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CommitLineData
1da177e4 1/*
1da177e4 2 * Copyright (C) 1991, 1992 Linus Torvalds
e5fa2d06 3 * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
1da177e4
LT
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
e5fa2d06 7 * 2000-2002 x86-64 support by Andi Kleen
1da177e4 8 */
c767a54b
JP
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
5c9b3a0c
HS
12#include <linux/sched.h>
13#include <linux/mm.h>
14#include <linux/smp.h>
1da177e4 15#include <linux/kernel.h>
1da177e4
LT
16#include <linux/errno.h>
17#include <linux/wait.h>
36a03308 18#include <linux/tracehook.h>
5c9b3a0c
HS
19#include <linux/unistd.h>
20#include <linux/stddef.h>
21#include <linux/personality.h>
22#include <linux/uaccess.h>
7c68af6e 23#include <linux/user-return-notifier.h>
0326f5a9 24#include <linux/uprobes.h>
91d1aa43 25#include <linux/context_tracking.h>
7e907f48 26
1da177e4
LT
27#include <asm/processor.h>
28#include <asm/ucontext.h>
78f7f1e5 29#include <asm/fpu/internal.h>
fcbc99c4 30#include <asm/fpu/signal.h>
6c3652ef 31#include <asm/vdso.h>
4efc0670 32#include <asm/mce.h>
f28f0c23 33#include <asm/sighandling.h>
ba3e127e 34#include <asm/vm86.h>
5c9b3a0c
HS
35
36#ifdef CONFIG_X86_64
37#include <asm/proto.h>
38#include <asm/ia32_unistd.h>
5c9b3a0c
HS
39#endif /* CONFIG_X86_64 */
40
bb57925f 41#include <asm/syscall.h>
bbc1f698 42#include <asm/syscalls.h>
7e907f48 43
41af86fa 44#include <asm/sigframe.h>
1da177e4 45
d9a89a26
TH
46#define COPY(x) do { \
47 get_user_ex(regs->x, &sc->x); \
48} while (0)
2601657d 49
d9a89a26
TH
50#define GET_SEG(seg) ({ \
51 unsigned short tmp; \
52 get_user_ex(tmp, &sc->seg); \
53 tmp; \
54})
2601657d 55
d9a89a26
TH
56#define COPY_SEG(seg) do { \
57 regs->seg = GET_SEG(seg); \
58} while (0)
2601657d 59
d9a89a26
TH
60#define COPY_SEG_CPL3(seg) do { \
61 regs->seg = GET_SEG(seg) | 3; \
62} while (0)
2601657d 63
6a3713f0 64int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
2601657d
HS
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 */
f56141e3 71 current->restart_block.fn = do_no_restart_syscall;
2601657d 72
98e3d45e
HS
73 get_user_try {
74
2601657d 75#ifdef CONFIG_X86_32
d9a89a26 76 set_user_gs(regs, GET_SEG(gs));
98e3d45e
HS
77 COPY_SEG(fs);
78 COPY_SEG(es);
79 COPY_SEG(ds);
2601657d
HS
80#endif /* CONFIG_X86_32 */
81
98e3d45e 82 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
6a3713f0 83 COPY(dx); COPY(cx); COPY(ip); COPY(ax);
2601657d
HS
84
85#ifdef CONFIG_X86_64
98e3d45e
HS
86 COPY(r8);
87 COPY(r9);
88 COPY(r10);
89 COPY(r11);
90 COPY(r12);
91 COPY(r13);
92 COPY(r14);
93 COPY(r15);
2601657d
HS
94#endif /* CONFIG_X86_64 */
95
ed596cde 96#ifdef CONFIG_X86_32
98e3d45e
HS
97 COPY_SEG_CPL3(cs);
98 COPY_SEG_CPL3(ss);
ed596cde
LT
99#else /* !CONFIG_X86_32 */
100 /* Kernel saves and restores only the CS segment register on signals,
101 * which is the bare minimum needed to allow mixed 32/64-bit code.
102 * App's signal handler can save/restore other segments if needed. */
103 COPY_SEG_CPL3(cs);
104#endif /* CONFIG_X86_32 */
2601657d 105
98e3d45e
HS
106 get_user_ex(tmpflags, &sc->flags);
107 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
108 regs->orig_ax = -1; /* disable syscall checks */
109
110 get_user_ex(buf, &sc->fpstate);
98e3d45e 111 } get_user_catch(err);
2601657d 112
9dfe99b7 113 err |= fpu__restore_sig(buf, config_enabled(CONFIG_X86_32));
5e88353d 114
1daeaa31
BG
115 force_iret();
116
2601657d
HS
117 return err;
118}
119
85139422
PA
120int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
121 struct pt_regs *regs, unsigned long mask)
2601657d
HS
122{
123 int err = 0;
124
98e3d45e 125 put_user_try {
2601657d 126
98e3d45e 127#ifdef CONFIG_X86_32
d9a89a26 128 put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs);
98e3d45e
HS
129 put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
130 put_user_ex(regs->es, (unsigned int __user *)&sc->es);
131 put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
2601657d
HS
132#endif /* CONFIG_X86_32 */
133
98e3d45e
HS
134 put_user_ex(regs->di, &sc->di);
135 put_user_ex(regs->si, &sc->si);
136 put_user_ex(regs->bp, &sc->bp);
137 put_user_ex(regs->sp, &sc->sp);
138 put_user_ex(regs->bx, &sc->bx);
139 put_user_ex(regs->dx, &sc->dx);
140 put_user_ex(regs->cx, &sc->cx);
141 put_user_ex(regs->ax, &sc->ax);
2601657d 142#ifdef CONFIG_X86_64
98e3d45e
HS
143 put_user_ex(regs->r8, &sc->r8);
144 put_user_ex(regs->r9, &sc->r9);
145 put_user_ex(regs->r10, &sc->r10);
146 put_user_ex(regs->r11, &sc->r11);
147 put_user_ex(regs->r12, &sc->r12);
148 put_user_ex(regs->r13, &sc->r13);
149 put_user_ex(regs->r14, &sc->r14);
150 put_user_ex(regs->r15, &sc->r15);
2601657d
HS
151#endif /* CONFIG_X86_64 */
152
51e7dc70 153 put_user_ex(current->thread.trap_nr, &sc->trapno);
98e3d45e
HS
154 put_user_ex(current->thread.error_code, &sc->err);
155 put_user_ex(regs->ip, &sc->ip);
2601657d 156#ifdef CONFIG_X86_32
98e3d45e
HS
157 put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
158 put_user_ex(regs->flags, &sc->flags);
159 put_user_ex(regs->sp, &sc->sp_at_signal);
160 put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
2601657d 161#else /* !CONFIG_X86_32 */
98e3d45e
HS
162 put_user_ex(regs->flags, &sc->flags);
163 put_user_ex(regs->cs, &sc->cs);
ed596cde
LT
164 put_user_ex(0, &sc->gs);
165 put_user_ex(0, &sc->fs);
2601657d
HS
166#endif /* CONFIG_X86_32 */
167
98e3d45e 168 put_user_ex(fpstate, &sc->fpstate);
2601657d 169
98e3d45e
HS
170 /* non-iBCS2 extensions.. */
171 put_user_ex(mask, &sc->oldmask);
172 put_user_ex(current->thread.cr2, &sc->cr2);
173 } put_user_catch(err);
2601657d
HS
174
175 return err;
176}
177
1da177e4 178/*
bfeb91a9 179 * Set up a signal frame.
1da177e4 180 */
1da177e4
LT
181
182/*
183 * Determine which stack to use..
184 */
1fae0279
HS
185static unsigned long align_sigframe(unsigned long sp)
186{
187#ifdef CONFIG_X86_32
188 /*
189 * Align the stack pointer according to the i386 ABI,
190 * i.e. so that on function entry ((sp + 4) & 15) == 0.
191 */
192 sp = ((sp + 4) & -16ul) - 4;
193#else /* !CONFIG_X86_32 */
194 sp = round_down(sp, 16) - 8;
195#endif
196 return sp;
197}
198
1da177e4 199static inline void __user *
3c1c7f10 200get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
144b0712 201 void __user **fpstate)
1da177e4 202{
1da177e4 203 /* Default to using normal stack */
72a671ce 204 unsigned long math_size = 0;
75779f05 205 unsigned long sp = regs->sp;
72a671ce 206 unsigned long buf_fx = 0;
14fc9fbc 207 int onsigstack = on_sig_stack(sp);
c5bedc68 208 struct fpu *fpu = &current->thread.fpu;
75779f05 209
75779f05 210 /* redzone */
050902c0
SS
211 if (config_enabled(CONFIG_X86_64))
212 sp -= 128;
1da177e4 213
14fc9fbc
HS
214 if (!onsigstack) {
215 /* This is the X/Open sanctioned signal stack switching. */
216 if (ka->sa.sa_flags & SA_ONSTACK) {
0f8f3089 217 if (current->sas_ss_size)
14fc9fbc 218 sp = current->sas_ss_sp + current->sas_ss_size;
050902c0
SS
219 } else if (config_enabled(CONFIG_X86_32) &&
220 (regs->ss & 0xffff) != __USER_DS &&
221 !(ka->sa.sa_flags & SA_RESTORER) &&
222 ka->sa.sa_restorer) {
223 /* This is the legacy signal stack switching. */
14fc9fbc 224 sp = (unsigned long) ka->sa.sa_restorer;
14fc9fbc 225 }
1da177e4
LT
226 }
227
c5bedc68 228 if (fpu->fpstate_active) {
82c0e45e
IM
229 sp = fpu__alloc_mathframe(sp, config_enabled(CONFIG_X86_32),
230 &buf_fx, &math_size);
25051702 231 *fpstate = (void __user *)sp;
3c1c7f10
SS
232 }
233
14fc9fbc
HS
234 sp = align_sigframe(sp - frame_size);
235
236 /*
237 * If we are on the alternate signal stack and would overflow it, don't.
238 * Return an always-bogus address instead so we will die with SIGSEGV.
239 */
240 if (onsigstack && !likely(on_sig_stack(sp)))
241 return (void __user *)-1L;
242
72a671ce 243 /* save i387 and extended state */
c5bedc68 244 if (fpu->fpstate_active &&
c8e14041 245 copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size) < 0)
14fc9fbc
HS
246 return (void __user *)-1L;
247
248 return (void __user *)sp;
1da177e4
LT
249}
250
75779f05
HS
251#ifdef CONFIG_X86_32
252static const struct {
253 u16 poplmovl;
254 u32 val;
255 u16 int80;
256} __attribute__((packed)) retcode = {
257 0xb858, /* popl %eax; movl $..., %eax */
258 __NR_sigreturn,
259 0x80cd, /* int $0x80 */
260};
261
262static const struct {
263 u8 movl;
264 u32 val;
265 u16 int80;
266 u8 pad;
267} __attribute__((packed)) rt_retcode = {
268 0xb8, /* movl $..., %eax */
269 __NR_rt_sigreturn,
270 0x80cd, /* int $0x80 */
271 0
272};
273
7e907f48 274static int
235b8022 275__setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
1d13024e 276 struct pt_regs *regs)
1da177e4 277{
1da177e4 278 struct sigframe __user *frame;
7e907f48 279 void __user *restorer;
1da177e4 280 int err = 0;
ab513701 281 void __user *fpstate = NULL;
1da177e4 282
235b8022 283 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
1da177e4
LT
284
285 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
3d0aedd9 286 return -EFAULT;
1da177e4 287
2ba48e16 288 if (__put_user(sig, &frame->sig))
3d0aedd9 289 return -EFAULT;
1da177e4 290
2ba48e16 291 if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
3d0aedd9 292 return -EFAULT;
1da177e4
LT
293
294 if (_NSIG_WORDS > 1) {
2ba48e16
HS
295 if (__copy_to_user(&frame->extramask, &set->sig[1],
296 sizeof(frame->extramask)))
3d0aedd9 297 return -EFAULT;
1da177e4
LT
298 }
299
1a3e4ca4 300 if (current->mm->context.vdso)
6f121e54
AL
301 restorer = current->mm->context.vdso +
302 selected_vdso32->sym___kernel_sigreturn;
9fbbd4dd 303 else
ade1af77 304 restorer = &frame->retcode;
235b8022
AV
305 if (ksig->ka.sa.sa_flags & SA_RESTORER)
306 restorer = ksig->ka.sa.sa_restorer;
1da177e4
LT
307
308 /* Set up to return from userspace. */
309 err |= __put_user(restorer, &frame->pretcode);
7e907f48 310
1da177e4 311 /*
7e907f48 312 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
1da177e4
LT
313 *
314 * WE DO NOT USE IT ANY MORE! It's only left here for historical
315 * reasons and because gdb uses it as a signature to notice
316 * signal handler stack frames.
317 */
4a612048 318 err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
1da177e4
LT
319
320 if (err)
3d0aedd9 321 return -EFAULT;
1da177e4
LT
322
323 /* Set up registers for signal handler */
7e907f48 324 regs->sp = (unsigned long)frame;
235b8022 325 regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
7e907f48 326 regs->ax = (unsigned long)sig;
92bc2056
HH
327 regs->dx = 0;
328 regs->cx = 0;
1da177e4 329
65ea5b03
PA
330 regs->ds = __USER_DS;
331 regs->es = __USER_DS;
332 regs->ss = __USER_DS;
333 regs->cs = __USER_CS;
1da177e4 334
283828f3 335 return 0;
1da177e4
LT
336}
337
235b8022 338static int __setup_rt_frame(int sig, struct ksignal *ksig,
1d13024e 339 sigset_t *set, struct pt_regs *regs)
1da177e4 340{
1da177e4 341 struct rt_sigframe __user *frame;
7e907f48 342 void __user *restorer;
1da177e4 343 int err = 0;
ab513701 344 void __user *fpstate = NULL;
1da177e4 345
235b8022 346 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
1da177e4
LT
347
348 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
3d0aedd9 349 return -EFAULT;
1da177e4 350
98e3d45e
HS
351 put_user_try {
352 put_user_ex(sig, &frame->sig);
353 put_user_ex(&frame->info, &frame->pinfo);
354 put_user_ex(&frame->uc, &frame->puc);
98e3d45e
HS
355
356 /* Create the ucontext. */
357 if (cpu_has_xsave)
358 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
359 else
360 put_user_ex(0, &frame->uc.uc_flags);
361 put_user_ex(0, &frame->uc.uc_link);
bd1c149a 362 save_altstack_ex(&frame->uc.uc_stack, regs->sp);
98e3d45e
HS
363
364 /* Set up to return from userspace. */
6f121e54 365 restorer = current->mm->context.vdso +
6ba19a67 366 selected_vdso32->sym___kernel_rt_sigreturn;
235b8022
AV
367 if (ksig->ka.sa.sa_flags & SA_RESTORER)
368 restorer = ksig->ka.sa.sa_restorer;
98e3d45e
HS
369 put_user_ex(restorer, &frame->pretcode);
370
371 /*
372 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
373 *
374 * WE DO NOT USE IT ANY MORE! It's only left here for historical
375 * reasons and because gdb uses it as a signature to notice
376 * signal handler stack frames.
377 */
378 put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
379 } put_user_catch(err);
49b8c695 380
235b8022 381 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
5e88353d
PA
382 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
383 regs, set->sig[0]);
384 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
1da177e4
LT
385
386 if (err)
3d0aedd9 387 return -EFAULT;
1da177e4
LT
388
389 /* Set up registers for signal handler */
7e907f48 390 regs->sp = (unsigned long)frame;
235b8022 391 regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
13ad7725 392 regs->ax = (unsigned long)sig;
7e907f48
IM
393 regs->dx = (unsigned long)&frame->info;
394 regs->cx = (unsigned long)&frame->uc;
1da177e4 395
65ea5b03
PA
396 regs->ds = __USER_DS;
397 regs->es = __USER_DS;
398 regs->ss = __USER_DS;
399 regs->cs = __USER_CS;
1da177e4 400
283828f3 401 return 0;
1da177e4 402}
bfeb91a9 403#else /* !CONFIG_X86_32 */
235b8022 404static int __setup_rt_frame(int sig, struct ksignal *ksig,
bfeb91a9
HS
405 sigset_t *set, struct pt_regs *regs)
406{
407 struct rt_sigframe __user *frame;
408 void __user *fp = NULL;
409 int err = 0;
bfeb91a9 410
235b8022 411 frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp);
bfeb91a9
HS
412
413 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
414 return -EFAULT;
415
235b8022
AV
416 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
417 if (copy_siginfo_to_user(&frame->info, &ksig->info))
bfeb91a9
HS
418 return -EFAULT;
419 }
420
98e3d45e
HS
421 put_user_try {
422 /* Create the ucontext. */
423 if (cpu_has_xsave)
424 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
425 else
426 put_user_ex(0, &frame->uc.uc_flags);
427 put_user_ex(0, &frame->uc.uc_link);
bd1c149a 428 save_altstack_ex(&frame->uc.uc_stack, regs->sp);
98e3d45e
HS
429
430 /* Set up to return from userspace. If provided, use a stub
431 already in userspace. */
432 /* x86-64 should always use SA_RESTORER. */
235b8022
AV
433 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
434 put_user_ex(ksig->ka.sa.sa_restorer, &frame->pretcode);
98e3d45e
HS
435 } else {
436 /* could use a vstub here */
437 err |= -EFAULT;
438 }
439 } put_user_catch(err);
bfeb91a9 440
5e88353d
PA
441 err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
442 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
443
bfeb91a9
HS
444 if (err)
445 return -EFAULT;
446
447 /* Set up registers for signal handler */
448 regs->di = sig;
449 /* In case the signal handler was declared without prototypes */
450 regs->ax = 0;
451
452 /* This also works for non SA_SIGINFO handlers because they expect the
453 next argument after the signal number on the stack. */
454 regs->si = (unsigned long)&frame->info;
455 regs->dx = (unsigned long)&frame->uc;
235b8022 456 regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
bfeb91a9
HS
457
458 regs->sp = (unsigned long)frame;
459
ed596cde
LT
460 /* Set up the CS register to run signal handlers in 64-bit mode,
461 even if the handler happens to be interrupting 32-bit code. */
bfeb91a9
HS
462 regs->cs = __USER_CS;
463
464 return 0;
465}
466#endif /* CONFIG_X86_32 */
467
235b8022
AV
468static int x32_setup_rt_frame(struct ksignal *ksig,
469 compat_sigset_t *set,
050902c0
SS
470 struct pt_regs *regs)
471{
472#ifdef CONFIG_X86_X32_ABI
473 struct rt_sigframe_x32 __user *frame;
474 void __user *restorer;
475 int err = 0;
476 void __user *fpstate = NULL;
477
235b8022 478 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
050902c0
SS
479
480 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
481 return -EFAULT;
482
235b8022
AV
483 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
484 if (copy_siginfo_to_user32(&frame->info, &ksig->info))
050902c0
SS
485 return -EFAULT;
486 }
487
488 put_user_try {
489 /* Create the ucontext. */
490 if (cpu_has_xsave)
491 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
492 else
493 put_user_ex(0, &frame->uc.uc_flags);
494 put_user_ex(0, &frame->uc.uc_link);
bd1c149a 495 compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
050902c0 496 put_user_ex(0, &frame->uc.uc__pad0);
050902c0 497
235b8022
AV
498 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
499 restorer = ksig->ka.sa.sa_restorer;
050902c0
SS
500 } else {
501 /* could use a vstub here */
502 restorer = NULL;
503 err |= -EFAULT;
504 }
505 put_user_ex(restorer, &frame->pretcode);
506 } put_user_catch(err);
507
49b8c695
PA
508 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
509 regs, set->sig[0]);
510 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
511
050902c0
SS
512 if (err)
513 return -EFAULT;
514
515 /* Set up registers for signal handler */
516 regs->sp = (unsigned long) frame;
235b8022 517 regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
050902c0
SS
518
519 /* We use the x32 calling convention here... */
235b8022 520 regs->di = ksig->sig;
050902c0
SS
521 regs->si = (unsigned long) &frame->info;
522 regs->dx = (unsigned long) &frame->uc;
523
524 loadsegment(ds, __USER_DS);
525 loadsegment(es, __USER_DS);
526
527 regs->cs = __USER_CS;
528 regs->ss = __USER_DS;
529#endif /* CONFIG_X86_X32_ABI */
530
531 return 0;
532}
533
bfeb91a9
HS
534/*
535 * Do a signal return; undo the signal stack.
536 */
e5fa2d06 537#ifdef CONFIG_X86_32
ff49103f 538asmlinkage unsigned long sys_sigreturn(void)
bfeb91a9 539{
3fe26fa3 540 struct pt_regs *regs = current_pt_regs();
bfeb91a9 541 struct sigframe __user *frame;
bfeb91a9
HS
542 sigset_t set;
543
bfeb91a9
HS
544 frame = (struct sigframe __user *)(regs->sp - 8);
545
546 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
547 goto badframe;
548 if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
549 && __copy_from_user(&set.sig[1], &frame->extramask,
550 sizeof(frame->extramask))))
551 goto badframe;
552
3982294b 553 set_current_blocked(&set);
bfeb91a9 554
6a3713f0 555 if (restore_sigcontext(regs, &frame->sc))
bfeb91a9 556 goto badframe;
6a3713f0 557 return regs->ax;
bfeb91a9
HS
558
559badframe:
ae417bb4 560 signal_fault(regs, frame, "sigreturn");
bfeb91a9
HS
561
562 return 0;
563}
e5fa2d06 564#endif /* CONFIG_X86_32 */
bfeb91a9 565
ff49103f 566asmlinkage long sys_rt_sigreturn(void)
bfeb91a9 567{
3fe26fa3 568 struct pt_regs *regs = current_pt_regs();
bfeb91a9 569 struct rt_sigframe __user *frame;
bfeb91a9
HS
570 sigset_t set;
571
572 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
573 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
574 goto badframe;
575 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
576 goto badframe;
577
e9bd3f0f 578 set_current_blocked(&set);
bfeb91a9 579
6a3713f0 580 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
bfeb91a9
HS
581 goto badframe;
582
c40702c4 583 if (restore_altstack(&frame->uc.uc_stack))
bfeb91a9
HS
584 goto badframe;
585
6a3713f0 586 return regs->ax;
bfeb91a9
HS
587
588badframe:
589 signal_fault(regs, frame, "rt_sigreturn");
590 return 0;
591}
592
05012c13
IM
593static inline int is_ia32_compat_frame(void)
594{
595 return config_enabled(CONFIG_IA32_EMULATION) &&
596 test_thread_flag(TIF_IA32);
597}
598
599static inline int is_ia32_frame(void)
600{
601 return config_enabled(CONFIG_X86_32) || is_ia32_compat_frame();
602}
603
604static inline int is_x32_frame(void)
605{
606 return config_enabled(CONFIG_X86_X32_ABI) && test_thread_flag(TIF_X32);
607}
608
1d13024e 609static int
235b8022 610setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
1d13024e 611{
3050a35f 612 int usig = ksig->sig;
b7f9a11a 613 sigset_t *set = sigmask_to_save();
050902c0 614 compat_sigset_t *cset = (compat_sigset_t *) set;
1d13024e
HS
615
616 /* Set up the stack frame */
050902c0 617 if (is_ia32_frame()) {
235b8022
AV
618 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
619 return ia32_setup_rt_frame(usig, ksig, cset, regs);
455edbc4 620 else
235b8022 621 return ia32_setup_frame(usig, ksig, cset, regs);
050902c0 622 } else if (is_x32_frame()) {
235b8022 623 return x32_setup_rt_frame(ksig, cset, regs);
c5a37394 624 } else {
235b8022 625 return __setup_rt_frame(ksig->sig, ksig, set, regs);
c5a37394 626 }
1d13024e
HS
627}
628
a610d6e6 629static void
235b8022 630handle_signal(struct ksignal *ksig, struct pt_regs *regs)
1da177e4 631{
fd0f86b6 632 bool stepping, failed;
c5bedc68 633 struct fpu *fpu = &current->thread.fpu;
fd0f86b6 634
5ed92a8a
BG
635 if (v8086_mode(regs))
636 save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL);
637
1da177e4 638 /* Are we from a system call? */
bb57925f 639 if (syscall_get_nr(current, regs) >= 0) {
1da177e4 640 /* If so, check system call restarting.. */
bb57925f 641 switch (syscall_get_error(current, regs)) {
ac66f3fd
HH
642 case -ERESTART_RESTARTBLOCK:
643 case -ERESTARTNOHAND:
644 regs->ax = -EINTR;
645 break;
646
647 case -ERESTARTSYS:
235b8022 648 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
65ea5b03 649 regs->ax = -EINTR;
1da177e4 650 break;
ac66f3fd
HH
651 }
652 /* fallthrough */
653 case -ERESTARTNOINTR:
654 regs->ax = regs->orig_ax;
655 regs->ip -= 2;
656 break;
1da177e4
LT
657 }
658 }
659
660 /*
fd0f86b6
ON
661 * If TF is set due to a debugger (TIF_FORCED_TF), clear TF now
662 * so that register information in the sigcontext is correct and
663 * then notify the tracer before entering the signal handler.
1da177e4 664 */
fd0f86b6
ON
665 stepping = test_thread_flag(TIF_SINGLESTEP);
666 if (stepping)
667 user_disable_single_step(current);
1da177e4 668
235b8022
AV
669 failed = (setup_rt_frame(ksig, regs) < 0);
670 if (!failed) {
671 /*
672 * Clear the direction flag as per the ABI for function entry.
ddd40da4 673 *
24cda109
JO
674 * Clear RF when entering the signal handler, because
675 * it might disable possible debug exception from the
676 * signal handler.
ddd40da4 677 *
fd0f86b6
ON
678 * Clear TF for the case when it wasn't set by debugger to
679 * avoid the recursive send_sigtrap() in SIGTRAP handler.
235b8022 680 */
ddd40da4 681 regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF);
66463db4
ON
682 /*
683 * Ensure the signal handler starts with the new fpu state.
684 */
c5bedc68 685 if (fpu->fpstate_active)
fbce7782 686 fpu__clear(fpu);
a610d6e6 687 }
fd0f86b6 688 signal_setup_done(failed, ksig, stepping);
1da177e4
LT
689}
690
57917752 691#ifdef CONFIG_X86_32
8fcd8e20 692#define NR_restart_syscall __NR_restart_syscall
57917752
HS
693#else /* !CONFIG_X86_32 */
694#define NR_restart_syscall \
695 test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
696#endif /* CONFIG_X86_32 */
697
1da177e4
LT
698/*
699 * Note that 'init' is a special process: it doesn't get signals it doesn't
700 * want to handle. Thus you cannot kill init even with a SIGKILL even by
701 * mistake.
702 */
1f484aa6 703void do_signal(struct pt_regs *regs)
1da177e4 704{
235b8022 705 struct ksignal ksig;
1da177e4 706
235b8022 707 if (get_signal(&ksig)) {
7e907f48 708 /* Whee! Actually deliver the signal. */
235b8022 709 handle_signal(&ksig, regs);
283828f3 710 return;
1da177e4
LT
711 }
712
1da177e4 713 /* Did we come from a system call? */
bb57925f 714 if (syscall_get_nr(current, regs) >= 0) {
1da177e4 715 /* Restart the system call - no handlers present */
bb57925f 716 switch (syscall_get_error(current, regs)) {
283828f3
DH
717 case -ERESTARTNOHAND:
718 case -ERESTARTSYS:
719 case -ERESTARTNOINTR:
65ea5b03
PA
720 regs->ax = regs->orig_ax;
721 regs->ip -= 2;
283828f3
DH
722 break;
723
724 case -ERESTART_RESTARTBLOCK:
8fcd8e20 725 regs->ax = NR_restart_syscall;
65ea5b03 726 regs->ip -= 2;
283828f3 727 break;
1da177e4
LT
728 }
729 }
283828f3 730
ac66f3fd
HH
731 /*
732 * If there's no signal to deliver, we just put the saved sigmask
733 * back.
734 */
51a7b448 735 restore_saved_sigmask();
1da177e4
LT
736}
737
72fa50f4
HS
738void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
739{
740 struct task_struct *me = current;
741
742 if (show_unhandled_signals && printk_ratelimit()) {
ae417bb4 743 printk("%s"
72fa50f4 744 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
ae417bb4 745 task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
72fa50f4
HS
746 me->comm, me->pid, where, frame,
747 regs->ip, regs->sp, regs->orig_ax);
748 print_vma_addr(" in ", regs->ip);
c767a54b 749 pr_cont("\n");
72fa50f4
HS
750 }
751
752 force_sig(SIGSEGV, me);
753}
c5a37394
PA
754
755#ifdef CONFIG_X86_X32_ABI
3fe26fa3 756asmlinkage long sys32_x32_rt_sigreturn(void)
c5a37394 757{
3fe26fa3 758 struct pt_regs *regs = current_pt_regs();
c5a37394
PA
759 struct rt_sigframe_x32 __user *frame;
760 sigset_t set;
c5a37394
PA
761
762 frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
763
764 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
765 goto badframe;
766 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
767 goto badframe;
768
c5a37394
PA
769 set_current_blocked(&set);
770
6a3713f0 771 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
c5a37394
PA
772 goto badframe;
773
90268439 774 if (compat_restore_altstack(&frame->uc.uc_stack))
c5a37394
PA
775 goto badframe;
776
6a3713f0 777 return regs->ax;
c5a37394
PA
778
779badframe:
780 signal_fault(regs, frame, "x32 rt_sigreturn");
781 return 0;
782}
783#endif