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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - arch/x86/kernel/signal_64.c
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
;
79 COPY(di
); COPY(si
); COPY(bp
); COPY(sp
); COPY(bx
);
80 COPY(dx
); COPY(cx
); COPY(ip
);
90 /* Kernel saves and restores only the CS segment register on signals,
91 * which is the bare minimum needed to allow mixed 32/64-bit code.
92 * App's signal handler can save/restore other segments if needed. */
95 err
|= __get_user(tmpflags
, &sc
->flags
);
96 regs
->flags
= (regs
->flags
& ~FIX_EFLAGS
) | (tmpflags
& FIX_EFLAGS
);
97 regs
->orig_ax
= -1; /* disable syscall checks */
99 err
|= __get_user(buf
, &sc
->fpstate
);
100 err
|= restore_i387_xstate(buf
);
102 err
|= __get_user(*pax
, &sc
->ax
);
106 static long do_rt_sigreturn(struct pt_regs
*regs
)
108 struct rt_sigframe __user
*frame
;
112 frame
= (struct rt_sigframe __user
*)(regs
->sp
- sizeof(long));
113 if (!access_ok(VERIFY_READ
, frame
, sizeof(*frame
)))
115 if (__copy_from_user(&set
, &frame
->uc
.uc_sigmask
, sizeof(set
)))
118 sigdelsetmask(&set
, ~_BLOCKABLE
);
119 spin_lock_irq(¤t
->sighand
->siglock
);
120 current
->blocked
= set
;
122 spin_unlock_irq(¤t
->sighand
->siglock
);
124 if (restore_sigcontext(regs
, &frame
->uc
.uc_mcontext
, &ax
))
127 if (do_sigaltstack(&frame
->uc
.uc_stack
, NULL
, regs
->sp
) == -EFAULT
)
133 signal_fault(regs
, frame
, "rt_sigreturn");
137 asmlinkage
long sys_rt_sigreturn(struct pt_regs
*regs
)
139 return do_rt_sigreturn(regs
);
143 * Set up a signal frame.
147 setup_sigcontext(struct sigcontext __user
*sc
, struct pt_regs
*regs
,
148 unsigned long mask
, struct task_struct
*me
)
152 err
|= __put_user(regs
->cs
, &sc
->cs
);
153 err
|= __put_user(0, &sc
->gs
);
154 err
|= __put_user(0, &sc
->fs
);
156 err
|= __put_user(regs
->di
, &sc
->di
);
157 err
|= __put_user(regs
->si
, &sc
->si
);
158 err
|= __put_user(regs
->bp
, &sc
->bp
);
159 err
|= __put_user(regs
->sp
, &sc
->sp
);
160 err
|= __put_user(regs
->bx
, &sc
->bx
);
161 err
|= __put_user(regs
->dx
, &sc
->dx
);
162 err
|= __put_user(regs
->cx
, &sc
->cx
);
163 err
|= __put_user(regs
->ax
, &sc
->ax
);
164 err
|= __put_user(regs
->r8
, &sc
->r8
);
165 err
|= __put_user(regs
->r9
, &sc
->r9
);
166 err
|= __put_user(regs
->r10
, &sc
->r10
);
167 err
|= __put_user(regs
->r11
, &sc
->r11
);
168 err
|= __put_user(regs
->r12
, &sc
->r12
);
169 err
|= __put_user(regs
->r13
, &sc
->r13
);
170 err
|= __put_user(regs
->r14
, &sc
->r14
);
171 err
|= __put_user(regs
->r15
, &sc
->r15
);
172 err
|= __put_user(me
->thread
.trap_no
, &sc
->trapno
);
173 err
|= __put_user(me
->thread
.error_code
, &sc
->err
);
174 err
|= __put_user(regs
->ip
, &sc
->ip
);
175 err
|= __put_user(regs
->flags
, &sc
->flags
);
176 err
|= __put_user(mask
, &sc
->oldmask
);
177 err
|= __put_user(me
->thread
.cr2
, &sc
->cr2
);
183 * Determine which stack to use..
187 get_stack(struct k_sigaction
*ka
, struct pt_regs
*regs
, unsigned long size
)
191 /* Default to using normal stack - redzone*/
194 /* This is the X/Open sanctioned signal stack switching. */
195 if (ka
->sa
.sa_flags
& SA_ONSTACK
) {
196 if (sas_ss_flags(sp
) == 0)
197 sp
= current
->sas_ss_sp
+ current
->sas_ss_size
;
200 return (void __user
*)round_down(sp
- size
, 64);
203 static int __setup_rt_frame(int sig
, struct k_sigaction
*ka
, siginfo_t
*info
,
204 sigset_t
*set
, struct pt_regs
*regs
)
206 struct rt_sigframe __user
*frame
;
207 void __user
*fp
= NULL
;
209 struct task_struct
*me
= current
;
212 fp
= get_stack(ka
, regs
, sig_xstate_size
);
213 frame
= (void __user
*)round_down(
214 (unsigned long)fp
- sizeof(struct rt_sigframe
), 16) - 8;
216 if (save_i387_xstate(fp
) < 0)
219 frame
= get_stack(ka
, regs
, sizeof(struct rt_sigframe
)) - 8;
221 if (!access_ok(VERIFY_WRITE
, frame
, sizeof(*frame
)))
224 if (ka
->sa
.sa_flags
& SA_SIGINFO
) {
225 if (copy_siginfo_to_user(&frame
->info
, info
))
229 /* Create the ucontext. */
231 err
|= __put_user(UC_FP_XSTATE
, &frame
->uc
.uc_flags
);
233 err
|= __put_user(0, &frame
->uc
.uc_flags
);
234 err
|= __put_user(0, &frame
->uc
.uc_link
);
235 err
|= __put_user(me
->sas_ss_sp
, &frame
->uc
.uc_stack
.ss_sp
);
236 err
|= __put_user(sas_ss_flags(regs
->sp
),
237 &frame
->uc
.uc_stack
.ss_flags
);
238 err
|= __put_user(me
->sas_ss_size
, &frame
->uc
.uc_stack
.ss_size
);
239 err
|= setup_sigcontext(&frame
->uc
.uc_mcontext
, regs
, set
->sig
[0], me
);
240 err
|= __put_user(fp
, &frame
->uc
.uc_mcontext
.fpstate
);
241 if (sizeof(*set
) == 16) {
242 __put_user(set
->sig
[0], &frame
->uc
.uc_sigmask
.sig
[0]);
243 __put_user(set
->sig
[1], &frame
->uc
.uc_sigmask
.sig
[1]);
245 err
|= __copy_to_user(&frame
->uc
.uc_sigmask
, set
, sizeof(*set
));
247 /* Set up to return from userspace. If provided, use a stub
248 already in userspace. */
249 /* x86-64 should always use SA_RESTORER. */
250 if (ka
->sa
.sa_flags
& SA_RESTORER
) {
251 err
|= __put_user(ka
->sa
.sa_restorer
, &frame
->pretcode
);
253 /* could use a vstub here */
260 /* Set up registers for signal handler */
262 /* In case the signal handler was declared without prototypes */
265 /* This also works for non SA_SIGINFO handlers because they expect the
266 next argument after the signal number on the stack. */
267 regs
->si
= (unsigned long)&frame
->info
;
268 regs
->dx
= (unsigned long)&frame
->uc
;
269 regs
->ip
= (unsigned long) ka
->sa
.sa_handler
;
271 regs
->sp
= (unsigned long)frame
;
273 /* Set up the CS register to run signal handlers in 64-bit mode,
274 even if the handler happens to be interrupting 32-bit code. */
275 regs
->cs
= __USER_CS
;
281 * OK, we're invoking a handler
283 static int signr_convert(int sig
)
288 #ifdef CONFIG_IA32_EMULATION
289 #define is_ia32 test_thread_flag(TIF_IA32)
295 setup_rt_frame(int sig
, struct k_sigaction
*ka
, siginfo_t
*info
,
296 sigset_t
*set
, struct pt_regs
*regs
)
298 int usig
= signr_convert(sig
);
301 /* Set up the stack frame */
303 if (ka
->sa
.sa_flags
& SA_SIGINFO
)
304 ret
= ia32_setup_rt_frame(usig
, ka
, info
, set
, regs
);
306 ret
= ia32_setup_frame(usig
, ka
, set
, regs
);
308 ret
= __setup_rt_frame(sig
, ka
, info
, set
, regs
);
311 force_sigsegv(sig
, current
);
319 handle_signal(unsigned long sig
, siginfo_t
*info
, struct k_sigaction
*ka
,
320 sigset_t
*oldset
, struct pt_regs
*regs
)
324 /* Are we from a system call? */
325 if (syscall_get_nr(current
, regs
) >= 0) {
326 /* If so, check system call restarting.. */
327 switch (syscall_get_error(current
, regs
)) {
328 case -ERESTART_RESTARTBLOCK
:
329 case -ERESTARTNOHAND
:
334 if (!(ka
->sa
.sa_flags
& SA_RESTART
)) {
339 case -ERESTARTNOINTR
:
340 regs
->ax
= regs
->orig_ax
;
347 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
348 * flag so that register information in the sigcontext is correct.
350 if (unlikely(regs
->flags
& X86_EFLAGS_TF
) &&
351 likely(test_and_clear_thread_flag(TIF_FORCED_TF
)))
352 regs
->flags
&= ~X86_EFLAGS_TF
;
354 ret
= setup_rt_frame(sig
, ka
, info
, oldset
, regs
);
361 * This has nothing to do with segment registers,
362 * despite the name. This magic affects uaccess.h
363 * macros' behavior. Reset it to the normal setting.
369 * Clear the direction flag as per the ABI for function entry.
371 regs
->flags
&= ~X86_EFLAGS_DF
;
374 * Clear TF when entering the signal handler, but
375 * notify any tracer that was single-stepping it.
376 * The tracer may want to single-step inside the
379 regs
->flags
&= ~X86_EFLAGS_TF
;
381 spin_lock_irq(¤t
->sighand
->siglock
);
382 sigorsets(¤t
->blocked
, ¤t
->blocked
, &ka
->sa
.sa_mask
);
383 if (!(ka
->sa
.sa_flags
& SA_NODEFER
))
384 sigaddset(¤t
->blocked
, sig
);
386 spin_unlock_irq(¤t
->sighand
->siglock
);
388 tracehook_signal_handler(sig
, info
, ka
, regs
,
389 test_thread_flag(TIF_SINGLESTEP
));
394 #define NR_restart_syscall \
395 test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
397 * Note that 'init' is a special process: it doesn't get signals it doesn't
398 * want to handle. Thus you cannot kill init even with a SIGKILL even by
401 static void do_signal(struct pt_regs
*regs
)
403 struct k_sigaction ka
;
409 * We want the common case to go fast, which is why we may in certain
410 * cases get here from kernel mode. Just return without doing anything
412 * X86_32: vm86 regs switched out by assembly code before reaching
413 * here, so testing against kernel CS suffices.
415 if (!user_mode(regs
))
418 if (current_thread_info()->status
& TS_RESTORE_SIGMASK
)
419 oldset
= ¤t
->saved_sigmask
;
421 oldset
= ¤t
->blocked
;
423 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
426 * Re-enable any watchpoints before delivering the
427 * signal to user space. The processor register will
428 * have been cleared if the watchpoint triggered
431 if (current
->thread
.debugreg7
)
432 set_debugreg(current
->thread
.debugreg7
, 7);
434 /* Whee! Actually deliver the signal. */
435 if (handle_signal(signr
, &info
, &ka
, oldset
, regs
) == 0) {
437 * A signal was successfully delivered; the saved
438 * sigmask will have been stored in the signal frame,
439 * and will be restored by sigreturn, so we can simply
440 * clear the TS_RESTORE_SIGMASK flag.
442 current_thread_info()->status
&= ~TS_RESTORE_SIGMASK
;
447 /* Did we come from a system call? */
448 if (syscall_get_nr(current
, regs
) >= 0) {
449 /* Restart the system call - no handlers present */
450 switch (syscall_get_error(current
, regs
)) {
451 case -ERESTARTNOHAND
:
453 case -ERESTARTNOINTR
:
454 regs
->ax
= regs
->orig_ax
;
458 case -ERESTART_RESTARTBLOCK
:
459 regs
->ax
= NR_restart_syscall
;
466 * If there's no signal to deliver, we just put the saved sigmask
469 if (current_thread_info()->status
& TS_RESTORE_SIGMASK
) {
470 current_thread_info()->status
&= ~TS_RESTORE_SIGMASK
;
471 sigprocmask(SIG_SETMASK
, ¤t
->saved_sigmask
, NULL
);
476 * notification of userspace execution resumption
477 * - triggered by the TIF_WORK_MASK flags
480 do_notify_resume(struct pt_regs
*regs
, void *unused
, __u32 thread_info_flags
)
482 #if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
483 /* notify userspace of pending MCEs */
484 if (thread_info_flags
& _TIF_MCE_NOTIFY
)
486 #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
488 /* deal with pending signal delivery */
489 if (thread_info_flags
& _TIF_SIGPENDING
)
492 if (thread_info_flags
& _TIF_NOTIFY_RESUME
) {
493 clear_thread_flag(TIF_NOTIFY_RESUME
);
494 tracehook_notify_resume(regs
);
498 clear_thread_flag(TIF_IRET
);
499 #endif /* CONFIG_X86_32 */
502 void signal_fault(struct pt_regs
*regs
, void __user
*frame
, char *where
)
504 struct task_struct
*me
= current
;
506 if (show_unhandled_signals
&& printk_ratelimit()) {
508 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
509 me
->comm
, me
->pid
, where
, frame
,
510 regs
->ip
, regs
->sp
, regs
->orig_ax
);
511 print_vma_addr(" in ", regs
->ip
);
512 printk(KERN_CONT
"\n");
515 force_sig(SIGSEGV
, me
);