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[PATCH] PCI: automatically set device_driver.owner
[linux-2.6/suspend2-2.6.18.git] / arch / i386 / kernel / signal.c
blobadcd069db91e8cae96ec53eeb2861f9c9e8c4b92
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(&current->sighand->siglock);
45 saveset = current->blocked;
46 siginitset(&current->blocked, mask);
47 recalc_sigpending();
48 spin_unlock_irq(&current->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(&current->sighand->siglock);
73 saveset = current->blocked;
74 current->blocked = newset;
75 recalc_sigpending();
76 spin_unlock_irq(&current->sighand->siglock);
77
78 regs.eax = -EINTR;
79 while (1) {
80 current->state = TASK_INTERRUPTIBLE;
81 schedule();
82 if (do_signal(&regs, &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(&current->sighand->siglock);
226 current->blocked = set;
227 recalc_sigpending();
228 spin_unlock_irq(&current->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(&current->sighand->siglock);
253 current->blocked = set;
254 recalc_sigpending();
255 spin_unlock_irq(&current->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 savesegment(gs, tmp);
282 err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
283 savesegment(fs, 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 esp -= frame_size;
342 /* Align the stack pointer according to the i386 ABI,
343 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
344 esp = ((esp + 4) & -16ul) - 4;
345 return (void __user *) esp;
346 }
347
348 /* These symbols are defined with the addresses in the vsyscall page.
349 See vsyscall-sigreturn.S. */
350 extern void __user __kernel_sigreturn;
351 extern void __user __kernel_rt_sigreturn;
352
353 static int setup_frame(int sig, struct k_sigaction *ka,
354 sigset_t *set, struct pt_regs * regs)
355 {
356 void __user *restorer;
357 struct sigframe __user *frame;
358 int err = 0;
359 int usig;
360
361 frame = get_sigframe(ka, regs, sizeof(*frame));
362
363 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
364 goto give_sigsegv;
365
366 usig = current_thread_info()->exec_domain
367 && current_thread_info()->exec_domain->signal_invmap
368 && sig < 32
369 ? current_thread_info()->exec_domain->signal_invmap[sig]
370 : sig;
371
372 err = __put_user(usig, &frame->sig);
373 if (err)
374 goto give_sigsegv;
375
376 err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]);
377 if (err)
378 goto give_sigsegv;
379
380 if (_NSIG_WORDS > 1) {
381 err = __copy_to_user(&frame->extramask, &set->sig[1],
382 sizeof(frame->extramask));
383 if (err)
384 goto give_sigsegv;
385 }
386
387 restorer = &__kernel_sigreturn;
388 if (ka->sa.sa_flags & SA_RESTORER)
389 restorer = ka->sa.sa_restorer;
390
391 /* Set up to return from userspace. */
392 err |= __put_user(restorer, &frame->pretcode);
393
394 /*
395 * This is popl %eax ; movl $,%eax ; int $0x80
396 *
397 * WE DO NOT USE IT ANY MORE! It's only left here for historical
398 * reasons and because gdb uses it as a signature to notice
399 * signal handler stack frames.
400 */
401 err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
402 err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
403 err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
404
405 if (err)
406 goto give_sigsegv;
407
408 /* Set up registers for signal handler */
409 regs->esp = (unsigned long) frame;
410 regs->eip = (unsigned long) ka->sa.sa_handler;
411 regs->eax = (unsigned long) sig;
412 regs->edx = (unsigned long) 0;
413 regs->ecx = (unsigned long) 0;
414
415 set_fs(USER_DS);
416 regs->xds = __USER_DS;
417 regs->xes = __USER_DS;
418 regs->xss = __USER_DS;
419 regs->xcs = __USER_CS;
420
421 /*
422 * Clear TF when entering the signal handler, but
423 * notify any tracer that was single-stepping it.
424 * The tracer may want to single-step inside the
425 * handler too.
426 */
427 regs->eflags &= ~TF_MASK;
428 if (test_thread_flag(TIF_SINGLESTEP))
429 ptrace_notify(SIGTRAP);
430
431 #if DEBUG_SIG
432 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
433 current->comm, current->pid, frame, regs->eip, frame->pretcode);
434 #endif
435
436 return 1;
437
438 give_sigsegv:
439 force_sigsegv(sig, current);
440 return 0;
441 }
442
443 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
444 sigset_t *set, struct pt_regs * regs)
445 {
446 void __user *restorer;
447 struct rt_sigframe __user *frame;
448 int err = 0;
449 int usig;
450
451 frame = get_sigframe(ka, regs, sizeof(*frame));
452
453 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
454 goto give_sigsegv;
455
456 usig = current_thread_info()->exec_domain
457 && current_thread_info()->exec_domain->signal_invmap
458 && sig < 32
459 ? current_thread_info()->exec_domain->signal_invmap[sig]
460 : sig;
461
462 err |= __put_user(usig, &frame->sig);
463 err |= __put_user(&frame->info, &frame->pinfo);
464 err |= __put_user(&frame->uc, &frame->puc);
465 err |= copy_siginfo_to_user(&frame->info, info);
466 if (err)
467 goto give_sigsegv;
468
469 /* Create the ucontext. */
470 err |= __put_user(0, &frame->uc.uc_flags);
471 err |= __put_user(0, &frame->uc.uc_link);
472 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
473 err |= __put_user(sas_ss_flags(regs->esp),
474 &frame->uc.uc_stack.ss_flags);
475 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
476 err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
477 regs, set->sig[0]);
478 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
479 if (err)
480 goto give_sigsegv;
481
482 /* Set up to return from userspace. */
483 restorer = &__kernel_rt_sigreturn;
484 if (ka->sa.sa_flags & SA_RESTORER)
485 restorer = ka->sa.sa_restorer;
486 err |= __put_user(restorer, &frame->pretcode);
487
488 /*
489 * This is movl $,%eax ; int $0x80
490 *
491 * WE DO NOT USE IT ANY MORE! It's only left here for historical
492 * reasons and because gdb uses it as a signature to notice
493 * signal handler stack frames.
494 */
495 err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
496 err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
497 err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
498
499 if (err)
500 goto give_sigsegv;
501
502 /* Set up registers for signal handler */
503 regs->esp = (unsigned long) frame;
504 regs->eip = (unsigned long) ka->sa.sa_handler;
505 regs->eax = (unsigned long) usig;
506 regs->edx = (unsigned long) &frame->info;
507 regs->ecx = (unsigned long) &frame->uc;
508
509 set_fs(USER_DS);
510 regs->xds = __USER_DS;
511 regs->xes = __USER_DS;
512 regs->xss = __USER_DS;
513 regs->xcs = __USER_CS;
514
515 /*
516 * Clear TF when entering the signal handler, but
517 * notify any tracer that was single-stepping it.
518 * The tracer may want to single-step inside the
519 * handler too.
520 */
521 regs->eflags &= ~TF_MASK;
522 if (test_thread_flag(TIF_SINGLESTEP))
523 ptrace_notify(SIGTRAP);
524
525 #if DEBUG_SIG
526 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
527 current->comm, current->pid, frame, regs->eip, frame->pretcode);
528 #endif
529
530 return 1;
531
532 give_sigsegv:
533 force_sigsegv(sig, current);
534 return 0;
535 }
536
537 /*
538 * OK, we're invoking a handler
539 */
540
541 static int
542 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
543 sigset_t *oldset, struct pt_regs * regs)
544 {
545 int ret;
546
547 /* Are we from a system call? */
548 if (regs->orig_eax >= 0) {
549 /* If so, check system call restarting.. */
550 switch (regs->eax) {
551 case -ERESTART_RESTARTBLOCK:
552 case -ERESTARTNOHAND:
553 regs->eax = -EINTR;
554 break;
555
556 case -ERESTARTSYS:
557 if (!(ka->sa.sa_flags & SA_RESTART)) {
558 regs->eax = -EINTR;
559 break;
560 }
561 /* fallthrough */
562 case -ERESTARTNOINTR:
563 regs->eax = regs->orig_eax;
564 regs->eip -= 2;
565 }
566 }
567
568 /*
569 * If TF is set due to a debugger (PT_DTRACE), clear the TF flag so
570 * that register information in the sigcontext is correct.
571 */
572 if (unlikely(regs->eflags & TF_MASK)
573 && likely(current->ptrace & PT_DTRACE)) {
574 current->ptrace &= ~PT_DTRACE;
575 regs->eflags &= ~TF_MASK;
576 }
577
578 /* Set up the stack frame */
579 if (ka->sa.sa_flags & SA_SIGINFO)
580 ret = setup_rt_frame(sig, ka, info, oldset, regs);
581 else
582 ret = setup_frame(sig, ka, oldset, regs);
583
584 if (ret) {
585 spin_lock_irq(&current->sighand->siglock);
586 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
587 if (!(ka->sa.sa_flags & SA_NODEFER))
588 sigaddset(&current->blocked,sig);
589 recalc_sigpending();
590 spin_unlock_irq(&current->sighand->siglock);
591 }
592
593 return ret;
594 }
595
596 /*
597 * Note that 'init' is a special process: it doesn't get signals it doesn't
598 * want to handle. Thus you cannot kill init even with a SIGKILL even by
599 * mistake.
600 */
601 int fastcall do_signal(struct pt_regs *regs, sigset_t *oldset)
602 {
603 siginfo_t info;
604 int signr;
605 struct k_sigaction ka;
606
607 /*
608 * We want the common case to go fast, which
609 * is why we may in certain cases get here from
610 * kernel mode. Just return without doing anything
611 * if so. vm86 regs switched out by assembly code
612 * before reaching here, so testing against kernel
613 * CS suffices.
614 */
615 if (!user_mode(regs))
616 return 1;
617
618 if (try_to_freeze())
619 goto no_signal;
620
621 if (!oldset)
622 oldset = &current->blocked;
623
624 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
625 if (signr > 0) {
626 /* Reenable any watchpoints before delivering the
627 * signal to user space. The processor register will
628 * have been cleared if the watchpoint triggered
629 * inside the kernel.
630 */
631 if (unlikely(current->thread.debugreg[7])) {
632 set_debugreg(current->thread.debugreg[7], 7);
633 }
634
635 /* Whee! Actually deliver the signal. */
636 return handle_signal(signr, &info, &ka, oldset, regs);
637 }
638
639 no_signal:
640 /* Did we come from a system call? */
641 if (regs->orig_eax >= 0) {
642 /* Restart the system call - no handlers present */
643 if (regs->eax == -ERESTARTNOHAND ||
644 regs->eax == -ERESTARTSYS ||
645 regs->eax == -ERESTARTNOINTR) {
646 regs->eax = regs->orig_eax;
647 regs->eip -= 2;
648 }
649 if (regs->eax == -ERESTART_RESTARTBLOCK){
650 regs->eax = __NR_restart_syscall;
651 regs->eip -= 2;
652 }
653 }
654 return 0;
655 }
656
657 /*
658 * notification of userspace execution resumption
659 * - triggered by current->work.notify_resume
660 */
661 __attribute__((regparm(3)))
662 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
663 __u32 thread_info_flags)
664 {
665 /* Pending single-step? */
666 if (thread_info_flags & _TIF_SINGLESTEP) {
667 regs->eflags |= TF_MASK;
668 clear_thread_flag(TIF_SINGLESTEP);
669 }
670 /* deal with pending signal delivery */
671 if (thread_info_flags & _TIF_SIGPENDING)
672 do_signal(regs,oldset);
673
674 clear_thread_flag(TIF_IRET);
675 }
Software Suspend 2 for 2.6.18.y (mirror)