Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/ptrace.c |
| 3 | * |
| 4 | * (C) Copyright 1999 Linus Torvalds |
| 5 | * |
| 6 | * Common interfaces for "ptrace()" which we do not want |
| 7 | * to continually duplicate across every architecture. |
| 8 | */ |
| 9 | |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 10 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/module.h> |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/errno.h> |
| 14 | #include <linux/mm.h> |
| 15 | #include <linux/highmem.h> |
| 16 | #include <linux/pagemap.h> |
| 17 | #include <linux/smp_lock.h> |
| 18 | #include <linux/ptrace.h> |
| 19 | #include <linux/security.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 20 | #include <linux/signal.h> |
Al Viro | a5cb013 | 2007-03-20 13:58:35 -0400 | [diff] [blame] | 21 | #include <linux/audit.h> |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 22 | #include <linux/pid_namespace.h> |
Adrian Bunk | f17d30a | 2008-02-06 01:36:44 -0800 | [diff] [blame] | 23 | #include <linux/syscalls.h> |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 24 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
Markus Metzger | bf53de9 | 2008-12-19 15:10:24 +0100 | [diff] [blame] | 26 | |
| 27 | /* |
| 28 | * Initialize a new task whose father had been ptraced. |
| 29 | * |
| 30 | * Called from copy_process(). |
| 31 | */ |
| 32 | void ptrace_fork(struct task_struct *child, unsigned long clone_flags) |
| 33 | { |
| 34 | arch_ptrace_fork(child, clone_flags); |
| 35 | } |
| 36 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | /* |
| 38 | * ptrace a task: make the debugger its new parent and |
| 39 | * move it to the ptrace list. |
| 40 | * |
| 41 | * Must be called with the tasklist lock write-held. |
| 42 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 43 | void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | { |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 45 | BUG_ON(!list_empty(&child->ptrace_entry)); |
| 46 | list_add(&child->ptrace_entry, &new_parent->ptraced); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | child->parent = new_parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | } |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 49 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | /* |
| 51 | * Turn a tracing stop into a normal stop now, since with no tracer there |
| 52 | * would be no way to wake it up with SIGCONT or SIGKILL. If there was a |
| 53 | * signal sent that would resume the child, but didn't because it was in |
| 54 | * TASK_TRACED, resume it now. |
| 55 | * Requires that irqs be disabled. |
| 56 | */ |
Adrian Bunk | b747c8c | 2008-10-18 20:28:21 -0700 | [diff] [blame] | 57 | static void ptrace_untrace(struct task_struct *child) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | { |
| 59 | spin_lock(&child->sighand->siglock); |
Matthew Wilcox | 6618a3e | 2007-12-06 11:06:16 -0500 | [diff] [blame] | 60 | if (task_is_traced(child)) { |
Oleg Nesterov | 1ee1184 | 2009-04-02 16:58:23 -0700 | [diff] [blame] | 61 | /* |
| 62 | * If the group stop is completed or in progress, |
| 63 | * this thread was already counted as stopped. |
| 64 | */ |
| 65 | if (child->signal->flags & SIGNAL_STOP_STOPPED || |
| 66 | child->signal->group_stop_count) |
Oleg Nesterov | d9ae90a | 2008-02-06 01:36:13 -0800 | [diff] [blame] | 67 | __set_task_state(child, TASK_STOPPED); |
Oleg Nesterov | 1ee1184 | 2009-04-02 16:58:23 -0700 | [diff] [blame] | 68 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | signal_wake_up(child, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | } |
| 71 | spin_unlock(&child->sighand->siglock); |
| 72 | } |
| 73 | |
| 74 | /* |
| 75 | * unptrace a task: move it back to its original parent and |
| 76 | * remove it from the ptrace list. |
| 77 | * |
| 78 | * Must be called with the tasklist lock write-held. |
| 79 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 80 | void __ptrace_unlink(struct task_struct *child) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | { |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 82 | BUG_ON(!child->ptrace); |
| 83 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | child->ptrace = 0; |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 85 | child->parent = child->real_parent; |
| 86 | list_del_init(&child->ptrace_entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | |
Markus Metzger | bf53de9 | 2008-12-19 15:10:24 +0100 | [diff] [blame] | 88 | arch_ptrace_untrace(child); |
Matthew Wilcox | 6618a3e | 2007-12-06 11:06:16 -0500 | [diff] [blame] | 89 | if (task_is_traced(child)) |
Roland McGrath | e57a505 | 2006-04-12 16:30:20 -0700 | [diff] [blame] | 90 | ptrace_untrace(child); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | } |
| 92 | |
| 93 | /* |
| 94 | * Check that we have indeed attached to the thing.. |
| 95 | */ |
| 96 | int ptrace_check_attach(struct task_struct *child, int kill) |
| 97 | { |
| 98 | int ret = -ESRCH; |
| 99 | |
| 100 | /* |
| 101 | * We take the read lock around doing both checks to close a |
| 102 | * possible race where someone else was tracing our child and |
| 103 | * detached between these two checks. After this locked check, |
| 104 | * we are sure that this is our traced child and that can only |
| 105 | * be changed by us so it's not changing right after this. |
| 106 | */ |
| 107 | read_lock(&tasklist_lock); |
Oleg Nesterov | c0c0b64 | 2008-02-08 04:19:00 -0800 | [diff] [blame] | 108 | if ((child->ptrace & PT_PTRACED) && child->parent == current) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | ret = 0; |
Oleg Nesterov | c0c0b64 | 2008-02-08 04:19:00 -0800 | [diff] [blame] | 110 | /* |
| 111 | * child->sighand can't be NULL, release_task() |
| 112 | * does ptrace_unlink() before __exit_signal(). |
| 113 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | spin_lock_irq(&child->sighand->siglock); |
Oleg Nesterov | d9ae90a | 2008-02-06 01:36:13 -0800 | [diff] [blame] | 115 | if (task_is_stopped(child)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | child->state = TASK_TRACED; |
Oleg Nesterov | d9ae90a | 2008-02-06 01:36:13 -0800 | [diff] [blame] | 117 | else if (!task_is_traced(child) && !kill) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | ret = -ESRCH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | spin_unlock_irq(&child->sighand->siglock); |
| 120 | } |
| 121 | read_unlock(&tasklist_lock); |
| 122 | |
Oleg Nesterov | d9ae90a | 2008-02-06 01:36:13 -0800 | [diff] [blame] | 123 | if (!ret && !kill) |
Roland McGrath | 85ba2d8 | 2008-07-25 19:45:58 -0700 | [diff] [blame] | 124 | ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | |
| 126 | /* All systems go.. */ |
| 127 | return ret; |
| 128 | } |
| 129 | |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 130 | int __ptrace_may_access(struct task_struct *task, unsigned int mode) |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 131 | { |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 132 | const struct cred *cred = current_cred(), *tcred; |
David Howells | b6dff3e | 2008-11-14 10:39:16 +1100 | [diff] [blame] | 133 | |
Eric W. Biederman | df26c40 | 2006-06-26 00:25:59 -0700 | [diff] [blame] | 134 | /* May we inspect the given task? |
| 135 | * This check is used both for attaching with ptrace |
| 136 | * and for allowing access to sensitive information in /proc. |
| 137 | * |
| 138 | * ptrace_attach denies several cases that /proc allows |
| 139 | * because setting up the necessary parent/child relationship |
| 140 | * or halting the specified task is impossible. |
| 141 | */ |
| 142 | int dumpable = 0; |
| 143 | /* Don't let security modules deny introspection */ |
| 144 | if (task == current) |
| 145 | return 0; |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 146 | rcu_read_lock(); |
| 147 | tcred = __task_cred(task); |
| 148 | if ((cred->uid != tcred->euid || |
| 149 | cred->uid != tcred->suid || |
| 150 | cred->uid != tcred->uid || |
| 151 | cred->gid != tcred->egid || |
| 152 | cred->gid != tcred->sgid || |
| 153 | cred->gid != tcred->gid) && |
| 154 | !capable(CAP_SYS_PTRACE)) { |
| 155 | rcu_read_unlock(); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 156 | return -EPERM; |
David Howells | c69e8d9 | 2008-11-14 10:39:19 +1100 | [diff] [blame] | 157 | } |
| 158 | rcu_read_unlock(); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 159 | smp_rmb(); |
Eric W. Biederman | df26c40 | 2006-06-26 00:25:59 -0700 | [diff] [blame] | 160 | if (task->mm) |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 161 | dumpable = get_dumpable(task->mm); |
Eric W. Biederman | df26c40 | 2006-06-26 00:25:59 -0700 | [diff] [blame] | 162 | if (!dumpable && !capable(CAP_SYS_PTRACE)) |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 163 | return -EPERM; |
| 164 | |
David Howells | 5cd9c58 | 2008-08-14 11:37:28 +0100 | [diff] [blame] | 165 | return security_ptrace_may_access(task, mode); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 166 | } |
| 167 | |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 168 | bool ptrace_may_access(struct task_struct *task, unsigned int mode) |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 169 | { |
| 170 | int err; |
| 171 | task_lock(task); |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 172 | err = __ptrace_may_access(task, mode); |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 173 | task_unlock(task); |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 174 | return !err; |
Miklos Szeredi | ab8d11b | 2005-09-06 15:18:24 -0700 | [diff] [blame] | 175 | } |
| 176 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | int ptrace_attach(struct task_struct *task) |
| 178 | { |
| 179 | int retval; |
Sripathi Kodi | 6175ecf | 2007-07-15 23:39:26 -0700 | [diff] [blame] | 180 | unsigned long flags; |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 181 | |
Al Viro | a5cb013 | 2007-03-20 13:58:35 -0400 | [diff] [blame] | 182 | audit_ptrace(task); |
| 183 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | retval = -EPERM; |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 185 | if (same_thread_group(task, current)) |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 186 | goto out; |
| 187 | |
David Howells | 5e751e9 | 2009-05-08 13:55:22 +0100 | [diff] [blame^] | 188 | /* Protect the target's credential calculations against our |
| 189 | * interference; SUID, SGID and LSM creds get determined differently |
| 190 | * under ptrace. |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 191 | */ |
David Howells | 5e751e9 | 2009-05-08 13:55:22 +0100 | [diff] [blame^] | 192 | retval = mutex_lock_interruptible(&task->cred_guard_mutex); |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 193 | if (retval < 0) |
| 194 | goto out; |
| 195 | |
| 196 | retval = -EPERM; |
Linus Torvalds | f358166 | 2006-05-11 11:08:49 -0700 | [diff] [blame] | 197 | repeat: |
| 198 | /* |
| 199 | * Nasty, nasty. |
| 200 | * |
| 201 | * We want to hold both the task-lock and the |
| 202 | * tasklist_lock for writing at the same time. |
| 203 | * But that's against the rules (tasklist_lock |
| 204 | * is taken for reading by interrupts on other |
| 205 | * cpu's that may have task_lock). |
| 206 | */ |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 207 | task_lock(task); |
Sripathi Kodi | 6175ecf | 2007-07-15 23:39:26 -0700 | [diff] [blame] | 208 | if (!write_trylock_irqsave(&tasklist_lock, flags)) { |
Linus Torvalds | f358166 | 2006-05-11 11:08:49 -0700 | [diff] [blame] | 209 | task_unlock(task); |
| 210 | do { |
| 211 | cpu_relax(); |
| 212 | } while (!write_can_lock(&tasklist_lock)); |
| 213 | goto repeat; |
| 214 | } |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 215 | |
Eric W. Biederman | df26c40 | 2006-06-26 00:25:59 -0700 | [diff] [blame] | 216 | if (!task->mm) |
| 217 | goto bad; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | /* the same process cannot be attached many times */ |
| 219 | if (task->ptrace & PT_PTRACED) |
| 220 | goto bad; |
Stephen Smalley | 006ebb4 | 2008-05-19 08:32:49 -0400 | [diff] [blame] | 221 | retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | if (retval) |
| 223 | goto bad; |
| 224 | |
| 225 | /* Go */ |
Oleg Nesterov | 6b39c7b | 2008-02-08 04:18:58 -0800 | [diff] [blame] | 226 | task->ptrace |= PT_PTRACED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | if (capable(CAP_SYS_PTRACE)) |
| 228 | task->ptrace |= PT_PTRACE_CAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | __ptrace_link(task, current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | |
Oleg Nesterov | 33e9fc7 | 2008-04-30 00:53:14 -0700 | [diff] [blame] | 232 | send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | bad: |
Sripathi Kodi | 6175ecf | 2007-07-15 23:39:26 -0700 | [diff] [blame] | 234 | write_unlock_irqrestore(&tasklist_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | task_unlock(task); |
David Howells | 5e751e9 | 2009-05-08 13:55:22 +0100 | [diff] [blame^] | 236 | mutex_unlock(&task->cred_guard_mutex); |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 237 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | return retval; |
| 239 | } |
| 240 | |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 241 | /* |
| 242 | * Called with irqs disabled, returns true if childs should reap themselves. |
| 243 | */ |
| 244 | static int ignoring_children(struct sighand_struct *sigh) |
| 245 | { |
| 246 | int ret; |
| 247 | spin_lock(&sigh->siglock); |
| 248 | ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) || |
| 249 | (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT); |
| 250 | spin_unlock(&sigh->siglock); |
| 251 | return ret; |
| 252 | } |
| 253 | |
| 254 | /* |
| 255 | * Called with tasklist_lock held for writing. |
| 256 | * Unlink a traced task, and clean it up if it was a traced zombie. |
| 257 | * Return true if it needs to be reaped with release_task(). |
| 258 | * (We can't call release_task() here because we already hold tasklist_lock.) |
| 259 | * |
| 260 | * If it's a zombie, our attachedness prevented normal parent notification |
| 261 | * or self-reaping. Do notification now if it would have happened earlier. |
| 262 | * If it should reap itself, return true. |
| 263 | * |
| 264 | * If it's our own child, there is no notification to do. |
| 265 | * But if our normal children self-reap, then this child |
| 266 | * was prevented by ptrace and we must reap it now. |
| 267 | */ |
| 268 | static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) |
| 269 | { |
| 270 | __ptrace_unlink(p); |
| 271 | |
| 272 | if (p->exit_state == EXIT_ZOMBIE) { |
| 273 | if (!task_detached(p) && thread_group_empty(p)) { |
| 274 | if (!same_thread_group(p->real_parent, tracer)) |
| 275 | do_notify_parent(p, p->exit_signal); |
| 276 | else if (ignoring_children(tracer->sighand)) |
| 277 | p->exit_signal = -1; |
| 278 | } |
| 279 | if (task_detached(p)) { |
| 280 | /* Mark it as in the process of being reaped. */ |
| 281 | p->exit_state = EXIT_DEAD; |
| 282 | return true; |
| 283 | } |
| 284 | } |
| 285 | |
| 286 | return false; |
| 287 | } |
| 288 | |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 289 | int ptrace_detach(struct task_struct *child, unsigned int data) |
| 290 | { |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 291 | bool dead = false; |
Oleg Nesterov | 4576145 | 2009-04-02 16:58:14 -0700 | [diff] [blame] | 292 | |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 293 | if (!valid_signal(data)) |
| 294 | return -EIO; |
| 295 | |
| 296 | /* Architecture-specific hardware disable .. */ |
| 297 | ptrace_disable(child); |
Roland McGrath | 7d94143 | 2007-09-05 03:05:56 -0700 | [diff] [blame] | 298 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
Oleg Nesterov | 5ecfbae | 2006-02-15 22:50:10 +0300 | [diff] [blame] | 299 | |
Oleg Nesterov | 95c3eb7 | 2009-04-02 16:58:11 -0700 | [diff] [blame] | 300 | write_lock_irq(&tasklist_lock); |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 301 | /* |
| 302 | * This child can be already killed. Make sure de_thread() or |
| 303 | * our sub-thread doing do_wait() didn't do release_task() yet. |
| 304 | */ |
Oleg Nesterov | 95c3eb7 | 2009-04-02 16:58:11 -0700 | [diff] [blame] | 305 | if (child->ptrace) { |
| 306 | child->exit_code = data; |
Oleg Nesterov | 4576145 | 2009-04-02 16:58:14 -0700 | [diff] [blame] | 307 | dead = __ptrace_detach(current, child); |
Oleg Nesterov | 95c3eb7 | 2009-04-02 16:58:11 -0700 | [diff] [blame] | 308 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | write_unlock_irq(&tasklist_lock); |
| 310 | |
Oleg Nesterov | 4576145 | 2009-04-02 16:58:14 -0700 | [diff] [blame] | 311 | if (unlikely(dead)) |
| 312 | release_task(child); |
| 313 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | return 0; |
| 315 | } |
| 316 | |
Oleg Nesterov | 39c626a | 2009-04-02 16:58:18 -0700 | [diff] [blame] | 317 | /* |
| 318 | * Detach all tasks we were using ptrace on. |
| 319 | */ |
| 320 | void exit_ptrace(struct task_struct *tracer) |
| 321 | { |
| 322 | struct task_struct *p, *n; |
| 323 | LIST_HEAD(ptrace_dead); |
| 324 | |
| 325 | write_lock_irq(&tasklist_lock); |
| 326 | list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) { |
| 327 | if (__ptrace_detach(tracer, p)) |
| 328 | list_add(&p->ptrace_entry, &ptrace_dead); |
| 329 | } |
| 330 | write_unlock_irq(&tasklist_lock); |
| 331 | |
| 332 | BUG_ON(!list_empty(&tracer->ptraced)); |
| 333 | |
| 334 | list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_entry) { |
| 335 | list_del_init(&p->ptrace_entry); |
| 336 | release_task(p); |
| 337 | } |
| 338 | } |
| 339 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len) |
| 341 | { |
| 342 | int copied = 0; |
| 343 | |
| 344 | while (len > 0) { |
| 345 | char buf[128]; |
| 346 | int this_len, retval; |
| 347 | |
| 348 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; |
| 349 | retval = access_process_vm(tsk, src, buf, this_len, 0); |
| 350 | if (!retval) { |
| 351 | if (copied) |
| 352 | break; |
| 353 | return -EIO; |
| 354 | } |
| 355 | if (copy_to_user(dst, buf, retval)) |
| 356 | return -EFAULT; |
| 357 | copied += retval; |
| 358 | src += retval; |
| 359 | dst += retval; |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 360 | len -= retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | } |
| 362 | return copied; |
| 363 | } |
| 364 | |
| 365 | int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len) |
| 366 | { |
| 367 | int copied = 0; |
| 368 | |
| 369 | while (len > 0) { |
| 370 | char buf[128]; |
| 371 | int this_len, retval; |
| 372 | |
| 373 | this_len = (len > sizeof(buf)) ? sizeof(buf) : len; |
| 374 | if (copy_from_user(buf, src, this_len)) |
| 375 | return -EFAULT; |
| 376 | retval = access_process_vm(tsk, dst, buf, this_len, 1); |
| 377 | if (!retval) { |
| 378 | if (copied) |
| 379 | break; |
| 380 | return -EIO; |
| 381 | } |
| 382 | copied += retval; |
| 383 | src += retval; |
| 384 | dst += retval; |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 385 | len -= retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | } |
| 387 | return copied; |
| 388 | } |
| 389 | |
| 390 | static int ptrace_setoptions(struct task_struct *child, long data) |
| 391 | { |
| 392 | child->ptrace &= ~PT_TRACE_MASK; |
| 393 | |
| 394 | if (data & PTRACE_O_TRACESYSGOOD) |
| 395 | child->ptrace |= PT_TRACESYSGOOD; |
| 396 | |
| 397 | if (data & PTRACE_O_TRACEFORK) |
| 398 | child->ptrace |= PT_TRACE_FORK; |
| 399 | |
| 400 | if (data & PTRACE_O_TRACEVFORK) |
| 401 | child->ptrace |= PT_TRACE_VFORK; |
| 402 | |
| 403 | if (data & PTRACE_O_TRACECLONE) |
| 404 | child->ptrace |= PT_TRACE_CLONE; |
| 405 | |
| 406 | if (data & PTRACE_O_TRACEEXEC) |
| 407 | child->ptrace |= PT_TRACE_EXEC; |
| 408 | |
| 409 | if (data & PTRACE_O_TRACEVFORKDONE) |
| 410 | child->ptrace |= PT_TRACE_VFORK_DONE; |
| 411 | |
| 412 | if (data & PTRACE_O_TRACEEXIT) |
| 413 | child->ptrace |= PT_TRACE_EXIT; |
| 414 | |
| 415 | return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; |
| 416 | } |
| 417 | |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 418 | static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | int error = -ESRCH; |
| 421 | |
| 422 | read_lock(&tasklist_lock); |
| 423 | if (likely(child->sighand != NULL)) { |
| 424 | error = -EINVAL; |
| 425 | spin_lock_irq(&child->sighand->siglock); |
| 426 | if (likely(child->last_siginfo != NULL)) { |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 427 | *info = *child->last_siginfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | error = 0; |
| 429 | } |
| 430 | spin_unlock_irq(&child->sighand->siglock); |
| 431 | } |
| 432 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | return error; |
| 434 | } |
| 435 | |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 436 | static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | int error = -ESRCH; |
| 439 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | read_lock(&tasklist_lock); |
| 441 | if (likely(child->sighand != NULL)) { |
| 442 | error = -EINVAL; |
| 443 | spin_lock_irq(&child->sighand->siglock); |
| 444 | if (likely(child->last_siginfo != NULL)) { |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 445 | *child->last_siginfo = *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | error = 0; |
| 447 | } |
| 448 | spin_unlock_irq(&child->sighand->siglock); |
| 449 | } |
| 450 | read_unlock(&tasklist_lock); |
| 451 | return error; |
| 452 | } |
| 453 | |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 454 | |
| 455 | #ifdef PTRACE_SINGLESTEP |
| 456 | #define is_singlestep(request) ((request) == PTRACE_SINGLESTEP) |
| 457 | #else |
| 458 | #define is_singlestep(request) 0 |
| 459 | #endif |
| 460 | |
Roland McGrath | 5b88abb | 2008-01-30 13:30:53 +0100 | [diff] [blame] | 461 | #ifdef PTRACE_SINGLEBLOCK |
| 462 | #define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK) |
| 463 | #else |
| 464 | #define is_singleblock(request) 0 |
| 465 | #endif |
| 466 | |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 467 | #ifdef PTRACE_SYSEMU |
| 468 | #define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP) |
| 469 | #else |
| 470 | #define is_sysemu_singlestep(request) 0 |
| 471 | #endif |
| 472 | |
| 473 | static int ptrace_resume(struct task_struct *child, long request, long data) |
| 474 | { |
| 475 | if (!valid_signal(data)) |
| 476 | return -EIO; |
| 477 | |
| 478 | if (request == PTRACE_SYSCALL) |
| 479 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 480 | else |
| 481 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 482 | |
| 483 | #ifdef TIF_SYSCALL_EMU |
| 484 | if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP) |
| 485 | set_tsk_thread_flag(child, TIF_SYSCALL_EMU); |
| 486 | else |
| 487 | clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); |
| 488 | #endif |
| 489 | |
Roland McGrath | 5b88abb | 2008-01-30 13:30:53 +0100 | [diff] [blame] | 490 | if (is_singleblock(request)) { |
| 491 | if (unlikely(!arch_has_block_step())) |
| 492 | return -EIO; |
| 493 | user_enable_block_step(child); |
| 494 | } else if (is_singlestep(request) || is_sysemu_singlestep(request)) { |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 495 | if (unlikely(!arch_has_single_step())) |
| 496 | return -EIO; |
| 497 | user_enable_single_step(child); |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 498 | } else { |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 499 | user_disable_single_step(child); |
Roland McGrath | 3a70970 | 2009-04-07 23:21:06 -0700 | [diff] [blame] | 500 | } |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 501 | |
| 502 | child->exit_code = data; |
| 503 | wake_up_process(child); |
| 504 | |
| 505 | return 0; |
| 506 | } |
| 507 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | int ptrace_request(struct task_struct *child, long request, |
| 509 | long addr, long data) |
| 510 | { |
| 511 | int ret = -EIO; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 512 | siginfo_t siginfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | |
| 514 | switch (request) { |
Roland McGrath | 16c3e38 | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 515 | case PTRACE_PEEKTEXT: |
| 516 | case PTRACE_PEEKDATA: |
| 517 | return generic_ptrace_peekdata(child, addr, data); |
| 518 | case PTRACE_POKETEXT: |
| 519 | case PTRACE_POKEDATA: |
| 520 | return generic_ptrace_pokedata(child, addr, data); |
| 521 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | #ifdef PTRACE_OLDSETOPTIONS |
| 523 | case PTRACE_OLDSETOPTIONS: |
| 524 | #endif |
| 525 | case PTRACE_SETOPTIONS: |
| 526 | ret = ptrace_setoptions(child, data); |
| 527 | break; |
| 528 | case PTRACE_GETEVENTMSG: |
| 529 | ret = put_user(child->ptrace_message, (unsigned long __user *) data); |
| 530 | break; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 531 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | case PTRACE_GETSIGINFO: |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 533 | ret = ptrace_getsiginfo(child, &siginfo); |
| 534 | if (!ret) |
| 535 | ret = copy_siginfo_to_user((siginfo_t __user *) data, |
| 536 | &siginfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | break; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 538 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | case PTRACE_SETSIGINFO: |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 540 | if (copy_from_user(&siginfo, (siginfo_t __user *) data, |
| 541 | sizeof siginfo)) |
| 542 | ret = -EFAULT; |
| 543 | else |
| 544 | ret = ptrace_setsiginfo(child, &siginfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | break; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 546 | |
Alexey Dobriyan | 1bcf548 | 2007-10-16 01:23:45 -0700 | [diff] [blame] | 547 | case PTRACE_DETACH: /* detach a process that was attached. */ |
| 548 | ret = ptrace_detach(child, data); |
| 549 | break; |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 550 | |
| 551 | #ifdef PTRACE_SINGLESTEP |
| 552 | case PTRACE_SINGLESTEP: |
| 553 | #endif |
Roland McGrath | 5b88abb | 2008-01-30 13:30:53 +0100 | [diff] [blame] | 554 | #ifdef PTRACE_SINGLEBLOCK |
| 555 | case PTRACE_SINGLEBLOCK: |
| 556 | #endif |
Roland McGrath | 36df29d | 2008-01-30 13:30:51 +0100 | [diff] [blame] | 557 | #ifdef PTRACE_SYSEMU |
| 558 | case PTRACE_SYSEMU: |
| 559 | case PTRACE_SYSEMU_SINGLESTEP: |
| 560 | #endif |
| 561 | case PTRACE_SYSCALL: |
| 562 | case PTRACE_CONT: |
| 563 | return ptrace_resume(child, request, data); |
| 564 | |
| 565 | case PTRACE_KILL: |
| 566 | if (child->exit_state) /* already dead */ |
| 567 | return 0; |
| 568 | return ptrace_resume(child, request, SIGKILL); |
| 569 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | default: |
| 571 | break; |
| 572 | } |
| 573 | |
| 574 | return ret; |
| 575 | } |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 576 | |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 577 | /** |
| 578 | * ptrace_traceme -- helper for PTRACE_TRACEME |
| 579 | * |
| 580 | * Performs checks and sets PT_PTRACED. |
| 581 | * Should be used by all ptrace implementations for PTRACE_TRACEME. |
| 582 | */ |
| 583 | int ptrace_traceme(void) |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 584 | { |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 585 | int ret = -EPERM; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 586 | |
| 587 | /* |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 588 | * Are we already being traced? |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 589 | */ |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 590 | repeat: |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 591 | task_lock(current); |
| 592 | if (!(current->ptrace & PT_PTRACED)) { |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 593 | /* |
| 594 | * See ptrace_attach() comments about the locking here. |
| 595 | */ |
| 596 | unsigned long flags; |
| 597 | if (!write_trylock_irqsave(&tasklist_lock, flags)) { |
| 598 | task_unlock(current); |
| 599 | do { |
| 600 | cpu_relax(); |
| 601 | } while (!write_can_lock(&tasklist_lock)); |
| 602 | goto repeat; |
| 603 | } |
| 604 | |
David Howells | 5cd9c58 | 2008-08-14 11:37:28 +0100 | [diff] [blame] | 605 | ret = security_ptrace_traceme(current->parent); |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 606 | |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 607 | /* |
Oleg Nesterov | f1671f6 | 2009-04-13 14:40:03 -0700 | [diff] [blame] | 608 | * Check PF_EXITING to ensure ->real_parent has not passed |
| 609 | * exit_ptrace(). Otherwise we don't report the error but |
| 610 | * pretend ->real_parent untraces us right after return. |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 611 | */ |
Oleg Nesterov | f1671f6 | 2009-04-13 14:40:03 -0700 | [diff] [blame] | 612 | if (!ret && !(current->real_parent->flags & PF_EXITING)) { |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 613 | current->ptrace |= PT_PTRACED; |
Roland McGrath | f470021 | 2008-03-24 18:36:23 -0700 | [diff] [blame] | 614 | __ptrace_link(current, current->real_parent); |
| 615 | } |
| 616 | |
| 617 | write_unlock_irqrestore(&tasklist_lock, flags); |
Linus Torvalds | f5b40e3 | 2006-05-07 10:49:33 -0700 | [diff] [blame] | 618 | } |
| 619 | task_unlock(current); |
| 620 | return ret; |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 621 | } |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 622 | |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 623 | /** |
| 624 | * ptrace_get_task_struct -- grab a task struct reference for ptrace |
| 625 | * @pid: process id to grab a task_struct reference of |
| 626 | * |
| 627 | * This function is a helper for ptrace implementations. It checks |
| 628 | * permissions and then grabs a task struct for use of the actual |
| 629 | * ptrace implementation. |
| 630 | * |
| 631 | * Returns the task_struct for @pid or an ERR_PTR() on failure. |
| 632 | */ |
| 633 | struct task_struct *ptrace_get_task_struct(pid_t pid) |
| 634 | { |
| 635 | struct task_struct *child; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 636 | |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 637 | read_lock(&tasklist_lock); |
Pavel Emelyanov | 228ebcb | 2007-10-18 23:40:16 -0700 | [diff] [blame] | 638 | child = find_task_by_vpid(pid); |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 639 | if (child) |
| 640 | get_task_struct(child); |
Sukadev Bhattiprolu | f400e19 | 2006-09-29 02:00:07 -0700 | [diff] [blame] | 641 | |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 642 | read_unlock(&tasklist_lock); |
| 643 | if (!child) |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 644 | return ERR_PTR(-ESRCH); |
| 645 | return child; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 646 | } |
| 647 | |
Christoph Hellwig | 0ac1555 | 2007-10-16 01:26:37 -0700 | [diff] [blame] | 648 | #ifndef arch_ptrace_attach |
| 649 | #define arch_ptrace_attach(child) do { } while (0) |
| 650 | #endif |
| 651 | |
Heiko Carstens | 1e7bfb2 | 2009-01-14 14:14:29 +0100 | [diff] [blame] | 652 | SYSCALL_DEFINE4(ptrace, long, request, long, pid, long, addr, long, data) |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 653 | { |
| 654 | struct task_struct *child; |
| 655 | long ret; |
| 656 | |
| 657 | /* |
| 658 | * This lock_kernel fixes a subtle race with suid exec |
| 659 | */ |
| 660 | lock_kernel(); |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 661 | if (request == PTRACE_TRACEME) { |
| 662 | ret = ptrace_traceme(); |
Haavard Skinnemoen | 6ea6dd9 | 2007-11-27 13:02:40 +0100 | [diff] [blame] | 663 | if (!ret) |
| 664 | arch_ptrace_attach(current); |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 665 | goto out; |
Christoph Hellwig | 6b9c7ed | 2006-01-08 01:02:33 -0800 | [diff] [blame] | 666 | } |
| 667 | |
| 668 | child = ptrace_get_task_struct(pid); |
| 669 | if (IS_ERR(child)) { |
| 670 | ret = PTR_ERR(child); |
| 671 | goto out; |
| 672 | } |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 673 | |
| 674 | if (request == PTRACE_ATTACH) { |
| 675 | ret = ptrace_attach(child); |
Christoph Hellwig | 0ac1555 | 2007-10-16 01:26:37 -0700 | [diff] [blame] | 676 | /* |
| 677 | * Some architectures need to do book-keeping after |
| 678 | * a ptrace attach. |
| 679 | */ |
| 680 | if (!ret) |
| 681 | arch_ptrace_attach(child); |
Christoph Hellwig | 005f18d | 2005-11-13 16:06:33 -0800 | [diff] [blame] | 682 | goto out_put_task_struct; |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 683 | } |
| 684 | |
| 685 | ret = ptrace_check_attach(child, request == PTRACE_KILL); |
| 686 | if (ret < 0) |
| 687 | goto out_put_task_struct; |
| 688 | |
| 689 | ret = arch_ptrace(child, request, addr, data); |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 690 | |
| 691 | out_put_task_struct: |
| 692 | put_task_struct(child); |
| 693 | out: |
| 694 | unlock_kernel(); |
| 695 | return ret; |
| 696 | } |
Alexey Dobriyan | 7664732 | 2007-07-17 04:03:43 -0700 | [diff] [blame] | 697 | |
| 698 | int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data) |
| 699 | { |
| 700 | unsigned long tmp; |
| 701 | int copied; |
| 702 | |
| 703 | copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), 0); |
| 704 | if (copied != sizeof(tmp)) |
| 705 | return -EIO; |
| 706 | return put_user(tmp, (unsigned long __user *)data); |
| 707 | } |
Alexey Dobriyan | f284ce7 | 2007-07-17 04:03:44 -0700 | [diff] [blame] | 708 | |
| 709 | int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data) |
| 710 | { |
| 711 | int copied; |
| 712 | |
| 713 | copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); |
| 714 | return (copied == sizeof(data)) ? 0 : -EIO; |
| 715 | } |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 716 | |
Christoph Hellwig | 96b8936 | 2008-11-25 08:10:03 +0100 | [diff] [blame] | 717 | #if defined CONFIG_COMPAT |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 718 | #include <linux/compat.h> |
| 719 | |
| 720 | int compat_ptrace_request(struct task_struct *child, compat_long_t request, |
| 721 | compat_ulong_t addr, compat_ulong_t data) |
| 722 | { |
| 723 | compat_ulong_t __user *datap = compat_ptr(data); |
| 724 | compat_ulong_t word; |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 725 | siginfo_t siginfo; |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 726 | int ret; |
| 727 | |
| 728 | switch (request) { |
| 729 | case PTRACE_PEEKTEXT: |
| 730 | case PTRACE_PEEKDATA: |
| 731 | ret = access_process_vm(child, addr, &word, sizeof(word), 0); |
| 732 | if (ret != sizeof(word)) |
| 733 | ret = -EIO; |
| 734 | else |
| 735 | ret = put_user(word, datap); |
| 736 | break; |
| 737 | |
| 738 | case PTRACE_POKETEXT: |
| 739 | case PTRACE_POKEDATA: |
| 740 | ret = access_process_vm(child, addr, &data, sizeof(data), 1); |
| 741 | ret = (ret != sizeof(data) ? -EIO : 0); |
| 742 | break; |
| 743 | |
| 744 | case PTRACE_GETEVENTMSG: |
| 745 | ret = put_user((compat_ulong_t) child->ptrace_message, datap); |
| 746 | break; |
| 747 | |
Roland McGrath | e16b278 | 2008-04-20 13:10:12 -0700 | [diff] [blame] | 748 | case PTRACE_GETSIGINFO: |
| 749 | ret = ptrace_getsiginfo(child, &siginfo); |
| 750 | if (!ret) |
| 751 | ret = copy_siginfo_to_user32( |
| 752 | (struct compat_siginfo __user *) datap, |
| 753 | &siginfo); |
| 754 | break; |
| 755 | |
| 756 | case PTRACE_SETSIGINFO: |
| 757 | memset(&siginfo, 0, sizeof siginfo); |
| 758 | if (copy_siginfo_from_user32( |
| 759 | &siginfo, (struct compat_siginfo __user *) datap)) |
| 760 | ret = -EFAULT; |
| 761 | else |
| 762 | ret = ptrace_setsiginfo(child, &siginfo); |
| 763 | break; |
| 764 | |
Roland McGrath | 032d82d | 2008-01-30 13:31:47 +0100 | [diff] [blame] | 765 | default: |
| 766 | ret = ptrace_request(child, request, addr, data); |
| 767 | } |
| 768 | |
| 769 | return ret; |
| 770 | } |
Roland McGrath | c269f19 | 2008-01-30 13:31:48 +0100 | [diff] [blame] | 771 | |
Roland McGrath | c269f19 | 2008-01-30 13:31:48 +0100 | [diff] [blame] | 772 | asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, |
| 773 | compat_long_t addr, compat_long_t data) |
| 774 | { |
| 775 | struct task_struct *child; |
| 776 | long ret; |
| 777 | |
| 778 | /* |
| 779 | * This lock_kernel fixes a subtle race with suid exec |
| 780 | */ |
| 781 | lock_kernel(); |
| 782 | if (request == PTRACE_TRACEME) { |
| 783 | ret = ptrace_traceme(); |
| 784 | goto out; |
| 785 | } |
| 786 | |
| 787 | child = ptrace_get_task_struct(pid); |
| 788 | if (IS_ERR(child)) { |
| 789 | ret = PTR_ERR(child); |
| 790 | goto out; |
| 791 | } |
| 792 | |
| 793 | if (request == PTRACE_ATTACH) { |
| 794 | ret = ptrace_attach(child); |
| 795 | /* |
| 796 | * Some architectures need to do book-keeping after |
| 797 | * a ptrace attach. |
| 798 | */ |
| 799 | if (!ret) |
| 800 | arch_ptrace_attach(child); |
| 801 | goto out_put_task_struct; |
| 802 | } |
| 803 | |
| 804 | ret = ptrace_check_attach(child, request == PTRACE_KILL); |
| 805 | if (!ret) |
| 806 | ret = compat_arch_ptrace(child, request, addr, data); |
| 807 | |
| 808 | out_put_task_struct: |
| 809 | put_task_struct(child); |
| 810 | out: |
| 811 | unlock_kernel(); |
| 812 | return ret; |
| 813 | } |
Christoph Hellwig | 96b8936 | 2008-11-25 08:10:03 +0100 | [diff] [blame] | 814 | #endif /* CONFIG_COMPAT */ |