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
10 #include <linux/sched.h>
12 #include <linux/smp.h>
13 #include <linux/kernel.h>
14 #include <linux/signal.h>
15 #include <linux/errno.h>
16 #include <linux/wait.h>
17 #include <linux/ptrace.h>
18 #include <linux/tracehook.h>
19 #include <linux/unistd.h>
20 #include <linux/stddef.h>
21 #include <linux/personality.h>
22 #include <linux/uaccess.h>
24 #include <asm/processor.h>
25 #include <asm/ucontext.h>
30 #include <asm/proto.h>
31 #include <asm/ia32_unistd.h>
33 #endif /* CONFIG_X86_64 */
35 #include <asm/syscall.h>
36 #include <asm/syscalls.h>
40 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
42 #define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
43 X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
44 X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
48 # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
50 # define FIX_EFLAGS __FIX_EFLAGS
54 asmlinkage int sys_sigaltstack(unsigned long bx)
57 * This is needed to make gcc realize it doesn't own the
60 struct pt_regs *regs = (struct pt_regs *)&bx;
61 const stack_t __user *uss = (const stack_t __user *)bx;
62 stack_t __user *uoss = (stack_t __user *)regs->cx;
64 return do_sigaltstack(uss, uoss, regs->sp);
66 #else /* !CONFIG_X86_32 */
68 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
71 return do_sigaltstack(uss, uoss, regs->sp);
73 #endif /* CONFIG_X86_32 */
76 err |= __get_user(regs->x, &sc->x); \
79 #define COPY_SEG_CPL3(seg) { \
81 err |= __get_user(tmp, &sc->seg); \
82 regs->seg = tmp | 3; \
86 * Do a signal return; undo the signal stack.
89 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
93 unsigned int tmpflags;
96 /* Always make any pending restarted system calls return -EINTR */
97 current_thread_info()->restart_block.fn = do_no_restart_syscall;
104 #endif /* CONFIG_X86_32 */
106 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
107 COPY(dx); COPY(cx); COPY(ip);
118 #endif /* CONFIG_X86_64 */
123 #else /* !CONFIG_X86_32 */
124 /* Kernel saves and restores only the CS segment register on signals,
125 * which is the bare minimum needed to allow mixed 32/64-bit code.
126 * App's signal handler can save/restore other segments if needed. */
128 #endif /* CONFIG_X86_32 */
130 err |= __get_user(tmpflags, &sc->flags);
131 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
132 regs->orig_ax = -1; /* disable syscall checks */
134 err |= __get_user(buf, &sc->fpstate);
135 err |= restore_i387_xstate(buf);
137 err |= __get_user(*pax, &sc->ax);
141 static long do_rt_sigreturn(struct pt_regs *regs)
143 struct rt_sigframe __user *frame;
147 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
148 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
150 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
153 sigdelsetmask(&set, ~_BLOCKABLE);
154 spin_lock_irq(¤t->sighand->siglock);
155 current->blocked = set;
157 spin_unlock_irq(¤t->sighand->siglock);
159 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
162 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
168 signal_fault(regs, frame, "rt_sigreturn");
173 asmlinkage int sys_rt_sigreturn(unsigned long __unused)
175 struct pt_regs *regs = (struct pt_regs *)&__unused;
177 return do_rt_sigreturn(regs);
179 #else /* !CONFIG_X86_32 */
180 asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
182 return do_rt_sigreturn(regs);
184 #endif /* CONFIG_X86_32 */
187 * Set up a signal frame.
190 setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
191 struct pt_regs *regs, unsigned long mask)
199 savesegment(gs, tmp);
200 err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
202 err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
203 err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
204 err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
205 #endif /* CONFIG_X86_32 */
207 err |= __put_user(regs->di, &sc->di);
208 err |= __put_user(regs->si, &sc->si);
209 err |= __put_user(regs->bp, &sc->bp);
210 err |= __put_user(regs->sp, &sc->sp);
211 err |= __put_user(regs->bx, &sc->bx);
212 err |= __put_user(regs->dx, &sc->dx);
213 err |= __put_user(regs->cx, &sc->cx);
214 err |= __put_user(regs->ax, &sc->ax);
216 err |= __put_user(regs->r8, &sc->r8);
217 err |= __put_user(regs->r9, &sc->r9);
218 err |= __put_user(regs->r10, &sc->r10);
219 err |= __put_user(regs->r11, &sc->r11);
220 err |= __put_user(regs->r12, &sc->r12);
221 err |= __put_user(regs->r13, &sc->r13);
222 err |= __put_user(regs->r14, &sc->r14);
223 err |= __put_user(regs->r15, &sc->r15);
224 #endif /* CONFIG_X86_64 */
226 err |= __put_user(current->thread.trap_no, &sc->trapno);
227 err |= __put_user(current->thread.error_code, &sc->err);
228 err |= __put_user(regs->ip, &sc->ip);
230 err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
231 err |= __put_user(regs->flags, &sc->flags);
232 err |= __put_user(regs->sp, &sc->sp_at_signal);
233 err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
234 #else /* !CONFIG_X86_32 */
235 err |= __put_user(regs->flags, &sc->flags);
236 err |= __put_user(regs->cs, &sc->cs);
237 err |= __put_user(0, &sc->gs);
238 err |= __put_user(0, &sc->fs);
239 #endif /* CONFIG_X86_32 */
241 err |= __put_user(fpstate, &sc->fpstate);
243 /* non-iBCS2 extensions.. */
244 err |= __put_user(mask, &sc->oldmask);
245 err |= __put_user(current->thread.cr2, &sc->cr2);
251 * Determine which stack to use..
255 get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size)
257 /* Default to using normal stack - redzone*/
260 /* This is the X/Open sanctioned signal stack switching. */
261 if (ka->sa.sa_flags & SA_ONSTACK) {
262 if (sas_ss_flags(sp) == 0)
263 sp = current->sas_ss_sp + current->sas_ss_size;
266 return (void __user *)round_down(sp - size, 64);
269 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
270 sigset_t *set, struct pt_regs *regs)
272 struct rt_sigframe __user *frame;
273 void __user *fp = NULL;
275 struct task_struct *me = current;
278 fp = get_stack(ka, regs->sp, sig_xstate_size);
279 frame = (void __user *)round_down(
280 (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
282 if (save_i387_xstate(fp) < 0)
285 frame = get_stack(ka, regs->sp, sizeof(struct rt_sigframe)) - 8;
287 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
290 if (ka->sa.sa_flags & SA_SIGINFO) {
291 if (copy_siginfo_to_user(&frame->info, info))
295 /* Create the ucontext. */
297 err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
299 err |= __put_user(0, &frame->uc.uc_flags);
300 err |= __put_user(0, &frame->uc.uc_link);
301 err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
302 err |= __put_user(sas_ss_flags(regs->sp),
303 &frame->uc.uc_stack.ss_flags);
304 err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
305 err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
306 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
308 /* Set up to return from userspace. If provided, use a stub
309 already in userspace. */
310 /* x86-64 should always use SA_RESTORER. */
311 if (ka->sa.sa_flags & SA_RESTORER) {
312 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
314 /* could use a vstub here */
321 /* Set up registers for signal handler */
323 /* In case the signal handler was declared without prototypes */
326 /* This also works for non SA_SIGINFO handlers because they expect the
327 next argument after the signal number on the stack. */
328 regs->si = (unsigned long)&frame->info;
329 regs->dx = (unsigned long)&frame->uc;
330 regs->ip = (unsigned long) ka->sa.sa_handler;
332 regs->sp = (unsigned long)frame;
334 /* Set up the CS register to run signal handlers in 64-bit mode,
335 even if the handler happens to be interrupting 32-bit code. */
336 regs->cs = __USER_CS;
342 * OK, we're invoking a handler
344 static int signr_convert(int sig)
347 struct thread_info *info = current_thread_info();
349 if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
350 return info->exec_domain->signal_invmap[sig];
351 #endif /* CONFIG_X86_32 */
358 #define ia32_setup_frame __setup_frame
359 #define ia32_setup_rt_frame __setup_rt_frame
361 #else /* !CONFIG_X86_32 */
363 #ifdef CONFIG_IA32_EMULATION
364 #define is_ia32 test_thread_flag(TIF_IA32)
365 #else /* !CONFIG_IA32_EMULATION */
367 #endif /* CONFIG_IA32_EMULATION */
369 #endif /* CONFIG_X86_32 */
372 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
373 sigset_t *set, struct pt_regs *regs)
375 int usig = signr_convert(sig);
378 /* Set up the stack frame */
380 if (ka->sa.sa_flags & SA_SIGINFO)
381 ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
383 ret = ia32_setup_frame(usig, ka, set, regs);
385 ret = __setup_rt_frame(sig, ka, info, set, regs);
388 force_sigsegv(sig, current);
396 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
397 sigset_t *oldset, struct pt_regs *regs)
401 /* Are we from a system call? */
402 if (syscall_get_nr(current, regs) >= 0) {
403 /* If so, check system call restarting.. */
404 switch (syscall_get_error(current, regs)) {
405 case -ERESTART_RESTARTBLOCK:
406 case -ERESTARTNOHAND:
411 if (!(ka->sa.sa_flags & SA_RESTART)) {
416 case -ERESTARTNOINTR:
417 regs->ax = regs->orig_ax;
424 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
425 * flag so that register information in the sigcontext is correct.
427 if (unlikely(regs->flags & X86_EFLAGS_TF) &&
428 likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
429 regs->flags &= ~X86_EFLAGS_TF;
431 ret = setup_rt_frame(sig, ka, info, oldset, regs);
438 * This has nothing to do with segment registers,
439 * despite the name. This magic affects uaccess.h
440 * macros' behavior. Reset it to the normal setting.
446 * Clear the direction flag as per the ABI for function entry.
448 regs->flags &= ~X86_EFLAGS_DF;
451 * Clear TF when entering the signal handler, but
452 * notify any tracer that was single-stepping it.
453 * The tracer may want to single-step inside the
456 regs->flags &= ~X86_EFLAGS_TF;
458 spin_lock_irq(¤t->sighand->siglock);
459 sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask);
460 if (!(ka->sa.sa_flags & SA_NODEFER))
461 sigaddset(¤t->blocked, sig);
463 spin_unlock_irq(¤t->sighand->siglock);
465 tracehook_signal_handler(sig, info, ka, regs,
466 test_thread_flag(TIF_SINGLESTEP));
472 #define NR_restart_syscall __NR_restart_syscall
473 #else /* !CONFIG_X86_32 */
474 #define NR_restart_syscall \
475 test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
476 #endif /* CONFIG_X86_32 */
479 * Note that 'init' is a special process: it doesn't get signals it doesn't
480 * want to handle. Thus you cannot kill init even with a SIGKILL even by
483 static void do_signal(struct pt_regs *regs)
485 struct k_sigaction ka;
491 * We want the common case to go fast, which is why we may in certain
492 * cases get here from kernel mode. Just return without doing anything
494 * X86_32: vm86 regs switched out by assembly code before reaching
495 * here, so testing against kernel CS suffices.
497 if (!user_mode(regs))
500 if (current_thread_info()->status & TS_RESTORE_SIGMASK)
501 oldset = ¤t->saved_sigmask;
503 oldset = ¤t->blocked;
505 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
508 * Re-enable any watchpoints before delivering the
509 * signal to user space. The processor register will
510 * have been cleared if the watchpoint triggered
513 if (current->thread.debugreg7)
514 set_debugreg(current->thread.debugreg7, 7);
516 /* Whee! Actually deliver the signal. */
517 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
519 * A signal was successfully delivered; the saved
520 * sigmask will have been stored in the signal frame,
521 * and will be restored by sigreturn, so we can simply
522 * clear the TS_RESTORE_SIGMASK flag.
524 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
529 /* Did we come from a system call? */
530 if (syscall_get_nr(current, regs) >= 0) {
531 /* Restart the system call - no handlers present */
532 switch (syscall_get_error(current, regs)) {
533 case -ERESTARTNOHAND:
535 case -ERESTARTNOINTR:
536 regs->ax = regs->orig_ax;
540 case -ERESTART_RESTARTBLOCK:
541 regs->ax = NR_restart_syscall;
548 * If there's no signal to deliver, we just put the saved sigmask
551 if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
552 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
553 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
558 * notification of userspace execution resumption
559 * - triggered by the TIF_WORK_MASK flags
562 do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
564 #if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
565 /* notify userspace of pending MCEs */
566 if (thread_info_flags & _TIF_MCE_NOTIFY)
568 #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
570 /* deal with pending signal delivery */
571 if (thread_info_flags & _TIF_SIGPENDING)
574 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
575 clear_thread_flag(TIF_NOTIFY_RESUME);
576 tracehook_notify_resume(regs);
580 clear_thread_flag(TIF_IRET);
581 #endif /* CONFIG_X86_32 */
584 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
586 struct task_struct *me = current;
588 if (show_unhandled_signals && printk_ratelimit()) {
590 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
591 me->comm, me->pid, where, frame,
592 regs->ip, regs->sp, regs->orig_ax);
593 print_vma_addr(" in ", regs->ip);
594 printk(KERN_CONT "\n");
597 force_sig(SIGSEGV, me);