2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
5 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
6 * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
7 * 2000-2002 x86-64 support by Andi Kleen
9 #include <linux/sched.h>
11 #include <linux/smp.h>
12 #include <linux/kernel.h>
13 #include <linux/signal.h>
14 #include <linux/errno.h>
15 #include <linux/wait.h>
16 #include <linux/ptrace.h>
17 #include <linux/tracehook.h>
18 #include <linux/unistd.h>
19 #include <linux/stddef.h>
20 #include <linux/personality.h>
21 #include <linux/uaccess.h>
22 #include <linux/user-return-notifier.h>
24 #include <asm/processor.h>
25 #include <asm/ucontext.h>
27 #include <asm/fpu-internal.h>
32 #include <asm/proto.h>
33 #include <asm/ia32_unistd.h>
34 #endif /* CONFIG_X86_64 */
36 #include <asm/syscall.h>
37 #include <asm/syscalls.h>
39 #include <asm/sigframe.h>
41 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
43 #define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
44 X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
45 X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
49 # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
51 # define FIX_EFLAGS __FIX_EFLAGS
54 #define COPY(x) do { \
55 get_user_ex(regs->x, &sc->x); \
58 #define GET_SEG(seg) ({ \
60 get_user_ex(tmp, &sc->seg); \
64 #define COPY_SEG(seg) do { \
65 regs->seg = GET_SEG(seg); \
68 #define COPY_SEG_CPL3(seg) do { \
69 regs->seg = GET_SEG(seg) | 3; \
73 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
77 unsigned int tmpflags;
80 /* Always make any pending restarted system calls return -EINTR */
81 current_thread_info()->restart_block.fn = do_no_restart_syscall;
86 set_user_gs(regs, GET_SEG(gs));
90 #endif /* CONFIG_X86_32 */
92 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
93 COPY(dx); COPY(cx); COPY(ip);
104 #endif /* CONFIG_X86_64 */
109 #else /* !CONFIG_X86_32 */
110 /* Kernel saves and restores only the CS segment register on signals,
111 * which is the bare minimum needed to allow mixed 32/64-bit code.
112 * App's signal handler can save/restore other segments if needed. */
114 #endif /* CONFIG_X86_32 */
116 get_user_ex(tmpflags, &sc->flags);
117 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
118 regs->orig_ax = -1; /* disable syscall checks */
120 get_user_ex(buf, &sc->fpstate);
121 err |= restore_i387_xstate(buf);
123 get_user_ex(*pax, &sc->ax);
124 } get_user_catch(err);
130 setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
131 struct pt_regs *regs, unsigned long mask)
138 put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs);
139 put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
140 put_user_ex(regs->es, (unsigned int __user *)&sc->es);
141 put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
142 #endif /* CONFIG_X86_32 */
144 put_user_ex(regs->di, &sc->di);
145 put_user_ex(regs->si, &sc->si);
146 put_user_ex(regs->bp, &sc->bp);
147 put_user_ex(regs->sp, &sc->sp);
148 put_user_ex(regs->bx, &sc->bx);
149 put_user_ex(regs->dx, &sc->dx);
150 put_user_ex(regs->cx, &sc->cx);
151 put_user_ex(regs->ax, &sc->ax);
153 put_user_ex(regs->r8, &sc->r8);
154 put_user_ex(regs->r9, &sc->r9);
155 put_user_ex(regs->r10, &sc->r10);
156 put_user_ex(regs->r11, &sc->r11);
157 put_user_ex(regs->r12, &sc->r12);
158 put_user_ex(regs->r13, &sc->r13);
159 put_user_ex(regs->r14, &sc->r14);
160 put_user_ex(regs->r15, &sc->r15);
161 #endif /* CONFIG_X86_64 */
163 put_user_ex(current->thread.trap_no, &sc->trapno);
164 put_user_ex(current->thread.error_code, &sc->err);
165 put_user_ex(regs->ip, &sc->ip);
167 put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
168 put_user_ex(regs->flags, &sc->flags);
169 put_user_ex(regs->sp, &sc->sp_at_signal);
170 put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
171 #else /* !CONFIG_X86_32 */
172 put_user_ex(regs->flags, &sc->flags);
173 put_user_ex(regs->cs, &sc->cs);
174 put_user_ex(0, &sc->gs);
175 put_user_ex(0, &sc->fs);
176 #endif /* CONFIG_X86_32 */
178 put_user_ex(fpstate, &sc->fpstate);
180 /* non-iBCS2 extensions.. */
181 put_user_ex(mask, &sc->oldmask);
182 put_user_ex(current->thread.cr2, &sc->cr2);
183 } put_user_catch(err);
189 * Set up a signal frame.
193 * Determine which stack to use..
195 static unsigned long align_sigframe(unsigned long sp)
199 * Align the stack pointer according to the i386 ABI,
200 * i.e. so that on function entry ((sp + 4) & 15) == 0.
202 sp = ((sp + 4) & -16ul) - 4;
203 #else /* !CONFIG_X86_32 */
204 sp = round_down(sp, 16) - 8;
209 static inline void __user *
210 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
211 void __user **fpstate)
213 /* Default to using normal stack */
214 unsigned long sp = regs->sp;
215 int onsigstack = on_sig_stack(sp);
220 #endif /* CONFIG_X86_64 */
223 /* This is the X/Open sanctioned signal stack switching. */
224 if (ka->sa.sa_flags & SA_ONSTACK) {
225 if (current->sas_ss_size)
226 sp = current->sas_ss_sp + current->sas_ss_size;
229 /* This is the legacy signal stack switching. */
230 if ((regs->ss & 0xffff) != __USER_DS &&
231 !(ka->sa.sa_flags & SA_RESTORER) &&
233 sp = (unsigned long) ka->sa.sa_restorer;
234 #endif /* CONFIG_X86_32 */
239 sp -= sig_xstate_size;
241 sp = round_down(sp, 64);
242 #endif /* CONFIG_X86_64 */
243 *fpstate = (void __user *)sp;
246 sp = align_sigframe(sp - frame_size);
249 * If we are on the alternate signal stack and would overflow it, don't.
250 * Return an always-bogus address instead so we will die with SIGSEGV.
252 if (onsigstack && !likely(on_sig_stack(sp)))
253 return (void __user *)-1L;
255 /* save i387 state */
256 if (used_math() && save_i387_xstate(*fpstate) < 0)
257 return (void __user *)-1L;
259 return (void __user *)sp;
263 static const struct {
267 } __attribute__((packed)) retcode = {
268 0xb858, /* popl %eax; movl $..., %eax */
270 0x80cd, /* int $0x80 */
273 static const struct {
278 } __attribute__((packed)) rt_retcode = {
279 0xb8, /* movl $..., %eax */
281 0x80cd, /* int $0x80 */
286 __setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
287 struct pt_regs *regs)
289 struct sigframe __user *frame;
290 void __user *restorer;
292 void __user *fpstate = NULL;
294 frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
296 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
299 if (__put_user(sig, &frame->sig))
302 if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
305 if (_NSIG_WORDS > 1) {
306 if (__copy_to_user(&frame->extramask, &set->sig[1],
307 sizeof(frame->extramask)))
311 if (current->mm->context.vdso)
312 restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
314 restorer = &frame->retcode;
315 if (ka->sa.sa_flags & SA_RESTORER)
316 restorer = ka->sa.sa_restorer;
318 /* Set up to return from userspace. */
319 err |= __put_user(restorer, &frame->pretcode);
322 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
324 * WE DO NOT USE IT ANY MORE! It's only left here for historical
325 * reasons and because gdb uses it as a signature to notice
326 * signal handler stack frames.
328 err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
333 /* Set up registers for signal handler */
334 regs->sp = (unsigned long)frame;
335 regs->ip = (unsigned long)ka->sa.sa_handler;
336 regs->ax = (unsigned long)sig;
340 regs->ds = __USER_DS;
341 regs->es = __USER_DS;
342 regs->ss = __USER_DS;
343 regs->cs = __USER_CS;
348 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
349 sigset_t *set, struct pt_regs *regs)
351 struct rt_sigframe __user *frame;
352 void __user *restorer;
354 void __user *fpstate = NULL;
356 frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
358 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
362 put_user_ex(sig, &frame->sig);
363 put_user_ex(&frame->info, &frame->pinfo);
364 put_user_ex(&frame->uc, &frame->puc);
365 err |= copy_siginfo_to_user(&frame->info, info);
367 /* Create the ucontext. */
369 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
371 put_user_ex(0, &frame->uc.uc_flags);
372 put_user_ex(0, &frame->uc.uc_link);
373 put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
374 put_user_ex(sas_ss_flags(regs->sp),
375 &frame->uc.uc_stack.ss_flags);
376 put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
377 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
379 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
381 /* Set up to return from userspace. */
382 restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
383 if (ka->sa.sa_flags & SA_RESTORER)
384 restorer = ka->sa.sa_restorer;
385 put_user_ex(restorer, &frame->pretcode);
388 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
390 * WE DO NOT USE IT ANY MORE! It's only left here for historical
391 * reasons and because gdb uses it as a signature to notice
392 * signal handler stack frames.
394 put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
395 } put_user_catch(err);
400 /* Set up registers for signal handler */
401 regs->sp = (unsigned long)frame;
402 regs->ip = (unsigned long)ka->sa.sa_handler;
403 regs->ax = (unsigned long)sig;
404 regs->dx = (unsigned long)&frame->info;
405 regs->cx = (unsigned long)&frame->uc;
407 regs->ds = __USER_DS;
408 regs->es = __USER_DS;
409 regs->ss = __USER_DS;
410 regs->cs = __USER_CS;
414 #else /* !CONFIG_X86_32 */
415 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
416 sigset_t *set, struct pt_regs *regs)
418 struct rt_sigframe __user *frame;
419 void __user *fp = NULL;
421 struct task_struct *me = current;
423 frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
425 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
428 if (ka->sa.sa_flags & SA_SIGINFO) {
429 if (copy_siginfo_to_user(&frame->info, info))
434 /* Create the ucontext. */
436 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
438 put_user_ex(0, &frame->uc.uc_flags);
439 put_user_ex(0, &frame->uc.uc_link);
440 put_user_ex(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
441 put_user_ex(sas_ss_flags(regs->sp),
442 &frame->uc.uc_stack.ss_flags);
443 put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
444 err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
445 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
447 /* Set up to return from userspace. If provided, use a stub
448 already in userspace. */
449 /* x86-64 should always use SA_RESTORER. */
450 if (ka->sa.sa_flags & SA_RESTORER) {
451 put_user_ex(ka->sa.sa_restorer, &frame->pretcode);
453 /* could use a vstub here */
456 } put_user_catch(err);
461 /* Set up registers for signal handler */
463 /* In case the signal handler was declared without prototypes */
466 /* This also works for non SA_SIGINFO handlers because they expect the
467 next argument after the signal number on the stack. */
468 regs->si = (unsigned long)&frame->info;
469 regs->dx = (unsigned long)&frame->uc;
470 regs->ip = (unsigned long) ka->sa.sa_handler;
472 regs->sp = (unsigned long)frame;
474 /* Set up the CS register to run signal handlers in 64-bit mode,
475 even if the handler happens to be interrupting 32-bit code. */
476 regs->cs = __USER_CS;
480 #endif /* CONFIG_X86_32 */
484 * Atomically swap in the new signal mask, and wait for a signal.
487 sys_sigsuspend(int history0, int history1, old_sigset_t mask)
491 current->saved_sigmask = current->blocked;
494 siginitset(&blocked, mask);
495 set_current_blocked(&blocked);
497 current->state = TASK_INTERRUPTIBLE;
500 set_restore_sigmask();
501 return -ERESTARTNOHAND;
505 sys_sigaction(int sig, const struct old_sigaction __user *act,
506 struct old_sigaction __user *oact)
508 struct k_sigaction new_ka, old_ka;
514 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
518 get_user_ex(new_ka.sa.sa_handler, &act->sa_handler);
519 get_user_ex(new_ka.sa.sa_flags, &act->sa_flags);
520 get_user_ex(mask, &act->sa_mask);
521 get_user_ex(new_ka.sa.sa_restorer, &act->sa_restorer);
522 } get_user_catch(ret);
526 siginitset(&new_ka.sa.sa_mask, mask);
529 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
532 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
536 put_user_ex(old_ka.sa.sa_handler, &oact->sa_handler);
537 put_user_ex(old_ka.sa.sa_flags, &oact->sa_flags);
538 put_user_ex(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
539 put_user_ex(old_ka.sa.sa_restorer, &oact->sa_restorer);
540 } put_user_catch(ret);
548 #endif /* CONFIG_X86_32 */
551 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
552 struct pt_regs *regs)
554 return do_sigaltstack(uss, uoss, regs->sp);
558 * Do a signal return; undo the signal stack.
561 unsigned long sys_sigreturn(struct pt_regs *regs)
563 struct sigframe __user *frame;
567 frame = (struct sigframe __user *)(regs->sp - 8);
569 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
571 if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
572 && __copy_from_user(&set.sig[1], &frame->extramask,
573 sizeof(frame->extramask))))
576 sigdelsetmask(&set, ~_BLOCKABLE);
577 set_current_blocked(&set);
579 if (restore_sigcontext(regs, &frame->sc, &ax))
584 signal_fault(regs, frame, "sigreturn");
588 #endif /* CONFIG_X86_32 */
590 long sys_rt_sigreturn(struct pt_regs *regs)
592 struct rt_sigframe __user *frame;
596 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
597 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
599 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
602 sigdelsetmask(&set, ~_BLOCKABLE);
603 set_current_blocked(&set);
605 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
608 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
614 signal_fault(regs, frame, "rt_sigreturn");
619 * OK, we're invoking a handler:
621 static int signr_convert(int sig)
624 struct thread_info *info = current_thread_info();
626 if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
627 return info->exec_domain->signal_invmap[sig];
628 #endif /* CONFIG_X86_32 */
635 #define ia32_setup_frame __setup_frame
636 #define ia32_setup_rt_frame __setup_rt_frame
638 #else /* !CONFIG_X86_32 */
640 #ifdef CONFIG_IA32_EMULATION
641 #define is_ia32 test_thread_flag(TIF_IA32)
642 #else /* !CONFIG_IA32_EMULATION */
644 #endif /* CONFIG_IA32_EMULATION */
646 int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
647 sigset_t *set, struct pt_regs *regs);
648 int ia32_setup_frame(int sig, struct k_sigaction *ka,
649 sigset_t *set, struct pt_regs *regs);
651 #endif /* CONFIG_X86_32 */
654 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
655 struct pt_regs *regs)
657 int usig = signr_convert(sig);
658 sigset_t *set = ¤t->blocked;
661 if (current_thread_info()->status & TS_RESTORE_SIGMASK)
662 set = ¤t->saved_sigmask;
664 /* Set up the stack frame */
666 if (ka->sa.sa_flags & SA_SIGINFO)
667 ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
669 ret = ia32_setup_frame(usig, ka, set, regs);
671 ret = __setup_rt_frame(sig, ka, info, set, regs);
674 force_sigsegv(sig, current);
678 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
683 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
684 struct pt_regs *regs)
688 /* Are we from a system call? */
689 if (syscall_get_nr(current, regs) >= 0) {
690 /* If so, check system call restarting.. */
691 switch (syscall_get_error(current, regs)) {
692 case -ERESTART_RESTARTBLOCK:
693 case -ERESTARTNOHAND:
698 if (!(ka->sa.sa_flags & SA_RESTART)) {
703 case -ERESTARTNOINTR:
704 regs->ax = regs->orig_ax;
711 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
712 * flag so that register information in the sigcontext is correct.
714 if (unlikely(regs->flags & X86_EFLAGS_TF) &&
715 likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
716 regs->flags &= ~X86_EFLAGS_TF;
718 ret = setup_rt_frame(sig, ka, info, regs);
724 * Clear the direction flag as per the ABI for function entry.
726 regs->flags &= ~X86_EFLAGS_DF;
729 * Clear TF when entering the signal handler, but
730 * notify any tracer that was single-stepping it.
731 * The tracer may want to single-step inside the
734 regs->flags &= ~X86_EFLAGS_TF;
736 block_sigmask(ka, sig);
738 tracehook_signal_handler(sig, info, ka, regs,
739 test_thread_flag(TIF_SINGLESTEP));
745 #define NR_restart_syscall __NR_restart_syscall
746 #else /* !CONFIG_X86_32 */
747 #define NR_restart_syscall \
748 test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
749 #endif /* CONFIG_X86_32 */
752 * Note that 'init' is a special process: it doesn't get signals it doesn't
753 * want to handle. Thus you cannot kill init even with a SIGKILL even by
756 static void do_signal(struct pt_regs *regs)
758 struct k_sigaction ka;
763 * We want the common case to go fast, which is why we may in certain
764 * cases get here from kernel mode. Just return without doing anything
766 * X86_32: vm86 regs switched out by assembly code before reaching
767 * here, so testing against kernel CS suffices.
769 if (!user_mode(regs))
772 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
774 /* Whee! Actually deliver the signal. */
775 handle_signal(signr, &info, &ka, regs);
779 /* Did we come from a system call? */
780 if (syscall_get_nr(current, regs) >= 0) {
781 /* Restart the system call - no handlers present */
782 switch (syscall_get_error(current, regs)) {
783 case -ERESTARTNOHAND:
785 case -ERESTARTNOINTR:
786 regs->ax = regs->orig_ax;
790 case -ERESTART_RESTARTBLOCK:
791 regs->ax = NR_restart_syscall;
798 * If there's no signal to deliver, we just put the saved sigmask
801 if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
802 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
803 set_current_blocked(¤t->saved_sigmask);
808 * notification of userspace execution resumption
809 * - triggered by the TIF_WORK_MASK flags
812 do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
814 #ifdef CONFIG_X86_MCE
815 /* notify userspace of pending MCEs */
816 if (thread_info_flags & _TIF_MCE_NOTIFY)
817 mce_notify_process();
818 #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
820 /* deal with pending signal delivery */
821 if (thread_info_flags & _TIF_SIGPENDING)
824 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
825 clear_thread_flag(TIF_NOTIFY_RESUME);
826 tracehook_notify_resume(regs);
827 if (current->replacement_session_keyring)
828 key_replace_session_keyring();
830 if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
831 fire_user_return_notifiers();
834 clear_thread_flag(TIF_IRET);
835 #endif /* CONFIG_X86_32 */
838 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
840 struct task_struct *me = current;
842 if (show_unhandled_signals && printk_ratelimit()) {
844 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
845 task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
846 me->comm, me->pid, where, frame,
847 regs->ip, regs->sp, regs->orig_ax);
848 print_vma_addr(" in ", regs->ip);
849 printk(KERN_CONT "\n");
852 force_sig(SIGSEGV, me);