projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
x86/mpx: Restrict the mmap() size check to bounds tables
[deliverable/linux.git] / arch / x86 / kernel / signal.c
1 /*
2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
4 *
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
8 */
9
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12 #include <linux/sched.h>
13 #include <linux/mm.h>
14 #include <linux/smp.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/wait.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>
23 #include <linux/user-return-notifier.h>
24 #include <linux/uprobes.h>
25 #include <linux/context_tracking.h>
26
27 #include <asm/processor.h>
28 #include <asm/ucontext.h>
29 #include <asm/fpu/internal.h>
30 #include <asm/fpu/signal.h>
31 #include <asm/vdso.h>
32 #include <asm/mce.h>
33 #include <asm/sighandling.h>
34
35 #ifdef CONFIG_X86_64
36 #include <asm/proto.h>
37 #include <asm/ia32_unistd.h>
38 #include <asm/sys_ia32.h>
39 #endif /* CONFIG_X86_64 */
40
41 #include <asm/syscall.h>
42 #include <asm/syscalls.h>
43
44 #include <asm/sigframe.h>
45
46 #define COPY(x) do { \
47 get_user_ex(regs->x, &sc->x); \
48 } while (0)
49
50 #define GET_SEG(seg) ({ \
51 unsigned short tmp; \
52 get_user_ex(tmp, &sc->seg); \
53 tmp; \
54 })
55
56 #define COPY_SEG(seg) do { \
57 regs->seg = GET_SEG(seg); \
58 } while (0)
59
60 #define COPY_SEG_CPL3(seg) do { \
61 regs->seg = GET_SEG(seg) | 3; \
62 } while (0)
63
64 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
65 {
66 void __user *buf;
67 unsigned int tmpflags;
68 unsigned int err = 0;
69
70 /* Always make any pending restarted system calls return -EINTR */
71 current->restart_block.fn = do_no_restart_syscall;
72
73 get_user_try {
74
75 #ifdef CONFIG_X86_32
76 set_user_gs(regs, GET_SEG(gs));
77 COPY_SEG(fs);
78 COPY_SEG(es);
79 COPY_SEG(ds);
80 #endif /* CONFIG_X86_32 */
81
82 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
83 COPY(dx); COPY(cx); COPY(ip); COPY(ax);
84
85 #ifdef CONFIG_X86_64
86 COPY(r8);
87 COPY(r9);
88 COPY(r10);
89 COPY(r11);
90 COPY(r12);
91 COPY(r13);
92 COPY(r14);
93 COPY(r15);
94 #endif /* CONFIG_X86_64 */
95
96 COPY_SEG_CPL3(cs);
97 COPY_SEG_CPL3(ss);
98
99 get_user_ex(tmpflags, &sc->flags);
100 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
101 regs->orig_ax = -1; /* disable syscall checks */
102
103 get_user_ex(buf, &sc->fpstate);
104 } get_user_catch(err);
105
106 err |= fpu__restore_sig(buf, config_enabled(CONFIG_X86_32));
107
108 force_iret();
109
110 return err;
111 }
112
113 int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
114 struct pt_regs *regs, unsigned long mask)
115 {
116 int err = 0;
117
118 put_user_try {
119
120 #ifdef CONFIG_X86_32
121 put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs);
122 put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
123 put_user_ex(regs->es, (unsigned int __user *)&sc->es);
124 put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
125 #endif /* CONFIG_X86_32 */
126
127 put_user_ex(regs->di, &sc->di);
128 put_user_ex(regs->si, &sc->si);
129 put_user_ex(regs->bp, &sc->bp);
130 put_user_ex(regs->sp, &sc->sp);
131 put_user_ex(regs->bx, &sc->bx);
132 put_user_ex(regs->dx, &sc->dx);
133 put_user_ex(regs->cx, &sc->cx);
134 put_user_ex(regs->ax, &sc->ax);
135 #ifdef CONFIG_X86_64
136 put_user_ex(regs->r8, &sc->r8);
137 put_user_ex(regs->r9, &sc->r9);
138 put_user_ex(regs->r10, &sc->r10);
139 put_user_ex(regs->r11, &sc->r11);
140 put_user_ex(regs->r12, &sc->r12);
141 put_user_ex(regs->r13, &sc->r13);
142 put_user_ex(regs->r14, &sc->r14);
143 put_user_ex(regs->r15, &sc->r15);
144 #endif /* CONFIG_X86_64 */
145
146 put_user_ex(current->thread.trap_nr, &sc->trapno);
147 put_user_ex(current->thread.error_code, &sc->err);
148 put_user_ex(regs->ip, &sc->ip);
149 #ifdef CONFIG_X86_32
150 put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
151 put_user_ex(regs->flags, &sc->flags);
152 put_user_ex(regs->sp, &sc->sp_at_signal);
153 put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
154 #else /* !CONFIG_X86_32 */
155 put_user_ex(regs->flags, &sc->flags);
156 put_user_ex(regs->cs, &sc->cs);
157 put_user_ex(0, &sc->__pad2);
158 put_user_ex(0, &sc->__pad1);
159 put_user_ex(regs->ss, &sc->ss);
160 #endif /* CONFIG_X86_32 */
161
162 put_user_ex(fpstate, &sc->fpstate);
163
164 /* non-iBCS2 extensions.. */
165 put_user_ex(mask, &sc->oldmask);
166 put_user_ex(current->thread.cr2, &sc->cr2);
167 } put_user_catch(err);
168
169 return err;
170 }
171
172 /*
173 * Set up a signal frame.
174 */
175
176 /*
177 * Determine which stack to use..
178 */
179 static unsigned long align_sigframe(unsigned long sp)
180 {
181 #ifdef CONFIG_X86_32
182 /*
183 * Align the stack pointer according to the i386 ABI,
184 * i.e. so that on function entry ((sp + 4) & 15) == 0.
185 */
186 sp = ((sp + 4) & -16ul) - 4;
187 #else /* !CONFIG_X86_32 */
188 sp = round_down(sp, 16) - 8;
189 #endif
190 return sp;
191 }
192
193 static inline void __user *
194 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
195 void __user **fpstate)
196 {
197 /* Default to using normal stack */
198 unsigned long math_size = 0;
199 unsigned long sp = regs->sp;
200 unsigned long buf_fx = 0;
201 int onsigstack = on_sig_stack(sp);
202 struct fpu *fpu = &current->thread.fpu;
203
204 /* redzone */
205 if (config_enabled(CONFIG_X86_64))
206 sp -= 128;
207
208 if (!onsigstack) {
209 /* This is the X/Open sanctioned signal stack switching. */
210 if (ka->sa.sa_flags & SA_ONSTACK) {
211 if (current->sas_ss_size)
212 sp = current->sas_ss_sp + current->sas_ss_size;
213 } else if (config_enabled(CONFIG_X86_32) &&
214 (regs->ss & 0xffff) != __USER_DS &&
215 !(ka->sa.sa_flags & SA_RESTORER) &&
216 ka->sa.sa_restorer) {
217 /* This is the legacy signal stack switching. */
218 sp = (unsigned long) ka->sa.sa_restorer;
219 }
220 }
221
222 if (fpu->fpstate_active) {
223 sp = fpu__alloc_mathframe(sp, config_enabled(CONFIG_X86_32),
224 &buf_fx, &math_size);
225 *fpstate = (void __user *)sp;
226 }
227
228 sp = align_sigframe(sp - frame_size);
229
230 /*
231 * If we are on the alternate signal stack and would overflow it, don't.
232 * Return an always-bogus address instead so we will die with SIGSEGV.
233 */
234 if (onsigstack && !likely(on_sig_stack(sp)))
235 return (void __user *)-1L;
236
237 /* save i387 and extended state */
238 if (fpu->fpstate_active &&
239 copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size) < 0)
240 return (void __user *)-1L;
241
242 return (void __user *)sp;
243 }
244
245 #ifdef CONFIG_X86_32
246 static const struct {
247 u16 poplmovl;
248 u32 val;
249 u16 int80;
250 } __attribute__((packed)) retcode = {
251 0xb858, /* popl %eax; movl $..., %eax */
252 __NR_sigreturn,
253 0x80cd, /* int $0x80 */
254 };
255
256 static const struct {
257 u8 movl;
258 u32 val;
259 u16 int80;
260 u8 pad;
261 } __attribute__((packed)) rt_retcode = {
262 0xb8, /* movl $..., %eax */
263 __NR_rt_sigreturn,
264 0x80cd, /* int $0x80 */
265 0
266 };
267
268 static int
269 __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
270 struct pt_regs *regs)
271 {
272 struct sigframe __user *frame;
273 void __user *restorer;
274 int err = 0;
275 void __user *fpstate = NULL;
276
277 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
278
279 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
280 return -EFAULT;
281
282 if (__put_user(sig, &frame->sig))
283 return -EFAULT;
284
285 if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
286 return -EFAULT;
287
288 if (_NSIG_WORDS > 1) {
289 if (__copy_to_user(&frame->extramask, &set->sig[1],
290 sizeof(frame->extramask)))
291 return -EFAULT;
292 }
293
294 if (current->mm->context.vdso)
295 restorer = current->mm->context.vdso +
296 selected_vdso32->sym___kernel_sigreturn;
297 else
298 restorer = &frame->retcode;
299 if (ksig->ka.sa.sa_flags & SA_RESTORER)
300 restorer = ksig->ka.sa.sa_restorer;
301
302 /* Set up to return from userspace. */
303 err |= __put_user(restorer, &frame->pretcode);
304
305 /*
306 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
307 *
308 * WE DO NOT USE IT ANY MORE! It's only left here for historical
309 * reasons and because gdb uses it as a signature to notice
310 * signal handler stack frames.
311 */
312 err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
313
314 if (err)
315 return -EFAULT;
316
317 /* Set up registers for signal handler */
318 regs->sp = (unsigned long)frame;
319 regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
320 regs->ax = (unsigned long)sig;
321 regs->dx = 0;
322 regs->cx = 0;
323
324 regs->ds = __USER_DS;
325 regs->es = __USER_DS;
326 regs->ss = __USER_DS;
327 regs->cs = __USER_CS;
328
329 return 0;
330 }
331
332 static int __setup_rt_frame(int sig, struct ksignal *ksig,
333 sigset_t *set, struct pt_regs *regs)
334 {
335 struct rt_sigframe __user *frame;
336 void __user *restorer;
337 int err = 0;
338 void __user *fpstate = NULL;
339
340 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
341
342 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
343 return -EFAULT;
344
345 put_user_try {
346 put_user_ex(sig, &frame->sig);
347 put_user_ex(&frame->info, &frame->pinfo);
348 put_user_ex(&frame->uc, &frame->puc);
349
350 /* Create the ucontext. */
351 if (cpu_has_xsave)
352 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
353 else
354 put_user_ex(0, &frame->uc.uc_flags);
355 put_user_ex(0, &frame->uc.uc_link);
356 save_altstack_ex(&frame->uc.uc_stack, regs->sp);
357
358 /* Set up to return from userspace. */
359 restorer = current->mm->context.vdso +
360 selected_vdso32->sym___kernel_rt_sigreturn;
361 if (ksig->ka.sa.sa_flags & SA_RESTORER)
362 restorer = ksig->ka.sa.sa_restorer;
363 put_user_ex(restorer, &frame->pretcode);
364
365 /*
366 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
367 *
368 * WE DO NOT USE IT ANY MORE! It's only left here for historical
369 * reasons and because gdb uses it as a signature to notice
370 * signal handler stack frames.
371 */
372 put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
373 } put_user_catch(err);
374
375 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
376 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
377 regs, set->sig[0]);
378 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
379
380 if (err)
381 return -EFAULT;
382
383 /* Set up registers for signal handler */
384 regs->sp = (unsigned long)frame;
385 regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
386 regs->ax = (unsigned long)sig;
387 regs->dx = (unsigned long)&frame->info;
388 regs->cx = (unsigned long)&frame->uc;
389
390 regs->ds = __USER_DS;
391 regs->es = __USER_DS;
392 regs->ss = __USER_DS;
393 regs->cs = __USER_CS;
394
395 return 0;
396 }
397 #else /* !CONFIG_X86_32 */
398 static int __setup_rt_frame(int sig, struct ksignal *ksig,
399 sigset_t *set, struct pt_regs *regs)
400 {
401 struct rt_sigframe __user *frame;
402 void __user *fp = NULL;
403 int err = 0;
404
405 frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp);
406
407 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
408 return -EFAULT;
409
410 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
411 if (copy_siginfo_to_user(&frame->info, &ksig->info))
412 return -EFAULT;
413 }
414
415 put_user_try {
416 /* Create the ucontext. */
417 if (cpu_has_xsave)
418 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
419 else
420 put_user_ex(0, &frame->uc.uc_flags);
421 put_user_ex(0, &frame->uc.uc_link);
422 save_altstack_ex(&frame->uc.uc_stack, regs->sp);
423
424 /* Set up to return from userspace. If provided, use a stub
425 already in userspace. */
426 /* x86-64 should always use SA_RESTORER. */
427 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
428 put_user_ex(ksig->ka.sa.sa_restorer, &frame->pretcode);
429 } else {
430 /* could use a vstub here */
431 err |= -EFAULT;
432 }
433 } put_user_catch(err);
434
435 err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
436 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
437
438 if (err)
439 return -EFAULT;
440
441 /* Set up registers for signal handler */
442 regs->di = sig;
443 /* In case the signal handler was declared without prototypes */
444 regs->ax = 0;
445
446 /* This also works for non SA_SIGINFO handlers because they expect the
447 next argument after the signal number on the stack. */
448 regs->si = (unsigned long)&frame->info;
449 regs->dx = (unsigned long)&frame->uc;
450 regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
451
452 regs->sp = (unsigned long)frame;
453
454 /*
455 * Set up the CS and SS registers to run signal handlers in
456 * 64-bit mode, even if the handler happens to be interrupting
457 * 32-bit or 16-bit code.
458 *
459 * SS is subtle. In 64-bit mode, we don't need any particular
460 * SS descriptor, but we do need SS to be valid. It's possible
461 * that the old SS is entirely bogus -- this can happen if the
462 * signal we're trying to deliver is #GP or #SS caused by a bad
463 * SS value.
464 */
465 regs->cs = __USER_CS;
466 regs->ss = __USER_DS;
467
468 return 0;
469 }
470 #endif /* CONFIG_X86_32 */
471
472 static int x32_setup_rt_frame(struct ksignal *ksig,
473 compat_sigset_t *set,
474 struct pt_regs *regs)
475 {
476 #ifdef CONFIG_X86_X32_ABI
477 struct rt_sigframe_x32 __user *frame;
478 void __user *restorer;
479 int err = 0;
480 void __user *fpstate = NULL;
481
482 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
483
484 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
485 return -EFAULT;
486
487 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
488 if (copy_siginfo_to_user32(&frame->info, &ksig->info))
489 return -EFAULT;
490 }
491
492 put_user_try {
493 /* Create the ucontext. */
494 if (cpu_has_xsave)
495 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
496 else
497 put_user_ex(0, &frame->uc.uc_flags);
498 put_user_ex(0, &frame->uc.uc_link);
499 compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
500 put_user_ex(0, &frame->uc.uc__pad0);
501
502 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
503 restorer = ksig->ka.sa.sa_restorer;
504 } else {
505 /* could use a vstub here */
506 restorer = NULL;
507 err |= -EFAULT;
508 }
509 put_user_ex(restorer, &frame->pretcode);
510 } put_user_catch(err);
511
512 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
513 regs, set->sig[0]);
514 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
515
516 if (err)
517 return -EFAULT;
518
519 /* Set up registers for signal handler */
520 regs->sp = (unsigned long) frame;
521 regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
522
523 /* We use the x32 calling convention here... */
524 regs->di = ksig->sig;
525 regs->si = (unsigned long) &frame->info;
526 regs->dx = (unsigned long) &frame->uc;
527
528 loadsegment(ds, __USER_DS);
529 loadsegment(es, __USER_DS);
530
531 regs->cs = __USER_CS;
532 regs->ss = __USER_DS;
533 #endif /* CONFIG_X86_X32_ABI */
534
535 return 0;
536 }
537
538 /*
539 * Do a signal return; undo the signal stack.
540 */
541 #ifdef CONFIG_X86_32
542 asmlinkage unsigned long sys_sigreturn(void)
543 {
544 struct pt_regs *regs = current_pt_regs();
545 struct sigframe __user *frame;
546 sigset_t set;
547
548 frame = (struct sigframe __user *)(regs->sp - 8);
549
550 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
551 goto badframe;
552 if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
553 && __copy_from_user(&set.sig[1], &frame->extramask,
554 sizeof(frame->extramask))))
555 goto badframe;
556
557 set_current_blocked(&set);
558
559 if (restore_sigcontext(regs, &frame->sc))
560 goto badframe;
561 return regs->ax;
562
563 badframe:
564 signal_fault(regs, frame, "sigreturn");
565
566 return 0;
567 }
568 #endif /* CONFIG_X86_32 */
569
570 asmlinkage long sys_rt_sigreturn(void)
571 {
572 struct pt_regs *regs = current_pt_regs();
573 struct rt_sigframe __user *frame;
574 sigset_t set;
575
576 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
577 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
578 goto badframe;
579 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
580 goto badframe;
581
582 set_current_blocked(&set);
583
584 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
585 goto badframe;
586
587 if (restore_altstack(&frame->uc.uc_stack))
588 goto badframe;
589
590 return regs->ax;
591
592 badframe:
593 signal_fault(regs, frame, "rt_sigreturn");
594 return 0;
595 }
596
597 static inline int is_ia32_compat_frame(void)
598 {
599 return config_enabled(CONFIG_IA32_EMULATION) &&
600 test_thread_flag(TIF_IA32);
601 }
602
603 static inline int is_ia32_frame(void)
604 {
605 return config_enabled(CONFIG_X86_32) || is_ia32_compat_frame();
606 }
607
608 static inline int is_x32_frame(void)
609 {
610 return config_enabled(CONFIG_X86_X32_ABI) && test_thread_flag(TIF_X32);
611 }
612
613 static int
614 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
615 {
616 int usig = ksig->sig;
617 sigset_t *set = sigmask_to_save();
618 compat_sigset_t *cset = (compat_sigset_t *) set;
619
620 /* Set up the stack frame */
621 if (is_ia32_frame()) {
622 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
623 return ia32_setup_rt_frame(usig, ksig, cset, regs);
624 else
625 return ia32_setup_frame(usig, ksig, cset, regs);
626 } else if (is_x32_frame()) {
627 return x32_setup_rt_frame(ksig, cset, regs);
628 } else {
629 return __setup_rt_frame(ksig->sig, ksig, set, regs);
630 }
631 }
632
633 static void
634 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
635 {
636 bool stepping, failed;
637 struct fpu *fpu = &current->thread.fpu;
638
639 /* Are we from a system call? */
640 if (syscall_get_nr(current, regs) >= 0) {
641 /* If so, check system call restarting.. */
642 switch (syscall_get_error(current, regs)) {
643 case -ERESTART_RESTARTBLOCK:
644 case -ERESTARTNOHAND:
645 regs->ax = -EINTR;
646 break;
647
648 case -ERESTARTSYS:
649 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
650 regs->ax = -EINTR;
651 break;
652 }
653 /* fallthrough */
654 case -ERESTARTNOINTR:
655 regs->ax = regs->orig_ax;
656 regs->ip -= 2;
657 break;
658 }
659 }
660
661 /*
662 * If TF is set due to a debugger (TIF_FORCED_TF), clear TF now
663 * so that register information in the sigcontext is correct and
664 * then notify the tracer before entering the signal handler.
665 */
666 stepping = test_thread_flag(TIF_SINGLESTEP);
667 if (stepping)
668 user_disable_single_step(current);
669
670 failed = (setup_rt_frame(ksig, regs) < 0);
671 if (!failed) {
672 /*
673 * Clear the direction flag as per the ABI for function entry.
674 *
675 * Clear RF when entering the signal handler, because
676 * it might disable possible debug exception from the
677 * signal handler.
678 *
679 * Clear TF for the case when it wasn't set by debugger to
680 * avoid the recursive send_sigtrap() in SIGTRAP handler.
681 */
682 regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF);
683 /*
684 * Ensure the signal handler starts with the new fpu state.
685 */
686 if (fpu->fpstate_active)
687 fpu__clear(fpu);
688 }
689 signal_setup_done(failed, ksig, stepping);
690 }
691
692 #ifdef CONFIG_X86_32
693 #define NR_restart_syscall __NR_restart_syscall
694 #else /* !CONFIG_X86_32 */
695 #define NR_restart_syscall \
696 test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
697 #endif /* CONFIG_X86_32 */
698
699 /*
700 * Note that 'init' is a special process: it doesn't get signals it doesn't
701 * want to handle. Thus you cannot kill init even with a SIGKILL even by
702 * mistake.
703 */
704 static void do_signal(struct pt_regs *regs)
705 {
706 struct ksignal ksig;
707
708 if (get_signal(&ksig)) {
709 /* Whee! Actually deliver the signal. */
710 handle_signal(&ksig, regs);
711 return;
712 }
713
714 /* Did we come from a system call? */
715 if (syscall_get_nr(current, regs) >= 0) {
716 /* Restart the system call - no handlers present */
717 switch (syscall_get_error(current, regs)) {
718 case -ERESTARTNOHAND:
719 case -ERESTARTSYS:
720 case -ERESTARTNOINTR:
721 regs->ax = regs->orig_ax;
722 regs->ip -= 2;
723 break;
724
725 case -ERESTART_RESTARTBLOCK:
726 regs->ax = NR_restart_syscall;
727 regs->ip -= 2;
728 break;
729 }
730 }
731
732 /*
733 * If there's no signal to deliver, we just put the saved sigmask
734 * back.
735 */
736 restore_saved_sigmask();
737 }
738
739 /*
740 * notification of userspace execution resumption
741 * - triggered by the TIF_WORK_MASK flags
742 */
743 __visible void
744 do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
745 {
746 user_exit();
747
748 if (thread_info_flags & _TIF_UPROBE)
749 uprobe_notify_resume(regs);
750
751 /* deal with pending signal delivery */
752 if (thread_info_flags & _TIF_SIGPENDING)
753 do_signal(regs);
754
755 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
756 clear_thread_flag(TIF_NOTIFY_RESUME);
757 tracehook_notify_resume(regs);
758 }
759 if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
760 fire_user_return_notifiers();
761
762 user_enter();
763 }
764
765 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
766 {
767 struct task_struct *me = current;
768
769 if (show_unhandled_signals && printk_ratelimit()) {
770 printk("%s"
771 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
772 task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
773 me->comm, me->pid, where, frame,
774 regs->ip, regs->sp, regs->orig_ax);
775 print_vma_addr(" in ", regs->ip);
776 pr_cont("\n");
777 }
778
779 force_sig(SIGSEGV, me);
780 }
781
782 #ifdef CONFIG_X86_X32_ABI
783 asmlinkage long sys32_x32_rt_sigreturn(void)
784 {
785 struct pt_regs *regs = current_pt_regs();
786 struct rt_sigframe_x32 __user *frame;
787 sigset_t set;
788
789 frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
790
791 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
792 goto badframe;
793 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
794 goto badframe;
795
796 set_current_blocked(&set);
797
798 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
799 goto badframe;
800
801 if (compat_restore_altstack(&frame->uc.uc_stack))
802 goto badframe;
803
804 return regs->ax;
805
806 badframe:
807 signal_fault(regs, frame, "x32 rt_sigreturn");
808 return 0;
809 }
810 #endif
Linux kernel - Deliverables
This page took 0.065185 seconds and 5 git commands to generate.