2 * linux/arch/i386/kernel/signal.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
6 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
7 * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
10 #include <linux/sched.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/elf.h>
23 #include <asm/processor.h>
24 #include <asm/ucontext.h>
25 #include <asm/uaccess.h>
31 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
34 * Atomically swap in the new signal mask, and wait for a signal.
37 sys_sigsuspend(int history0, int history1, old_sigset_t mask)
39 struct pt_regs * regs = (struct pt_regs *) &history0;
43 spin_lock_irq(¤t->sighand->siglock);
44 saveset = current->blocked;
45 siginitset(¤t->blocked, mask);
47 spin_unlock_irq(¤t->sighand->siglock);
51 current->state = TASK_INTERRUPTIBLE;
53 if (do_signal(regs, &saveset))
59 sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize)
61 struct pt_regs * regs = (struct pt_regs *) &unewset;
62 sigset_t saveset, newset;
64 /* XXX: Don't preclude handling different sized sigset_t's. */
65 if (sigsetsize != sizeof(sigset_t))
68 if (copy_from_user(&newset, unewset, sizeof(newset)))
70 sigdelsetmask(&newset, ~_BLOCKABLE);
72 spin_lock_irq(¤t->sighand->siglock);
73 saveset = current->blocked;
74 current->blocked = newset;
76 spin_unlock_irq(¤t->sighand->siglock);
80 current->state = TASK_INTERRUPTIBLE;
82 if (do_signal(regs, &saveset))
88 sys_sigaction(int sig, const struct old_sigaction __user *act,
89 struct old_sigaction __user *oact)
91 struct k_sigaction new_ka, old_ka;
96 if (verify_area(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))
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);
105 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
108 if (verify_area(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))
112 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
113 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
120 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
122 struct pt_regs *regs = (struct pt_regs *) &uss;
123 return do_sigaltstack(uss, uoss, regs->esp);
128 * Do a signal return; undo the signal stack.
132 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax)
134 unsigned int err = 0;
136 /* Always make any pending restarted system calls return -EINTR */
137 current_thread_info()->restart_block.fn = do_no_restart_syscall;
139 #define COPY(x) err |= __get_user(regs->x, &sc->x)
141 #define COPY_SEG(seg) \
142 { unsigned short tmp; \
143 err |= __get_user(tmp, &sc->seg); \
144 regs->x##seg = tmp; }
146 #define COPY_SEG_STRICT(seg) \
147 { unsigned short tmp; \
148 err |= __get_user(tmp, &sc->seg); \
149 regs->x##seg = tmp|3; }
151 #define GET_SEG(seg) \
152 { unsigned short tmp; \
153 err |= __get_user(tmp, &sc->seg); \
154 loadsegment(seg,tmp); }
156 #define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | X86_EFLAGS_DF | \
157 X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \
158 X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF)
176 unsigned int tmpflags;
177 err |= __get_user(tmpflags, &sc->eflags);
178 regs->eflags = (regs->eflags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
179 regs->orig_eax = -1; /* disable syscall checks */
183 struct _fpstate __user * buf;
184 err |= __get_user(buf, &sc->fpstate);
186 if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
188 err |= restore_i387(buf);
192 err |= __get_user(*peax, &sc->eax);
199 asmlinkage int sys_sigreturn(unsigned long __unused)
201 struct pt_regs *regs = (struct pt_regs *) &__unused;
202 struct sigframe __user *frame = (struct sigframe __user *)(regs->esp - 8);
206 if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
208 if (__get_user(set.sig[0], &frame->sc.oldmask)
210 && __copy_from_user(&set.sig[1], &frame->extramask,
211 sizeof(frame->extramask))))
214 sigdelsetmask(&set, ~_BLOCKABLE);
215 spin_lock_irq(¤t->sighand->siglock);
216 current->blocked = set;
218 spin_unlock_irq(¤t->sighand->siglock);
220 if (restore_sigcontext(regs, &frame->sc, &eax))
225 force_sig(SIGSEGV, current);
229 asmlinkage int sys_rt_sigreturn(unsigned long __unused)
231 struct pt_regs *regs = (struct pt_regs *) &__unused;
232 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->esp - 4);
237 if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
239 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
242 sigdelsetmask(&set, ~_BLOCKABLE);
243 spin_lock_irq(¤t->sighand->siglock);
244 current->blocked = set;
246 spin_unlock_irq(¤t->sighand->siglock);
248 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax))
251 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
253 /* It is more difficult to avoid calling this function than to
254 call it and ignore errors. */
256 * THIS CANNOT WORK! "&st" is a kernel address, and "do_sigaltstack()"
257 * takes a user address (and verifies that it is a user address). End
258 * result: it does exactly _nothing_.
260 do_sigaltstack(&st, NULL, regs->esp);
265 force_sig(SIGSEGV, current);
270 * Set up a signal frame.
274 setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
275 struct pt_regs *regs, unsigned long mask)
280 __asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp));
281 err |= __put_user(tmp, (unsigned int *)&sc->gs);
282 __asm__("movl %%fs,%0" : "=r"(tmp): "0"(tmp));
283 err |= __put_user(tmp, (unsigned int *)&sc->fs);
285 err |= __put_user(regs->xes, (unsigned int *)&sc->es);
286 err |= __put_user(regs->xds, (unsigned int *)&sc->ds);
287 err |= __put_user(regs->edi, &sc->edi);
288 err |= __put_user(regs->esi, &sc->esi);
289 err |= __put_user(regs->ebp, &sc->ebp);
290 err |= __put_user(regs->esp, &sc->esp);
291 err |= __put_user(regs->ebx, &sc->ebx);
292 err |= __put_user(regs->edx, &sc->edx);
293 err |= __put_user(regs->ecx, &sc->ecx);
294 err |= __put_user(regs->eax, &sc->eax);
295 err |= __put_user(current->thread.trap_no, &sc->trapno);
296 err |= __put_user(current->thread.error_code, &sc->err);
297 err |= __put_user(regs->eip, &sc->eip);
298 err |= __put_user(regs->xcs, (unsigned int *)&sc->cs);
299 err |= __put_user(regs->eflags, &sc->eflags);
300 err |= __put_user(regs->esp, &sc->esp_at_signal);
301 err |= __put_user(regs->xss, (unsigned int *)&sc->ss);
303 tmp = save_i387(fpstate);
307 err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate);
309 /* non-iBCS2 extensions.. */
310 err |= __put_user(mask, &sc->oldmask);
311 err |= __put_user(current->thread.cr2, &sc->cr2);
317 * Determine which stack to use..
319 static inline void __user *
320 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
324 /* Default to using normal stack */
327 /* This is the X/Open sanctioned signal stack switching. */
328 if (ka->sa.sa_flags & SA_ONSTACK) {
329 if (sas_ss_flags(esp) == 0)
330 esp = current->sas_ss_sp + current->sas_ss_size;
333 /* This is the legacy signal stack switching. */
334 else if ((regs->xss & 0xffff) != __USER_DS &&
335 !(ka->sa.sa_flags & SA_RESTORER) &&
336 ka->sa.sa_restorer) {
337 esp = (unsigned long) ka->sa.sa_restorer;
340 return (void __user *)((esp - frame_size) & -8ul);
343 /* These symbols are defined with the addresses in the vsyscall page.
344 See vsyscall-sigreturn.S. */
345 extern void __kernel_sigreturn, __kernel_rt_sigreturn;
347 static void setup_frame(int sig, struct k_sigaction *ka,
348 sigset_t *set, struct pt_regs * regs)
351 struct sigframe __user *frame;
354 frame = get_sigframe(ka, regs, sizeof(*frame));
356 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
359 err |= __put_user((current_thread_info()->exec_domain
360 && current_thread_info()->exec_domain->signal_invmap
362 ? current_thread_info()->exec_domain->signal_invmap[sig]
368 err |= setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]);
372 if (_NSIG_WORDS > 1) {
373 err |= __copy_to_user(&frame->extramask, &set->sig[1],
374 sizeof(frame->extramask));
379 restorer = &__kernel_sigreturn;
380 if (ka->sa.sa_flags & SA_RESTORER)
381 restorer = ka->sa.sa_restorer;
383 /* Set up to return from userspace. */
384 err |= __put_user(restorer, &frame->pretcode);
387 * This is popl %eax ; movl $,%eax ; int $0x80
389 * WE DO NOT USE IT ANY MORE! It's only left here for historical
390 * reasons and because gdb uses it as a signature to notice
391 * signal handler stack frames.
393 err |= __put_user(0xb858, (short *)(frame->retcode+0));
394 err |= __put_user(__NR_sigreturn, (int *)(frame->retcode+2));
395 err |= __put_user(0x80cd, (short *)(frame->retcode+6));
400 /* Set up registers for signal handler */
401 regs->esp = (unsigned long) frame;
402 regs->eip = (unsigned long) ka->sa.sa_handler;
405 regs->xds = __USER_DS;
406 regs->xes = __USER_DS;
407 regs->xss = __USER_DS;
408 regs->xcs = __USER_CS;
409 regs->eflags &= ~TF_MASK;
412 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
413 current->comm, current->pid, frame, regs->eip, frame->pretcode);
420 ka->sa.sa_handler = SIG_DFL;
421 force_sig(SIGSEGV, current);
424 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
425 sigset_t *set, struct pt_regs * regs)
428 struct rt_sigframe __user *frame;
431 frame = get_sigframe(ka, regs, sizeof(*frame));
433 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
436 err |= __put_user((current_thread_info()->exec_domain
437 && current_thread_info()->exec_domain->signal_invmap
439 ? current_thread_info()->exec_domain->signal_invmap[sig]
442 err |= __put_user(&frame->info, &frame->pinfo);
443 err |= __put_user(&frame->uc, &frame->puc);
444 err |= copy_siginfo_to_user(&frame->info, info);
448 /* Create the ucontext. */
449 err |= __put_user(0, &frame->uc.uc_flags);
450 err |= __put_user(0, &frame->uc.uc_link);
451 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
452 err |= __put_user(sas_ss_flags(regs->esp),
453 &frame->uc.uc_stack.ss_flags);
454 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
455 err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
457 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
461 /* Set up to return from userspace. */
462 restorer = &__kernel_rt_sigreturn;
463 if (ka->sa.sa_flags & SA_RESTORER)
464 restorer = ka->sa.sa_restorer;
465 err |= __put_user(restorer, &frame->pretcode);
468 * This is movl $,%eax ; int $0x80
470 * WE DO NOT USE IT ANY MORE! It's only left here for historical
471 * reasons and because gdb uses it as a signature to notice
472 * signal handler stack frames.
474 err |= __put_user(0xb8, (char *)(frame->retcode+0));
475 err |= __put_user(__NR_rt_sigreturn, (int *)(frame->retcode+1));
476 err |= __put_user(0x80cd, (short *)(frame->retcode+5));
481 /* Set up registers for signal handler */
482 regs->esp = (unsigned long) frame;
483 regs->eip = (unsigned long) ka->sa.sa_handler;
486 regs->xds = __USER_DS;
487 regs->xes = __USER_DS;
488 regs->xss = __USER_DS;
489 regs->xcs = __USER_CS;
490 regs->eflags &= ~TF_MASK;
493 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
494 current->comm, current->pid, frame, regs->eip, frame->pretcode);
501 ka->sa.sa_handler = SIG_DFL;
502 force_sig(SIGSEGV, current);
506 * OK, we're invoking a handler
510 handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
511 struct pt_regs * regs)
513 struct k_sigaction *ka = ¤t->sighand->action[sig-1];
515 /* Are we from a system call? */
516 if (regs->orig_eax >= 0) {
517 /* If so, check system call restarting.. */
519 case -ERESTART_RESTARTBLOCK:
520 case -ERESTARTNOHAND:
525 if (!(ka->sa.sa_flags & SA_RESTART)) {
530 case -ERESTARTNOINTR:
531 regs->eax = regs->orig_eax;
536 /* Set up the stack frame */
537 if (ka->sa.sa_flags & SA_SIGINFO)
538 setup_rt_frame(sig, ka, info, oldset, regs);
540 setup_frame(sig, ka, oldset, regs);
542 if (ka->sa.sa_flags & SA_ONESHOT)
543 ka->sa.sa_handler = SIG_DFL;
545 if (!(ka->sa.sa_flags & SA_NODEFER)) {
546 spin_lock_irq(¤t->sighand->siglock);
547 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
548 sigaddset(¤t->blocked,sig);
550 spin_unlock_irq(¤t->sighand->siglock);
555 * Note that 'init' is a special process: it doesn't get signals it doesn't
556 * want to handle. Thus you cannot kill init even with a SIGKILL even by
559 int fastcall do_signal(struct pt_regs *regs, sigset_t *oldset)
565 * We want the common case to go fast, which
566 * is why we may in certain cases get here from
567 * kernel mode. Just return without doing anything
570 if ((regs->xcs & 3) != 3)
573 if (current->flags & PF_FREEZE) {
579 oldset = ¤t->blocked;
581 signr = get_signal_to_deliver(&info, regs, NULL);
583 /* Reenable any watchpoints before delivering the
584 * signal to user space. The processor register will
585 * have been cleared if the watchpoint triggered
588 __asm__("movl %0,%%db7" : : "r" (current->thread.debugreg[7]));
590 /* Whee! Actually deliver the signal. */
591 handle_signal(signr, &info, oldset, regs);
596 /* Did we come from a system call? */
597 if (regs->orig_eax >= 0) {
598 /* Restart the system call - no handlers present */
599 if (regs->eax == -ERESTARTNOHAND ||
600 regs->eax == -ERESTARTSYS ||
601 regs->eax == -ERESTARTNOINTR) {
602 regs->eax = regs->orig_eax;
605 if (regs->eax == -ERESTART_RESTARTBLOCK){
606 regs->eax = __NR_restart_syscall;
614 * notification of userspace execution resumption
615 * - triggered by current->work.notify_resume
617 __attribute__((regparm(3)))
618 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
619 __u32 thread_info_flags)
621 /* Pending single-step? */
622 if (thread_info_flags & _TIF_SINGLESTEP) {
623 regs->eflags |= TF_MASK;
624 clear_thread_flag(TIF_SINGLESTEP);
626 /* deal with pending signal delivery */
627 if (thread_info_flags & _TIF_SIGPENDING)
628 do_signal(regs,oldset);
630 clear_thread_flag(TIF_IRET);