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/ptrace.h>
23 #include <linux/elf.h>
24 #include <asm/processor.h>
25 #include <asm/ucontext.h>
26 #include <asm/uaccess.h>
32 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
35 * Atomically swap in the new signal mask, and wait for a signal.
38 sys_sigsuspend(int history0, int history1, old_sigset_t mask)
40 struct pt_regs * regs = (struct pt_regs *) &history0;
44 spin_lock_irq(¤t->sighand->siglock);
45 saveset = current->blocked;
46 siginitset(¤t->blocked, mask);
48 spin_unlock_irq(¤t->sighand->siglock);
52 current->state = TASK_INTERRUPTIBLE;
54 if (do_signal(regs, &saveset))
60 sys_rt_sigsuspend(struct pt_regs regs)
62 sigset_t saveset, newset;
64 /* XXX: Don't preclude handling different sized sigset_t's. */
65 if (regs.ecx != sizeof(sigset_t))
68 if (copy_from_user(&newset, (sigset_t __user *)regs.ebx, 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(®s, &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(unsigned long ebx)
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;
127 return do_sigaltstack(uss, uoss, regs->esp);
132 * Do a signal return; undo the signal stack.
136 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax)
138 unsigned int err = 0;
140 /* Always make any pending restarted system calls return -EINTR */
141 current_thread_info()->restart_block.fn = do_no_restart_syscall;
143 #define COPY(x) err |= __get_user(regs->x, &sc->x)
145 #define COPY_SEG(seg) \
146 { unsigned short tmp; \
147 err |= __get_user(tmp, &sc->seg); \
148 regs->x##seg = tmp; }
150 #define COPY_SEG_STRICT(seg) \
151 { unsigned short tmp; \
152 err |= __get_user(tmp, &sc->seg); \
153 regs->x##seg = tmp|3; }
155 #define GET_SEG(seg) \
156 { unsigned short tmp; \
157 err |= __get_user(tmp, &sc->seg); \
158 loadsegment(seg,tmp); }
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)
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 */
187 struct _fpstate __user * buf;
188 err |= __get_user(buf, &sc->fpstate);
190 if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
192 err |= restore_i387(buf);
196 err |= __get_user(*peax, &sc->eax);
203 asmlinkage int sys_sigreturn(unsigned long __unused)
205 struct pt_regs *regs = (struct pt_regs *) &__unused;
206 struct sigframe __user *frame = (struct sigframe __user *)(regs->esp - 8);
210 if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
212 if (__get_user(set.sig[0], &frame->sc.oldmask)
214 && __copy_from_user(&set.sig[1], &frame->extramask,
215 sizeof(frame->extramask))))
218 sigdelsetmask(&set, ~_BLOCKABLE);
219 spin_lock_irq(¤t->sighand->siglock);
220 current->blocked = set;
222 spin_unlock_irq(¤t->sighand->siglock);
224 if (restore_sigcontext(regs, &frame->sc, &eax))
229 force_sig(SIGSEGV, current);
233 asmlinkage int sys_rt_sigreturn(unsigned long __unused)
235 struct pt_regs *regs = (struct pt_regs *) &__unused;
236 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->esp - 4);
240 if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
242 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
245 sigdelsetmask(&set, ~_BLOCKABLE);
246 spin_lock_irq(¤t->sighand->siglock);
247 current->blocked = set;
249 spin_unlock_irq(¤t->sighand->siglock);
251 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax))
254 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->esp) == -EFAULT)
260 force_sig(SIGSEGV, current);
265 * Set up a signal frame.
269 setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
270 struct pt_regs *regs, unsigned long mask)
273 unsigned long eflags;
276 __asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp));
277 err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
278 __asm__("movl %%fs,%0" : "=r"(tmp): "0"(tmp));
279 err |= __put_user(tmp, (unsigned int __user *)&sc->fs);
281 err |= __put_user(regs->xes, (unsigned int __user *)&sc->es);
282 err |= __put_user(regs->xds, (unsigned int __user *)&sc->ds);
283 err |= __put_user(regs->edi, &sc->edi);
284 err |= __put_user(regs->esi, &sc->esi);
285 err |= __put_user(regs->ebp, &sc->ebp);
286 err |= __put_user(regs->esp, &sc->esp);
287 err |= __put_user(regs->ebx, &sc->ebx);
288 err |= __put_user(regs->edx, &sc->edx);
289 err |= __put_user(regs->ecx, &sc->ecx);
290 err |= __put_user(regs->eax, &sc->eax);
291 err |= __put_user(current->thread.trap_no, &sc->trapno);
292 err |= __put_user(current->thread.error_code, &sc->err);
293 err |= __put_user(regs->eip, &sc->eip);
294 err |= __put_user(regs->xcs, (unsigned int __user *)&sc->cs);
295 eflags = regs->eflags;
296 if (current->ptrace & PT_PTRACED) {
299 err |= __put_user(eflags, &sc->eflags);
300 err |= __put_user(regs->esp, &sc->esp_at_signal);
301 err |= __put_user(regs->xss, (unsigned int __user *)&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 __user __kernel_sigreturn;
346 extern void __user __kernel_rt_sigreturn;
348 static void setup_frame(int sig, struct k_sigaction *ka,
349 sigset_t *set, struct pt_regs * regs)
351 void __user *restorer;
352 struct sigframe __user *frame;
356 frame = get_sigframe(ka, regs, sizeof(*frame));
358 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
361 usig = current_thread_info()->exec_domain
362 && current_thread_info()->exec_domain->signal_invmap
364 ? current_thread_info()->exec_domain->signal_invmap[sig]
367 err |= __put_user(usig, &frame->sig);
371 err |= setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]);
375 if (_NSIG_WORDS > 1) {
376 err |= __copy_to_user(&frame->extramask, &set->sig[1],
377 sizeof(frame->extramask));
382 restorer = &__kernel_sigreturn;
383 if (ka->sa.sa_flags & SA_RESTORER)
384 restorer = ka->sa.sa_restorer;
386 /* Set up to return from userspace. */
387 err |= __put_user(restorer, &frame->pretcode);
390 * This is popl %eax ; movl $,%eax ; int $0x80
392 * WE DO NOT USE IT ANY MORE! It's only left here for historical
393 * reasons and because gdb uses it as a signature to notice
394 * signal handler stack frames.
396 err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
397 err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
398 err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
403 /* Set up registers for signal handler */
404 regs->esp = (unsigned long) frame;
405 regs->eip = (unsigned long) ka->sa.sa_handler;
406 regs->eax = (unsigned long) sig;
407 regs->edx = (unsigned long) 0;
408 regs->ecx = (unsigned long) 0;
411 regs->xds = __USER_DS;
412 regs->xes = __USER_DS;
413 regs->xss = __USER_DS;
414 regs->xcs = __USER_CS;
415 if (regs->eflags & TF_MASK) {
416 if (current->ptrace & PT_PTRACED) {
417 ptrace_notify(SIGTRAP);
419 regs->eflags &= ~TF_MASK;
424 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
425 current->comm, current->pid, frame, regs->eip, frame->pretcode);
431 force_sigsegv(sig, current);
434 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
435 sigset_t *set, struct pt_regs * regs)
437 void __user *restorer;
438 struct rt_sigframe __user *frame;
442 frame = get_sigframe(ka, regs, sizeof(*frame));
444 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
447 usig = current_thread_info()->exec_domain
448 && current_thread_info()->exec_domain->signal_invmap
450 ? current_thread_info()->exec_domain->signal_invmap[sig]
453 err |= __put_user(usig, &frame->sig);
454 err |= __put_user(&frame->info, &frame->pinfo);
455 err |= __put_user(&frame->uc, &frame->puc);
456 err |= copy_siginfo_to_user(&frame->info, info);
460 /* Create the ucontext. */
461 err |= __put_user(0, &frame->uc.uc_flags);
462 err |= __put_user(0, &frame->uc.uc_link);
463 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
464 err |= __put_user(sas_ss_flags(regs->esp),
465 &frame->uc.uc_stack.ss_flags);
466 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
467 err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
469 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
473 /* Set up to return from userspace. */
474 restorer = &__kernel_rt_sigreturn;
475 if (ka->sa.sa_flags & SA_RESTORER)
476 restorer = ka->sa.sa_restorer;
477 err |= __put_user(restorer, &frame->pretcode);
480 * This is movl $,%eax ; int $0x80
482 * WE DO NOT USE IT ANY MORE! It's only left here for historical
483 * reasons and because gdb uses it as a signature to notice
484 * signal handler stack frames.
486 err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
487 err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
488 err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
493 /* Set up registers for signal handler */
494 regs->esp = (unsigned long) frame;
495 regs->eip = (unsigned long) ka->sa.sa_handler;
496 regs->eax = (unsigned long) usig;
497 regs->edx = (unsigned long) &frame->info;
498 regs->ecx = (unsigned long) &frame->uc;
501 regs->xds = __USER_DS;
502 regs->xes = __USER_DS;
503 regs->xss = __USER_DS;
504 regs->xcs = __USER_CS;
505 if (regs->eflags & TF_MASK) {
506 if (current->ptrace & PT_PTRACED) {
507 ptrace_notify(SIGTRAP);
509 regs->eflags &= ~TF_MASK;
514 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
515 current->comm, current->pid, frame, regs->eip, frame->pretcode);
521 force_sigsegv(sig, current);
525 * OK, we're invoking a handler
529 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
530 sigset_t *oldset, struct pt_regs * regs)
532 /* Are we from a system call? */
533 if (regs->orig_eax >= 0) {
534 /* If so, check system call restarting.. */
536 case -ERESTART_RESTARTBLOCK:
537 case -ERESTARTNOHAND:
542 if (!(ka->sa.sa_flags & SA_RESTART)) {
547 case -ERESTARTNOINTR:
548 regs->eax = regs->orig_eax;
553 /* Set up the stack frame */
554 if (ka->sa.sa_flags & SA_SIGINFO)
555 setup_rt_frame(sig, ka, info, oldset, regs);
557 setup_frame(sig, ka, oldset, regs);
559 if (!(ka->sa.sa_flags & SA_NODEFER)) {
560 spin_lock_irq(¤t->sighand->siglock);
561 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
562 sigaddset(¤t->blocked,sig);
564 spin_unlock_irq(¤t->sighand->siglock);
569 * Note that 'init' is a special process: it doesn't get signals it doesn't
570 * want to handle. Thus you cannot kill init even with a SIGKILL even by
573 int fastcall do_signal(struct pt_regs *regs, sigset_t *oldset)
577 struct k_sigaction ka;
580 * We want the common case to go fast, which
581 * is why we may in certain cases get here from
582 * kernel mode. Just return without doing anything
585 if ((regs->xcs & 3) != 3)
588 if (current->flags & PF_FREEZE) {
594 oldset = ¤t->blocked;
596 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
598 /* Reenable any watchpoints before delivering the
599 * signal to user space. The processor register will
600 * have been cleared if the watchpoint triggered
603 __asm__("movl %0,%%db7" : : "r" (current->thread.debugreg[7]));
605 /* Whee! Actually deliver the signal. */
606 handle_signal(signr, &info, &ka, oldset, regs);
611 /* Did we come from a system call? */
612 if (regs->orig_eax >= 0) {
613 /* Restart the system call - no handlers present */
614 if (regs->eax == -ERESTARTNOHAND ||
615 regs->eax == -ERESTARTSYS ||
616 regs->eax == -ERESTARTNOINTR) {
617 regs->eax = regs->orig_eax;
620 if (regs->eax == -ERESTART_RESTARTBLOCK){
621 regs->eax = __NR_restart_syscall;
629 * notification of userspace execution resumption
630 * - triggered by current->work.notify_resume
632 __attribute__((regparm(3)))
633 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
634 __u32 thread_info_flags)
636 /* Pending single-step? */
637 if (thread_info_flags & _TIF_SINGLESTEP) {
638 regs->eflags |= TF_MASK;
639 clear_thread_flag(TIF_SINGLESTEP);
641 /* deal with pending signal delivery */
642 if (thread_info_flags & _TIF_SIGPENDING)
643 do_signal(regs,oldset);
645 clear_thread_flag(TIF_IRET);