Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Signal handling |
| 3 | * |
| 4 | * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> |
| 5 | * Copyright (C) 2008-2009 PetaLogix |
| 6 | * Copyright (C) 2003,2004 John Williams <jwilliams@itee.uq.edu.au> |
| 7 | * Copyright (C) 2001 NEC Corporation |
| 8 | * Copyright (C) 2001 Miles Bader <miles@gnu.org> |
| 9 | * Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima |
| 10 | * Copyright (C) 1991,1992 Linus Torvalds |
| 11 | * |
| 12 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson |
| 13 | * |
| 14 | * This file was was derived from the sh version, arch/sh/kernel/signal.c |
| 15 | * |
| 16 | * This file is subject to the terms and conditions of the GNU General |
| 17 | * Public License. See the file COPYING in the main directory of this |
| 18 | * archive for more details. |
| 19 | */ |
| 20 | |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/mm.h> |
| 23 | #include <linux/smp.h> |
| 24 | #include <linux/smp_lock.h> |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/signal.h> |
| 27 | #include <linux/errno.h> |
| 28 | #include <linux/wait.h> |
| 29 | #include <linux/ptrace.h> |
| 30 | #include <linux/unistd.h> |
| 31 | #include <linux/stddef.h> |
| 32 | #include <linux/personality.h> |
| 33 | #include <linux/percpu.h> |
| 34 | #include <linux/linkage.h> |
| 35 | #include <asm/entry.h> |
| 36 | #include <asm/ucontext.h> |
| 37 | #include <linux/uaccess.h> |
| 38 | #include <asm/pgtable.h> |
| 39 | #include <asm/pgalloc.h> |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 40 | #include <linux/syscalls.h> |
| 41 | #include <asm/cacheflush.h> |
| 42 | #include <asm/syscalls.h> |
| 43 | |
| 44 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| 45 | |
| 46 | asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_sycall); |
| 47 | |
| 48 | /* |
| 49 | * Atomically swap in the new signal mask, and wait for a signal. |
| 50 | */ |
| 51 | asmlinkage int |
| 52 | sys_sigsuspend(old_sigset_t mask, struct pt_regs *regs) |
| 53 | { |
| 54 | sigset_t saveset; |
| 55 | |
| 56 | mask &= _BLOCKABLE; |
| 57 | spin_lock_irq(¤t->sighand->siglock); |
| 58 | saveset = current->blocked; |
| 59 | siginitset(¤t->blocked, mask); |
| 60 | recalc_sigpending(); |
| 61 | spin_unlock_irq(¤t->sighand->siglock); |
| 62 | |
| 63 | regs->r3 = -EINTR; |
| 64 | while (1) { |
| 65 | current->state = TASK_INTERRUPTIBLE; |
| 66 | schedule(); |
| 67 | if (do_signal(regs, &saveset, 1)) |
| 68 | return -EINTR; |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | asmlinkage int |
| 73 | sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, |
| 74 | struct pt_regs *regs) |
| 75 | { |
| 76 | sigset_t saveset, newset; |
| 77 | |
| 78 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 79 | if (sigsetsize != sizeof(sigset_t)) |
| 80 | return -EINVAL; |
| 81 | |
| 82 | if (copy_from_user(&newset, unewset, sizeof(newset))) |
| 83 | return -EFAULT; |
| 84 | sigdelsetmask(&newset, ~_BLOCKABLE); |
| 85 | spin_lock_irq(¤t->sighand->siglock); |
| 86 | saveset = current->blocked; |
| 87 | current->blocked = newset; |
| 88 | recalc_sigpending(); |
| 89 | spin_unlock_irq(¤t->sighand->siglock); |
| 90 | |
| 91 | regs->r3 = -EINTR; |
| 92 | while (1) { |
| 93 | current->state = TASK_INTERRUPTIBLE; |
| 94 | schedule(); |
| 95 | if (do_signal(regs, &saveset, 1)) |
| 96 | return -EINTR; |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | asmlinkage int |
| 101 | sys_sigaction(int sig, const struct old_sigaction *act, |
| 102 | struct old_sigaction *oact) |
| 103 | { |
| 104 | struct k_sigaction new_ka, old_ka; |
| 105 | int ret; |
| 106 | |
| 107 | if (act) { |
| 108 | old_sigset_t mask; |
| 109 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || |
| 110 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || |
| 111 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) |
| 112 | return -EFAULT; |
| 113 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); |
| 114 | __get_user(mask, &act->sa_mask); |
| 115 | siginitset(&new_ka.sa.sa_mask, mask); |
| 116 | } |
| 117 | |
| 118 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); |
| 119 | |
| 120 | if (!ret && oact) { |
| 121 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || |
| 122 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || |
| 123 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) |
| 124 | return -EFAULT; |
| 125 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
| 126 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); |
| 127 | } |
| 128 | |
| 129 | return ret; |
| 130 | } |
| 131 | |
| 132 | asmlinkage int |
| 133 | sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, |
| 134 | struct pt_regs *regs) |
| 135 | { |
| 136 | return do_sigaltstack(uss, uoss, regs->r1); |
| 137 | } |
| 138 | |
| 139 | /* |
| 140 | * Do a signal return; undo the signal stack. |
| 141 | */ |
| 142 | |
| 143 | struct sigframe { |
| 144 | struct sigcontext sc; |
| 145 | unsigned long extramask[_NSIG_WORDS-1]; |
| 146 | unsigned long tramp[2]; /* signal trampoline */ |
| 147 | }; |
| 148 | |
| 149 | struct rt_sigframe { |
| 150 | struct siginfo info; |
| 151 | struct ucontext uc; |
| 152 | unsigned long tramp[2]; /* signal trampoline */ |
| 153 | }; |
| 154 | |
Arnd Bergmann | 353b431 | 2009-05-01 13:37:46 +0000 | [diff] [blame^] | 155 | static int restore_sigcontext(struct pt_regs *regs, |
| 156 | struct sigcontext __user *sc, int *rval_p) |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 157 | { |
| 158 | unsigned int err = 0; |
| 159 | |
| 160 | #define COPY(x) {err |= __get_user(regs->x, &sc->regs.x); } |
| 161 | COPY(r0); |
| 162 | COPY(r1); |
| 163 | COPY(r2); COPY(r3); COPY(r4); COPY(r5); |
| 164 | COPY(r6); COPY(r7); COPY(r8); COPY(r9); |
| 165 | COPY(r10); COPY(r11); COPY(r12); COPY(r13); |
| 166 | COPY(r14); COPY(r15); COPY(r16); COPY(r17); |
| 167 | COPY(r18); COPY(r19); COPY(r20); COPY(r21); |
| 168 | COPY(r22); COPY(r23); COPY(r24); COPY(r25); |
| 169 | COPY(r26); COPY(r27); COPY(r28); COPY(r29); |
| 170 | COPY(r30); COPY(r31); |
| 171 | COPY(pc); COPY(ear); COPY(esr); COPY(fsr); |
| 172 | #undef COPY |
| 173 | |
| 174 | *rval_p = regs->r3; |
| 175 | |
| 176 | return err; |
| 177 | } |
| 178 | |
| 179 | asmlinkage int sys_sigreturn(struct pt_regs *regs) |
| 180 | { |
Michal Simek | 2921e2b | 2009-04-21 14:08:47 +0200 | [diff] [blame] | 181 | struct sigframe *frame = |
| 182 | (struct sigframe *)(regs->r1 + STATE_SAVE_ARG_SPACE); |
| 183 | |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 184 | sigset_t set; |
| 185 | int rval; |
| 186 | |
| 187 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| 188 | goto badframe; |
| 189 | |
| 190 | if (__get_user(set.sig[0], &frame->sc.oldmask) |
| 191 | || (_NSIG_WORDS > 1 |
| 192 | && __copy_from_user(&set.sig[1], &frame->extramask, |
| 193 | sizeof(frame->extramask)))) |
| 194 | goto badframe; |
| 195 | |
| 196 | sigdelsetmask(&set, ~_BLOCKABLE); |
| 197 | |
| 198 | spin_lock_irq(¤t->sighand->siglock); |
| 199 | current->blocked = set; |
| 200 | recalc_sigpending(); |
| 201 | spin_unlock_irq(¤t->sighand->siglock); |
| 202 | |
| 203 | if (restore_sigcontext(regs, &frame->sc, &rval)) |
| 204 | goto badframe; |
| 205 | return rval; |
| 206 | |
| 207 | badframe: |
| 208 | force_sig(SIGSEGV, current); |
| 209 | return 0; |
| 210 | } |
| 211 | |
| 212 | asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) |
| 213 | { |
Arnd Bergmann | 353b431 | 2009-05-01 13:37:46 +0000 | [diff] [blame^] | 214 | struct rt_sigframe __user *frame = |
| 215 | (struct rt_sigframe __user *)(regs->r1 + STATE_SAVE_ARG_SPACE); |
Michal Simek | 2921e2b | 2009-04-21 14:08:47 +0200 | [diff] [blame] | 216 | |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 217 | sigset_t set; |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 218 | int rval; |
| 219 | |
| 220 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| 221 | goto badframe; |
| 222 | |
| 223 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) |
| 224 | goto badframe; |
| 225 | |
| 226 | sigdelsetmask(&set, ~_BLOCKABLE); |
| 227 | spin_lock_irq(¤t->sighand->siglock); |
| 228 | current->blocked = set; |
| 229 | recalc_sigpending(); |
| 230 | spin_unlock_irq(¤t->sighand->siglock); |
| 231 | |
| 232 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval)) |
| 233 | goto badframe; |
| 234 | |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 235 | /* It is more difficult to avoid calling this function than to |
| 236 | call it and ignore errors. */ |
Arnd Bergmann | 353b431 | 2009-05-01 13:37:46 +0000 | [diff] [blame^] | 237 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->r1)) |
| 238 | goto badframe; |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 239 | |
| 240 | return rval; |
| 241 | |
| 242 | badframe: |
| 243 | force_sig(SIGSEGV, current); |
| 244 | return 0; |
| 245 | } |
| 246 | |
| 247 | /* |
| 248 | * Set up a signal frame. |
| 249 | */ |
| 250 | |
| 251 | static int |
Arnd Bergmann | 353b431 | 2009-05-01 13:37:46 +0000 | [diff] [blame^] | 252 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 253 | unsigned long mask) |
| 254 | { |
| 255 | int err = 0; |
| 256 | |
| 257 | #define COPY(x) {err |= __put_user(regs->x, &sc->regs.x); } |
| 258 | COPY(r0); |
| 259 | COPY(r1); |
| 260 | COPY(r2); COPY(r3); COPY(r4); COPY(r5); |
| 261 | COPY(r6); COPY(r7); COPY(r8); COPY(r9); |
| 262 | COPY(r10); COPY(r11); COPY(r12); COPY(r13); |
| 263 | COPY(r14); COPY(r15); COPY(r16); COPY(r17); |
| 264 | COPY(r18); COPY(r19); COPY(r20); COPY(r21); |
| 265 | COPY(r22); COPY(r23); COPY(r24); COPY(r25); |
| 266 | COPY(r26); COPY(r27); COPY(r28); COPY(r29); |
| 267 | COPY(r30); COPY(r31); |
| 268 | COPY(pc); COPY(ear); COPY(esr); COPY(fsr); |
| 269 | #undef COPY |
| 270 | |
| 271 | err |= __put_user(mask, &sc->oldmask); |
| 272 | |
| 273 | return err; |
| 274 | } |
| 275 | |
| 276 | /* |
| 277 | * Determine which stack to use.. |
| 278 | */ |
Arnd Bergmann | 353b431 | 2009-05-01 13:37:46 +0000 | [diff] [blame^] | 279 | static inline void __user * |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 280 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) |
| 281 | { |
| 282 | /* Default to using normal stack */ |
| 283 | unsigned long sp = regs->r1; |
| 284 | |
| 285 | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack(sp)) |
| 286 | sp = current->sas_ss_sp + current->sas_ss_size; |
| 287 | |
Arnd Bergmann | 353b431 | 2009-05-01 13:37:46 +0000 | [diff] [blame^] | 288 | return (void __user *)((sp - frame_size) & -8UL); |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 289 | } |
| 290 | |
| 291 | static void setup_frame(int sig, struct k_sigaction *ka, |
| 292 | sigset_t *set, struct pt_regs *regs) |
| 293 | { |
| 294 | struct sigframe *frame; |
| 295 | int err = 0; |
| 296 | int signal; |
| 297 | |
| 298 | frame = get_sigframe(ka, regs, sizeof(*frame)); |
| 299 | |
| 300 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| 301 | goto give_sigsegv; |
| 302 | |
| 303 | signal = current_thread_info()->exec_domain |
| 304 | && current_thread_info()->exec_domain->signal_invmap |
| 305 | && sig < 32 |
| 306 | ? current_thread_info()->exec_domain->signal_invmap[sig] |
| 307 | : sig; |
| 308 | |
| 309 | err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); |
| 310 | |
| 311 | if (_NSIG_WORDS > 1) { |
| 312 | err |= __copy_to_user(frame->extramask, &set->sig[1], |
| 313 | sizeof(frame->extramask)); |
| 314 | } |
| 315 | |
| 316 | /* Set up to return from userspace. If provided, use a stub |
| 317 | already in userspace. */ |
| 318 | /* minus 8 is offset to cater for "rtsd r15,8" offset */ |
| 319 | if (ka->sa.sa_flags & SA_RESTORER) { |
| 320 | regs->r15 = ((unsigned long)ka->sa.sa_restorer)-8; |
| 321 | } else { |
| 322 | /* Note, these encodings are _big endian_! */ |
| 323 | |
| 324 | /* addi r12, r0, __NR_sigreturn */ |
| 325 | err |= __put_user(0x31800000 | __NR_sigreturn , |
| 326 | frame->tramp + 0); |
| 327 | /* brki r14, 0x8 */ |
| 328 | err |= __put_user(0xb9cc0008, frame->tramp + 1); |
| 329 | |
| 330 | /* Return from sighandler will jump to the tramp. |
| 331 | Negative 8 offset because return is rtsd r15, 8 */ |
| 332 | regs->r15 = ((unsigned long)frame->tramp)-8; |
| 333 | |
| 334 | __invalidate_cache_sigtramp((unsigned long)frame->tramp); |
| 335 | } |
| 336 | |
| 337 | if (err) |
| 338 | goto give_sigsegv; |
| 339 | |
| 340 | /* Set up registers for signal handler */ |
Michal Simek | 2921e2b | 2009-04-21 14:08:47 +0200 | [diff] [blame] | 341 | regs->r1 = (unsigned long) frame - STATE_SAVE_ARG_SPACE; |
| 342 | |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 343 | /* Signal handler args: */ |
| 344 | regs->r5 = signal; /* Arg 0: signum */ |
| 345 | regs->r6 = (unsigned long) &frame->sc; /* arg 1: sigcontext */ |
| 346 | |
| 347 | /* Offset of 4 to handle microblaze rtid r14, 0 */ |
| 348 | regs->pc = (unsigned long)ka->sa.sa_handler; |
| 349 | |
| 350 | set_fs(USER_DS); |
| 351 | |
| 352 | #ifdef DEBUG_SIG |
| 353 | printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n", |
| 354 | current->comm, current->pid, frame, regs->pc); |
| 355 | #endif |
| 356 | |
| 357 | return; |
| 358 | |
| 359 | give_sigsegv: |
| 360 | if (sig == SIGSEGV) |
| 361 | ka->sa.sa_handler = SIG_DFL; |
| 362 | force_sig(SIGSEGV, current); |
| 363 | } |
| 364 | |
| 365 | static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
| 366 | sigset_t *set, struct pt_regs *regs) |
| 367 | { |
Arnd Bergmann | 353b431 | 2009-05-01 13:37:46 +0000 | [diff] [blame^] | 368 | struct rt_sigframe __user *frame; |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 369 | int err = 0; |
| 370 | int signal; |
| 371 | |
| 372 | frame = get_sigframe(ka, regs, sizeof(*frame)); |
| 373 | |
| 374 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| 375 | goto give_sigsegv; |
| 376 | |
| 377 | signal = current_thread_info()->exec_domain |
| 378 | && current_thread_info()->exec_domain->signal_invmap |
| 379 | && sig < 32 |
| 380 | ? current_thread_info()->exec_domain->signal_invmap[sig] |
| 381 | : sig; |
| 382 | |
| 383 | err |= copy_siginfo_to_user(&frame->info, info); |
| 384 | |
| 385 | /* Create the ucontext. */ |
| 386 | err |= __put_user(0, &frame->uc.uc_flags); |
| 387 | err |= __put_user(0, &frame->uc.uc_link); |
| 388 | err |= __put_user((void *)current->sas_ss_sp, |
| 389 | &frame->uc.uc_stack.ss_sp); |
| 390 | err |= __put_user(sas_ss_flags(regs->r1), |
| 391 | &frame->uc.uc_stack.ss_flags); |
| 392 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); |
| 393 | err |= setup_sigcontext(&frame->uc.uc_mcontext, |
| 394 | regs, set->sig[0]); |
| 395 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
| 396 | |
| 397 | /* Set up to return from userspace. If provided, use a stub |
| 398 | already in userspace. */ |
| 399 | /* minus 8 is offset to cater for "rtsd r15,8" */ |
| 400 | if (ka->sa.sa_flags & SA_RESTORER) { |
| 401 | regs->r15 = ((unsigned long)ka->sa.sa_restorer)-8; |
| 402 | } else { |
| 403 | /* addi r12, r0, __NR_sigreturn */ |
| 404 | err |= __put_user(0x31800000 | __NR_rt_sigreturn , |
| 405 | frame->tramp + 0); |
| 406 | /* brki r14, 0x8 */ |
| 407 | err |= __put_user(0xb9cc0008, frame->tramp + 1); |
| 408 | |
| 409 | /* Return from sighandler will jump to the tramp. |
| 410 | Negative 8 offset because return is rtsd r15, 8 */ |
| 411 | regs->r15 = ((unsigned long)frame->tramp)-8; |
| 412 | |
| 413 | __invalidate_cache_sigtramp((unsigned long)frame->tramp); |
| 414 | } |
| 415 | |
| 416 | if (err) |
| 417 | goto give_sigsegv; |
| 418 | |
| 419 | /* Set up registers for signal handler */ |
Michal Simek | 2921e2b | 2009-04-21 14:08:47 +0200 | [diff] [blame] | 420 | regs->r1 = (unsigned long) frame - STATE_SAVE_ARG_SPACE; |
| 421 | |
Michal Simek | 2148daa9 | 2009-03-27 14:25:14 +0100 | [diff] [blame] | 422 | /* Signal handler args: */ |
| 423 | regs->r5 = signal; /* arg 0: signum */ |
| 424 | regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */ |
| 425 | regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */ |
| 426 | /* Offset to handle microblaze rtid r14, 0 */ |
| 427 | regs->pc = (unsigned long)ka->sa.sa_handler; |
| 428 | |
| 429 | set_fs(USER_DS); |
| 430 | |
| 431 | #ifdef DEBUG_SIG |
| 432 | printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n", |
| 433 | current->comm, current->pid, frame, regs->pc); |
| 434 | #endif |
| 435 | |
| 436 | return; |
| 437 | |
| 438 | give_sigsegv: |
| 439 | if (sig == SIGSEGV) |
| 440 | ka->sa.sa_handler = SIG_DFL; |
| 441 | force_sig(SIGSEGV, current); |
| 442 | } |
| 443 | |
| 444 | /* Handle restarting system calls */ |
| 445 | static inline void |
| 446 | handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) |
| 447 | { |
| 448 | switch (regs->r3) { |
| 449 | case -ERESTART_RESTARTBLOCK: |
| 450 | case -ERESTARTNOHAND: |
| 451 | if (!has_handler) |
| 452 | goto do_restart; |
| 453 | regs->r3 = -EINTR; |
| 454 | break; |
| 455 | case -ERESTARTSYS: |
| 456 | if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { |
| 457 | regs->r3 = -EINTR; |
| 458 | break; |
| 459 | } |
| 460 | /* fallthrough */ |
| 461 | case -ERESTARTNOINTR: |
| 462 | do_restart: |
| 463 | /* offset of 4 bytes to re-execute trap (brki) instruction */ |
| 464 | regs->pc -= 4; |
| 465 | break; |
| 466 | } |
| 467 | } |
| 468 | |
| 469 | /* |
| 470 | * OK, we're invoking a handler |
| 471 | */ |
| 472 | |
| 473 | static void |
| 474 | handle_signal(unsigned long sig, struct k_sigaction *ka, |
| 475 | siginfo_t *info, sigset_t *oldset, struct pt_regs *regs) |
| 476 | { |
| 477 | /* Set up the stack frame */ |
| 478 | if (ka->sa.sa_flags & SA_SIGINFO) |
| 479 | setup_rt_frame(sig, ka, info, oldset, regs); |
| 480 | else |
| 481 | setup_frame(sig, ka, oldset, regs); |
| 482 | |
| 483 | if (ka->sa.sa_flags & SA_ONESHOT) |
| 484 | ka->sa.sa_handler = SIG_DFL; |
| 485 | |
| 486 | if (!(ka->sa.sa_flags & SA_NODEFER)) { |
| 487 | spin_lock_irq(¤t->sighand->siglock); |
| 488 | sigorsets(¤t->blocked, |
| 489 | ¤t->blocked, &ka->sa.sa_mask); |
| 490 | sigaddset(¤t->blocked, sig); |
| 491 | recalc_sigpending(); |
| 492 | spin_unlock_irq(¤t->sighand->siglock); |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | /* |
| 497 | * Note that 'init' is a special process: it doesn't get signals it doesn't |
| 498 | * want to handle. Thus you cannot kill init even with a SIGKILL even by |
| 499 | * mistake. |
| 500 | * |
| 501 | * Note that we go through the signals twice: once to check the signals that |
| 502 | * the kernel can handle, and then we build all the user-level signal handling |
| 503 | * stack-frames in one go after that. |
| 504 | */ |
| 505 | int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_syscall) |
| 506 | { |
| 507 | siginfo_t info; |
| 508 | int signr; |
| 509 | struct k_sigaction ka; |
| 510 | #ifdef DEBUG_SIG |
| 511 | printk(KERN_INFO "do signal: %p %p %d\n", regs, oldset, in_syscall); |
| 512 | printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1, |
| 513 | regs->r12, current_thread_info()->flags); |
| 514 | #endif |
| 515 | /* |
| 516 | * We want the common case to go fast, which |
| 517 | * is why we may in certain cases get here from |
| 518 | * kernel mode. Just return without doing anything |
| 519 | * if so. |
| 520 | */ |
| 521 | if (kernel_mode(regs)) |
| 522 | return 1; |
| 523 | |
| 524 | if (!oldset) |
| 525 | oldset = ¤t->blocked; |
| 526 | |
| 527 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| 528 | if (signr > 0) { |
| 529 | /* Whee! Actually deliver the signal. */ |
| 530 | if (in_syscall) |
| 531 | handle_restart(regs, &ka, 1); |
| 532 | handle_signal(signr, &ka, &info, oldset, regs); |
| 533 | return 1; |
| 534 | } |
| 535 | |
| 536 | if (in_syscall) |
| 537 | handle_restart(regs, NULL, 0); |
| 538 | |
| 539 | /* Did we come from a system call? */ |
| 540 | return 0; |
| 541 | } |