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/compiler.h>
23 #include <linux/uaccess.h>
25 #include <asm/processor.h>
26 #include <asm/ucontext.h>
28 #include <asm/proto.h>
29 #include <asm/ia32_unistd.h>
31 #include <asm/syscall.h>
32 #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 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
52 return do_sigaltstack(uss, uoss, regs->sp);
56 err |= __get_user(regs->x, &sc->x); \
59 #define COPY_SEG_STRICT(seg) { \
61 err |= __get_user(tmp, &sc->seg); \
62 regs->seg = tmp | 3; \
66 * Do a signal return; undo the signal stack.
69 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
73 unsigned int tmpflags;
76 /* Always make any pending restarted system calls return -EINTR */
77 current_thread_info()->restart_block.fn = do_no_restart_syscall;
84 #endif /* CONFIG_X86_32 */
86 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
87 COPY(dx); COPY(cx); COPY(ip);
98 #endif /* CONFIG_X86_64 */
103 #else /* !CONFIG_X86_32 */
104 /* Kernel saves and restores only the CS segment register on signals,
105 * which is the bare minimum needed to allow mixed 32/64-bit code.
106 * App's signal handler can save/restore other segments if needed. */
108 #endif /* CONFIG_X86_32 */
110 err |= __get_user(tmpflags, &sc->flags);
111 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
112 regs->orig_ax = -1; /* disable syscall checks */
114 err |= __get_user(buf, &sc->fpstate);
115 err |= restore_i387_xstate(buf);
117 err |= __get_user(*pax, &sc->ax);
121 static long do_rt_sigreturn(struct pt_regs *regs)
123 struct rt_sigframe __user *frame;
127 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
128 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
130 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
133 sigdelsetmask(&set, ~_BLOCKABLE);
134 spin_lock_irq(¤t->sighand->siglock);
135 current->blocked = set;
137 spin_unlock_irq(¤t->sighand->siglock);
139 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
142 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
148 signal_fault(regs, frame, "rt_sigreturn");
152 asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
154 return do_rt_sigreturn(regs);
158 * Set up a signal frame.
162 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
163 unsigned long mask, struct task_struct *me)
167 err |= __put_user(regs->cs, &sc->cs);
168 err |= __put_user(0, &sc->gs);
169 err |= __put_user(0, &sc->fs);
171 err |= __put_user(regs->di, &sc->di);
172 err |= __put_user(regs->si, &sc->si);
173 err |= __put_user(regs->bp, &sc->bp);
174 err |= __put_user(regs->sp, &sc->sp);
175 err |= __put_user(regs->bx, &sc->bx);
176 err |= __put_user(regs->dx, &sc->dx);
177 err |= __put_user(regs->cx, &sc->cx);
178 err |= __put_user(regs->ax, &sc->ax);
179 err |= __put_user(regs->r8, &sc->r8);
180 err |= __put_user(regs->r9, &sc->r9);
181 err |= __put_user(regs->r10, &sc->r10);
182 err |= __put_user(regs->r11, &sc->r11);
183 err |= __put_user(regs->r12, &sc->r12);
184 err |= __put_user(regs->r13, &sc->r13);
185 err |= __put_user(regs->r14, &sc->r14);
186 err |= __put_user(regs->r15, &sc->r15);
187 err |= __put_user(me->thread.trap_no, &sc->trapno);
188 err |= __put_user(me->thread.error_code, &sc->err);
189 err |= __put_user(regs->ip, &sc->ip);
190 err |= __put_user(regs->flags, &sc->flags);
191 err |= __put_user(mask, &sc->oldmask);
192 err |= __put_user(me->thread.cr2, &sc->cr2);
198 * Determine which stack to use..
202 get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size)
204 /* Default to using normal stack - redzone*/
207 /* This is the X/Open sanctioned signal stack switching. */
208 if (ka->sa.sa_flags & SA_ONSTACK) {
209 if (sas_ss_flags(sp) == 0)
210 sp = current->sas_ss_sp + current->sas_ss_size;
213 return (void __user *)round_down(sp - size, 64);
216 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
217 sigset_t *set, struct pt_regs *regs)
219 struct rt_sigframe __user *frame;
220 void __user *fp = NULL;
222 struct task_struct *me = current;
225 fp = get_stack(ka, regs->sp, sig_xstate_size);
226 frame = (void __user *)round_down(
227 (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
229 if (save_i387_xstate(fp) < 0)
232 frame = get_stack(ka, regs->sp, sizeof(struct rt_sigframe)) - 8;
234 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
237 if (ka->sa.sa_flags & SA_SIGINFO) {
238 if (copy_siginfo_to_user(&frame->info, info))
242 /* Create the ucontext. */
244 err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
246 err |= __put_user(0, &frame->uc.uc_flags);
247 err |= __put_user(0, &frame->uc.uc_link);
248 err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
249 err |= __put_user(sas_ss_flags(regs->sp),
250 &frame->uc.uc_stack.ss_flags);
251 err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
252 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
253 err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
254 if (sizeof(*set) == 16) {
255 __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
256 __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
258 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
260 /* Set up to return from userspace. If provided, use a stub
261 already in userspace. */
262 /* x86-64 should always use SA_RESTORER. */
263 if (ka->sa.sa_flags & SA_RESTORER) {
264 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
266 /* could use a vstub here */
273 /* Set up registers for signal handler */
275 /* In case the signal handler was declared without prototypes */
278 /* This also works for non SA_SIGINFO handlers because they expect the
279 next argument after the signal number on the stack. */
280 regs->si = (unsigned long)&frame->info;
281 regs->dx = (unsigned long)&frame->uc;
282 regs->ip = (unsigned long) ka->sa.sa_handler;
284 regs->sp = (unsigned long)frame;
286 /* Set up the CS register to run signal handlers in 64-bit mode,
287 even if the handler happens to be interrupting 32-bit code. */
288 regs->cs = __USER_CS;
294 * OK, we're invoking a handler
296 static int signr_convert(int sig)
301 #ifdef CONFIG_IA32_EMULATION
302 #define is_ia32 test_thread_flag(TIF_IA32)
308 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
309 sigset_t *set, struct pt_regs *regs)
311 int usig = signr_convert(sig);
314 /* Set up the stack frame */
316 if (ka->sa.sa_flags & SA_SIGINFO)
317 ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
319 ret = ia32_setup_frame(usig, ka, set, regs);
321 ret = __setup_rt_frame(sig, ka, info, set, regs);
324 force_sigsegv(sig, current);
332 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
333 sigset_t *oldset, struct pt_regs *regs)
337 /* Are we from a system call? */
338 if (syscall_get_nr(current, regs) >= 0) {
339 /* If so, check system call restarting.. */
340 switch (syscall_get_error(current, regs)) {
341 case -ERESTART_RESTARTBLOCK:
342 case -ERESTARTNOHAND:
347 if (!(ka->sa.sa_flags & SA_RESTART)) {
352 case -ERESTARTNOINTR:
353 regs->ax = regs->orig_ax;
360 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
361 * flag so that register information in the sigcontext is correct.
363 if (unlikely(regs->flags & X86_EFLAGS_TF) &&
364 likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
365 regs->flags &= ~X86_EFLAGS_TF;
367 ret = setup_rt_frame(sig, ka, info, oldset, regs);
374 * This has nothing to do with segment registers,
375 * despite the name. This magic affects uaccess.h
376 * macros' behavior. Reset it to the normal setting.
382 * Clear the direction flag as per the ABI for function entry.
384 regs->flags &= ~X86_EFLAGS_DF;
387 * Clear TF when entering the signal handler, but
388 * notify any tracer that was single-stepping it.
389 * The tracer may want to single-step inside the
392 regs->flags &= ~X86_EFLAGS_TF;
394 spin_lock_irq(¤t->sighand->siglock);
395 sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask);
396 if (!(ka->sa.sa_flags & SA_NODEFER))
397 sigaddset(¤t->blocked, sig);
399 spin_unlock_irq(¤t->sighand->siglock);
401 tracehook_signal_handler(sig, info, ka, regs,
402 test_thread_flag(TIF_SINGLESTEP));
407 #define NR_restart_syscall \
408 test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
410 * Note that 'init' is a special process: it doesn't get signals it doesn't
411 * want to handle. Thus you cannot kill init even with a SIGKILL even by
414 static void do_signal(struct pt_regs *regs)
416 struct k_sigaction ka;
422 * We want the common case to go fast, which is why we may in certain
423 * cases get here from kernel mode. Just return without doing anything
425 * X86_32: vm86 regs switched out by assembly code before reaching
426 * here, so testing against kernel CS suffices.
428 if (!user_mode(regs))
431 if (current_thread_info()->status & TS_RESTORE_SIGMASK)
432 oldset = ¤t->saved_sigmask;
434 oldset = ¤t->blocked;
436 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
439 * Re-enable any watchpoints before delivering the
440 * signal to user space. The processor register will
441 * have been cleared if the watchpoint triggered
444 if (current->thread.debugreg7)
445 set_debugreg(current->thread.debugreg7, 7);
447 /* Whee! Actually deliver the signal. */
448 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
450 * A signal was successfully delivered; the saved
451 * sigmask will have been stored in the signal frame,
452 * and will be restored by sigreturn, so we can simply
453 * clear the TS_RESTORE_SIGMASK flag.
455 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
460 /* Did we come from a system call? */
461 if (syscall_get_nr(current, regs) >= 0) {
462 /* Restart the system call - no handlers present */
463 switch (syscall_get_error(current, regs)) {
464 case -ERESTARTNOHAND:
466 case -ERESTARTNOINTR:
467 regs->ax = regs->orig_ax;
471 case -ERESTART_RESTARTBLOCK:
472 regs->ax = NR_restart_syscall;
479 * If there's no signal to deliver, we just put the saved sigmask
482 if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
483 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
484 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
489 * notification of userspace execution resumption
490 * - triggered by the TIF_WORK_MASK flags
493 do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
495 #if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
496 /* notify userspace of pending MCEs */
497 if (thread_info_flags & _TIF_MCE_NOTIFY)
499 #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
501 /* deal with pending signal delivery */
502 if (thread_info_flags & _TIF_SIGPENDING)
505 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
506 clear_thread_flag(TIF_NOTIFY_RESUME);
507 tracehook_notify_resume(regs);
511 clear_thread_flag(TIF_IRET);
512 #endif /* CONFIG_X86_32 */
515 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
517 struct task_struct *me = current;
519 if (show_unhandled_signals && printk_ratelimit()) {
521 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
522 me->comm, me->pid, where, frame,
523 regs->ip, regs->sp, regs->orig_ax);
524 print_vma_addr(" in ", regs->ip);
525 printk(KERN_CONT "\n");
528 force_sig(SIGSEGV, me);