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)
146 unsigned int tmpflags
;
147 err
|= __get_user(tmpflags
, &sc
->flags
);
148 regs
->flags
= (regs
->flags
& ~FIX_EFLAGS
) | (tmpflags
& FIX_EFLAGS
);
149 regs
->orig_ax
= -1; /* disable syscall checks */
153 struct _fpstate __user
* buf
;
154 err
|= __get_user(buf
, &sc
->fpstate
);
156 if (!access_ok(VERIFY_READ
, buf
, sizeof(*buf
)))
158 err
|= restore_i387(buf
);
160 struct task_struct
*me
= current
;
168 err
|= __get_user(*peax
, &sc
->ax
);
175 asmlinkage
int sys_sigreturn(unsigned long __unused
)
177 struct pt_regs
*regs
= (struct pt_regs
*) &__unused
;
178 struct sigframe __user
*frame
= (struct sigframe __user
*)(regs
->sp
- 8);
182 if (!access_ok(VERIFY_READ
, frame
, sizeof(*frame
)))
184 if (__get_user(set
.sig
[0], &frame
->sc
.oldmask
)
186 && __copy_from_user(&set
.sig
[1], &frame
->extramask
,
187 sizeof(frame
->extramask
))))
190 sigdelsetmask(&set
, ~_BLOCKABLE
);
191 spin_lock_irq(¤t
->sighand
->siglock
);
192 current
->blocked
= set
;
194 spin_unlock_irq(¤t
->sighand
->siglock
);
196 if (restore_sigcontext(regs
, &frame
->sc
, &ax
))
201 if (show_unhandled_signals
&& printk_ratelimit())
202 printk("%s%s[%d] bad frame in sigreturn frame:%p ip:%lx"
203 " sp:%lx oeax:%lx\n",
204 task_pid_nr(current
) > 1 ? KERN_INFO
: KERN_EMERG
,
205 current
->comm
, task_pid_nr(current
), frame
, regs
->ip
,
206 regs
->sp
, regs
->orig_ax
);
208 force_sig(SIGSEGV
, current
);
212 asmlinkage
int sys_rt_sigreturn(unsigned long __unused
)
214 struct pt_regs
*regs
= (struct pt_regs
*) &__unused
;
215 struct rt_sigframe __user
*frame
= (struct rt_sigframe __user
*)(regs
->sp
- 4);
219 if (!access_ok(VERIFY_READ
, frame
, sizeof(*frame
)))
221 if (__copy_from_user(&set
, &frame
->uc
.uc_sigmask
, sizeof(set
)))
224 sigdelsetmask(&set
, ~_BLOCKABLE
);
225 spin_lock_irq(¤t
->sighand
->siglock
);
226 current
->blocked
= set
;
228 spin_unlock_irq(¤t
->sighand
->siglock
);
230 if (restore_sigcontext(regs
, &frame
->uc
.uc_mcontext
, &ax
))
233 if (do_sigaltstack(&frame
->uc
.uc_stack
, NULL
, regs
->sp
) == -EFAULT
)
239 force_sig(SIGSEGV
, current
);
244 * Set up a signal frame.
248 setup_sigcontext(struct sigcontext __user
*sc
, struct _fpstate __user
*fpstate
,
249 struct pt_regs
*regs
, unsigned long mask
)
253 err
|= __put_user(regs
->fs
, (unsigned int __user
*)&sc
->fs
);
254 savesegment(gs
, tmp
);
255 err
|= __put_user(tmp
, (unsigned int __user
*)&sc
->gs
);
257 err
|= __put_user(regs
->es
, (unsigned int __user
*)&sc
->es
);
258 err
|= __put_user(regs
->ds
, (unsigned int __user
*)&sc
->ds
);
259 err
|= __put_user(regs
->di
, &sc
->di
);
260 err
|= __put_user(regs
->si
, &sc
->si
);
261 err
|= __put_user(regs
->bp
, &sc
->bp
);
262 err
|= __put_user(regs
->sp
, &sc
->sp
);
263 err
|= __put_user(regs
->bx
, &sc
->bx
);
264 err
|= __put_user(regs
->dx
, &sc
->dx
);
265 err
|= __put_user(regs
->cx
, &sc
->cx
);
266 err
|= __put_user(regs
->ax
, &sc
->ax
);
267 err
|= __put_user(current
->thread
.trap_no
, &sc
->trapno
);
268 err
|= __put_user(current
->thread
.error_code
, &sc
->err
);
269 err
|= __put_user(regs
->ip
, &sc
->ip
);
270 err
|= __put_user(regs
->cs
, (unsigned int __user
*)&sc
->cs
);
271 err
|= __put_user(regs
->flags
, &sc
->flags
);
272 err
|= __put_user(regs
->sp
, &sc
->sp_at_signal
);
273 err
|= __put_user(regs
->ss
, (unsigned int __user
*)&sc
->ss
);
275 tmp
= save_i387(fpstate
);
279 err
|= __put_user(tmp
? fpstate
: NULL
, &sc
->fpstate
);
281 /* non-iBCS2 extensions.. */
282 err
|= __put_user(mask
, &sc
->oldmask
);
283 err
|= __put_user(current
->thread
.cr2
, &sc
->cr2
);
289 * Determine which stack to use..
291 static inline void __user
*
292 get_sigframe(struct k_sigaction
*ka
, struct pt_regs
* regs
, size_t frame_size
)
296 /* Default to using normal stack */
300 * If we are on the alternate signal stack and would overflow it, don't.
301 * Return an always-bogus address instead so we will die with SIGSEGV.
303 if (on_sig_stack(sp
) && !likely(on_sig_stack(sp
- frame_size
)))
304 return (void __user
*) -1L;
306 /* This is the X/Open sanctioned signal stack switching. */
307 if (ka
->sa
.sa_flags
& SA_ONSTACK
) {
308 if (sas_ss_flags(sp
) == 0)
309 sp
= current
->sas_ss_sp
+ current
->sas_ss_size
;
312 /* This is the legacy signal stack switching. */
313 else if ((regs
->ss
& 0xffff) != __USER_DS
&&
314 !(ka
->sa
.sa_flags
& SA_RESTORER
) &&
315 ka
->sa
.sa_restorer
) {
316 sp
= (unsigned long) ka
->sa
.sa_restorer
;
320 /* Align the stack pointer according to the i386 ABI,
321 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
322 sp
= ((sp
+ 4) & -16ul) - 4;
323 return (void __user
*) sp
;
326 /* These symbols are defined with the addresses in the vsyscall page.
327 See vsyscall-sigreturn.S. */
328 extern void __user __kernel_sigreturn
;
329 extern void __user __kernel_rt_sigreturn
;
331 static int setup_frame(int sig
, struct k_sigaction
*ka
,
332 sigset_t
*set
, struct pt_regs
* regs
)
334 void __user
*restorer
;
335 struct sigframe __user
*frame
;
339 frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
341 if (!access_ok(VERIFY_WRITE
, frame
, sizeof(*frame
)))
344 usig
= current_thread_info()->exec_domain
345 && current_thread_info()->exec_domain
->signal_invmap
347 ? current_thread_info()->exec_domain
->signal_invmap
[sig
]
350 err
= __put_user(usig
, &frame
->sig
);
354 err
= setup_sigcontext(&frame
->sc
, &frame
->fpstate
, regs
, set
->sig
[0]);
358 if (_NSIG_WORDS
> 1) {
359 err
= __copy_to_user(&frame
->extramask
, &set
->sig
[1],
360 sizeof(frame
->extramask
));
365 if (current
->binfmt
->hasvdso
)
366 restorer
= VDSO32_SYMBOL(current
->mm
->context
.vdso
, sigreturn
);
368 restorer
= (void *)&frame
->retcode
;
369 if (ka
->sa
.sa_flags
& SA_RESTORER
)
370 restorer
= ka
->sa
.sa_restorer
;
372 /* Set up to return from userspace. */
373 err
|= __put_user(restorer
, &frame
->pretcode
);
376 * This is popl %eax ; movl $,%eax ; int $0x80
378 * WE DO NOT USE IT ANY MORE! It's only left here for historical
379 * reasons and because gdb uses it as a signature to notice
380 * signal handler stack frames.
382 err
|= __put_user(0xb858, (short __user
*)(frame
->retcode
+0));
383 err
|= __put_user(__NR_sigreturn
, (int __user
*)(frame
->retcode
+2));
384 err
|= __put_user(0x80cd, (short __user
*)(frame
->retcode
+6));
389 /* Set up registers for signal handler */
390 regs
->sp
= (unsigned long) frame
;
391 regs
->ip
= (unsigned long) ka
->sa
.sa_handler
;
392 regs
->ax
= (unsigned long) sig
;
393 regs
->dx
= (unsigned long) 0;
394 regs
->cx
= (unsigned long) 0;
396 regs
->ds
= __USER_DS
;
397 regs
->es
= __USER_DS
;
398 regs
->ss
= __USER_DS
;
399 regs
->cs
= __USER_CS
;
402 * Clear TF when entering the signal handler, but
403 * notify any tracer that was single-stepping it.
404 * The tracer may want to single-step inside the
407 regs
->flags
&= ~TF_MASK
;
408 if (test_thread_flag(TIF_SINGLESTEP
))
409 ptrace_notify(SIGTRAP
);
412 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
413 current
->comm
, current
->pid
, frame
, regs
->ip
, frame
->pretcode
);
419 force_sigsegv(sig
, current
);
423 static int setup_rt_frame(int sig
, struct k_sigaction
*ka
, siginfo_t
*info
,
424 sigset_t
*set
, struct pt_regs
* regs
)
426 void __user
*restorer
;
427 struct rt_sigframe __user
*frame
;
431 frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
433 if (!access_ok(VERIFY_WRITE
, frame
, sizeof(*frame
)))
436 usig
= current_thread_info()->exec_domain
437 && current_thread_info()->exec_domain
->signal_invmap
439 ? current_thread_info()->exec_domain
->signal_invmap
[sig
]
442 err
|= __put_user(usig
, &frame
->sig
);
443 err
|= __put_user(&frame
->info
, &frame
->pinfo
);
444 err
|= __put_user(&frame
->uc
, &frame
->puc
);
445 err
|= copy_siginfo_to_user(&frame
->info
, info
);
449 /* Create the ucontext. */
450 err
|= __put_user(0, &frame
->uc
.uc_flags
);
451 err
|= __put_user(0, &frame
->uc
.uc_link
);
452 err
|= __put_user(current
->sas_ss_sp
, &frame
->uc
.uc_stack
.ss_sp
);
453 err
|= __put_user(sas_ss_flags(regs
->sp
),
454 &frame
->uc
.uc_stack
.ss_flags
);
455 err
|= __put_user(current
->sas_ss_size
, &frame
->uc
.uc_stack
.ss_size
);
456 err
|= setup_sigcontext(&frame
->uc
.uc_mcontext
, &frame
->fpstate
,
458 err
|= __copy_to_user(&frame
->uc
.uc_sigmask
, set
, sizeof(*set
));
462 /* Set up to return from userspace. */
463 restorer
= VDSO32_SYMBOL(current
->mm
->context
.vdso
, rt_sigreturn
);
464 if (ka
->sa
.sa_flags
& SA_RESTORER
)
465 restorer
= ka
->sa
.sa_restorer
;
466 err
|= __put_user(restorer
, &frame
->pretcode
);
469 * This is movl $,%ax ; int $0x80
471 * WE DO NOT USE IT ANY MORE! It's only left here for historical
472 * reasons and because gdb uses it as a signature to notice
473 * signal handler stack frames.
475 err
|= __put_user(0xb8, (char __user
*)(frame
->retcode
+0));
476 err
|= __put_user(__NR_rt_sigreturn
, (int __user
*)(frame
->retcode
+1));
477 err
|= __put_user(0x80cd, (short __user
*)(frame
->retcode
+5));
482 /* Set up registers for signal handler */
483 regs
->sp
= (unsigned long) frame
;
484 regs
->ip
= (unsigned long) ka
->sa
.sa_handler
;
485 regs
->ax
= (unsigned long) usig
;
486 regs
->dx
= (unsigned long) &frame
->info
;
487 regs
->cx
= (unsigned long) &frame
->uc
;
489 regs
->ds
= __USER_DS
;
490 regs
->es
= __USER_DS
;
491 regs
->ss
= __USER_DS
;
492 regs
->cs
= __USER_CS
;
495 * Clear TF when entering the signal handler, but
496 * notify any tracer that was single-stepping it.
497 * The tracer may want to single-step inside the
500 regs
->flags
&= ~TF_MASK
;
501 if (test_thread_flag(TIF_SINGLESTEP
))
502 ptrace_notify(SIGTRAP
);
505 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
506 current
->comm
, current
->pid
, frame
, regs
->ip
, frame
->pretcode
);
512 force_sigsegv(sig
, current
);
517 * OK, we're invoking a handler
521 handle_signal(unsigned long sig
, siginfo_t
*info
, struct k_sigaction
*ka
,
522 sigset_t
*oldset
, struct pt_regs
* regs
)
526 /* Are we from a system call? */
527 if (regs
->orig_ax
>= 0) {
528 /* If so, check system call restarting.. */
530 case -ERESTART_RESTARTBLOCK
:
531 case -ERESTARTNOHAND
:
536 if (!(ka
->sa
.sa_flags
& SA_RESTART
)) {
541 case -ERESTARTNOINTR
:
542 regs
->ax
= regs
->orig_ax
;
548 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
549 * flag so that register information in the sigcontext is correct.
551 if (unlikely(regs
->flags
& X86_EFLAGS_TF
) &&
552 likely(test_and_clear_thread_flag(TIF_FORCED_TF
)))
553 regs
->flags
&= ~X86_EFLAGS_TF
;
555 /* Set up the stack frame */
556 if (ka
->sa
.sa_flags
& SA_SIGINFO
)
557 ret
= setup_rt_frame(sig
, ka
, info
, oldset
, regs
);
559 ret
= setup_frame(sig
, ka
, oldset
, regs
);
562 spin_lock_irq(¤t
->sighand
->siglock
);
563 sigorsets(¤t
->blocked
,¤t
->blocked
,&ka
->sa
.sa_mask
);
564 if (!(ka
->sa
.sa_flags
& SA_NODEFER
))
565 sigaddset(¤t
->blocked
,sig
);
567 spin_unlock_irq(¤t
->sighand
->siglock
);
574 * Note that 'init' is a special process: it doesn't get signals it doesn't
575 * want to handle. Thus you cannot kill init even with a SIGKILL even by
578 static void do_signal(struct pt_regs
*regs
)
582 struct k_sigaction ka
;
586 * We want the common case to go fast, which
587 * is why we may in certain cases get here from
588 * kernel mode. Just return without doing anything
589 * if so. vm86 regs switched out by assembly code
590 * before reaching here, so testing against kernel
593 if (!user_mode(regs
))
596 if (test_thread_flag(TIF_RESTORE_SIGMASK
))
597 oldset
= ¤t
->saved_sigmask
;
599 oldset
= ¤t
->blocked
;
601 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
603 /* Re-enable any watchpoints before delivering the
604 * signal to user space. The processor register will
605 * have been cleared if the watchpoint triggered
608 if (unlikely(current
->thread
.debugreg7
))
609 set_debugreg(current
->thread
.debugreg7
, 7);
611 /* Whee! Actually deliver the signal. */
612 if (handle_signal(signr
, &info
, &ka
, oldset
, regs
) == 0) {
613 /* a signal was successfully delivered; the saved
614 * sigmask will have been stored in the signal frame,
615 * and will be restored by sigreturn, so we can simply
616 * clear the TIF_RESTORE_SIGMASK flag */
617 if (test_thread_flag(TIF_RESTORE_SIGMASK
))
618 clear_thread_flag(TIF_RESTORE_SIGMASK
);
624 /* Did we come from a system call? */
625 if (regs
->orig_ax
>= 0) {
626 /* Restart the system call - no handlers present */
628 case -ERESTARTNOHAND
:
630 case -ERESTARTNOINTR
:
631 regs
->ax
= regs
->orig_ax
;
635 case -ERESTART_RESTARTBLOCK
:
636 regs
->ax
= __NR_restart_syscall
;
642 /* if there's no signal to deliver, we just put the saved sigmask
644 if (test_thread_flag(TIF_RESTORE_SIGMASK
)) {
645 clear_thread_flag(TIF_RESTORE_SIGMASK
);
646 sigprocmask(SIG_SETMASK
, ¤t
->saved_sigmask
, NULL
);
651 * notification of userspace execution resumption
652 * - triggered by the TIF_WORK_MASK flags
654 __attribute__((regparm(3)))
655 void do_notify_resume(struct pt_regs
*regs
, void *_unused
,
656 __u32 thread_info_flags
)
658 /* Pending single-step? */
659 if (thread_info_flags
& _TIF_SINGLESTEP
) {
660 regs
->flags
|= TF_MASK
;
661 clear_thread_flag(TIF_SINGLESTEP
);
664 /* deal with pending signal delivery */
665 if (thread_info_flags
& (_TIF_SIGPENDING
| _TIF_RESTORE_SIGMASK
))
668 if (thread_info_flags
& _TIF_HRTICK_RESCHED
)
671 clear_thread_flag(TIF_IRET
);