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>
27 #include "sigframe_32.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)
40 spin_lock_irq(¤t->sighand->siglock);
41 current->saved_sigmask = current->blocked;
42 siginitset(¤t->blocked, mask);
44 spin_unlock_irq(¤t->sighand->siglock);
46 current->state = TASK_INTERRUPTIBLE;
48 set_thread_flag(TIF_RESTORE_SIGMASK);
49 return -ERESTARTNOHAND;
53 sys_sigaction(int sig, const struct old_sigaction __user *act,
54 struct old_sigaction __user *oact)
56 struct k_sigaction new_ka, old_ka;
61 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
62 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
63 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
65 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
66 __get_user(mask, &act->sa_mask);
67 siginitset(&new_ka.sa.sa_mask, mask);
70 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
73 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
74 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
75 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
77 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
78 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
85 sys_sigaltstack(unsigned long bx)
87 /* This is needed to make gcc realize it doesn't own the "struct pt_regs" */
88 struct pt_regs *regs = (struct pt_regs *)&bx;
89 const stack_t __user *uss = (const stack_t __user *)bx;
90 stack_t __user *uoss = (stack_t __user *)regs->cx;
92 return do_sigaltstack(uss, uoss, regs->sp);
97 * Do a signal return; undo the signal stack.
101 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax)
103 unsigned int err = 0;
105 /* Always make any pending restarted system calls return -EINTR */
106 current_thread_info()->restart_block.fn = do_no_restart_syscall;
108 #define COPY(x) err |= __get_user(regs->x, &sc->x)
110 #define COPY_SEG(seg) \
111 { unsigned short tmp; \
112 err |= __get_user(tmp, &sc->seg); \
115 #define COPY_SEG_STRICT(seg) \
116 { unsigned short tmp; \
117 err |= __get_user(tmp, &sc->seg); \
120 #define GET_SEG(seg) \
121 { unsigned short tmp; \
122 err |= __get_user(tmp, &sc->seg); \
123 loadsegment(seg,tmp); }
125 #define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_RF | \
126 X86_EFLAGS_OF | X86_EFLAGS_DF | \
127 X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \
128 X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF)
134 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
135 COPY(dx); COPY(cx); COPY(ip);
140 unsigned int tmpflags;
141 err |= __get_user(tmpflags, &sc->flags);
142 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
143 regs->orig_ax = -1; /* disable syscall checks */
147 struct _fpstate __user * buf;
148 err |= __get_user(buf, &sc->fpstate);
150 if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
152 err |= restore_i387(buf);
154 struct task_struct *me = current;
162 err |= __get_user(*peax, &sc->ax);
169 asmlinkage int sys_sigreturn(unsigned long __unused)
171 struct pt_regs *regs = (struct pt_regs *) &__unused;
172 struct sigframe __user *frame = (struct sigframe __user *)(regs->sp - 8);
176 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
178 if (__get_user(set.sig[0], &frame->sc.oldmask)
180 && __copy_from_user(&set.sig[1], &frame->extramask,
181 sizeof(frame->extramask))))
184 sigdelsetmask(&set, ~_BLOCKABLE);
185 spin_lock_irq(¤t->sighand->siglock);
186 current->blocked = set;
188 spin_unlock_irq(¤t->sighand->siglock);
190 if (restore_sigcontext(regs, &frame->sc, &ax))
195 if (show_unhandled_signals && printk_ratelimit()) {
196 printk("%s%s[%d] bad frame in sigreturn frame:%p ip:%lx"
198 task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
199 current->comm, task_pid_nr(current), frame, regs->ip,
200 regs->sp, regs->orig_ax);
201 print_vma_addr(" in ", regs->ip);
205 force_sig(SIGSEGV, current);
209 asmlinkage int sys_rt_sigreturn(unsigned long __unused)
211 struct pt_regs *regs = (struct pt_regs *) &__unused;
212 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->sp - 4);
216 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
218 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
221 sigdelsetmask(&set, ~_BLOCKABLE);
222 spin_lock_irq(¤t->sighand->siglock);
223 current->blocked = set;
225 spin_unlock_irq(¤t->sighand->siglock);
227 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
230 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
236 force_sig(SIGSEGV, current);
241 * Set up a signal frame.
245 setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
246 struct pt_regs *regs, unsigned long mask)
250 err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
251 savesegment(gs, tmp);
252 err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
254 err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
255 err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
256 err |= __put_user(regs->di, &sc->di);
257 err |= __put_user(regs->si, &sc->si);
258 err |= __put_user(regs->bp, &sc->bp);
259 err |= __put_user(regs->sp, &sc->sp);
260 err |= __put_user(regs->bx, &sc->bx);
261 err |= __put_user(regs->dx, &sc->dx);
262 err |= __put_user(regs->cx, &sc->cx);
263 err |= __put_user(regs->ax, &sc->ax);
264 err |= __put_user(current->thread.trap_no, &sc->trapno);
265 err |= __put_user(current->thread.error_code, &sc->err);
266 err |= __put_user(regs->ip, &sc->ip);
267 err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
268 err |= __put_user(regs->flags, &sc->flags);
269 err |= __put_user(regs->sp, &sc->sp_at_signal);
270 err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
272 tmp = save_i387(fpstate);
276 err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate);
278 /* non-iBCS2 extensions.. */
279 err |= __put_user(mask, &sc->oldmask);
280 err |= __put_user(current->thread.cr2, &sc->cr2);
286 * Determine which stack to use..
288 static inline void __user *
289 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
293 /* Default to using normal stack */
297 * If we are on the alternate signal stack and would overflow it, don't.
298 * Return an always-bogus address instead so we will die with SIGSEGV.
300 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
301 return (void __user *) -1L;
303 /* This is the X/Open sanctioned signal stack switching. */
304 if (ka->sa.sa_flags & SA_ONSTACK) {
305 if (sas_ss_flags(sp) == 0)
306 sp = current->sas_ss_sp + current->sas_ss_size;
309 /* This is the legacy signal stack switching. */
310 else if ((regs->ss & 0xffff) != __USER_DS &&
311 !(ka->sa.sa_flags & SA_RESTORER) &&
312 ka->sa.sa_restorer) {
313 sp = (unsigned long) ka->sa.sa_restorer;
317 /* Align the stack pointer according to the i386 ABI,
318 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
319 sp = ((sp + 4) & -16ul) - 4;
320 return (void __user *) sp;
323 /* These symbols are defined with the addresses in the vsyscall page.
324 See vsyscall-sigreturn.S. */
325 extern void __user __kernel_sigreturn;
326 extern void __user __kernel_rt_sigreturn;
328 static int setup_frame(int sig, struct k_sigaction *ka,
329 sigset_t *set, struct pt_regs * regs)
331 void __user *restorer;
332 struct sigframe __user *frame;
336 frame = get_sigframe(ka, regs, sizeof(*frame));
338 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
341 usig = current_thread_info()->exec_domain
342 && current_thread_info()->exec_domain->signal_invmap
344 ? current_thread_info()->exec_domain->signal_invmap[sig]
347 err = __put_user(usig, &frame->sig);
351 err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]);
355 if (_NSIG_WORDS > 1) {
356 err = __copy_to_user(&frame->extramask, &set->sig[1],
357 sizeof(frame->extramask));
362 if (current->mm->context.vdso)
363 restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
365 restorer = &frame->retcode;
366 if (ka->sa.sa_flags & SA_RESTORER)
367 restorer = ka->sa.sa_restorer;
369 /* Set up to return from userspace. */
370 err |= __put_user(restorer, &frame->pretcode);
373 * This is popl %eax ; movl $,%eax ; int $0x80
375 * WE DO NOT USE IT ANY MORE! It's only left here for historical
376 * reasons and because gdb uses it as a signature to notice
377 * signal handler stack frames.
379 err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
380 err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
381 err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
386 /* Set up registers for signal handler */
387 regs->sp = (unsigned long) frame;
388 regs->ip = (unsigned long) ka->sa.sa_handler;
389 regs->ax = (unsigned long) sig;
393 regs->ds = __USER_DS;
394 regs->es = __USER_DS;
395 regs->ss = __USER_DS;
396 regs->cs = __USER_CS;
399 * Clear TF when entering the signal handler, but
400 * notify any tracer that was single-stepping it.
401 * The tracer may want to single-step inside the
404 regs->flags &= ~(TF_MASK | X86_EFLAGS_DF);
405 if (test_thread_flag(TIF_SINGLESTEP))
406 ptrace_notify(SIGTRAP);
409 printk("SIG deliver (%s:%d): sp=%p pc=%lx ra=%p\n",
410 current->comm, current->pid, frame, regs->ip, frame->pretcode);
416 force_sigsegv(sig, current);
420 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
421 sigset_t *set, struct pt_regs * regs)
423 void __user *restorer;
424 struct rt_sigframe __user *frame;
428 frame = get_sigframe(ka, regs, sizeof(*frame));
430 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
433 usig = current_thread_info()->exec_domain
434 && current_thread_info()->exec_domain->signal_invmap
436 ? current_thread_info()->exec_domain->signal_invmap[sig]
439 err |= __put_user(usig, &frame->sig);
440 err |= __put_user(&frame->info, &frame->pinfo);
441 err |= __put_user(&frame->uc, &frame->puc);
442 err |= copy_siginfo_to_user(&frame->info, info);
446 /* Create the ucontext. */
447 err |= __put_user(0, &frame->uc.uc_flags);
448 err |= __put_user(0, &frame->uc.uc_link);
449 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
450 err |= __put_user(sas_ss_flags(regs->sp),
451 &frame->uc.uc_stack.ss_flags);
452 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
453 err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
455 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
459 /* Set up to return from userspace. */
460 restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
461 if (ka->sa.sa_flags & SA_RESTORER)
462 restorer = ka->sa.sa_restorer;
463 err |= __put_user(restorer, &frame->pretcode);
466 * This is movl $,%ax ; int $0x80
468 * WE DO NOT USE IT ANY MORE! It's only left here for historical
469 * reasons and because gdb uses it as a signature to notice
470 * signal handler stack frames.
472 err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
473 err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
474 err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
479 /* Set up registers for signal handler */
480 regs->sp = (unsigned long) frame;
481 regs->ip = (unsigned long) ka->sa.sa_handler;
482 regs->ax = (unsigned long) usig;
483 regs->dx = (unsigned long) &frame->info;
484 regs->cx = (unsigned long) &frame->uc;
486 regs->ds = __USER_DS;
487 regs->es = __USER_DS;
488 regs->ss = __USER_DS;
489 regs->cs = __USER_CS;
492 * Clear TF when entering the signal handler, but
493 * notify any tracer that was single-stepping it.
494 * The tracer may want to single-step inside the
497 regs->flags &= ~(TF_MASK | X86_EFLAGS_DF);
498 if (test_thread_flag(TIF_SINGLESTEP))
499 ptrace_notify(SIGTRAP);
502 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
503 current->comm, current->pid, frame, regs->ip, frame->pretcode);
509 force_sigsegv(sig, current);
514 * OK, we're invoking a handler
518 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
519 sigset_t *oldset, struct pt_regs *regs)
523 /* Are we from a system call? */
524 if ((long)regs->orig_ax >= 0) {
525 /* If so, check system call restarting.. */
527 case -ERESTART_RESTARTBLOCK:
528 case -ERESTARTNOHAND:
533 if (!(ka->sa.sa_flags & SA_RESTART)) {
538 case -ERESTARTNOINTR:
539 regs->ax = regs->orig_ax;
546 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
547 * flag so that register information in the sigcontext is correct.
549 if (unlikely(regs->flags & X86_EFLAGS_TF) &&
550 likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
551 regs->flags &= ~X86_EFLAGS_TF;
553 /* Set up the stack frame */
554 if (ka->sa.sa_flags & SA_SIGINFO)
555 ret = setup_rt_frame(sig, ka, info, oldset, regs);
557 ret = setup_frame(sig, ka, oldset, regs);
560 spin_lock_irq(¤t->sighand->siglock);
561 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
562 if (!(ka->sa.sa_flags & SA_NODEFER))
563 sigaddset(¤t->blocked,sig);
565 spin_unlock_irq(¤t->sighand->siglock);
572 * Note that 'init' is a special process: it doesn't get signals it doesn't
573 * want to handle. Thus you cannot kill init even with a SIGKILL even by
576 static void do_signal(struct pt_regs *regs)
578 struct k_sigaction ka;
584 * We want the common case to go fast, which is why we may in certain
585 * cases get here from kernel mode. Just return without doing anything
587 * X86_32: vm86 regs switched out by assembly code before reaching
588 * here, so testing against kernel CS suffices.
590 if (!user_mode(regs))
593 if (test_thread_flag(TIF_RESTORE_SIGMASK))
594 oldset = ¤t->saved_sigmask;
596 oldset = ¤t->blocked;
598 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
600 /* Re-enable any watchpoints before delivering the
601 * signal to user space. The processor register will
602 * have been cleared if the watchpoint triggered
605 if (current->thread.debugreg7)
606 set_debugreg(current->thread.debugreg7, 7);
608 /* Whee! Actually deliver the signal. */
609 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
610 /* a signal was successfully delivered; the saved
611 * sigmask will have been stored in the signal frame,
612 * and will be restored by sigreturn, so we can simply
613 * clear the TIF_RESTORE_SIGMASK flag */
614 if (test_thread_flag(TIF_RESTORE_SIGMASK))
615 clear_thread_flag(TIF_RESTORE_SIGMASK);
621 /* Did we come from a system call? */
622 if ((long)regs->orig_ax >= 0) {
623 /* Restart the system call - no handlers present */
625 case -ERESTARTNOHAND:
627 case -ERESTARTNOINTR:
628 regs->ax = regs->orig_ax;
632 case -ERESTART_RESTARTBLOCK:
633 regs->ax = __NR_restart_syscall;
640 * If there's no signal to deliver, we just put the saved sigmask
643 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
644 clear_thread_flag(TIF_RESTORE_SIGMASK);
645 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
650 * notification of userspace execution resumption
651 * - triggered by the TIF_WORK_MASK flags
653 void do_notify_resume(struct pt_regs *regs, void *unused,
654 __u32 thread_info_flags)
656 /* Pending single-step? */
657 if (thread_info_flags & _TIF_SINGLESTEP) {
658 regs->flags |= X86_EFLAGS_TF;
659 clear_thread_flag(TIF_SINGLESTEP);
662 /* deal with pending signal delivery */
663 if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
666 if (thread_info_flags & _TIF_HRTICK_RESCHED)
669 clear_thread_flag(TIF_IRET);