] [blame] | 3173 | spin_unlock_irq(&p->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3174 | return 0; |
| 3175 | } |
| 3176 | |
Oleg Nesterov | c09c144 | 2014-06-06 14:36:50 -0700 | [diff] [blame] | 3177 | static int |
Will Deacon | 1e7066a | 2018-09-05 15:34:42 +0100 | [diff] [blame] | 3178 | do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp, |
| 3179 | size_t min_ss_size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3180 | { |
| 3181 | stack_t oss; |
| 3182 | int error; |
| 3183 | |
Linus Torvalds | 0083fc2 | 2009-08-01 10:34:56 -0700 | [diff] [blame] | 3184 | oss.ss_sp = (void __user *) current->sas_ss_sp; |
| 3185 | oss.ss_size = current->sas_ss_size; |
Andy Lutomirski | 0318bc8 | 2016-05-03 10:31:51 -0700 | [diff] [blame] | 3186 | oss.ss_flags = sas_ss_flags(sp) | |
| 3187 | (current->sas_ss_flags & SS_FLAG_BITS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3188 | |
| 3189 | if (uss) { |
| 3190 | void __user *ss_sp; |
| 3191 | size_t ss_size; |
Stas Sergeev | 407bc16 | 2016-04-14 23:20:03 +0300 | [diff] [blame] | 3192 | unsigned ss_flags; |
| 3193 | int ss_mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3194 | |
| 3195 | error = -EFAULT; |
Linus Torvalds | 0dd8486 | 2009-08-01 11:18:56 -0700 | [diff] [blame] | 3196 | if (!access_ok(VERIFY_READ, uss, sizeof(*uss))) |
| 3197 | goto out; |
| 3198 | error = __get_user(ss_sp, &uss->ss_sp) | |
| 3199 | __get_user(ss_flags, &uss->ss_flags) | |
| 3200 | __get_user(ss_size, &uss->ss_size); |
| 3201 | if (error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3202 | goto out; |
| 3203 | |
| 3204 | error = -EPERM; |
| 3205 | if (on_sig_stack(sp)) |
| 3206 | goto out; |
| 3207 | |
Stas Sergeev | 407bc16 | 2016-04-14 23:20:03 +0300 | [diff] [blame] | 3208 | ss_mode = ss_flags & ~SS_FLAG_BITS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3209 | error = -EINVAL; |
Stas Sergeev | 407bc16 | 2016-04-14 23:20:03 +0300 | [diff] [blame] | 3210 | if (ss_mode != SS_DISABLE && ss_mode != SS_ONSTACK && |
| 3211 | ss_mode != 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3212 | goto out; |
| 3213 | |
Stas Sergeev | 407bc16 | 2016-04-14 23:20:03 +0300 | [diff] [blame] | 3214 | if (ss_mode == SS_DISABLE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3215 | ss_size = 0; |
| 3216 | ss_sp = NULL; |
| 3217 | } else { |
Will Deacon | 1e7066a | 2018-09-05 15:34:42 +0100 | [diff] [blame] | 3218 | if (unlikely(ss_size < min_ss_size)) |
| 3219 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3220 | } |
| 3221 | |
| 3222 | current->sas_ss_sp = (unsigned long) ss_sp; |
| 3223 | current->sas_ss_size = ss_size; |
Stas Sergeev | 2a74213 | 2016-04-14 23:20:04 +0300 | [diff] [blame] | 3224 | current->sas_ss_flags = ss_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3225 | } |
| 3226 | |
Linus Torvalds | 0083fc2 | 2009-08-01 10:34:56 -0700 | [diff] [blame] | 3227 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3228 | if (uoss) { |
| 3229 | error = -EFAULT; |
Linus Torvalds | 0083fc2 | 2009-08-01 10:34:56 -0700 | [diff] [blame] | 3230 | if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3231 | goto out; |
Linus Torvalds | 0083fc2 | 2009-08-01 10:34:56 -0700 | [diff] [blame] | 3232 | error = __put_user(oss.ss_sp, &uoss->ss_sp) | |
| 3233 | __put_user(oss.ss_size, &uoss->ss_size) | |
| 3234 | __put_user(oss.ss_flags, &uoss->ss_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3235 | } |
| 3236 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3237 | out: |
| 3238 | return error; |
| 3239 | } |
Al Viro | 6bf9adf | 2012-12-14 14:09:47 -0500 | [diff] [blame] | 3240 | SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss) |
| 3241 | { |
Will Deacon | 1e7066a | 2018-09-05 15:34:42 +0100 | [diff] [blame] | 3242 | return do_sigaltstack(uss, uoss, current_user_stack_pointer(), |
| 3243 | MINSIGSTKSZ); |
Al Viro | 6bf9adf | 2012-12-14 14:09:47 -0500 | [diff] [blame] | 3244 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3245 | |
Al Viro | 5c49574 | 2012-11-18 15:29:16 -0500 | [diff] [blame] | 3246 | int restore_altstack(const stack_t __user *uss) |
| 3247 | { |
Will Deacon | 1e7066a | 2018-09-05 15:34:42 +0100 | [diff] [blame] | 3248 | int err = do_sigaltstack(uss, NULL, current_user_stack_pointer(), |
| 3249 | MINSIGSTKSZ); |
Al Viro | 5c49574 | 2012-11-18 15:29:16 -0500 | [diff] [blame] | 3250 | /* squash all but EFAULT for now */ |
| 3251 | return err == -EFAULT ? err : 0; |
| 3252 | } |
| 3253 | |
Al Viro | c40702c | 2012-11-20 14:24:26 -0500 | [diff] [blame] | 3254 | int __save_altstack(stack_t __user *uss, unsigned long sp) |
| 3255 | { |
| 3256 | struct task_struct *t = current; |
Stas Sergeev | 2a74213 | 2016-04-14 23:20:04 +0300 | [diff] [blame] | 3257 | int err = __put_user((void __user *)t->sas_ss_sp, &uss->ss_sp) | |
| 3258 | __put_user(t->sas_ss_flags, &uss->ss_flags) | |
Al Viro | c40702c | 2012-11-20 14:24:26 -0500 | [diff] [blame] | 3259 | __put_user(t->sas_ss_size, &uss->ss_size); |
Stas Sergeev | 2a74213 | 2016-04-14 23:20:04 +0300 | [diff] [blame] | 3260 | if (err) |
| 3261 | return err; |
| 3262 | if (t->sas_ss_flags & SS_AUTODISARM) |
| 3263 | sas_ss_reset(t); |
| 3264 | return 0; |
Al Viro | c40702c | 2012-11-20 14:24:26 -0500 | [diff] [blame] | 3265 | } |
| 3266 | |
Al Viro | 9026843 | 2012-12-14 14:47:53 -0500 | [diff] [blame] | 3267 | #ifdef CONFIG_COMPAT |
Al Viro | 90228fc | 2012-12-23 03:33:38 -0500 | [diff] [blame] | 3268 | COMPAT_SYSCALL_DEFINE2(sigaltstack, |
| 3269 | const compat_stack_t __user *, uss_ptr, |
| 3270 | compat_stack_t __user *, uoss_ptr) |
Al Viro | 9026843 | 2012-12-14 14:47:53 -0500 | [diff] [blame] | 3271 | { |
| 3272 | stack_t uss, uoss; |
| 3273 | int ret; |
| 3274 | mm_segment_t seg; |
| 3275 | |
| 3276 | if (uss_ptr) { |
| 3277 | compat_stack_t uss32; |
| 3278 | |
| 3279 | memset(&uss, 0, sizeof(stack_t)); |
| 3280 | if (copy_from_user(&uss32, uss_ptr, sizeof(compat_stack_t))) |
| 3281 | return -EFAULT; |
| 3282 | uss.ss_sp = compat_ptr(uss32.ss_sp); |
| 3283 | uss.ss_flags = uss32.ss_flags; |
| 3284 | uss.ss_size = uss32.ss_size; |
| 3285 | } |
| 3286 | seg = get_fs(); |
| 3287 | set_fs(KERNEL_DS); |
| 3288 | ret = do_sigaltstack((stack_t __force __user *) (uss_ptr ? &uss : NULL), |
| 3289 | (stack_t __force __user *) &uoss, |
Will Deacon | 1e7066a | 2018-09-05 15:34:42 +0100 | [diff] [blame] | 3290 | compat_user_stack_pointer(), |
| 3291 | COMPAT_MINSIGSTKSZ); |
Al Viro | 9026843 | 2012-12-14 14:47:53 -0500 | [diff] [blame] | 3292 | set_fs(seg); |
| 3293 | if (ret >= 0 && uoss_ptr) { |
| 3294 | if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(compat_stack_t)) || |
| 3295 | __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) || |
| 3296 | __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) || |
| 3297 | __put_user(uoss.ss_size, &uoss_ptr->ss_size)) |
| 3298 | ret = -EFAULT; |
| 3299 | } |
| 3300 | return ret; |
| 3301 | } |
| 3302 | |
| 3303 | int compat_restore_altstack(const compat_stack_t __user *uss) |
| 3304 | { |
| 3305 | int err = compat_sys_sigaltstack(uss, NULL); |
| 3306 | /* squash all but -EFAULT for now */ |
| 3307 | return err == -EFAULT ? err : 0; |
| 3308 | } |
Al Viro | c40702c | 2012-11-20 14:24:26 -0500 | [diff] [blame] | 3309 | |
| 3310 | int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp) |
| 3311 | { |
Stas Sergeev | 6d94a6b | 2017-02-27 14:27:25 -0800 | [diff] [blame] | 3312 | int err; |
Al Viro | c40702c | 2012-11-20 14:24:26 -0500 | [diff] [blame] | 3313 | struct task_struct *t = current; |
Stas Sergeev | 6d94a6b | 2017-02-27 14:27:25 -0800 | [diff] [blame] | 3314 | err = __put_user(ptr_to_compat((void __user *)t->sas_ss_sp), |
| 3315 | &uss->ss_sp) | |
| 3316 | __put_user(t->sas_ss_flags, &uss->ss_flags) | |
Al Viro | c40702c | 2012-11-20 14:24:26 -0500 | [diff] [blame] | 3317 | __put_user(t->sas_ss_size, &uss->ss_size); |
Stas Sergeev | 6d94a6b | 2017-02-27 14:27:25 -0800 | [diff] [blame] | 3318 | if (err) |
| 3319 | return err; |
| 3320 | if (t->sas_ss_flags & SS_AUTODISARM) |
| 3321 | sas_ss_reset(t); |
| 3322 | return 0; |
Al Viro | c40702c | 2012-11-20 14:24:26 -0500 | [diff] [blame] | 3323 | } |
Al Viro | 9026843 | 2012-12-14 14:47:53 -0500 | [diff] [blame] | 3324 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3325 | |
| 3326 | #ifdef __ARCH_WANT_SYS_SIGPENDING |
| 3327 | |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 3328 | /** |
| 3329 | * sys_sigpending - examine pending signals |
| 3330 | * @set: where mask of pending signal is returned |
| 3331 | */ |
Heiko Carstens | b290ebe | 2009-01-14 14:14:06 +0100 | [diff] [blame] | 3332 | SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3333 | { |
Al Viro | fe9c1db | 2012-12-25 14:31:38 -0500 | [diff] [blame] | 3334 | return sys_rt_sigpending((sigset_t __user *)set, sizeof(old_sigset_t)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3335 | } |
| 3336 | |
| 3337 | #endif |
| 3338 | |
| 3339 | #ifdef __ARCH_WANT_SYS_SIGPROCMASK |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 3340 | /** |
| 3341 | * sys_sigprocmask - examine and change blocked signals |
| 3342 | * @how: whether to add, remove, or set signals |
Oleg Nesterov | b013c39 | 2011-04-28 11:36:20 +0200 | [diff] [blame] | 3343 | * @nset: signals to add or remove (if non-null) |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 3344 | * @oset: previous value of signal mask if non-null |
| 3345 | * |
Randy Dunlap | 5aba085 | 2011-04-04 14:59:31 -0700 | [diff] [blame] | 3346 | * Some platforms have their own version with special arguments; |
| 3347 | * others support only sys_rt_sigprocmask. |
| 3348 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3349 | |
Oleg Nesterov | b013c39 | 2011-04-28 11:36:20 +0200 | [diff] [blame] | 3350 | SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset, |
Heiko Carstens | b290ebe | 2009-01-14 14:14:06 +0100 | [diff] [blame] | 3351 | old_sigset_t __user *, oset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3352 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3353 | old_sigset_t old_set, new_set; |
Oleg Nesterov | 2e4f7c7 | 2011-05-09 13:48:56 +0200 | [diff] [blame] | 3354 | sigset_t new_blocked; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3355 | |
Oleg Nesterov | b013c39 | 2011-04-28 11:36:20 +0200 | [diff] [blame] | 3356 | old_set = current->blocked.sig[0]; |
| 3357 | |
| 3358 | if (nset) { |
| 3359 | if (copy_from_user(&new_set, nset, sizeof(*nset))) |
| 3360 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3361 | |
Oleg Nesterov | 2e4f7c7 | 2011-05-09 13:48:56 +0200 | [diff] [blame] | 3362 | new_blocked = current->blocked; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3363 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3364 | switch (how) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3365 | case SIG_BLOCK: |
Oleg Nesterov | 2e4f7c7 | 2011-05-09 13:48:56 +0200 | [diff] [blame] | 3366 | sigaddsetmask(&new_blocked, new_set); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3367 | break; |
| 3368 | case SIG_UNBLOCK: |
Oleg Nesterov | 2e4f7c7 | 2011-05-09 13:48:56 +0200 | [diff] [blame] | 3369 | sigdelsetmask(&new_blocked, new_set); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3370 | break; |
| 3371 | case SIG_SETMASK: |
Oleg Nesterov | 2e4f7c7 | 2011-05-09 13:48:56 +0200 | [diff] [blame] | 3372 | new_blocked.sig[0] = new_set; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3373 | break; |
Oleg Nesterov | 2e4f7c7 | 2011-05-09 13:48:56 +0200 | [diff] [blame] | 3374 | default: |
| 3375 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3376 | } |
| 3377 | |
Oleg Nesterov | 0c4a842 | 2013-01-05 19:13:29 +0100 | [diff] [blame] | 3378 | set_current_blocked(&new_blocked); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3379 | } |
Oleg Nesterov | b013c39 | 2011-04-28 11:36:20 +0200 | [diff] [blame] | 3380 | |
| 3381 | if (oset) { |
| 3382 | if (copy_to_user(oset, &old_set, sizeof(*oset))) |
| 3383 | return -EFAULT; |
| 3384 | } |
| 3385 | |
| 3386 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3387 | } |
| 3388 | #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ |
| 3389 | |
Al Viro | eaca6ea | 2012-11-25 23:12:10 -0500 | [diff] [blame] | 3390 | #ifndef CONFIG_ODD_RT_SIGACTION |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 3391 | /** |
| 3392 | * sys_rt_sigaction - alter an action taken by a process |
| 3393 | * @sig: signal to be sent |
Randy Dunlap | f9fa0bc | 2011-04-08 10:53:46 -0700 | [diff] [blame] | 3394 | * @act: new sigaction |
| 3395 | * @oact: used to save the previous sigaction |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 3396 | * @sigsetsize: size of sigset_t type |
| 3397 | */ |
Heiko Carstens | d4e8204 | 2009-01-14 14:14:34 +0100 | [diff] [blame] | 3398 | SYSCALL_DEFINE4(rt_sigaction, int, sig, |
| 3399 | const struct sigaction __user *, act, |
| 3400 | struct sigaction __user *, oact, |
| 3401 | size_t, sigsetsize) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3402 | { |
| 3403 | struct k_sigaction new_sa, old_sa; |
| 3404 | int ret = -EINVAL; |
| 3405 | |
| 3406 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 3407 | if (sigsetsize != sizeof(sigset_t)) |
| 3408 | goto out; |
| 3409 | |
| 3410 | if (act) { |
| 3411 | if (copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa))) |
| 3412 | return -EFAULT; |
| 3413 | } |
| 3414 | |
| 3415 | ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); |
| 3416 | |
| 3417 | if (!ret && oact) { |
| 3418 | if (copy_to_user(oact, &old_sa.sa, sizeof(old_sa.sa))) |
| 3419 | return -EFAULT; |
| 3420 | } |
| 3421 | out: |
| 3422 | return ret; |
| 3423 | } |
Al Viro | 08d32fe | 2012-12-25 18:38:15 -0500 | [diff] [blame] | 3424 | #ifdef CONFIG_COMPAT |
Al Viro | 08d32fe | 2012-12-25 18:38:15 -0500 | [diff] [blame] | 3425 | COMPAT_SYSCALL_DEFINE4(rt_sigaction, int, sig, |
| 3426 | const struct compat_sigaction __user *, act, |
| 3427 | struct compat_sigaction __user *, oact, |
| 3428 | compat_size_t, sigsetsize) |
| 3429 | { |
| 3430 | struct k_sigaction new_ka, old_ka; |
| 3431 | compat_sigset_t mask; |
| 3432 | #ifdef __ARCH_HAS_SA_RESTORER |
| 3433 | compat_uptr_t restorer; |
| 3434 | #endif |
| 3435 | int ret; |
| 3436 | |
| 3437 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 3438 | if (sigsetsize != sizeof(compat_sigset_t)) |
| 3439 | return -EINVAL; |
| 3440 | |
| 3441 | if (act) { |
| 3442 | compat_uptr_t handler; |
| 3443 | ret = get_user(handler, &act->sa_handler); |
| 3444 | new_ka.sa.sa_handler = compat_ptr(handler); |
| 3445 | #ifdef __ARCH_HAS_SA_RESTORER |
| 3446 | ret |= get_user(restorer, &act->sa_restorer); |
| 3447 | new_ka.sa.sa_restorer = compat_ptr(restorer); |
| 3448 | #endif |
| 3449 | ret |= copy_from_user(&mask, &act->sa_mask, sizeof(mask)); |
Mathieu Desnoyers | 3ddc5b4 | 2013-09-11 14:23:18 -0700 | [diff] [blame] | 3450 | ret |= get_user(new_ka.sa.sa_flags, &act->sa_flags); |
Al Viro | 08d32fe | 2012-12-25 18:38:15 -0500 | [diff] [blame] | 3451 | if (ret) |
| 3452 | return -EFAULT; |
| 3453 | sigset_from_compat(&new_ka.sa.sa_mask, &mask); |
| 3454 | } |
| 3455 | |
| 3456 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); |
| 3457 | if (!ret && oact) { |
| 3458 | sigset_to_compat(&mask, &old_ka.sa.sa_mask); |
| 3459 | ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), |
| 3460 | &oact->sa_handler); |
| 3461 | ret |= copy_to_user(&oact->sa_mask, &mask, sizeof(mask)); |
Mathieu Desnoyers | 3ddc5b4 | 2013-09-11 14:23:18 -0700 | [diff] [blame] | 3462 | ret |= put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
Al Viro | 08d32fe | 2012-12-25 18:38:15 -0500 | [diff] [blame] | 3463 | #ifdef __ARCH_HAS_SA_RESTORER |
| 3464 | ret |= put_user(ptr_to_compat(old_ka.sa.sa_restorer), |
| 3465 | &oact->sa_restorer); |
| 3466 | #endif |
| 3467 | } |
| 3468 | return ret; |
| 3469 | } |
| 3470 | #endif |
Al Viro | eaca6ea | 2012-11-25 23:12:10 -0500 | [diff] [blame] | 3471 | #endif /* !CONFIG_ODD_RT_SIGACTION */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3472 | |
Al Viro | 495dfbf | 2012-12-25 19:09:45 -0500 | [diff] [blame] | 3473 | #ifdef CONFIG_OLD_SIGACTION |
| 3474 | SYSCALL_DEFINE3(sigaction, int, sig, |
| 3475 | const struct old_sigaction __user *, act, |
| 3476 | struct old_sigaction __user *, oact) |
| 3477 | { |
| 3478 | struct k_sigaction new_ka, old_ka; |
| 3479 | int ret; |
| 3480 | |
| 3481 | if (act) { |
| 3482 | old_sigset_t mask; |
| 3483 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || |
| 3484 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || |
| 3485 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) || |
| 3486 | __get_user(new_ka.sa.sa_flags, &act->sa_flags) || |
| 3487 | __get_user(mask, &act->sa_mask)) |
| 3488 | return -EFAULT; |
| 3489 | #ifdef __ARCH_HAS_KA_RESTORER |
| 3490 | new_ka.ka_restorer = NULL; |
| 3491 | #endif |
| 3492 | siginitset(&new_ka.sa.sa_mask, mask); |
| 3493 | } |
| 3494 | |
| 3495 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); |
| 3496 | |
| 3497 | if (!ret && oact) { |
| 3498 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || |
| 3499 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || |
| 3500 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) || |
| 3501 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || |
| 3502 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) |
| 3503 | return -EFAULT; |
| 3504 | } |
| 3505 | |
| 3506 | return ret; |
| 3507 | } |
| 3508 | #endif |
| 3509 | #ifdef CONFIG_COMPAT_OLD_SIGACTION |
| 3510 | COMPAT_SYSCALL_DEFINE3(sigaction, int, sig, |
| 3511 | const struct compat_old_sigaction __user *, act, |
| 3512 | struct compat_old_sigaction __user *, oact) |
| 3513 | { |
| 3514 | struct k_sigaction new_ka, old_ka; |
| 3515 | int ret; |
| 3516 | compat_old_sigset_t mask; |
| 3517 | compat_uptr_t handler, restorer; |
| 3518 | |
| 3519 | if (act) { |
| 3520 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || |
| 3521 | __get_user(handler, &act->sa_handler) || |
| 3522 | __get_user(restorer, &act->sa_restorer) || |
| 3523 | __get_user(new_ka.sa.sa_flags, &act->sa_flags) || |
| 3524 | __get_user(mask, &act->sa_mask)) |
| 3525 | return -EFAULT; |
| 3526 | |
| 3527 | #ifdef __ARCH_HAS_KA_RESTORER |
| 3528 | new_ka.ka_restorer = NULL; |
| 3529 | #endif |
| 3530 | new_ka.sa.sa_handler = compat_ptr(handler); |
| 3531 | new_ka.sa.sa_restorer = compat_ptr(restorer); |
| 3532 | siginitset(&new_ka.sa.sa_mask, mask); |
| 3533 | } |
| 3534 | |
| 3535 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); |
| 3536 | |
| 3537 | if (!ret && oact) { |
| 3538 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || |
| 3539 | __put_user(ptr_to_compat(old_ka.sa.sa_handler), |
| 3540 | &oact->sa_handler) || |
| 3541 | __put_user(ptr_to_compat(old_ka.sa.sa_restorer), |
| 3542 | &oact->sa_restorer) || |
| 3543 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || |
| 3544 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) |
| 3545 | return -EFAULT; |
| 3546 | } |
| 3547 | return ret; |
| 3548 | } |
| 3549 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3550 | |
Fabian Frederick | f618776 | 2014-06-04 16:11:12 -0700 | [diff] [blame] | 3551 | #ifdef CONFIG_SGETMASK_SYSCALL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3552 | |
| 3553 | /* |
| 3554 | * For backwards compatibility. Functionality superseded by sigprocmask. |
| 3555 | */ |
Heiko Carstens | a5f8fa9 | 2009-01-14 14:14:11 +0100 | [diff] [blame] | 3556 | SYSCALL_DEFINE0(sgetmask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3557 | { |
| 3558 | /* SMP safe */ |
| 3559 | return current->blocked.sig[0]; |
| 3560 | } |
| 3561 | |
Heiko Carstens | a5f8fa9 | 2009-01-14 14:14:11 +0100 | [diff] [blame] | 3562 | SYSCALL_DEFINE1(ssetmask, int, newmask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3563 | { |
Oleg Nesterov | c1095c6 | 2011-07-27 12:49:44 -0700 | [diff] [blame] | 3564 | int old = current->blocked.sig[0]; |
| 3565 | sigset_t newset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3566 | |
Oleg Nesterov | 5ba53ff | 2013-01-05 19:13:13 +0100 | [diff] [blame] | 3567 | siginitset(&newset, newmask); |
Oleg Nesterov | c1095c6 | 2011-07-27 12:49:44 -0700 | [diff] [blame] | 3568 | set_current_blocked(&newset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3569 | |
| 3570 | return old; |
| 3571 | } |
Fabian Frederick | f618776 | 2014-06-04 16:11:12 -0700 | [diff] [blame] | 3572 | #endif /* CONFIG_SGETMASK_SYSCALL */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3573 | |
| 3574 | #ifdef __ARCH_WANT_SYS_SIGNAL |
| 3575 | /* |
| 3576 | * For backwards compatibility. Functionality superseded by sigaction. |
| 3577 | */ |
Heiko Carstens | a5f8fa9 | 2009-01-14 14:14:11 +0100 | [diff] [blame] | 3578 | SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3579 | { |
| 3580 | struct k_sigaction new_sa, old_sa; |
| 3581 | int ret; |
| 3582 | |
| 3583 | new_sa.sa.sa_handler = handler; |
| 3584 | new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; |
Oleg Nesterov | c70d3d70 | 2006-02-09 22:41:41 +0300 | [diff] [blame] | 3585 | sigemptyset(&new_sa.sa.sa_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3586 | |
| 3587 | ret = do_sigaction(sig, &new_sa, &old_sa); |
| 3588 | |
| 3589 | return ret ? ret : (unsigned long)old_sa.sa.sa_handler; |
| 3590 | } |
| 3591 | #endif /* __ARCH_WANT_SYS_SIGNAL */ |
| 3592 | |
| 3593 | #ifdef __ARCH_WANT_SYS_PAUSE |
| 3594 | |
Heiko Carstens | a5f8fa9 | 2009-01-14 14:14:11 +0100 | [diff] [blame] | 3595 | SYSCALL_DEFINE0(pause) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3596 | { |
Oleg Nesterov | d92fcf0 | 2011-05-25 19:22:27 +0200 | [diff] [blame] | 3597 | while (!signal_pending(current)) { |
Davidlohr Bueso | 1df0135 | 2015-02-17 13:45:41 -0800 | [diff] [blame] | 3598 | __set_current_state(TASK_INTERRUPTIBLE); |
Oleg Nesterov | d92fcf0 | 2011-05-25 19:22:27 +0200 | [diff] [blame] | 3599 | schedule(); |
| 3600 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3601 | return -ERESTARTNOHAND; |
| 3602 | } |
| 3603 | |
| 3604 | #endif |
| 3605 | |
Richard Weinberger | 9d8a765 | 2015-11-20 15:57:21 -0800 | [diff] [blame] | 3606 | static int sigsuspend(sigset_t *set) |
Al Viro | 68f3f16 | 2012-05-21 21:42:32 -0400 | [diff] [blame] | 3607 | { |
Al Viro | 68f3f16 | 2012-05-21 21:42:32 -0400 | [diff] [blame] | 3608 | current->saved_sigmask = current->blocked; |
| 3609 | set_current_blocked(set); |
| 3610 | |
Sasha Levin | 823dd32 | 2016-02-05 15:36:05 -0800 | [diff] [blame] | 3611 | while (!signal_pending(current)) { |
| 3612 | __set_current_state(TASK_INTERRUPTIBLE); |
| 3613 | schedule(); |
| 3614 | } |
Al Viro | 68f3f16 | 2012-05-21 21:42:32 -0400 | [diff] [blame] | 3615 | set_restore_sigmask(); |
| 3616 | return -ERESTARTNOHAND; |
| 3617 | } |
Al Viro | 68f3f16 | 2012-05-21 21:42:32 -0400 | [diff] [blame] | 3618 | |
Randy Dunlap | 41c5789 | 2011-04-04 15:00:26 -0700 | [diff] [blame] | 3619 | /** |
| 3620 | * sys_rt_sigsuspend - replace the signal mask for a value with the |
| 3621 | * @unewset value until a signal is received |
| 3622 | * @unewset: new signal mask value |
| 3623 | * @sigsetsize: size of sigset_t type |
| 3624 | */ |
Heiko Carstens | d4e8204 | 2009-01-14 14:14:34 +0100 | [diff] [blame] | 3625 | SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize) |
David Woodhouse | 150256d | 2006-01-18 17:43:57 -0800 | [diff] [blame] | 3626 | { |
| 3627 | sigset_t newset; |
| 3628 | |
| 3629 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 3630 | if (sigsetsize != sizeof(sigset_t)) |
| 3631 | return -EINVAL; |
| 3632 | |
| 3633 | if (copy_from_user(&newset, unewset, sizeof(newset))) |
| 3634 | return -EFAULT; |
Al Viro | 68f3f16 | 2012-05-21 21:42:32 -0400 | [diff] [blame] | 3635 | return sigsuspend(&newset); |
David Woodhouse | 150256d | 2006-01-18 17:43:57 -0800 | [diff] [blame] | 3636 | } |
Al Viro | ad4b65a | 2012-12-24 21:43:56 -0500 | [diff] [blame] | 3637 | |
| 3638 | #ifdef CONFIG_COMPAT |
| 3639 | COMPAT_SYSCALL_DEFINE2(rt_sigsuspend, compat_sigset_t __user *, unewset, compat_size_t, sigsetsize) |
| 3640 | { |
| 3641 | #ifdef __BIG_ENDIAN |
| 3642 | sigset_t newset; |
| 3643 | compat_sigset_t newset32; |
| 3644 | |
| 3645 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 3646 | if (sigsetsize != sizeof(sigset_t)) |
| 3647 | return -EINVAL; |
| 3648 | |
| 3649 | if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t))) |
| 3650 | return -EFAULT; |
| 3651 | sigset_from_compat(&newset, &newset32); |
| 3652 | return sigsuspend(&newset); |
| 3653 | #else |
| 3654 | /* on little-endian bitmaps don't care about granularity */ |
| 3655 | return sys_rt_sigsuspend((sigset_t __user *)unewset, sigsetsize); |
| 3656 | #endif |
| 3657 | } |
| 3658 | #endif |
David Woodhouse | 150256d | 2006-01-18 17:43:57 -0800 | [diff] [blame] | 3659 | |
Al Viro | 0a0e8cd | 2012-12-25 16:04:12 -0500 | [diff] [blame] | 3660 | #ifdef CONFIG_OLD_SIGSUSPEND |
| 3661 | SYSCALL_DEFINE1(sigsuspend, old_sigset_t, mask) |
| 3662 | { |
| 3663 | sigset_t blocked; |
| 3664 | siginitset(&blocked, mask); |
| 3665 | return sigsuspend(&blocked); |
| 3666 | } |
| 3667 | #endif |
| 3668 | #ifdef CONFIG_OLD_SIGSUSPEND3 |
| 3669 | SYSCALL_DEFINE3(sigsuspend, int, unused1, int, unused2, old_sigset_t, mask) |
| 3670 | { |
| 3671 | sigset_t blocked; |
| 3672 | siginitset(&blocked, mask); |
| 3673 | return sigsuspend(&blocked); |
| 3674 | } |
| 3675 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3676 | |
Gideon Israel Dsouza | 52f5684c | 2014-04-07 15:39:20 -0700 | [diff] [blame] | 3677 | __weak const char *arch_vma_name(struct vm_area_struct *vma) |
David Howells | f269fdd | 2006-09-27 01:50:23 -0700 | [diff] [blame] | 3678 | { |
| 3679 | return NULL; |
| 3680 | } |
| 3681 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3682 | void __init signals_init(void) |
| 3683 | { |
Helge Deller | 41b2715 | 2016-03-22 14:27:54 -0700 | [diff] [blame] | 3684 | /* If this check fails, the __ARCH_SI_PREAMBLE_SIZE value is wrong! */ |
| 3685 | BUILD_BUG_ON(__ARCH_SI_PREAMBLE_SIZE |
| 3686 | != offsetof(struct siginfo, _sifields._pad)); |
| 3687 | |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 3688 | sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3689 | } |
Jason Wessel | 67fc4e0 | 2010-05-20 21:04:21 -0500 | [diff] [blame] | 3690 | |
| 3691 | #ifdef CONFIG_KGDB_KDB |
| 3692 | #include <linux/kdb.h> |
| 3693 | /* |
| 3694 | * kdb_send_sig_info - Allows kdb to send signals without exposing |
| 3695 | * signal internals. This function checks if the required locks are |
| 3696 | * available before calling the main signal code, to avoid kdb |
| 3697 | * deadlocks. |
| 3698 | */ |
| 3699 | void |
| 3700 | kdb_send_sig_info(struct task_struct *t, struct siginfo *info) |
| 3701 | { |
| 3702 | static struct task_struct *kdb_prev_t; |
| 3703 | int sig, new_t; |
| 3704 | if (!spin_trylock(&t->sighand->siglock)) { |
| 3705 | kdb_printf("Can't do kill command now.\n" |
| 3706 | "The sigmask lock is held somewhere else in " |
| 3707 | "kernel, try again later\n"); |
| 3708 | return; |
| 3709 | } |
| 3710 | spin_unlock(&t->sighand->siglock); |
| 3711 | new_t = kdb_prev_t != t; |
| 3712 | kdb_prev_t = t; |
| 3713 | if (t->state != TASK_RUNNING && new_t) { |
| 3714 | kdb_printf("Process is not RUNNING, sending a signal from " |
| 3715 | "kdb risks deadlock\n" |
| 3716 | "on the run queue locks. " |
| 3717 | "The signal has _not_ been sent.\n" |
| 3718 | "Reissue the kill command if you want to risk " |
| 3719 | "the deadlock.\n"); |
| 3720 | return; |
| 3721 | } |
| 3722 | sig = info->si_signo; |
| 3723 | if (send_sig_info(sig, info, t)) |
| 3724 | kdb_printf("Fail to deliver Signal %d to process %d.\n", |
| 3725 | sig, t->pid); |
| 3726 | else |
| 3727 | kdb_printf("Signal %d is sent to process %d.\n", sig, t->pid); |
| 3728 | } |
| 3729 | #endif /* CONFIG_KGDB_KDB */ |