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1da177e4 LT |
1 | /* |
2 | * linux/arch/i386/kernel/signal.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
6 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson | |
7 | * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes | |
8 | */ | |
9 | ||
10 | #include <linux/sched.h> | |
11 | #include <linux/mm.h> | |
12 | #include <linux/smp.h> | |
13 | #include <linux/smp_lock.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/signal.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/wait.h> | |
18 | #include <linux/unistd.h> | |
19 | #include <linux/stddef.h> | |
20 | #include <linux/personality.h> | |
21 | #include <linux/suspend.h> | |
22 | #include <linux/ptrace.h> | |
23 | #include <linux/elf.h> | |
24 | #include <asm/processor.h> | |
25 | #include <asm/ucontext.h> | |
26 | #include <asm/uaccess.h> | |
27 | #include <asm/i387.h> | |
28 | #include "sigframe.h" | |
29 | ||
30 | #define DEBUG_SIG 0 | |
31 | ||
32 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
33 | ||
34 | /* | |
35 | * Atomically swap in the new signal mask, and wait for a signal. | |
36 | */ | |
37 | asmlinkage int | |
38 | sys_sigsuspend(int history0, int history1, old_sigset_t mask) | |
39 | { | |
40 | struct pt_regs * regs = (struct pt_regs *) &history0; | |
41 | sigset_t saveset; | |
42 | ||
43 | mask &= _BLOCKABLE; | |
44 | spin_lock_irq(¤t->sighand->siglock); | |
45 | saveset = current->blocked; | |
46 | siginitset(¤t->blocked, mask); | |
47 | recalc_sigpending(); | |
48 | spin_unlock_irq(¤t->sighand->siglock); | |
49 | ||
50 | regs->eax = -EINTR; | |
51 | while (1) { | |
52 | current->state = TASK_INTERRUPTIBLE; | |
53 | schedule(); | |
54 | if (do_signal(regs, &saveset)) | |
55 | return -EINTR; | |
56 | } | |
57 | } | |
58 | ||
59 | asmlinkage int | |
60 | sys_rt_sigsuspend(struct pt_regs regs) | |
61 | { | |
62 | sigset_t saveset, newset; | |
63 | ||
64 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
65 | if (regs.ecx != sizeof(sigset_t)) | |
66 | return -EINVAL; | |
67 | ||
68 | if (copy_from_user(&newset, (sigset_t __user *)regs.ebx, sizeof(newset))) | |
69 | return -EFAULT; | |
70 | sigdelsetmask(&newset, ~_BLOCKABLE); | |
71 | ||
72 | spin_lock_irq(¤t->sighand->siglock); | |
73 | saveset = current->blocked; | |
74 | current->blocked = newset; | |
75 | recalc_sigpending(); | |
76 | spin_unlock_irq(¤t->sighand->siglock); | |
77 | ||
78 | regs.eax = -EINTR; | |
79 | while (1) { | |
80 | current->state = TASK_INTERRUPTIBLE; | |
81 | schedule(); | |
82 | if (do_signal(®s, &saveset)) | |
83 | return -EINTR; | |
84 | } | |
85 | } | |
86 | ||
87 | asmlinkage int | |
88 | sys_sigaction(int sig, const struct old_sigaction __user *act, | |
89 | struct old_sigaction __user *oact) | |
90 | { | |
91 | struct k_sigaction new_ka, old_ka; | |
92 | int ret; | |
93 | ||
94 | if (act) { | |
95 | old_sigset_t mask; | |
96 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
97 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
98 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
99 | return -EFAULT; | |
100 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); | |
101 | __get_user(mask, &act->sa_mask); | |
102 | siginitset(&new_ka.sa.sa_mask, mask); | |
103 | } | |
104 | ||
105 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
106 | ||
107 | if (!ret && oact) { | |
108 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
109 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
110 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
111 | return -EFAULT; | |
112 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); | |
113 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
114 | } | |
115 | ||
116 | return ret; | |
117 | } | |
118 | ||
119 | asmlinkage int | |
120 | sys_sigaltstack(unsigned long ebx) | |
121 | { | |
122 | /* This is needed to make gcc realize it doesn't own the "struct pt_regs" */ | |
123 | struct pt_regs *regs = (struct pt_regs *)&ebx; | |
124 | const stack_t __user *uss = (const stack_t __user *)ebx; | |
125 | stack_t __user *uoss = (stack_t __user *)regs->ecx; | |
126 | ||
127 | return do_sigaltstack(uss, uoss, regs->esp); | |
128 | } | |
129 | ||
130 | ||
131 | /* | |
132 | * Do a signal return; undo the signal stack. | |
133 | */ | |
134 | ||
135 | static int | |
136 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax) | |
137 | { | |
138 | unsigned int err = 0; | |
139 | ||
140 | /* Always make any pending restarted system calls return -EINTR */ | |
141 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
142 | ||
143 | #define COPY(x) err |= __get_user(regs->x, &sc->x) | |
144 | ||
145 | #define COPY_SEG(seg) \ | |
146 | { unsigned short tmp; \ | |
147 | err |= __get_user(tmp, &sc->seg); \ | |
148 | regs->x##seg = tmp; } | |
149 | ||
150 | #define COPY_SEG_STRICT(seg) \ | |
151 | { unsigned short tmp; \ | |
152 | err |= __get_user(tmp, &sc->seg); \ | |
153 | regs->x##seg = tmp|3; } | |
154 | ||
155 | #define GET_SEG(seg) \ | |
156 | { unsigned short tmp; \ | |
157 | err |= __get_user(tmp, &sc->seg); \ | |
158 | loadsegment(seg,tmp); } | |
159 | ||
160 | #define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | X86_EFLAGS_DF | \ | |
161 | X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \ | |
162 | X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF) | |
163 | ||
164 | GET_SEG(gs); | |
165 | GET_SEG(fs); | |
166 | COPY_SEG(es); | |
167 | COPY_SEG(ds); | |
168 | COPY(edi); | |
169 | COPY(esi); | |
170 | COPY(ebp); | |
171 | COPY(esp); | |
172 | COPY(ebx); | |
173 | COPY(edx); | |
174 | COPY(ecx); | |
175 | COPY(eip); | |
176 | COPY_SEG_STRICT(cs); | |
177 | COPY_SEG_STRICT(ss); | |
178 | ||
179 | { | |
180 | unsigned int tmpflags; | |
181 | err |= __get_user(tmpflags, &sc->eflags); | |
182 | regs->eflags = (regs->eflags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); | |
183 | regs->orig_eax = -1; /* disable syscall checks */ | |
184 | } | |
185 | ||
186 | { | |
187 | struct _fpstate __user * buf; | |
188 | err |= __get_user(buf, &sc->fpstate); | |
189 | if (buf) { | |
190 | if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) | |
191 | goto badframe; | |
192 | err |= restore_i387(buf); | |
193 | } else { | |
194 | struct task_struct *me = current; | |
195 | if (used_math()) { | |
196 | clear_fpu(me); | |
197 | clear_used_math(); | |
198 | } | |
199 | } | |
200 | } | |
201 | ||
202 | err |= __get_user(*peax, &sc->eax); | |
203 | return err; | |
204 | ||
205 | badframe: | |
206 | return 1; | |
207 | } | |
208 | ||
209 | asmlinkage int sys_sigreturn(unsigned long __unused) | |
210 | { | |
211 | struct pt_regs *regs = (struct pt_regs *) &__unused; | |
212 | struct sigframe __user *frame = (struct sigframe __user *)(regs->esp - 8); | |
213 | sigset_t set; | |
214 | int eax; | |
215 | ||
216 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
217 | goto badframe; | |
218 | if (__get_user(set.sig[0], &frame->sc.oldmask) | |
219 | || (_NSIG_WORDS > 1 | |
220 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
221 | sizeof(frame->extramask)))) | |
222 | goto badframe; | |
223 | ||
224 | sigdelsetmask(&set, ~_BLOCKABLE); | |
225 | spin_lock_irq(¤t->sighand->siglock); | |
226 | current->blocked = set; | |
227 | recalc_sigpending(); | |
228 | spin_unlock_irq(¤t->sighand->siglock); | |
229 | ||
230 | if (restore_sigcontext(regs, &frame->sc, &eax)) | |
231 | goto badframe; | |
232 | return eax; | |
233 | ||
234 | badframe: | |
235 | force_sig(SIGSEGV, current); | |
236 | return 0; | |
237 | } | |
238 | ||
239 | asmlinkage int sys_rt_sigreturn(unsigned long __unused) | |
240 | { | |
241 | struct pt_regs *regs = (struct pt_regs *) &__unused; | |
242 | struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->esp - 4); | |
243 | sigset_t set; | |
244 | int eax; | |
245 | ||
246 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
247 | goto badframe; | |
248 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
249 | goto badframe; | |
250 | ||
251 | sigdelsetmask(&set, ~_BLOCKABLE); | |
252 | spin_lock_irq(¤t->sighand->siglock); | |
253 | current->blocked = set; | |
254 | recalc_sigpending(); | |
255 | spin_unlock_irq(¤t->sighand->siglock); | |
256 | ||
257 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax)) | |
258 | goto badframe; | |
259 | ||
260 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->esp) == -EFAULT) | |
261 | goto badframe; | |
262 | ||
263 | return eax; | |
264 | ||
265 | badframe: | |
266 | force_sig(SIGSEGV, current); | |
267 | return 0; | |
268 | } | |
269 | ||
270 | /* | |
271 | * Set up a signal frame. | |
272 | */ | |
273 | ||
274 | static int | |
275 | setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, | |
276 | struct pt_regs *regs, unsigned long mask) | |
277 | { | |
278 | int tmp, err = 0; | |
279 | ||
280 | tmp = 0; | |
281 | __asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp)); | |
282 | err |= __put_user(tmp, (unsigned int __user *)&sc->gs); | |
283 | __asm__("movl %%fs,%0" : "=r"(tmp): "0"(tmp)); | |
284 | err |= __put_user(tmp, (unsigned int __user *)&sc->fs); | |
285 | ||
286 | err |= __put_user(regs->xes, (unsigned int __user *)&sc->es); | |
287 | err |= __put_user(regs->xds, (unsigned int __user *)&sc->ds); | |
288 | err |= __put_user(regs->edi, &sc->edi); | |
289 | err |= __put_user(regs->esi, &sc->esi); | |
290 | err |= __put_user(regs->ebp, &sc->ebp); | |
291 | err |= __put_user(regs->esp, &sc->esp); | |
292 | err |= __put_user(regs->ebx, &sc->ebx); | |
293 | err |= __put_user(regs->edx, &sc->edx); | |
294 | err |= __put_user(regs->ecx, &sc->ecx); | |
295 | err |= __put_user(regs->eax, &sc->eax); | |
296 | err |= __put_user(current->thread.trap_no, &sc->trapno); | |
297 | err |= __put_user(current->thread.error_code, &sc->err); | |
298 | err |= __put_user(regs->eip, &sc->eip); | |
299 | err |= __put_user(regs->xcs, (unsigned int __user *)&sc->cs); | |
300 | err |= __put_user(regs->eflags, &sc->eflags); | |
301 | err |= __put_user(regs->esp, &sc->esp_at_signal); | |
302 | err |= __put_user(regs->xss, (unsigned int __user *)&sc->ss); | |
303 | ||
304 | tmp = save_i387(fpstate); | |
305 | if (tmp < 0) | |
306 | err = 1; | |
307 | else | |
308 | err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); | |
309 | ||
310 | /* non-iBCS2 extensions.. */ | |
311 | err |= __put_user(mask, &sc->oldmask); | |
312 | err |= __put_user(current->thread.cr2, &sc->cr2); | |
313 | ||
314 | return err; | |
315 | } | |
316 | ||
317 | /* | |
318 | * Determine which stack to use.. | |
319 | */ | |
320 | static inline void __user * | |
321 | get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) | |
322 | { | |
323 | unsigned long esp; | |
324 | ||
325 | /* Default to using normal stack */ | |
326 | esp = regs->esp; | |
327 | ||
328 | /* This is the X/Open sanctioned signal stack switching. */ | |
329 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
330 | if (sas_ss_flags(esp) == 0) | |
331 | esp = current->sas_ss_sp + current->sas_ss_size; | |
332 | } | |
333 | ||
334 | /* This is the legacy signal stack switching. */ | |
335 | else if ((regs->xss & 0xffff) != __USER_DS && | |
336 | !(ka->sa.sa_flags & SA_RESTORER) && | |
337 | ka->sa.sa_restorer) { | |
338 | esp = (unsigned long) ka->sa.sa_restorer; | |
339 | } | |
340 | ||
341 | return (void __user *)((esp - frame_size) & -8ul); | |
342 | } | |
343 | ||
344 | /* These symbols are defined with the addresses in the vsyscall page. | |
345 | See vsyscall-sigreturn.S. */ | |
346 | extern void __user __kernel_sigreturn; | |
347 | extern void __user __kernel_rt_sigreturn; | |
348 | ||
349 | static void setup_frame(int sig, struct k_sigaction *ka, | |
350 | sigset_t *set, struct pt_regs * regs) | |
351 | { | |
352 | void __user *restorer; | |
353 | struct sigframe __user *frame; | |
354 | int err = 0; | |
355 | int usig; | |
356 | ||
357 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
358 | ||
359 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
360 | goto give_sigsegv; | |
361 | ||
362 | usig = current_thread_info()->exec_domain | |
363 | && current_thread_info()->exec_domain->signal_invmap | |
364 | && sig < 32 | |
365 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
366 | : sig; | |
367 | ||
368 | err = __put_user(usig, &frame->sig); | |
369 | if (err) | |
370 | goto give_sigsegv; | |
371 | ||
372 | err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]); | |
373 | if (err) | |
374 | goto give_sigsegv; | |
375 | ||
376 | if (_NSIG_WORDS > 1) { | |
377 | err = __copy_to_user(&frame->extramask, &set->sig[1], | |
378 | sizeof(frame->extramask)); | |
379 | if (err) | |
380 | goto give_sigsegv; | |
381 | } | |
382 | ||
383 | restorer = &__kernel_sigreturn; | |
384 | if (ka->sa.sa_flags & SA_RESTORER) | |
385 | restorer = ka->sa.sa_restorer; | |
386 | ||
387 | /* Set up to return from userspace. */ | |
388 | err |= __put_user(restorer, &frame->pretcode); | |
389 | ||
390 | /* | |
391 | * This is popl %eax ; movl $,%eax ; int $0x80 | |
392 | * | |
393 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
394 | * reasons and because gdb uses it as a signature to notice | |
395 | * signal handler stack frames. | |
396 | */ | |
397 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); | |
398 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); | |
399 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); | |
400 | ||
401 | if (err) | |
402 | goto give_sigsegv; | |
403 | ||
404 | /* Set up registers for signal handler */ | |
405 | regs->esp = (unsigned long) frame; | |
406 | regs->eip = (unsigned long) ka->sa.sa_handler; | |
407 | regs->eax = (unsigned long) sig; | |
408 | regs->edx = (unsigned long) 0; | |
409 | regs->ecx = (unsigned long) 0; | |
410 | ||
411 | set_fs(USER_DS); | |
412 | regs->xds = __USER_DS; | |
413 | regs->xes = __USER_DS; | |
414 | regs->xss = __USER_DS; | |
415 | regs->xcs = __USER_CS; | |
416 | ||
417 | /* | |
418 | * Clear TF when entering the signal handler, but | |
419 | * notify any tracer that was single-stepping it. | |
420 | * The tracer may want to single-step inside the | |
421 | * handler too. | |
422 | */ | |
423 | regs->eflags &= ~TF_MASK; | |
424 | if (test_thread_flag(TIF_SINGLESTEP)) | |
425 | ptrace_notify(SIGTRAP); | |
426 | ||
427 | #if DEBUG_SIG | |
428 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
429 | current->comm, current->pid, frame, regs->eip, frame->pretcode); | |
430 | #endif | |
431 | ||
432 | return; | |
433 | ||
434 | give_sigsegv: | |
435 | force_sigsegv(sig, current); | |
436 | } | |
437 | ||
438 | static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | |
439 | sigset_t *set, struct pt_regs * regs) | |
440 | { | |
441 | void __user *restorer; | |
442 | struct rt_sigframe __user *frame; | |
443 | int err = 0; | |
444 | int usig; | |
445 | ||
446 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
447 | ||
448 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
449 | goto give_sigsegv; | |
450 | ||
451 | usig = current_thread_info()->exec_domain | |
452 | && current_thread_info()->exec_domain->signal_invmap | |
453 | && sig < 32 | |
454 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
455 | : sig; | |
456 | ||
457 | err |= __put_user(usig, &frame->sig); | |
458 | err |= __put_user(&frame->info, &frame->pinfo); | |
459 | err |= __put_user(&frame->uc, &frame->puc); | |
460 | err |= copy_siginfo_to_user(&frame->info, info); | |
461 | if (err) | |
462 | goto give_sigsegv; | |
463 | ||
464 | /* Create the ucontext. */ | |
465 | err |= __put_user(0, &frame->uc.uc_flags); | |
466 | err |= __put_user(0, &frame->uc.uc_link); | |
467 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
468 | err |= __put_user(sas_ss_flags(regs->esp), | |
469 | &frame->uc.uc_stack.ss_flags); | |
470 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
471 | err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate, | |
472 | regs, set->sig[0]); | |
473 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
474 | if (err) | |
475 | goto give_sigsegv; | |
476 | ||
477 | /* Set up to return from userspace. */ | |
478 | restorer = &__kernel_rt_sigreturn; | |
479 | if (ka->sa.sa_flags & SA_RESTORER) | |
480 | restorer = ka->sa.sa_restorer; | |
481 | err |= __put_user(restorer, &frame->pretcode); | |
482 | ||
483 | /* | |
484 | * This is movl $,%eax ; int $0x80 | |
485 | * | |
486 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
487 | * reasons and because gdb uses it as a signature to notice | |
488 | * signal handler stack frames. | |
489 | */ | |
490 | err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); | |
491 | err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); | |
492 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); | |
493 | ||
494 | if (err) | |
495 | goto give_sigsegv; | |
496 | ||
497 | /* Set up registers for signal handler */ | |
498 | regs->esp = (unsigned long) frame; | |
499 | regs->eip = (unsigned long) ka->sa.sa_handler; | |
500 | regs->eax = (unsigned long) usig; | |
501 | regs->edx = (unsigned long) &frame->info; | |
502 | regs->ecx = (unsigned long) &frame->uc; | |
503 | ||
504 | set_fs(USER_DS); | |
505 | regs->xds = __USER_DS; | |
506 | regs->xes = __USER_DS; | |
507 | regs->xss = __USER_DS; | |
508 | regs->xcs = __USER_CS; | |
509 | ||
510 | /* | |
511 | * Clear TF when entering the signal handler, but | |
512 | * notify any tracer that was single-stepping it. | |
513 | * The tracer may want to single-step inside the | |
514 | * handler too. | |
515 | */ | |
516 | regs->eflags &= ~TF_MASK; | |
517 | if (test_thread_flag(TIF_SINGLESTEP)) | |
518 | ptrace_notify(SIGTRAP); | |
519 | ||
520 | #if DEBUG_SIG | |
521 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
522 | current->comm, current->pid, frame, regs->eip, frame->pretcode); | |
523 | #endif | |
524 | ||
525 | return; | |
526 | ||
527 | give_sigsegv: | |
528 | force_sigsegv(sig, current); | |
529 | } | |
530 | ||
531 | /* | |
532 | * OK, we're invoking a handler | |
533 | */ | |
534 | ||
535 | static void | |
536 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, | |
537 | sigset_t *oldset, struct pt_regs * regs) | |
538 | { | |
539 | /* Are we from a system call? */ | |
540 | if (regs->orig_eax >= 0) { | |
541 | /* If so, check system call restarting.. */ | |
542 | switch (regs->eax) { | |
543 | case -ERESTART_RESTARTBLOCK: | |
544 | case -ERESTARTNOHAND: | |
545 | regs->eax = -EINTR; | |
546 | break; | |
547 | ||
548 | case -ERESTARTSYS: | |
549 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
550 | regs->eax = -EINTR; | |
551 | break; | |
552 | } | |
553 | /* fallthrough */ | |
554 | case -ERESTARTNOINTR: | |
555 | regs->eax = regs->orig_eax; | |
556 | regs->eip -= 2; | |
557 | } | |
558 | } | |
559 | ||
560 | /* | |
561 | * If TF is set due to a debugger (PT_DTRACE), clear the TF flag so | |
562 | * that register information in the sigcontext is correct. | |
563 | */ | |
564 | if (unlikely(regs->eflags & TF_MASK) | |
565 | && likely(current->ptrace & PT_DTRACE)) { | |
566 | current->ptrace &= ~PT_DTRACE; | |
567 | regs->eflags &= ~TF_MASK; | |
568 | } | |
569 | ||
570 | /* Set up the stack frame */ | |
571 | if (ka->sa.sa_flags & SA_SIGINFO) | |
572 | setup_rt_frame(sig, ka, info, oldset, regs); | |
573 | else | |
574 | setup_frame(sig, ka, oldset, regs); | |
575 | ||
576 | if (!(ka->sa.sa_flags & SA_NODEFER)) { | |
577 | spin_lock_irq(¤t->sighand->siglock); | |
578 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | |
579 | sigaddset(¤t->blocked,sig); | |
580 | recalc_sigpending(); | |
581 | spin_unlock_irq(¤t->sighand->siglock); | |
582 | } | |
583 | } | |
584 | ||
585 | /* | |
586 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
587 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
588 | * mistake. | |
589 | */ | |
590 | int fastcall do_signal(struct pt_regs *regs, sigset_t *oldset) | |
591 | { | |
592 | siginfo_t info; | |
593 | int signr; | |
594 | struct k_sigaction ka; | |
595 | ||
596 | /* | |
597 | * We want the common case to go fast, which | |
598 | * is why we may in certain cases get here from | |
599 | * kernel mode. Just return without doing anything | |
600 | * if so. | |
601 | */ | |
602 | if ((regs->xcs & 3) != 3) | |
603 | return 1; | |
604 | ||
605 | if (current->flags & PF_FREEZE) { | |
606 | refrigerator(0); | |
607 | goto no_signal; | |
608 | } | |
609 | ||
610 | if (!oldset) | |
611 | oldset = ¤t->blocked; | |
612 | ||
613 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
614 | if (signr > 0) { | |
615 | /* Reenable any watchpoints before delivering the | |
616 | * signal to user space. The processor register will | |
617 | * have been cleared if the watchpoint triggered | |
618 | * inside the kernel. | |
619 | */ | |
620 | if (unlikely(current->thread.debugreg[7])) { | |
621 | __asm__("movl %0,%%db7" : : "r" (current->thread.debugreg[7])); | |
622 | } | |
623 | ||
624 | /* Whee! Actually deliver the signal. */ | |
625 | handle_signal(signr, &info, &ka, oldset, regs); | |
626 | return 1; | |
627 | } | |
628 | ||
629 | no_signal: | |
630 | /* Did we come from a system call? */ | |
631 | if (regs->orig_eax >= 0) { | |
632 | /* Restart the system call - no handlers present */ | |
633 | if (regs->eax == -ERESTARTNOHAND || | |
634 | regs->eax == -ERESTARTSYS || | |
635 | regs->eax == -ERESTARTNOINTR) { | |
636 | regs->eax = regs->orig_eax; | |
637 | regs->eip -= 2; | |
638 | } | |
639 | if (regs->eax == -ERESTART_RESTARTBLOCK){ | |
640 | regs->eax = __NR_restart_syscall; | |
641 | regs->eip -= 2; | |
642 | } | |
643 | } | |
644 | return 0; | |
645 | } | |
646 | ||
647 | /* | |
648 | * notification of userspace execution resumption | |
649 | * - triggered by current->work.notify_resume | |
650 | */ | |
651 | __attribute__((regparm(3))) | |
652 | void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, | |
653 | __u32 thread_info_flags) | |
654 | { | |
655 | /* Pending single-step? */ | |
656 | if (thread_info_flags & _TIF_SINGLESTEP) { | |
657 | regs->eflags |= TF_MASK; | |
658 | clear_thread_flag(TIF_SINGLESTEP); | |
659 | } | |
660 | /* deal with pending signal delivery */ | |
661 | if (thread_info_flags & _TIF_SIGPENDING) | |
662 | do_signal(regs,oldset); | |
663 | ||
664 | clear_thread_flag(TIF_IRET); | |
665 | } |