2 * Copyright (C) 1991, 1992 Linus Torvalds
4 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
5 * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
7 #include <linux/list.h>
9 #include <linux/personality.h>
10 #include <linux/binfmts.h>
11 #include <linux/suspend.h>
12 #include <linux/kernel.h>
13 #include <linux/ptrace.h>
14 #include <linux/signal.h>
15 #include <linux/stddef.h>
16 #include <linux/unistd.h>
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/wait.h>
20 #include <linux/tracehook.h>
21 #include <linux/elf.h>
22 #include <linux/smp.h>
25 #include <asm/processor.h>
26 #include <asm/ucontext.h>
27 #include <asm/uaccess.h>
30 #include <asm/syscall.h>
31 #include <asm/syscalls.h>
35 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
37 #define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
38 X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
39 X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
43 # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
45 # define FIX_EFLAGS __FIX_EFLAGS
49 * Atomically swap in the new signal mask, and wait for a signal.
52 sys_sigsuspend(int history0, int history1, old_sigset_t mask)
55 spin_lock_irq(¤t->sighand->siglock);
56 current->saved_sigmask = current->blocked;
57 siginitset(¤t->blocked, mask);
59 spin_unlock_irq(¤t->sighand->siglock);
61 current->state = TASK_INTERRUPTIBLE;
63 set_restore_sigmask();
65 return -ERESTARTNOHAND;
69 sys_sigaction(int sig, const struct old_sigaction __user *act,
70 struct old_sigaction __user *oact)
72 struct k_sigaction new_ka, old_ka;
78 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
79 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
80 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
83 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
84 __get_user(mask, &act->sa_mask);
85 siginitset(&new_ka.sa.sa_mask, mask);
88 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
91 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
92 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
93 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
96 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
97 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
103 asmlinkage int sys_sigaltstack(unsigned long bx)
106 * This is needed to make gcc realize it doesn't own the
109 struct pt_regs *regs = (struct pt_regs *)&bx;
110 const stack_t __user *uss = (const stack_t __user *)bx;
111 stack_t __user *uoss = (stack_t __user *)regs->cx;
113 return do_sigaltstack(uss, uoss, regs->sp);
118 * Do a signal return; undo the signal stack.
121 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
124 unsigned int err = 0;
126 /* Always make any pending restarted system calls return -EINTR */
127 current_thread_info()->restart_block.fn = do_no_restart_syscall;
129 #define COPY(x) err |= __get_user(regs->x, &sc->x)
131 #define COPY_SEG(seg) \
132 { unsigned short tmp; \
133 err |= __get_user(tmp, &sc->seg); \
136 #define COPY_SEG_STRICT(seg) \
137 { unsigned short tmp; \
138 err |= __get_user(tmp, &sc->seg); \
141 #define GET_SEG(seg) \
142 { unsigned short tmp; \
143 err |= __get_user(tmp, &sc->seg); \
144 loadsegment(seg, tmp); }
150 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
151 COPY(dx); COPY(cx); COPY(ip);
156 unsigned int tmpflags;
158 err |= __get_user(tmpflags, &sc->flags);
159 regs->flags = (regs->flags & ~FIX_EFLAGS) |
160 (tmpflags & FIX_EFLAGS);
161 regs->orig_ax = -1; /* disable syscall checks */
167 err |= __get_user(buf, &sc->fpstate);
168 err |= restore_i387_xstate(buf);
171 err |= __get_user(*pax, &sc->ax);
175 asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
177 struct sigframe __user *frame;
178 struct pt_regs *regs;
182 regs = (struct pt_regs *) &__unused;
183 frame = (struct sigframe __user *)(regs->sp - 8);
185 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
187 if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
188 && __copy_from_user(&set.sig[1], &frame->extramask,
189 sizeof(frame->extramask))))
192 sigdelsetmask(&set, ~_BLOCKABLE);
193 spin_lock_irq(¤t->sighand->siglock);
194 current->blocked = set;
196 spin_unlock_irq(¤t->sighand->siglock);
198 if (restore_sigcontext(regs, &frame->sc, &ax))
203 if (show_unhandled_signals && printk_ratelimit()) {
204 printk("%s%s[%d] bad frame in sigreturn frame:"
205 "%p ip:%lx sp:%lx oeax:%lx",
206 task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
207 current->comm, task_pid_nr(current), frame, regs->ip,
208 regs->sp, regs->orig_ax);
209 print_vma_addr(" in ", regs->ip);
210 printk(KERN_CONT "\n");
213 force_sig(SIGSEGV, current);
218 asmlinkage int sys_rt_sigreturn(unsigned long __unused)
220 struct pt_regs *regs = (struct pt_regs *)&__unused;
221 struct rt_sigframe __user *frame;
225 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
226 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
228 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
231 sigdelsetmask(&set, ~_BLOCKABLE);
232 spin_lock_irq(¤t->sighand->siglock);
233 current->blocked = set;
235 spin_unlock_irq(¤t->sighand->siglock);
237 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
240 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
246 signal_fault(regs, frame, "rt sigreturn");
251 * Set up a signal frame.
254 setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
255 struct pt_regs *regs, unsigned long mask)
259 err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
260 savesegment(gs, tmp);
261 err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
263 err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
264 err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
265 err |= __put_user(regs->di, &sc->di);
266 err |= __put_user(regs->si, &sc->si);
267 err |= __put_user(regs->bp, &sc->bp);
268 err |= __put_user(regs->sp, &sc->sp);
269 err |= __put_user(regs->bx, &sc->bx);
270 err |= __put_user(regs->dx, &sc->dx);
271 err |= __put_user(regs->cx, &sc->cx);
272 err |= __put_user(regs->ax, &sc->ax);
273 err |= __put_user(current->thread.trap_no, &sc->trapno);
274 err |= __put_user(current->thread.error_code, &sc->err);
275 err |= __put_user(regs->ip, &sc->ip);
276 err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
277 err |= __put_user(regs->flags, &sc->flags);
278 err |= __put_user(regs->sp, &sc->sp_at_signal);
279 err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
281 tmp = save_i387_xstate(fpstate);
285 err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate);
287 /* non-iBCS2 extensions.. */
288 err |= __put_user(mask, &sc->oldmask);
289 err |= __put_user(current->thread.cr2, &sc->cr2);
295 * Determine which stack to use..
297 static inline void __user *
298 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
303 /* Default to using normal stack */
307 * If we are on the alternate signal stack and would overflow it, don't.
308 * Return an always-bogus address instead so we will die with SIGSEGV.
310 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
311 return (void __user *) -1L;
313 /* This is the X/Open sanctioned signal stack switching. */
314 if (ka->sa.sa_flags & SA_ONSTACK) {
315 if (sas_ss_flags(sp) == 0)
316 sp = current->sas_ss_sp + current->sas_ss_size;
318 /* This is the legacy signal stack switching. */
319 if ((regs->ss & 0xffff) != __USER_DS &&
320 !(ka->sa.sa_flags & SA_RESTORER) &&
322 sp = (unsigned long) ka->sa.sa_restorer;
326 sp = sp - sig_xstate_size;
327 *fpstate = (struct _fpstate *) sp;
332 * Align the stack pointer according to the i386 ABI,
333 * i.e. so that on function entry ((sp + 4) & 15) == 0.
335 sp = ((sp + 4) & -16ul) - 4;
337 return (void __user *) sp;
341 __setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
342 struct pt_regs *regs)
344 struct sigframe __user *frame;
345 void __user *restorer;
347 void __user *fpstate = NULL;
349 frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
351 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
354 err = __put_user(sig, &frame->sig);
358 err = setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]);
362 if (_NSIG_WORDS > 1) {
363 err = __copy_to_user(&frame->extramask, &set->sig[1],
364 sizeof(frame->extramask));
369 if (current->mm->context.vdso)
370 restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
372 restorer = &frame->retcode;
373 if (ka->sa.sa_flags & SA_RESTORER)
374 restorer = ka->sa.sa_restorer;
376 /* Set up to return from userspace. */
377 err |= __put_user(restorer, &frame->pretcode);
380 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
382 * WE DO NOT USE IT ANY MORE! It's only left here for historical
383 * reasons and because gdb uses it as a signature to notice
384 * signal handler stack frames.
386 err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
387 err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
388 err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
393 /* Set up registers for signal handler */
394 regs->sp = (unsigned long)frame;
395 regs->ip = (unsigned long)ka->sa.sa_handler;
396 regs->ax = (unsigned long)sig;
400 regs->ds = __USER_DS;
401 regs->es = __USER_DS;
402 regs->ss = __USER_DS;
403 regs->cs = __USER_CS;
408 force_sigsegv(sig, current);
412 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
413 sigset_t *set, struct pt_regs *regs)
415 struct rt_sigframe __user *frame;
416 void __user *restorer;
418 void __user *fpstate = NULL;
420 frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
422 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
425 err |= __put_user(sig, &frame->sig);
426 err |= __put_user(&frame->info, &frame->pinfo);
427 err |= __put_user(&frame->uc, &frame->puc);
428 err |= copy_siginfo_to_user(&frame->info, info);
432 /* Create the ucontext. */
434 err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
436 err |= __put_user(0, &frame->uc.uc_flags);
437 err |= __put_user(0, &frame->uc.uc_link);
438 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
439 err |= __put_user(sas_ss_flags(regs->sp),
440 &frame->uc.uc_stack.ss_flags);
441 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
442 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
444 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
448 /* Set up to return from userspace. */
449 restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
450 if (ka->sa.sa_flags & SA_RESTORER)
451 restorer = ka->sa.sa_restorer;
452 err |= __put_user(restorer, &frame->pretcode);
455 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
457 * WE DO NOT USE IT ANY MORE! It's only left here for historical
458 * reasons and because gdb uses it as a signature to notice
459 * signal handler stack frames.
461 err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
462 err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
463 err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
468 /* Set up registers for signal handler */
469 regs->sp = (unsigned long)frame;
470 regs->ip = (unsigned long)ka->sa.sa_handler;
471 regs->ax = (unsigned long)sig;
472 regs->dx = (unsigned long)&frame->info;
473 regs->cx = (unsigned long)&frame->uc;
475 regs->ds = __USER_DS;
476 regs->es = __USER_DS;
477 regs->ss = __USER_DS;
478 regs->cs = __USER_CS;
483 force_sigsegv(sig, current);
488 * OK, we're invoking a handler:
491 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
492 sigset_t *set, struct pt_regs *regs)
497 usig = current_thread_info()->exec_domain
498 && current_thread_info()->exec_domain->signal_invmap
500 ? current_thread_info()->exec_domain->signal_invmap[sig]
503 /* Set up the stack frame */
504 if (ka->sa.sa_flags & SA_SIGINFO)
505 ret = __setup_rt_frame(usig, ka, info, set, regs);
507 ret = __setup_frame(usig, ka, set, regs);
513 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
514 sigset_t *oldset, struct pt_regs *regs)
518 /* Are we from a system call? */
519 if (syscall_get_nr(current, regs) >= 0) {
520 /* If so, check system call restarting.. */
521 switch (syscall_get_error(current, regs)) {
522 case -ERESTART_RESTARTBLOCK:
523 case -ERESTARTNOHAND:
528 if (!(ka->sa.sa_flags & SA_RESTART)) {
533 case -ERESTARTNOINTR:
534 regs->ax = regs->orig_ax;
541 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
542 * flag so that register information in the sigcontext is correct.
544 if (unlikely(regs->flags & X86_EFLAGS_TF) &&
545 likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
546 regs->flags &= ~X86_EFLAGS_TF;
548 ret = setup_rt_frame(sig, ka, info, oldset, regs);
554 * Clear the direction flag as per the ABI for function entry.
556 regs->flags &= ~X86_EFLAGS_DF;
559 * Clear TF when entering the signal handler, but
560 * notify any tracer that was single-stepping it.
561 * The tracer may want to single-step inside the
564 regs->flags &= ~X86_EFLAGS_TF;
566 spin_lock_irq(¤t->sighand->siglock);
567 sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask);
568 if (!(ka->sa.sa_flags & SA_NODEFER))
569 sigaddset(¤t->blocked, sig);
571 spin_unlock_irq(¤t->sighand->siglock);
573 tracehook_signal_handler(sig, info, ka, regs,
574 test_thread_flag(TIF_SINGLESTEP));
579 #define NR_restart_syscall __NR_restart_syscall
581 * Note that 'init' is a special process: it doesn't get signals it doesn't
582 * want to handle. Thus you cannot kill init even with a SIGKILL even by
585 static void do_signal(struct pt_regs *regs)
587 struct k_sigaction ka;
593 * We want the common case to go fast, which is why we may in certain
594 * cases get here from kernel mode. Just return without doing anything
596 * X86_32: vm86 regs switched out by assembly code before reaching
597 * here, so testing against kernel CS suffices.
599 if (!user_mode(regs))
602 if (current_thread_info()->status & TS_RESTORE_SIGMASK)
603 oldset = ¤t->saved_sigmask;
605 oldset = ¤t->blocked;
607 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
610 * Re-enable any watchpoints before delivering the
611 * signal to user space. The processor register will
612 * have been cleared if the watchpoint triggered
615 if (current->thread.debugreg7)
616 set_debugreg(current->thread.debugreg7, 7);
618 /* Whee! Actually deliver the signal. */
619 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
621 * A signal was successfully delivered; the saved
622 * sigmask will have been stored in the signal frame,
623 * and will be restored by sigreturn, so we can simply
624 * clear the TS_RESTORE_SIGMASK flag.
626 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
631 /* Did we come from a system call? */
632 if (syscall_get_nr(current, regs) >= 0) {
633 /* Restart the system call - no handlers present */
634 switch (syscall_get_error(current, regs)) {
635 case -ERESTARTNOHAND:
637 case -ERESTARTNOINTR:
638 regs->ax = regs->orig_ax;
642 case -ERESTART_RESTARTBLOCK:
643 regs->ax = NR_restart_syscall;
650 * If there's no signal to deliver, we just put the saved sigmask
653 if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
654 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
655 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
660 * notification of userspace execution resumption
661 * - triggered by the TIF_WORK_MASK flags
664 do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
666 /* deal with pending signal delivery */
667 if (thread_info_flags & _TIF_SIGPENDING)
670 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
671 clear_thread_flag(TIF_NOTIFY_RESUME);
672 tracehook_notify_resume(regs);
675 clear_thread_flag(TIF_IRET);
678 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
680 struct task_struct *me = current;
682 if (show_unhandled_signals && printk_ratelimit()) {
684 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
685 me->comm, me->pid, where, frame,
686 regs->ip, regs->sp, regs->orig_ax);
687 print_vma_addr(" in ", regs->ip);
688 printk(KERN_CONT "\n");
691 force_sig(SIGSEGV, me);