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
8 #include <linux/sched.h>
10 #include <linux/smp.h>
11 #include <linux/kernel.h>
12 #include <linux/signal.h>
13 #include <linux/errno.h>
14 #include <linux/wait.h>
15 #include <linux/unistd.h>
16 #include <linux/stddef.h>
17 #include <linux/personality.h>
18 #include <linux/suspend.h>
19 #include <linux/ptrace.h>
20 #include <linux/elf.h>
21 #include <linux/binfmts.h>
22 #include <asm/processor.h>
23 #include <asm/ucontext.h>
24 #include <asm/uaccess.h>
26 #include "sigframe_32.h"
30 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
33 * Atomically swap in the new signal mask, and wait for a signal.
36 sys_sigsuspend(int history0, int history1, old_sigset_t mask)
39 spin_lock_irq(¤t->sighand->siglock);
40 current->saved_sigmask = current->blocked;
41 siginitset(¤t->blocked, mask);
43 spin_unlock_irq(¤t->sighand->siglock);
45 current->state = TASK_INTERRUPTIBLE;
47 set_thread_flag(TIF_RESTORE_SIGMASK);
48 return -ERESTARTNOHAND;
52 sys_sigaction(int sig, const struct old_sigaction __user *act,
53 struct old_sigaction __user *oact)
55 struct k_sigaction new_ka, old_ka;
60 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
61 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
62 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
64 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
65 __get_user(mask, &act->sa_mask);
66 siginitset(&new_ka.sa.sa_mask, mask);
69 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
72 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
73 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
74 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
76 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
77 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
84 sys_sigaltstack(unsigned long ebx)
86 /* This is needed to make gcc realize it doesn't own the "struct pt_regs" */
87 struct pt_regs *regs = (struct pt_regs *)&ebx;
88 const stack_t __user *uss = (const stack_t __user *)ebx;
89 stack_t __user *uoss = (stack_t __user *)regs->ecx;
91 return do_sigaltstack(uss, uoss, regs->esp);
96 * Do a signal return; undo the signal stack.
100 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax)
102 unsigned int err = 0;
104 /* Always make any pending restarted system calls return -EINTR */
105 current_thread_info()->restart_block.fn = do_no_restart_syscall;
107 #define COPY(x) err |= __get_user(regs->x, &sc->x)
109 #define COPY_SEG(seg) \
110 { unsigned short tmp; \
111 err |= __get_user(tmp, &sc->seg); \
112 regs->x##seg = tmp; }
114 #define COPY_SEG_STRICT(seg) \
115 { unsigned short tmp; \
116 err |= __get_user(tmp, &sc->seg); \
117 regs->x##seg = tmp|3; }
119 #define GET_SEG(seg) \
120 { unsigned short tmp; \
121 err |= __get_user(tmp, &sc->seg); \
122 loadsegment(seg,tmp); }
124 #define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_RF | \
125 X86_EFLAGS_OF | X86_EFLAGS_DF | \
126 X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \
127 X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF)
145 unsigned int tmpflags;
146 err |= __get_user(tmpflags, &sc->eflags);
147 regs->eflags = (regs->eflags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
148 regs->orig_eax = -1; /* disable syscall checks */
152 struct _fpstate __user * buf;
153 err |= __get_user(buf, &sc->fpstate);
155 if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
157 err |= restore_i387(buf);
159 struct task_struct *me = current;
167 err |= __get_user(*peax, &sc->eax);
174 asmlinkage int sys_sigreturn(unsigned long __unused)
176 struct pt_regs *regs = (struct pt_regs *) &__unused;
177 struct sigframe __user *frame = (struct sigframe __user *)(regs->esp - 8);
181 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
183 if (__get_user(set.sig[0], &frame->sc.oldmask)
185 && __copy_from_user(&set.sig[1], &frame->extramask,
186 sizeof(frame->extramask))))
189 sigdelsetmask(&set, ~_BLOCKABLE);
190 spin_lock_irq(¤t->sighand->siglock);
191 current->blocked = set;
193 spin_unlock_irq(¤t->sighand->siglock);
195 if (restore_sigcontext(regs, &frame->sc, &eax))
200 if (show_unhandled_signals && printk_ratelimit())
201 printk("%s%s[%d] bad frame in sigreturn frame:%p eip:%lx"
202 " esp:%lx oeax:%lx\n",
203 task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
204 current->comm, task_pid_nr(current), frame, regs->eip,
205 regs->esp, regs->orig_eax);
207 force_sig(SIGSEGV, current);
211 asmlinkage int sys_rt_sigreturn(unsigned long __unused)
213 struct pt_regs *regs = (struct pt_regs *) &__unused;
214 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->esp - 4);
218 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
220 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
223 sigdelsetmask(&set, ~_BLOCKABLE);
224 spin_lock_irq(¤t->sighand->siglock);
225 current->blocked = set;
227 spin_unlock_irq(¤t->sighand->siglock);
229 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax))
232 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->esp) == -EFAULT)
238 force_sig(SIGSEGV, current);
243 * Set up a signal frame.
247 setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
248 struct pt_regs *regs, unsigned long mask)
252 err |= __put_user(regs->xfs, (unsigned int __user *)&sc->fs);
253 savesegment(gs, tmp);
254 err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
256 err |= __put_user(regs->xes, (unsigned int __user *)&sc->es);
257 err |= __put_user(regs->xds, (unsigned int __user *)&sc->ds);
258 err |= __put_user(regs->edi, &sc->edi);
259 err |= __put_user(regs->esi, &sc->esi);
260 err |= __put_user(regs->ebp, &sc->ebp);
261 err |= __put_user(regs->esp, &sc->esp);
262 err |= __put_user(regs->ebx, &sc->ebx);
263 err |= __put_user(regs->edx, &sc->edx);
264 err |= __put_user(regs->ecx, &sc->ecx);
265 err |= __put_user(regs->eax, &sc->eax);
266 err |= __put_user(current->thread.trap_no, &sc->trapno);
267 err |= __put_user(current->thread.error_code, &sc->err);
268 err |= __put_user(regs->eip, &sc->eip);
269 err |= __put_user(regs->xcs, (unsigned int __user *)&sc->cs);
270 err |= __put_user(regs->eflags, &sc->eflags);
271 err |= __put_user(regs->esp, &sc->esp_at_signal);
272 err |= __put_user(regs->xss, (unsigned int __user *)&sc->ss);
274 tmp = save_i387(fpstate);
278 err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate);
280 /* non-iBCS2 extensions.. */
281 err |= __put_user(mask, &sc->oldmask);
282 err |= __put_user(current->thread.cr2, &sc->cr2);
288 * Determine which stack to use..
290 static inline void __user *
291 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
295 /* Default to using normal stack */
299 * If we are on the alternate signal stack and would overflow it, don't.
300 * Return an always-bogus address instead so we will die with SIGSEGV.
302 if (on_sig_stack(esp) && !likely(on_sig_stack(esp - frame_size)))
303 return (void __user *) -1L;
305 /* This is the X/Open sanctioned signal stack switching. */
306 if (ka->sa.sa_flags & SA_ONSTACK) {
307 if (sas_ss_flags(esp) == 0)
308 esp = current->sas_ss_sp + current->sas_ss_size;
311 /* This is the legacy signal stack switching. */
312 else if ((regs->xss & 0xffff) != __USER_DS &&
313 !(ka->sa.sa_flags & SA_RESTORER) &&
314 ka->sa.sa_restorer) {
315 esp = (unsigned long) ka->sa.sa_restorer;
319 /* Align the stack pointer according to the i386 ABI,
320 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
321 esp = ((esp + 4) & -16ul) - 4;
322 return (void __user *) esp;
325 /* These symbols are defined with the addresses in the vsyscall page.
326 See vsyscall-sigreturn.S. */
327 extern void __user __kernel_sigreturn;
328 extern void __user __kernel_rt_sigreturn;
330 static int setup_frame(int sig, struct k_sigaction *ka,
331 sigset_t *set, struct pt_regs * regs)
333 void __user *restorer;
334 struct sigframe __user *frame;
338 frame = get_sigframe(ka, regs, sizeof(*frame));
340 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
343 usig = current_thread_info()->exec_domain
344 && current_thread_info()->exec_domain->signal_invmap
346 ? current_thread_info()->exec_domain->signal_invmap[sig]
349 err = __put_user(usig, &frame->sig);
353 err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]);
357 if (_NSIG_WORDS > 1) {
358 err = __copy_to_user(&frame->extramask, &set->sig[1],
359 sizeof(frame->extramask));
364 if (current->binfmt->hasvdso)
365 restorer = (void *)VDSO_SYM(&__kernel_sigreturn);
367 restorer = (void *)&frame->retcode;
368 if (ka->sa.sa_flags & SA_RESTORER)
369 restorer = ka->sa.sa_restorer;
371 /* Set up to return from userspace. */
372 err |= __put_user(restorer, &frame->pretcode);
375 * This is popl %eax ; movl $,%eax ; int $0x80
377 * WE DO NOT USE IT ANY MORE! It's only left here for historical
378 * reasons and because gdb uses it as a signature to notice
379 * signal handler stack frames.
381 err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
382 err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
383 err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
388 /* Set up registers for signal handler */
389 regs->esp = (unsigned long) frame;
390 regs->eip = (unsigned long) ka->sa.sa_handler;
391 regs->eax = (unsigned long) sig;
392 regs->edx = (unsigned long) 0;
393 regs->ecx = (unsigned long) 0;
395 regs->xds = __USER_DS;
396 regs->xes = __USER_DS;
397 regs->xss = __USER_DS;
398 regs->xcs = __USER_CS;
401 * Clear TF when entering the signal handler, but
402 * notify any tracer that was single-stepping it.
403 * The tracer may want to single-step inside the
406 regs->eflags &= ~TF_MASK;
407 if (test_thread_flag(TIF_SINGLESTEP))
408 ptrace_notify(SIGTRAP);
411 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
412 current->comm, current->pid, frame, regs->eip, frame->pretcode);
418 force_sigsegv(sig, current);
422 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
423 sigset_t *set, struct pt_regs * regs)
425 void __user *restorer;
426 struct rt_sigframe __user *frame;
430 frame = get_sigframe(ka, regs, sizeof(*frame));
432 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
435 usig = current_thread_info()->exec_domain
436 && current_thread_info()->exec_domain->signal_invmap
438 ? current_thread_info()->exec_domain->signal_invmap[sig]
441 err |= __put_user(usig, &frame->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 = (void *)VDSO_SYM(&__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 __user *)(frame->retcode+0));
475 err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
476 err |= __put_user(0x80cd, (short __user *)(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;
484 regs->eax = (unsigned long) usig;
485 regs->edx = (unsigned long) &frame->info;
486 regs->ecx = (unsigned long) &frame->uc;
488 regs->xds = __USER_DS;
489 regs->xes = __USER_DS;
490 regs->xss = __USER_DS;
491 regs->xcs = __USER_CS;
494 * Clear TF when entering the signal handler, but
495 * notify any tracer that was single-stepping it.
496 * The tracer may want to single-step inside the
499 regs->eflags &= ~TF_MASK;
500 if (test_thread_flag(TIF_SINGLESTEP))
501 ptrace_notify(SIGTRAP);
504 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
505 current->comm, current->pid, frame, regs->eip, frame->pretcode);
511 force_sigsegv(sig, current);
516 * OK, we're invoking a handler
520 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
521 sigset_t *oldset, struct pt_regs * regs)
525 /* Are we from a system call? */
526 if (regs->orig_eax >= 0) {
527 /* If so, check system call restarting.. */
529 case -ERESTART_RESTARTBLOCK:
530 case -ERESTARTNOHAND:
535 if (!(ka->sa.sa_flags & SA_RESTART)) {
540 case -ERESTARTNOINTR:
541 regs->eax = regs->orig_eax;
547 * If TF is set due to a debugger (PT_DTRACE), clear the TF flag so
548 * that register information in the sigcontext is correct.
550 if (unlikely(regs->eflags & TF_MASK)
551 && likely(current->ptrace & PT_DTRACE)) {
552 current->ptrace &= ~PT_DTRACE;
553 regs->eflags &= ~TF_MASK;
556 /* Set up the stack frame */
557 if (ka->sa.sa_flags & SA_SIGINFO)
558 ret = setup_rt_frame(sig, ka, info, oldset, regs);
560 ret = setup_frame(sig, ka, oldset, regs);
563 spin_lock_irq(¤t->sighand->siglock);
564 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
565 if (!(ka->sa.sa_flags & SA_NODEFER))
566 sigaddset(¤t->blocked,sig);
568 spin_unlock_irq(¤t->sighand->siglock);
575 * Note that 'init' is a special process: it doesn't get signals it doesn't
576 * want to handle. Thus you cannot kill init even with a SIGKILL even by
579 static void fastcall do_signal(struct pt_regs *regs)
583 struct k_sigaction ka;
587 * We want the common case to go fast, which
588 * is why we may in certain cases get here from
589 * kernel mode. Just return without doing anything
590 * if so. vm86 regs switched out by assembly code
591 * before reaching here, so testing against kernel
594 if (!user_mode(regs))
597 if (test_thread_flag(TIF_RESTORE_SIGMASK))
598 oldset = ¤t->saved_sigmask;
600 oldset = ¤t->blocked;
602 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
604 /* Re-enable any watchpoints before delivering the
605 * signal to user space. The processor register will
606 * have been cleared if the watchpoint triggered
609 if (unlikely(current->thread.debugreg[7]))
610 set_debugreg(current->thread.debugreg[7], 7);
612 /* Whee! Actually deliver the signal. */
613 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
614 /* a signal was successfully delivered; the saved
615 * sigmask will have been stored in the signal frame,
616 * and will be restored by sigreturn, so we can simply
617 * clear the TIF_RESTORE_SIGMASK flag */
618 if (test_thread_flag(TIF_RESTORE_SIGMASK))
619 clear_thread_flag(TIF_RESTORE_SIGMASK);
625 /* Did we come from a system call? */
626 if (regs->orig_eax >= 0) {
627 /* Restart the system call - no handlers present */
629 case -ERESTARTNOHAND:
631 case -ERESTARTNOINTR:
632 regs->eax = regs->orig_eax;
636 case -ERESTART_RESTARTBLOCK:
637 regs->eax = __NR_restart_syscall;
643 /* if there's no signal to deliver, we just put the saved sigmask
645 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
646 clear_thread_flag(TIF_RESTORE_SIGMASK);
647 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
652 * notification of userspace execution resumption
653 * - triggered by the TIF_WORK_MASK flags
655 __attribute__((regparm(3)))
656 void do_notify_resume(struct pt_regs *regs, void *_unused,
657 __u32 thread_info_flags)
659 /* Pending single-step? */
660 if (thread_info_flags & _TIF_SINGLESTEP) {
661 regs->eflags |= TF_MASK;
662 clear_thread_flag(TIF_SINGLESTEP);
665 /* deal with pending signal delivery */
666 if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
669 if (thread_info_flags & _TIF_HRTICK_RESCHED)
672 clear_thread_flag(TIF_IRET);