1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
6 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
7 * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
8 * 2000-2002 x86-64 support by Andi Kleen
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/sched.h>
14 #include <linux/sched/task_stack.h>
16 #include <linux/smp.h>
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/wait.h>
20 #include <linux/tracehook.h>
21 #include <linux/unistd.h>
22 #include <linux/stddef.h>
23 #include <linux/personality.h>
24 #include <linux/uaccess.h>
25 #include <linux/user-return-notifier.h>
26 #include <linux/uprobes.h>
27 #include <linux/context_tracking.h>
28 #include <linux/syscalls.h>
30 #include <asm/processor.h>
31 #include <asm/ucontext.h>
32 #include <asm/fpu/internal.h>
33 #include <asm/fpu/signal.h>
36 #include <asm/sighandling.h>
40 #include <asm/proto.h>
41 #include <asm/ia32_unistd.h>
42 #endif /* CONFIG_X86_64 */
44 #include <asm/syscall.h>
45 #include <asm/syscalls.h>
47 #include <asm/sigframe.h>
48 #include <asm/signal.h>
50 #define COPY(x) do { \
51 get_user_ex(regs->x, &sc->x); \
54 #define GET_SEG(seg) ({ \
56 get_user_ex(tmp, &sc->seg); \
60 #define COPY_SEG(seg) do { \
61 regs->seg = GET_SEG(seg); \
64 #define COPY_SEG_CPL3(seg) do { \
65 regs->seg = GET_SEG(seg) | 3; \
70 * If regs->ss will cause an IRET fault, change it. Otherwise leave it
71 * alone. Using this generally makes no sense unless
72 * user_64bit_mode(regs) would return true.
74 static void force_valid_ss(struct pt_regs *regs)
77 asm volatile ("lar %[old_ss], %[ar]\n\t"
78 "jz 1f\n\t" /* If invalid: */
79 "xorl %[ar], %[ar]\n\t" /* set ar = 0 */
82 : [old_ss] "rm" ((u16)regs->ss));
85 * For a valid 64-bit user context, we need DPL 3, type
86 * read-write data or read-write exp-down data, and S and P
87 * set. We can't use VERW because VERW doesn't check the
90 ar &= AR_DPL_MASK | AR_S | AR_P | AR_TYPE_MASK;
91 if (ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA) &&
92 ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN))
97 static int restore_sigcontext(struct pt_regs *regs,
98 struct sigcontext __user *sc,
99 unsigned long uc_flags)
101 unsigned long buf_val;
103 unsigned int tmpflags;
104 unsigned int err = 0;
106 /* Always make any pending restarted system calls return -EINTR */
107 current->restart_block.fn = do_no_restart_syscall;
112 set_user_gs(regs, GET_SEG(gs));
116 #endif /* CONFIG_X86_32 */
118 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
119 COPY(dx); COPY(cx); COPY(ip); COPY(ax);
130 #endif /* CONFIG_X86_64 */
135 get_user_ex(tmpflags, &sc->flags);
136 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
137 regs->orig_ax = -1; /* disable syscall checks */
139 get_user_ex(buf_val, &sc->fpstate);
140 buf = (void __user *)buf_val;
141 } get_user_catch(err);
145 * Fix up SS if needed for the benefit of old DOSEMU and
148 if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && user_64bit_mode(regs)))
149 force_valid_ss(regs);
152 err |= fpu__restore_sig(buf, IS_ENABLED(CONFIG_X86_32));
159 int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
160 struct pt_regs *regs, unsigned long mask)
167 put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs);
168 put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
169 put_user_ex(regs->es, (unsigned int __user *)&sc->es);
170 put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
171 #endif /* CONFIG_X86_32 */
173 put_user_ex(regs->di, &sc->di);
174 put_user_ex(regs->si, &sc->si);
175 put_user_ex(regs->bp, &sc->bp);
176 put_user_ex(regs->sp, &sc->sp);
177 put_user_ex(regs->bx, &sc->bx);
178 put_user_ex(regs->dx, &sc->dx);
179 put_user_ex(regs->cx, &sc->cx);
180 put_user_ex(regs->ax, &sc->ax);
182 put_user_ex(regs->r8, &sc->r8);
183 put_user_ex(regs->r9, &sc->r9);
184 put_user_ex(regs->r10, &sc->r10);
185 put_user_ex(regs->r11, &sc->r11);
186 put_user_ex(regs->r12, &sc->r12);
187 put_user_ex(regs->r13, &sc->r13);
188 put_user_ex(regs->r14, &sc->r14);
189 put_user_ex(regs->r15, &sc->r15);
190 #endif /* CONFIG_X86_64 */
192 put_user_ex(current->thread.trap_nr, &sc->trapno);
193 put_user_ex(current->thread.error_code, &sc->err);
194 put_user_ex(regs->ip, &sc->ip);
196 put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
197 put_user_ex(regs->flags, &sc->flags);
198 put_user_ex(regs->sp, &sc->sp_at_signal);
199 put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
200 #else /* !CONFIG_X86_32 */
201 put_user_ex(regs->flags, &sc->flags);
202 put_user_ex(regs->cs, &sc->cs);
203 put_user_ex(0, &sc->gs);
204 put_user_ex(0, &sc->fs);
205 put_user_ex(regs->ss, &sc->ss);
206 #endif /* CONFIG_X86_32 */
208 put_user_ex(fpstate, &sc->fpstate);
210 /* non-iBCS2 extensions.. */
211 put_user_ex(mask, &sc->oldmask);
212 put_user_ex(current->thread.cr2, &sc->cr2);
213 } put_user_catch(err);
219 * Set up a signal frame.
223 * Determine which stack to use..
225 static unsigned long align_sigframe(unsigned long sp)
229 * Align the stack pointer according to the i386 ABI,
230 * i.e. so that on function entry ((sp + 4) & 15) == 0.
232 sp = ((sp + 4) & -16ul) - 4;
233 #else /* !CONFIG_X86_32 */
234 sp = round_down(sp, 16) - 8;
240 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
241 void __user **fpstate)
243 /* Default to using normal stack */
244 unsigned long math_size = 0;
245 unsigned long sp = regs->sp;
246 unsigned long buf_fx = 0;
247 int onsigstack = on_sig_stack(sp);
248 struct fpu *fpu = ¤t->thread.fpu;
251 if (IS_ENABLED(CONFIG_X86_64))
254 /* This is the X/Open sanctioned signal stack switching. */
255 if (ka->sa.sa_flags & SA_ONSTACK) {
256 if (sas_ss_flags(sp) == 0)
257 sp = current->sas_ss_sp + current->sas_ss_size;
258 } else if (IS_ENABLED(CONFIG_X86_32) &&
260 regs->ss != __USER_DS &&
261 !(ka->sa.sa_flags & SA_RESTORER) &&
262 ka->sa.sa_restorer) {
263 /* This is the legacy signal stack switching. */
264 sp = (unsigned long) ka->sa.sa_restorer;
267 if (fpu->initialized) {
268 sp = fpu__alloc_mathframe(sp, IS_ENABLED(CONFIG_X86_32),
269 &buf_fx, &math_size);
270 *fpstate = (void __user *)sp;
273 sp = align_sigframe(sp - frame_size);
276 * If we are on the alternate signal stack and would overflow it, don't.
277 * Return an always-bogus address instead so we will die with SIGSEGV.
279 if (onsigstack && !likely(on_sig_stack(sp)))
280 return (void __user *)-1L;
282 /* save i387 and extended state */
283 if (fpu->initialized &&
284 copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size) < 0)
285 return (void __user *)-1L;
287 return (void __user *)sp;
291 static const struct {
295 } __attribute__((packed)) retcode = {
296 0xb858, /* popl %eax; movl $..., %eax */
298 0x80cd, /* int $0x80 */
301 static const struct {
306 } __attribute__((packed)) rt_retcode = {
307 0xb8, /* movl $..., %eax */
309 0x80cd, /* int $0x80 */
314 __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
315 struct pt_regs *regs)
317 struct sigframe __user *frame;
318 void __user *restorer;
320 void __user *fpstate = NULL;
322 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
324 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
327 if (__put_user(sig, &frame->sig))
330 if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
333 if (_NSIG_WORDS > 1) {
334 if (__copy_to_user(&frame->extramask, &set->sig[1],
335 sizeof(frame->extramask)))
339 if (current->mm->context.vdso)
340 restorer = current->mm->context.vdso +
341 vdso_image_32.sym___kernel_sigreturn;
343 restorer = &frame->retcode;
344 if (ksig->ka.sa.sa_flags & SA_RESTORER)
345 restorer = ksig->ka.sa.sa_restorer;
347 /* Set up to return from userspace. */
348 err |= __put_user(restorer, &frame->pretcode);
351 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
353 * WE DO NOT USE IT ANY MORE! It's only left here for historical
354 * reasons and because gdb uses it as a signature to notice
355 * signal handler stack frames.
357 err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
362 /* Set up registers for signal handler */
363 regs->sp = (unsigned long)frame;
364 regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
365 regs->ax = (unsigned long)sig;
369 regs->ds = __USER_DS;
370 regs->es = __USER_DS;
371 regs->ss = __USER_DS;
372 regs->cs = __USER_CS;
377 static int __setup_rt_frame(int sig, struct ksignal *ksig,
378 sigset_t *set, struct pt_regs *regs)
380 struct rt_sigframe __user *frame;
381 void __user *restorer;
383 void __user *fpstate = NULL;
385 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
387 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
391 put_user_ex(sig, &frame->sig);
392 put_user_ex(&frame->info, &frame->pinfo);
393 put_user_ex(&frame->uc, &frame->puc);
395 /* Create the ucontext. */
396 if (boot_cpu_has(X86_FEATURE_XSAVE))
397 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
399 put_user_ex(0, &frame->uc.uc_flags);
400 put_user_ex(0, &frame->uc.uc_link);
401 save_altstack_ex(&frame->uc.uc_stack, regs->sp);
403 /* Set up to return from userspace. */
404 restorer = current->mm->context.vdso +
405 vdso_image_32.sym___kernel_rt_sigreturn;
406 if (ksig->ka.sa.sa_flags & SA_RESTORER)
407 restorer = ksig->ka.sa.sa_restorer;
408 put_user_ex(restorer, &frame->pretcode);
411 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
413 * WE DO NOT USE IT ANY MORE! It's only left here for historical
414 * reasons and because gdb uses it as a signature to notice
415 * signal handler stack frames.
417 put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
418 } put_user_catch(err);
420 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
421 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
423 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
428 /* Set up registers for signal handler */
429 regs->sp = (unsigned long)frame;
430 regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
431 regs->ax = (unsigned long)sig;
432 regs->dx = (unsigned long)&frame->info;
433 regs->cx = (unsigned long)&frame->uc;
435 regs->ds = __USER_DS;
436 regs->es = __USER_DS;
437 regs->ss = __USER_DS;
438 regs->cs = __USER_CS;
442 #else /* !CONFIG_X86_32 */
443 static unsigned long frame_uc_flags(struct pt_regs *regs)
447 if (boot_cpu_has(X86_FEATURE_XSAVE))
448 flags = UC_FP_XSTATE | UC_SIGCONTEXT_SS;
450 flags = UC_SIGCONTEXT_SS;
452 if (likely(user_64bit_mode(regs)))
453 flags |= UC_STRICT_RESTORE_SS;
458 static int __setup_rt_frame(int sig, struct ksignal *ksig,
459 sigset_t *set, struct pt_regs *regs)
461 struct rt_sigframe __user *frame;
462 void __user *fp = NULL;
463 unsigned long uc_flags;
466 frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp);
468 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
471 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
472 if (copy_siginfo_to_user(&frame->info, &ksig->info))
476 uc_flags = frame_uc_flags(regs);
479 /* Create the ucontext. */
480 put_user_ex(uc_flags, &frame->uc.uc_flags);
481 put_user_ex(0, &frame->uc.uc_link);
482 save_altstack_ex(&frame->uc.uc_stack, regs->sp);
484 /* Set up to return from userspace. If provided, use a stub
485 already in userspace. */
486 /* x86-64 should always use SA_RESTORER. */
487 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
488 put_user_ex(ksig->ka.sa.sa_restorer, &frame->pretcode);
490 /* could use a vstub here */
493 } put_user_catch(err);
495 err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
496 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
501 /* Set up registers for signal handler */
503 /* In case the signal handler was declared without prototypes */
506 /* This also works for non SA_SIGINFO handlers because they expect the
507 next argument after the signal number on the stack. */
508 regs->si = (unsigned long)&frame->info;
509 regs->dx = (unsigned long)&frame->uc;
510 regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
512 regs->sp = (unsigned long)frame;
515 * Set up the CS and SS registers to run signal handlers in
516 * 64-bit mode, even if the handler happens to be interrupting
517 * 32-bit or 16-bit code.
519 * SS is subtle. In 64-bit mode, we don't need any particular
520 * SS descriptor, but we do need SS to be valid. It's possible
521 * that the old SS is entirely bogus -- this can happen if the
522 * signal we're trying to deliver is #GP or #SS caused by a bad
523 * SS value. We also have a compatbility issue here: DOSEMU
524 * relies on the contents of the SS register indicating the
525 * SS value at the time of the signal, even though that code in
526 * DOSEMU predates sigreturn's ability to restore SS. (DOSEMU
527 * avoids relying on sigreturn to restore SS; instead it uses
528 * a trampoline.) So we do our best: if the old SS was valid,
529 * we keep it. Otherwise we replace it.
531 regs->cs = __USER_CS;
533 if (unlikely(regs->ss != __USER_DS))
534 force_valid_ss(regs);
538 #endif /* CONFIG_X86_32 */
540 static int x32_setup_rt_frame(struct ksignal *ksig,
541 compat_sigset_t *set,
542 struct pt_regs *regs)
544 #ifdef CONFIG_X86_X32_ABI
545 struct rt_sigframe_x32 __user *frame;
546 unsigned long uc_flags;
547 void __user *restorer;
549 void __user *fpstate = NULL;
551 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
553 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
556 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
557 if (__copy_siginfo_to_user32(&frame->info, &ksig->info, true))
561 uc_flags = frame_uc_flags(regs);
564 /* Create the ucontext. */
565 put_user_ex(uc_flags, &frame->uc.uc_flags);
566 put_user_ex(0, &frame->uc.uc_link);
567 compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
568 put_user_ex(0, &frame->uc.uc__pad0);
570 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
571 restorer = ksig->ka.sa.sa_restorer;
573 /* could use a vstub here */
577 put_user_ex(restorer, &frame->pretcode);
578 } put_user_catch(err);
580 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
582 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
587 /* Set up registers for signal handler */
588 regs->sp = (unsigned long) frame;
589 regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
591 /* We use the x32 calling convention here... */
592 regs->di = ksig->sig;
593 regs->si = (unsigned long) &frame->info;
594 regs->dx = (unsigned long) &frame->uc;
596 loadsegment(ds, __USER_DS);
597 loadsegment(es, __USER_DS);
599 regs->cs = __USER_CS;
600 regs->ss = __USER_DS;
601 #endif /* CONFIG_X86_X32_ABI */
607 * Do a signal return; undo the signal stack.
610 SYSCALL_DEFINE0(sigreturn)
612 struct pt_regs *regs = current_pt_regs();
613 struct sigframe __user *frame;
616 frame = (struct sigframe __user *)(regs->sp - 8);
618 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
620 if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
621 && __copy_from_user(&set.sig[1], &frame->extramask,
622 sizeof(frame->extramask))))
625 set_current_blocked(&set);
628 * x86_32 has no uc_flags bits relevant to restore_sigcontext.
629 * Save a few cycles by skipping the __get_user.
631 if (restore_sigcontext(regs, &frame->sc, 0))
636 signal_fault(regs, frame, "sigreturn");
640 #endif /* CONFIG_X86_32 */
642 SYSCALL_DEFINE0(rt_sigreturn)
644 struct pt_regs *regs = current_pt_regs();
645 struct rt_sigframe __user *frame;
647 unsigned long uc_flags;
649 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
650 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
652 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
654 if (__get_user(uc_flags, &frame->uc.uc_flags))
657 set_current_blocked(&set);
659 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
662 if (restore_altstack(&frame->uc.uc_stack))
668 signal_fault(regs, frame, "rt_sigreturn");
672 static inline int is_ia32_compat_frame(struct ksignal *ksig)
674 return IS_ENABLED(CONFIG_IA32_EMULATION) &&
675 ksig->ka.sa.sa_flags & SA_IA32_ABI;
678 static inline int is_ia32_frame(struct ksignal *ksig)
680 return IS_ENABLED(CONFIG_X86_32) || is_ia32_compat_frame(ksig);
683 static inline int is_x32_frame(struct ksignal *ksig)
685 return IS_ENABLED(CONFIG_X86_X32_ABI) &&
686 ksig->ka.sa.sa_flags & SA_X32_ABI;
690 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
692 int usig = ksig->sig;
693 sigset_t *set = sigmask_to_save();
694 compat_sigset_t *cset = (compat_sigset_t *) set;
697 * Increment event counter and perform fixup for the pre-signal
700 rseq_signal_deliver(ksig, regs);
702 /* Set up the stack frame */
703 if (is_ia32_frame(ksig)) {
704 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
705 return ia32_setup_rt_frame(usig, ksig, cset, regs);
707 return ia32_setup_frame(usig, ksig, cset, regs);
708 } else if (is_x32_frame(ksig)) {
709 return x32_setup_rt_frame(ksig, cset, regs);
711 return __setup_rt_frame(ksig->sig, ksig, set, regs);
716 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
718 bool stepping, failed;
719 struct fpu *fpu = ¤t->thread.fpu;
721 if (v8086_mode(regs))
722 save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL);
724 /* Are we from a system call? */
725 if (syscall_get_nr(current, regs) >= 0) {
726 /* If so, check system call restarting.. */
727 switch (syscall_get_error(current, regs)) {
728 case -ERESTART_RESTARTBLOCK:
729 case -ERESTARTNOHAND:
734 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
739 case -ERESTARTNOINTR:
740 regs->ax = regs->orig_ax;
747 * If TF is set due to a debugger (TIF_FORCED_TF), clear TF now
748 * so that register information in the sigcontext is correct and
749 * then notify the tracer before entering the signal handler.
751 stepping = test_thread_flag(TIF_SINGLESTEP);
753 user_disable_single_step(current);
755 failed = (setup_rt_frame(ksig, regs) < 0);
758 * Clear the direction flag as per the ABI for function entry.
760 * Clear RF when entering the signal handler, because
761 * it might disable possible debug exception from the
764 * Clear TF for the case when it wasn't set by debugger to
765 * avoid the recursive send_sigtrap() in SIGTRAP handler.
767 regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF);
769 * Ensure the signal handler starts with the new fpu state.
771 if (fpu->initialized)
774 signal_setup_done(failed, ksig, stepping);
777 static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
780 * This function is fundamentally broken as currently
783 * The idea is that we want to trigger a call to the
784 * restart_block() syscall and that we want in_ia32_syscall(),
785 * in_x32_syscall(), etc. to match whatever they were in the
786 * syscall being restarted. We assume that the syscall
787 * instruction at (regs->ip - 2) matches whatever syscall
788 * instruction we used to enter in the first place.
790 * The problem is that we can get here when ptrace pokes
791 * syscall-like values into regs even if we're not in a syscall
794 * For now, we maintain historical behavior and guess based on
795 * stored state. We could do better by saving the actual
796 * syscall arch in restart_block or (with caveats on x32) by
797 * checking if regs->ip points to 'int $0x80'. The current
798 * behavior is incorrect if a tracer has a different bitness
801 #ifdef CONFIG_IA32_EMULATION
802 if (current_thread_info()->status & (TS_COMPAT|TS_I386_REGS_POKED))
803 return __NR_ia32_restart_syscall;
805 #ifdef CONFIG_X86_X32_ABI
806 return __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
808 return __NR_restart_syscall;
813 * Note that 'init' is a special process: it doesn't get signals it doesn't
814 * want to handle. Thus you cannot kill init even with a SIGKILL even by
817 void do_signal(struct pt_regs *regs)
821 if (get_signal(&ksig)) {
822 /* Whee! Actually deliver the signal. */
823 handle_signal(&ksig, regs);
827 /* Did we come from a system call? */
828 if (syscall_get_nr(current, regs) >= 0) {
829 /* Restart the system call - no handlers present */
830 switch (syscall_get_error(current, regs)) {
831 case -ERESTARTNOHAND:
833 case -ERESTARTNOINTR:
834 regs->ax = regs->orig_ax;
838 case -ERESTART_RESTARTBLOCK:
839 regs->ax = get_nr_restart_syscall(regs);
846 * If there's no signal to deliver, we just put the saved sigmask
849 restore_saved_sigmask();
852 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
854 struct task_struct *me = current;
856 if (show_unhandled_signals && printk_ratelimit()) {
858 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
859 task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
860 me->comm, me->pid, where, frame,
861 regs->ip, regs->sp, regs->orig_ax);
862 print_vma_addr(KERN_CONT " in ", regs->ip);
866 force_sig(SIGSEGV, me);
869 #ifdef CONFIG_X86_X32_ABI
870 asmlinkage long sys32_x32_rt_sigreturn(void)
872 struct pt_regs *regs = current_pt_regs();
873 struct rt_sigframe_x32 __user *frame;
875 unsigned long uc_flags;
877 frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
879 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
881 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
883 if (__get_user(uc_flags, &frame->uc.uc_flags))
886 set_current_blocked(&set);
888 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags))
891 if (compat_restore_altstack(&frame->uc.uc_stack))
897 signal_fault(regs, frame, "x32 rt_sigreturn");