Commit | Line | Data |
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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> | |
1da177e4 LT |
13 | #include <linux/kernel.h> |
14 | #include <linux/signal.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/wait.h> | |
17 | #include <linux/unistd.h> | |
18 | #include <linux/stddef.h> | |
19 | #include <linux/personality.h> | |
20 | #include <linux/suspend.h> | |
21 | #include <linux/ptrace.h> | |
22 | #include <linux/elf.h> | |
9fbbd4dd | 23 | #include <linux/binfmts.h> |
1da177e4 LT |
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 | { | |
1da177e4 LT |
40 | mask &= _BLOCKABLE; |
41 | spin_lock_irq(¤t->sighand->siglock); | |
283828f3 | 42 | current->saved_sigmask = current->blocked; |
1da177e4 LT |
43 | siginitset(¤t->blocked, mask); |
44 | recalc_sigpending(); | |
45 | spin_unlock_irq(¤t->sighand->siglock); | |
46 | ||
283828f3 DH |
47 | current->state = TASK_INTERRUPTIBLE; |
48 | schedule(); | |
49 | set_thread_flag(TIF_RESTORE_SIGMASK); | |
50 | return -ERESTARTNOHAND; | |
1da177e4 LT |
51 | } |
52 | ||
53 | asmlinkage int | |
54 | sys_sigaction(int sig, const struct old_sigaction __user *act, | |
55 | struct old_sigaction __user *oact) | |
56 | { | |
57 | struct k_sigaction new_ka, old_ka; | |
58 | int ret; | |
59 | ||
60 | if (act) { | |
61 | old_sigset_t mask; | |
62 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
63 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
64 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
65 | return -EFAULT; | |
66 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); | |
67 | __get_user(mask, &act->sa_mask); | |
68 | siginitset(&new_ka.sa.sa_mask, mask); | |
69 | } | |
70 | ||
71 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
72 | ||
73 | if (!ret && oact) { | |
74 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
75 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
76 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
77 | return -EFAULT; | |
78 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); | |
79 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
80 | } | |
81 | ||
82 | return ret; | |
83 | } | |
84 | ||
85 | asmlinkage int | |
86 | sys_sigaltstack(unsigned long ebx) | |
87 | { | |
88 | /* This is needed to make gcc realize it doesn't own the "struct pt_regs" */ | |
89 | struct pt_regs *regs = (struct pt_regs *)&ebx; | |
90 | const stack_t __user *uss = (const stack_t __user *)ebx; | |
91 | stack_t __user *uoss = (stack_t __user *)regs->ecx; | |
92 | ||
93 | return do_sigaltstack(uss, uoss, regs->esp); | |
94 | } | |
95 | ||
96 | ||
97 | /* | |
98 | * Do a signal return; undo the signal stack. | |
99 | */ | |
100 | ||
101 | static int | |
102 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax) | |
103 | { | |
104 | unsigned int err = 0; | |
105 | ||
106 | /* Always make any pending restarted system calls return -EINTR */ | |
107 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
108 | ||
109 | #define COPY(x) err |= __get_user(regs->x, &sc->x) | |
110 | ||
111 | #define COPY_SEG(seg) \ | |
112 | { unsigned short tmp; \ | |
113 | err |= __get_user(tmp, &sc->seg); \ | |
114 | regs->x##seg = tmp; } | |
115 | ||
116 | #define COPY_SEG_STRICT(seg) \ | |
117 | { unsigned short tmp; \ | |
118 | err |= __get_user(tmp, &sc->seg); \ | |
119 | regs->x##seg = tmp|3; } | |
120 | ||
121 | #define GET_SEG(seg) \ | |
122 | { unsigned short tmp; \ | |
123 | err |= __get_user(tmp, &sc->seg); \ | |
124 | loadsegment(seg,tmp); } | |
125 | ||
8bed51cd CE |
126 | #define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_RF | \ |
127 | X86_EFLAGS_OF | X86_EFLAGS_DF | \ | |
1da177e4 LT |
128 | X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \ |
129 | X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF) | |
130 | ||
464d1a78 JF |
131 | GET_SEG(gs); |
132 | COPY_SEG(fs); | |
1da177e4 LT |
133 | COPY_SEG(es); |
134 | COPY_SEG(ds); | |
135 | COPY(edi); | |
136 | COPY(esi); | |
137 | COPY(ebp); | |
138 | COPY(esp); | |
139 | COPY(ebx); | |
140 | COPY(edx); | |
141 | COPY(ecx); | |
142 | COPY(eip); | |
143 | COPY_SEG_STRICT(cs); | |
144 | COPY_SEG_STRICT(ss); | |
145 | ||
146 | { | |
147 | unsigned int tmpflags; | |
148 | err |= __get_user(tmpflags, &sc->eflags); | |
149 | regs->eflags = (regs->eflags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); | |
150 | regs->orig_eax = -1; /* disable syscall checks */ | |
151 | } | |
152 | ||
153 | { | |
154 | struct _fpstate __user * buf; | |
155 | err |= __get_user(buf, &sc->fpstate); | |
156 | if (buf) { | |
157 | if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) | |
158 | goto badframe; | |
159 | err |= restore_i387(buf); | |
160 | } else { | |
161 | struct task_struct *me = current; | |
162 | if (used_math()) { | |
163 | clear_fpu(me); | |
164 | clear_used_math(); | |
165 | } | |
166 | } | |
167 | } | |
168 | ||
169 | err |= __get_user(*peax, &sc->eax); | |
170 | return err; | |
171 | ||
172 | badframe: | |
173 | return 1; | |
174 | } | |
175 | ||
176 | asmlinkage int sys_sigreturn(unsigned long __unused) | |
177 | { | |
178 | struct pt_regs *regs = (struct pt_regs *) &__unused; | |
179 | struct sigframe __user *frame = (struct sigframe __user *)(regs->esp - 8); | |
180 | sigset_t set; | |
181 | int eax; | |
182 | ||
183 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
184 | goto badframe; | |
185 | if (__get_user(set.sig[0], &frame->sc.oldmask) | |
186 | || (_NSIG_WORDS > 1 | |
187 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
188 | sizeof(frame->extramask)))) | |
189 | goto badframe; | |
190 | ||
191 | sigdelsetmask(&set, ~_BLOCKABLE); | |
192 | spin_lock_irq(¤t->sighand->siglock); | |
193 | current->blocked = set; | |
194 | recalc_sigpending(); | |
195 | spin_unlock_irq(¤t->sighand->siglock); | |
196 | ||
197 | if (restore_sigcontext(regs, &frame->sc, &eax)) | |
198 | goto badframe; | |
199 | return eax; | |
200 | ||
201 | badframe: | |
abd4f750 MAS |
202 | if (show_unhandled_signals && printk_ratelimit()) |
203 | printk("%s%s[%d] bad frame in sigreturn frame:%p eip:%lx" | |
204 | " esp:%lx oeax:%lx\n", | |
205 | current->pid > 1 ? KERN_INFO : KERN_EMERG, | |
206 | current->comm, current->pid, frame, regs->eip, | |
207 | regs->esp, regs->orig_eax); | |
208 | ||
1da177e4 LT |
209 | force_sig(SIGSEGV, current); |
210 | return 0; | |
211 | } | |
212 | ||
213 | asmlinkage int sys_rt_sigreturn(unsigned long __unused) | |
214 | { | |
215 | struct pt_regs *regs = (struct pt_regs *) &__unused; | |
216 | struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->esp - 4); | |
217 | sigset_t set; | |
218 | int eax; | |
219 | ||
220 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
221 | goto badframe; | |
222 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
223 | goto badframe; | |
224 | ||
225 | sigdelsetmask(&set, ~_BLOCKABLE); | |
226 | spin_lock_irq(¤t->sighand->siglock); | |
227 | current->blocked = set; | |
228 | recalc_sigpending(); | |
229 | spin_unlock_irq(¤t->sighand->siglock); | |
230 | ||
231 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax)) | |
232 | goto badframe; | |
233 | ||
234 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->esp) == -EFAULT) | |
235 | goto badframe; | |
236 | ||
237 | return eax; | |
238 | ||
239 | badframe: | |
240 | force_sig(SIGSEGV, current); | |
241 | return 0; | |
242 | } | |
243 | ||
244 | /* | |
245 | * Set up a signal frame. | |
246 | */ | |
247 | ||
248 | static int | |
249 | setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, | |
250 | struct pt_regs *regs, unsigned long mask) | |
251 | { | |
252 | int tmp, err = 0; | |
253 | ||
464d1a78 JF |
254 | err |= __put_user(regs->xfs, (unsigned int __user *)&sc->fs); |
255 | savesegment(gs, tmp); | |
256 | err |= __put_user(tmp, (unsigned int __user *)&sc->gs); | |
1da177e4 LT |
257 | |
258 | err |= __put_user(regs->xes, (unsigned int __user *)&sc->es); | |
259 | err |= __put_user(regs->xds, (unsigned int __user *)&sc->ds); | |
260 | err |= __put_user(regs->edi, &sc->edi); | |
261 | err |= __put_user(regs->esi, &sc->esi); | |
262 | err |= __put_user(regs->ebp, &sc->ebp); | |
263 | err |= __put_user(regs->esp, &sc->esp); | |
264 | err |= __put_user(regs->ebx, &sc->ebx); | |
265 | err |= __put_user(regs->edx, &sc->edx); | |
266 | err |= __put_user(regs->ecx, &sc->ecx); | |
267 | err |= __put_user(regs->eax, &sc->eax); | |
268 | err |= __put_user(current->thread.trap_no, &sc->trapno); | |
269 | err |= __put_user(current->thread.error_code, &sc->err); | |
270 | err |= __put_user(regs->eip, &sc->eip); | |
271 | err |= __put_user(regs->xcs, (unsigned int __user *)&sc->cs); | |
272 | err |= __put_user(regs->eflags, &sc->eflags); | |
273 | err |= __put_user(regs->esp, &sc->esp_at_signal); | |
274 | err |= __put_user(regs->xss, (unsigned int __user *)&sc->ss); | |
275 | ||
276 | tmp = save_i387(fpstate); | |
277 | if (tmp < 0) | |
278 | err = 1; | |
279 | else | |
280 | err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); | |
281 | ||
282 | /* non-iBCS2 extensions.. */ | |
283 | err |= __put_user(mask, &sc->oldmask); | |
284 | err |= __put_user(current->thread.cr2, &sc->cr2); | |
285 | ||
286 | return err; | |
287 | } | |
288 | ||
289 | /* | |
290 | * Determine which stack to use.. | |
291 | */ | |
292 | static inline void __user * | |
293 | get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) | |
294 | { | |
295 | unsigned long esp; | |
296 | ||
297 | /* Default to using normal stack */ | |
298 | esp = regs->esp; | |
299 | ||
300 | /* This is the X/Open sanctioned signal stack switching. */ | |
301 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
302 | if (sas_ss_flags(esp) == 0) | |
303 | esp = current->sas_ss_sp + current->sas_ss_size; | |
304 | } | |
305 | ||
306 | /* This is the legacy signal stack switching. */ | |
307 | else if ((regs->xss & 0xffff) != __USER_DS && | |
308 | !(ka->sa.sa_flags & SA_RESTORER) && | |
309 | ka->sa.sa_restorer) { | |
310 | esp = (unsigned long) ka->sa.sa_restorer; | |
311 | } | |
312 | ||
d347f372 MO |
313 | esp -= frame_size; |
314 | /* Align the stack pointer according to the i386 ABI, | |
315 | * i.e. so that on function entry ((sp + 4) & 15) == 0. */ | |
316 | esp = ((esp + 4) & -16ul) - 4; | |
317 | return (void __user *) esp; | |
1da177e4 LT |
318 | } |
319 | ||
320 | /* These symbols are defined with the addresses in the vsyscall page. | |
321 | See vsyscall-sigreturn.S. */ | |
322 | extern void __user __kernel_sigreturn; | |
323 | extern void __user __kernel_rt_sigreturn; | |
324 | ||
7c1def16 RM |
325 | static int setup_frame(int sig, struct k_sigaction *ka, |
326 | sigset_t *set, struct pt_regs * regs) | |
1da177e4 LT |
327 | { |
328 | void __user *restorer; | |
329 | struct sigframe __user *frame; | |
330 | int err = 0; | |
331 | int usig; | |
332 | ||
333 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
334 | ||
335 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
336 | goto give_sigsegv; | |
337 | ||
338 | usig = current_thread_info()->exec_domain | |
339 | && current_thread_info()->exec_domain->signal_invmap | |
340 | && sig < 32 | |
341 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
342 | : sig; | |
343 | ||
344 | err = __put_user(usig, &frame->sig); | |
345 | if (err) | |
346 | goto give_sigsegv; | |
347 | ||
348 | err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]); | |
349 | if (err) | |
350 | goto give_sigsegv; | |
351 | ||
352 | if (_NSIG_WORDS > 1) { | |
353 | err = __copy_to_user(&frame->extramask, &set->sig[1], | |
354 | sizeof(frame->extramask)); | |
355 | if (err) | |
356 | goto give_sigsegv; | |
357 | } | |
358 | ||
9fbbd4dd AK |
359 | if (current->binfmt->hasvdso) |
360 | restorer = (void *)VDSO_SYM(&__kernel_sigreturn); | |
361 | else | |
362 | restorer = (void *)&frame->retcode; | |
1da177e4 LT |
363 | if (ka->sa.sa_flags & SA_RESTORER) |
364 | restorer = ka->sa.sa_restorer; | |
365 | ||
366 | /* Set up to return from userspace. */ | |
367 | err |= __put_user(restorer, &frame->pretcode); | |
368 | ||
369 | /* | |
370 | * This is popl %eax ; movl $,%eax ; int $0x80 | |
371 | * | |
372 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
373 | * reasons and because gdb uses it as a signature to notice | |
374 | * signal handler stack frames. | |
375 | */ | |
376 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); | |
377 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); | |
378 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); | |
379 | ||
380 | if (err) | |
381 | goto give_sigsegv; | |
382 | ||
383 | /* Set up registers for signal handler */ | |
384 | regs->esp = (unsigned long) frame; | |
385 | regs->eip = (unsigned long) ka->sa.sa_handler; | |
386 | regs->eax = (unsigned long) sig; | |
387 | regs->edx = (unsigned long) 0; | |
388 | regs->ecx = (unsigned long) 0; | |
389 | ||
390 | set_fs(USER_DS); | |
391 | regs->xds = __USER_DS; | |
392 | regs->xes = __USER_DS; | |
393 | regs->xss = __USER_DS; | |
394 | regs->xcs = __USER_CS; | |
395 | ||
396 | /* | |
397 | * Clear TF when entering the signal handler, but | |
398 | * notify any tracer that was single-stepping it. | |
399 | * The tracer may want to single-step inside the | |
400 | * handler too. | |
401 | */ | |
402 | regs->eflags &= ~TF_MASK; | |
403 | if (test_thread_flag(TIF_SINGLESTEP)) | |
404 | ptrace_notify(SIGTRAP); | |
405 | ||
406 | #if DEBUG_SIG | |
407 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
408 | current->comm, current->pid, frame, regs->eip, frame->pretcode); | |
409 | #endif | |
410 | ||
283828f3 | 411 | return 0; |
1da177e4 LT |
412 | |
413 | give_sigsegv: | |
414 | force_sigsegv(sig, current); | |
283828f3 | 415 | return -EFAULT; |
1da177e4 LT |
416 | } |
417 | ||
7c1def16 | 418 | static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
1da177e4 LT |
419 | sigset_t *set, struct pt_regs * regs) |
420 | { | |
421 | void __user *restorer; | |
422 | struct rt_sigframe __user *frame; | |
423 | int err = 0; | |
424 | int usig; | |
425 | ||
426 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
427 | ||
428 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
429 | goto give_sigsegv; | |
430 | ||
431 | usig = current_thread_info()->exec_domain | |
432 | && current_thread_info()->exec_domain->signal_invmap | |
433 | && sig < 32 | |
434 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
435 | : sig; | |
436 | ||
437 | err |= __put_user(usig, &frame->sig); | |
438 | err |= __put_user(&frame->info, &frame->pinfo); | |
439 | err |= __put_user(&frame->uc, &frame->puc); | |
440 | err |= copy_siginfo_to_user(&frame->info, info); | |
441 | if (err) | |
442 | goto give_sigsegv; | |
443 | ||
444 | /* Create the ucontext. */ | |
445 | err |= __put_user(0, &frame->uc.uc_flags); | |
446 | err |= __put_user(0, &frame->uc.uc_link); | |
447 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
448 | err |= __put_user(sas_ss_flags(regs->esp), | |
449 | &frame->uc.uc_stack.ss_flags); | |
450 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
451 | err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate, | |
452 | regs, set->sig[0]); | |
453 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
454 | if (err) | |
455 | goto give_sigsegv; | |
456 | ||
457 | /* Set up to return from userspace. */ | |
e6e5494c | 458 | restorer = (void *)VDSO_SYM(&__kernel_rt_sigreturn); |
1da177e4 LT |
459 | if (ka->sa.sa_flags & SA_RESTORER) |
460 | restorer = ka->sa.sa_restorer; | |
461 | err |= __put_user(restorer, &frame->pretcode); | |
462 | ||
463 | /* | |
464 | * This is movl $,%eax ; int $0x80 | |
465 | * | |
466 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
467 | * reasons and because gdb uses it as a signature to notice | |
468 | * signal handler stack frames. | |
469 | */ | |
470 | err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); | |
471 | err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); | |
472 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); | |
473 | ||
474 | if (err) | |
475 | goto give_sigsegv; | |
476 | ||
477 | /* Set up registers for signal handler */ | |
478 | regs->esp = (unsigned long) frame; | |
479 | regs->eip = (unsigned long) ka->sa.sa_handler; | |
480 | regs->eax = (unsigned long) usig; | |
481 | regs->edx = (unsigned long) &frame->info; | |
482 | regs->ecx = (unsigned long) &frame->uc; | |
483 | ||
484 | set_fs(USER_DS); | |
485 | regs->xds = __USER_DS; | |
486 | regs->xes = __USER_DS; | |
487 | regs->xss = __USER_DS; | |
488 | regs->xcs = __USER_CS; | |
489 | ||
490 | /* | |
491 | * Clear TF when entering the signal handler, but | |
492 | * notify any tracer that was single-stepping it. | |
493 | * The tracer may want to single-step inside the | |
494 | * handler too. | |
495 | */ | |
496 | regs->eflags &= ~TF_MASK; | |
497 | if (test_thread_flag(TIF_SINGLESTEP)) | |
498 | ptrace_notify(SIGTRAP); | |
499 | ||
500 | #if DEBUG_SIG | |
501 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
502 | current->comm, current->pid, frame, regs->eip, frame->pretcode); | |
503 | #endif | |
504 | ||
283828f3 | 505 | return 0; |
1da177e4 LT |
506 | |
507 | give_sigsegv: | |
508 | force_sigsegv(sig, current); | |
283828f3 | 509 | return -EFAULT; |
1da177e4 LT |
510 | } |
511 | ||
512 | /* | |
513 | * OK, we're invoking a handler | |
514 | */ | |
515 | ||
7c1def16 | 516 | static int |
1da177e4 LT |
517 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, |
518 | sigset_t *oldset, struct pt_regs * regs) | |
519 | { | |
7c1def16 RM |
520 | int ret; |
521 | ||
1da177e4 LT |
522 | /* Are we from a system call? */ |
523 | if (regs->orig_eax >= 0) { | |
524 | /* If so, check system call restarting.. */ | |
525 | switch (regs->eax) { | |
526 | case -ERESTART_RESTARTBLOCK: | |
527 | case -ERESTARTNOHAND: | |
528 | regs->eax = -EINTR; | |
529 | break; | |
530 | ||
531 | case -ERESTARTSYS: | |
532 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
533 | regs->eax = -EINTR; | |
534 | break; | |
535 | } | |
536 | /* fallthrough */ | |
537 | case -ERESTARTNOINTR: | |
538 | regs->eax = regs->orig_eax; | |
539 | regs->eip -= 2; | |
540 | } | |
541 | } | |
542 | ||
543 | /* | |
544 | * If TF is set due to a debugger (PT_DTRACE), clear the TF flag so | |
545 | * that register information in the sigcontext is correct. | |
546 | */ | |
547 | if (unlikely(regs->eflags & TF_MASK) | |
548 | && likely(current->ptrace & PT_DTRACE)) { | |
549 | current->ptrace &= ~PT_DTRACE; | |
550 | regs->eflags &= ~TF_MASK; | |
551 | } | |
552 | ||
553 | /* Set up the stack frame */ | |
554 | if (ka->sa.sa_flags & SA_SIGINFO) | |
7c1def16 | 555 | ret = setup_rt_frame(sig, ka, info, oldset, regs); |
1da177e4 | 556 | else |
7c1def16 | 557 | ret = setup_frame(sig, ka, oldset, regs); |
1da177e4 | 558 | |
283828f3 | 559 | if (ret == 0) { |
1da177e4 LT |
560 | spin_lock_irq(¤t->sighand->siglock); |
561 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | |
69be8f18 SR |
562 | if (!(ka->sa.sa_flags & SA_NODEFER)) |
563 | sigaddset(¤t->blocked,sig); | |
1da177e4 LT |
564 | recalc_sigpending(); |
565 | spin_unlock_irq(¤t->sighand->siglock); | |
566 | } | |
7c1def16 RM |
567 | |
568 | return ret; | |
1da177e4 LT |
569 | } |
570 | ||
571 | /* | |
572 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
573 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
574 | * mistake. | |
575 | */ | |
283828f3 | 576 | static void fastcall do_signal(struct pt_regs *regs) |
1da177e4 LT |
577 | { |
578 | siginfo_t info; | |
579 | int signr; | |
580 | struct k_sigaction ka; | |
283828f3 | 581 | sigset_t *oldset; |
1da177e4 LT |
582 | |
583 | /* | |
584 | * We want the common case to go fast, which | |
585 | * is why we may in certain cases get here from | |
586 | * kernel mode. Just return without doing anything | |
0998e422 ZA |
587 | * if so. vm86 regs switched out by assembly code |
588 | * before reaching here, so testing against kernel | |
589 | * CS suffices. | |
1da177e4 | 590 | */ |
717b594a | 591 | if (!user_mode(regs)) |
283828f3 | 592 | return; |
1da177e4 | 593 | |
283828f3 DH |
594 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
595 | oldset = ¤t->saved_sigmask; | |
596 | else | |
1da177e4 LT |
597 | oldset = ¤t->blocked; |
598 | ||
599 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
600 | if (signr > 0) { | |
601 | /* Reenable any watchpoints before delivering the | |
602 | * signal to user space. The processor register will | |
603 | * have been cleared if the watchpoint triggered | |
604 | * inside the kernel. | |
605 | */ | |
283828f3 | 606 | if (unlikely(current->thread.debugreg[7])) |
1cc6f12e | 607 | set_debugreg(current->thread.debugreg[7], 7); |
1da177e4 LT |
608 | |
609 | /* Whee! Actually deliver the signal. */ | |
283828f3 DH |
610 | if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { |
611 | /* a signal was successfully delivered; the saved | |
612 | * sigmask will have been stored in the signal frame, | |
613 | * and will be restored by sigreturn, so we can simply | |
614 | * clear the TIF_RESTORE_SIGMASK flag */ | |
615 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) | |
616 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
617 | } | |
618 | ||
619 | return; | |
1da177e4 LT |
620 | } |
621 | ||
1da177e4 LT |
622 | /* Did we come from a system call? */ |
623 | if (regs->orig_eax >= 0) { | |
624 | /* Restart the system call - no handlers present */ | |
283828f3 DH |
625 | switch (regs->eax) { |
626 | case -ERESTARTNOHAND: | |
627 | case -ERESTARTSYS: | |
628 | case -ERESTARTNOINTR: | |
1da177e4 LT |
629 | regs->eax = regs->orig_eax; |
630 | regs->eip -= 2; | |
283828f3 DH |
631 | break; |
632 | ||
633 | case -ERESTART_RESTARTBLOCK: | |
1da177e4 LT |
634 | regs->eax = __NR_restart_syscall; |
635 | regs->eip -= 2; | |
283828f3 | 636 | break; |
1da177e4 LT |
637 | } |
638 | } | |
283828f3 DH |
639 | |
640 | /* if there's no signal to deliver, we just put the saved sigmask | |
641 | * back */ | |
642 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { | |
643 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
644 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | |
645 | } | |
1da177e4 LT |
646 | } |
647 | ||
648 | /* | |
649 | * notification of userspace execution resumption | |
283828f3 | 650 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 LT |
651 | */ |
652 | __attribute__((regparm(3))) | |
283828f3 | 653 | void do_notify_resume(struct pt_regs *regs, void *_unused, |
1da177e4 LT |
654 | __u32 thread_info_flags) |
655 | { | |
656 | /* Pending single-step? */ | |
657 | if (thread_info_flags & _TIF_SINGLESTEP) { | |
658 | regs->eflags |= TF_MASK; | |
659 | clear_thread_flag(TIF_SINGLESTEP); | |
660 | } | |
283828f3 | 661 | |
1da177e4 | 662 | /* deal with pending signal delivery */ |
283828f3 DH |
663 | if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) |
664 | do_signal(regs); | |
1da177e4 LT |
665 | |
666 | clear_thread_flag(TIF_IRET); | |
667 | } |