Commit | Line | Data |
---|---|---|
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> | |
1da177e4 | 29 | #include <asm/i387.h> |
1361b83a | 30 | #include <asm/fpu-internal.h> |
6c3652ef | 31 | #include <asm/vdso.h> |
4efc0670 | 32 | #include <asm/mce.h> |
f28f0c23 | 33 | #include <asm/sighandling.h> |
5c9b3a0c HS |
34 | |
35 | #ifdef CONFIG_X86_64 | |
36 | #include <asm/proto.h> | |
37 | #include <asm/ia32_unistd.h> | |
c5a37394 | 38 | #include <asm/sys_ia32.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 | 64 | int 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 | ||
98e3d45e HS |
96 | COPY_SEG_CPL3(cs); |
97 | COPY_SEG_CPL3(ss); | |
2601657d | 98 | |
98e3d45e HS |
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); | |
98e3d45e | 104 | } get_user_catch(err); |
2601657d | 105 | |
49b8c695 | 106 | err |= restore_xstate_sig(buf, config_enabled(CONFIG_X86_32)); |
5e88353d | 107 | |
1daeaa31 BG |
108 | force_iret(); |
109 | ||
2601657d HS |
110 | return err; |
111 | } | |
112 | ||
85139422 PA |
113 | int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, |
114 | struct pt_regs *regs, unsigned long mask) | |
2601657d HS |
115 | { |
116 | int err = 0; | |
117 | ||
98e3d45e | 118 | put_user_try { |
2601657d | 119 | |
98e3d45e | 120 | #ifdef CONFIG_X86_32 |
d9a89a26 | 121 | put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs); |
98e3d45e HS |
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); | |
2601657d HS |
125 | #endif /* CONFIG_X86_32 */ |
126 | ||
98e3d45e HS |
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); | |
2601657d | 135 | #ifdef CONFIG_X86_64 |
98e3d45e HS |
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); | |
2601657d HS |
144 | #endif /* CONFIG_X86_64 */ |
145 | ||
51e7dc70 | 146 | put_user_ex(current->thread.trap_nr, &sc->trapno); |
98e3d45e HS |
147 | put_user_ex(current->thread.error_code, &sc->err); |
148 | put_user_ex(regs->ip, &sc->ip); | |
2601657d | 149 | #ifdef CONFIG_X86_32 |
98e3d45e HS |
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); | |
2601657d | 154 | #else /* !CONFIG_X86_32 */ |
98e3d45e HS |
155 | put_user_ex(regs->flags, &sc->flags); |
156 | put_user_ex(regs->cs, &sc->cs); | |
9a036b93 AL |
157 | put_user_ex(0, &sc->__pad2); |
158 | put_user_ex(0, &sc->__pad1); | |
c6f20629 | 159 | put_user_ex(regs->ss, &sc->ss); |
2601657d HS |
160 | #endif /* CONFIG_X86_32 */ |
161 | ||
98e3d45e | 162 | put_user_ex(fpstate, &sc->fpstate); |
2601657d | 163 | |
98e3d45e HS |
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); | |
2601657d HS |
168 | |
169 | return err; | |
170 | } | |
171 | ||
1da177e4 | 172 | /* |
bfeb91a9 | 173 | * Set up a signal frame. |
1da177e4 | 174 | */ |
1da177e4 LT |
175 | |
176 | /* | |
177 | * Determine which stack to use.. | |
178 | */ | |
1fae0279 HS |
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 | ||
1da177e4 | 193 | static inline void __user * |
3c1c7f10 | 194 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, |
144b0712 | 195 | void __user **fpstate) |
1da177e4 | 196 | { |
1da177e4 | 197 | /* Default to using normal stack */ |
72a671ce | 198 | unsigned long math_size = 0; |
75779f05 | 199 | unsigned long sp = regs->sp; |
72a671ce | 200 | unsigned long buf_fx = 0; |
14fc9fbc | 201 | int onsigstack = on_sig_stack(sp); |
75779f05 | 202 | |
75779f05 | 203 | /* redzone */ |
050902c0 SS |
204 | if (config_enabled(CONFIG_X86_64)) |
205 | sp -= 128; | |
1da177e4 | 206 | |
14fc9fbc HS |
207 | if (!onsigstack) { |
208 | /* This is the X/Open sanctioned signal stack switching. */ | |
209 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
0f8f3089 | 210 | if (current->sas_ss_size) |
14fc9fbc | 211 | sp = current->sas_ss_sp + current->sas_ss_size; |
050902c0 SS |
212 | } else if (config_enabled(CONFIG_X86_32) && |
213 | (regs->ss & 0xffff) != __USER_DS && | |
214 | !(ka->sa.sa_flags & SA_RESTORER) && | |
215 | ka->sa.sa_restorer) { | |
216 | /* This is the legacy signal stack switching. */ | |
14fc9fbc | 217 | sp = (unsigned long) ka->sa.sa_restorer; |
14fc9fbc | 218 | } |
1da177e4 LT |
219 | } |
220 | ||
3c1c7f10 | 221 | if (used_math()) { |
72a671ce SS |
222 | sp = alloc_mathframe(sp, config_enabled(CONFIG_X86_32), |
223 | &buf_fx, &math_size); | |
25051702 | 224 | *fpstate = (void __user *)sp; |
3c1c7f10 SS |
225 | } |
226 | ||
14fc9fbc HS |
227 | sp = align_sigframe(sp - frame_size); |
228 | ||
229 | /* | |
230 | * If we are on the alternate signal stack and would overflow it, don't. | |
231 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
232 | */ | |
233 | if (onsigstack && !likely(on_sig_stack(sp))) | |
234 | return (void __user *)-1L; | |
235 | ||
72a671ce SS |
236 | /* save i387 and extended state */ |
237 | if (used_math() && | |
238 | save_xstate_sig(*fpstate, (void __user *)buf_fx, math_size) < 0) | |
14fc9fbc HS |
239 | return (void __user *)-1L; |
240 | ||
241 | return (void __user *)sp; | |
1da177e4 LT |
242 | } |
243 | ||
75779f05 HS |
244 | #ifdef CONFIG_X86_32 |
245 | static const struct { | |
246 | u16 poplmovl; | |
247 | u32 val; | |
248 | u16 int80; | |
249 | } __attribute__((packed)) retcode = { | |
250 | 0xb858, /* popl %eax; movl $..., %eax */ | |
251 | __NR_sigreturn, | |
252 | 0x80cd, /* int $0x80 */ | |
253 | }; | |
254 | ||
255 | static const struct { | |
256 | u8 movl; | |
257 | u32 val; | |
258 | u16 int80; | |
259 | u8 pad; | |
260 | } __attribute__((packed)) rt_retcode = { | |
261 | 0xb8, /* movl $..., %eax */ | |
262 | __NR_rt_sigreturn, | |
263 | 0x80cd, /* int $0x80 */ | |
264 | 0 | |
265 | }; | |
266 | ||
7e907f48 | 267 | static int |
235b8022 | 268 | __setup_frame(int sig, struct ksignal *ksig, sigset_t *set, |
1d13024e | 269 | struct pt_regs *regs) |
1da177e4 | 270 | { |
1da177e4 | 271 | struct sigframe __user *frame; |
7e907f48 | 272 | void __user *restorer; |
1da177e4 | 273 | int err = 0; |
ab513701 | 274 | void __user *fpstate = NULL; |
1da177e4 | 275 | |
235b8022 | 276 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
277 | |
278 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 279 | return -EFAULT; |
1da177e4 | 280 | |
2ba48e16 | 281 | if (__put_user(sig, &frame->sig)) |
3d0aedd9 | 282 | return -EFAULT; |
1da177e4 | 283 | |
2ba48e16 | 284 | if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) |
3d0aedd9 | 285 | return -EFAULT; |
1da177e4 LT |
286 | |
287 | if (_NSIG_WORDS > 1) { | |
2ba48e16 HS |
288 | if (__copy_to_user(&frame->extramask, &set->sig[1], |
289 | sizeof(frame->extramask))) | |
3d0aedd9 | 290 | return -EFAULT; |
1da177e4 LT |
291 | } |
292 | ||
1a3e4ca4 | 293 | if (current->mm->context.vdso) |
6f121e54 AL |
294 | restorer = current->mm->context.vdso + |
295 | selected_vdso32->sym___kernel_sigreturn; | |
9fbbd4dd | 296 | else |
ade1af77 | 297 | restorer = &frame->retcode; |
235b8022 AV |
298 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
299 | restorer = ksig->ka.sa.sa_restorer; | |
1da177e4 LT |
300 | |
301 | /* Set up to return from userspace. */ | |
302 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 303 | |
1da177e4 | 304 | /* |
7e907f48 | 305 | * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
1da177e4 LT |
306 | * |
307 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
308 | * reasons and because gdb uses it as a signature to notice | |
309 | * signal handler stack frames. | |
310 | */ | |
4a612048 | 311 | err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode); |
1da177e4 LT |
312 | |
313 | if (err) | |
3d0aedd9 | 314 | return -EFAULT; |
1da177e4 LT |
315 | |
316 | /* Set up registers for signal handler */ | |
7e907f48 | 317 | regs->sp = (unsigned long)frame; |
235b8022 | 318 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
7e907f48 | 319 | regs->ax = (unsigned long)sig; |
92bc2056 HH |
320 | regs->dx = 0; |
321 | regs->cx = 0; | |
1da177e4 | 322 | |
65ea5b03 PA |
323 | regs->ds = __USER_DS; |
324 | regs->es = __USER_DS; | |
325 | regs->ss = __USER_DS; | |
326 | regs->cs = __USER_CS; | |
1da177e4 | 327 | |
283828f3 | 328 | return 0; |
1da177e4 LT |
329 | } |
330 | ||
235b8022 | 331 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
1d13024e | 332 | sigset_t *set, struct pt_regs *regs) |
1da177e4 | 333 | { |
1da177e4 | 334 | struct rt_sigframe __user *frame; |
7e907f48 | 335 | void __user *restorer; |
1da177e4 | 336 | int err = 0; |
ab513701 | 337 | void __user *fpstate = NULL; |
1da177e4 | 338 | |
235b8022 | 339 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
340 | |
341 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 342 | return -EFAULT; |
1da177e4 | 343 | |
98e3d45e HS |
344 | put_user_try { |
345 | put_user_ex(sig, &frame->sig); | |
346 | put_user_ex(&frame->info, &frame->pinfo); | |
347 | put_user_ex(&frame->uc, &frame->puc); | |
98e3d45e HS |
348 | |
349 | /* Create the ucontext. */ | |
350 | if (cpu_has_xsave) | |
351 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | |
352 | else | |
353 | put_user_ex(0, &frame->uc.uc_flags); | |
354 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 355 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
356 | |
357 | /* Set up to return from userspace. */ | |
6f121e54 | 358 | restorer = current->mm->context.vdso + |
6ba19a67 | 359 | selected_vdso32->sym___kernel_rt_sigreturn; |
235b8022 AV |
360 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
361 | restorer = ksig->ka.sa.sa_restorer; | |
98e3d45e HS |
362 | put_user_ex(restorer, &frame->pretcode); |
363 | ||
364 | /* | |
365 | * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 | |
366 | * | |
367 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
368 | * reasons and because gdb uses it as a signature to notice | |
369 | * signal handler stack frames. | |
370 | */ | |
371 | put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode); | |
372 | } put_user_catch(err); | |
49b8c695 | 373 | |
235b8022 | 374 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
5e88353d PA |
375 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
376 | regs, set->sig[0]); | |
377 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
1da177e4 LT |
378 | |
379 | if (err) | |
3d0aedd9 | 380 | return -EFAULT; |
1da177e4 LT |
381 | |
382 | /* Set up registers for signal handler */ | |
7e907f48 | 383 | regs->sp = (unsigned long)frame; |
235b8022 | 384 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
13ad7725 | 385 | regs->ax = (unsigned long)sig; |
7e907f48 IM |
386 | regs->dx = (unsigned long)&frame->info; |
387 | regs->cx = (unsigned long)&frame->uc; | |
1da177e4 | 388 | |
65ea5b03 PA |
389 | regs->ds = __USER_DS; |
390 | regs->es = __USER_DS; | |
391 | regs->ss = __USER_DS; | |
392 | regs->cs = __USER_CS; | |
1da177e4 | 393 | |
283828f3 | 394 | return 0; |
1da177e4 | 395 | } |
bfeb91a9 | 396 | #else /* !CONFIG_X86_32 */ |
235b8022 | 397 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
bfeb91a9 HS |
398 | sigset_t *set, struct pt_regs *regs) |
399 | { | |
400 | struct rt_sigframe __user *frame; | |
401 | void __user *fp = NULL; | |
402 | int err = 0; | |
bfeb91a9 | 403 | |
235b8022 | 404 | frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp); |
bfeb91a9 HS |
405 | |
406 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
407 | return -EFAULT; | |
408 | ||
235b8022 AV |
409 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
410 | if (copy_siginfo_to_user(&frame->info, &ksig->info)) | |
bfeb91a9 HS |
411 | return -EFAULT; |
412 | } | |
413 | ||
98e3d45e HS |
414 | put_user_try { |
415 | /* Create the ucontext. */ | |
416 | if (cpu_has_xsave) | |
417 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | |
418 | else | |
419 | put_user_ex(0, &frame->uc.uc_flags); | |
420 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 421 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
422 | |
423 | /* Set up to return from userspace. If provided, use a stub | |
424 | already in userspace. */ | |
425 | /* x86-64 should always use SA_RESTORER. */ | |
235b8022 AV |
426 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
427 | put_user_ex(ksig->ka.sa.sa_restorer, &frame->pretcode); | |
98e3d45e HS |
428 | } else { |
429 | /* could use a vstub here */ | |
430 | err |= -EFAULT; | |
431 | } | |
432 | } put_user_catch(err); | |
bfeb91a9 | 433 | |
5e88353d PA |
434 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]); |
435 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
436 | ||
bfeb91a9 HS |
437 | if (err) |
438 | return -EFAULT; | |
439 | ||
440 | /* Set up registers for signal handler */ | |
441 | regs->di = sig; | |
442 | /* In case the signal handler was declared without prototypes */ | |
443 | regs->ax = 0; | |
444 | ||
445 | /* This also works for non SA_SIGINFO handlers because they expect the | |
446 | next argument after the signal number on the stack. */ | |
447 | regs->si = (unsigned long)&frame->info; | |
448 | regs->dx = (unsigned long)&frame->uc; | |
235b8022 | 449 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
bfeb91a9 HS |
450 | |
451 | regs->sp = (unsigned long)frame; | |
452 | ||
c6f20629 AL |
453 | /* |
454 | * Set up the CS and SS registers to run signal handlers in | |
455 | * 64-bit mode, even if the handler happens to be interrupting | |
456 | * 32-bit or 16-bit code. | |
457 | * | |
458 | * SS is subtle. In 64-bit mode, we don't need any particular | |
459 | * SS descriptor, but we do need SS to be valid. It's possible | |
460 | * that the old SS is entirely bogus -- this can happen if the | |
461 | * signal we're trying to deliver is #GP or #SS caused by a bad | |
462 | * SS value. | |
463 | */ | |
bfeb91a9 | 464 | regs->cs = __USER_CS; |
c6f20629 | 465 | regs->ss = __USER_DS; |
bfeb91a9 HS |
466 | |
467 | return 0; | |
468 | } | |
469 | #endif /* CONFIG_X86_32 */ | |
470 | ||
235b8022 AV |
471 | static int x32_setup_rt_frame(struct ksignal *ksig, |
472 | compat_sigset_t *set, | |
050902c0 SS |
473 | struct pt_regs *regs) |
474 | { | |
475 | #ifdef CONFIG_X86_X32_ABI | |
476 | struct rt_sigframe_x32 __user *frame; | |
477 | void __user *restorer; | |
478 | int err = 0; | |
479 | void __user *fpstate = NULL; | |
480 | ||
235b8022 | 481 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
050902c0 SS |
482 | |
483 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
484 | return -EFAULT; | |
485 | ||
235b8022 AV |
486 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
487 | if (copy_siginfo_to_user32(&frame->info, &ksig->info)) | |
050902c0 SS |
488 | return -EFAULT; |
489 | } | |
490 | ||
491 | put_user_try { | |
492 | /* Create the ucontext. */ | |
493 | if (cpu_has_xsave) | |
494 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | |
495 | else | |
496 | put_user_ex(0, &frame->uc.uc_flags); | |
497 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 498 | compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
050902c0 | 499 | put_user_ex(0, &frame->uc.uc__pad0); |
050902c0 | 500 | |
235b8022 AV |
501 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
502 | restorer = ksig->ka.sa.sa_restorer; | |
050902c0 SS |
503 | } else { |
504 | /* could use a vstub here */ | |
505 | restorer = NULL; | |
506 | err |= -EFAULT; | |
507 | } | |
508 | put_user_ex(restorer, &frame->pretcode); | |
509 | } put_user_catch(err); | |
510 | ||
49b8c695 PA |
511 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
512 | regs, set->sig[0]); | |
513 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
514 | ||
050902c0 SS |
515 | if (err) |
516 | return -EFAULT; | |
517 | ||
518 | /* Set up registers for signal handler */ | |
519 | regs->sp = (unsigned long) frame; | |
235b8022 | 520 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
050902c0 SS |
521 | |
522 | /* We use the x32 calling convention here... */ | |
235b8022 | 523 | regs->di = ksig->sig; |
050902c0 SS |
524 | regs->si = (unsigned long) &frame->info; |
525 | regs->dx = (unsigned long) &frame->uc; | |
526 | ||
527 | loadsegment(ds, __USER_DS); | |
528 | loadsegment(es, __USER_DS); | |
529 | ||
530 | regs->cs = __USER_CS; | |
531 | regs->ss = __USER_DS; | |
532 | #endif /* CONFIG_X86_X32_ABI */ | |
533 | ||
534 | return 0; | |
535 | } | |
536 | ||
bfeb91a9 HS |
537 | /* |
538 | * Do a signal return; undo the signal stack. | |
539 | */ | |
e5fa2d06 | 540 | #ifdef CONFIG_X86_32 |
ff49103f | 541 | asmlinkage unsigned long sys_sigreturn(void) |
bfeb91a9 | 542 | { |
3fe26fa3 | 543 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 | 544 | struct sigframe __user *frame; |
bfeb91a9 HS |
545 | sigset_t set; |
546 | ||
bfeb91a9 HS |
547 | frame = (struct sigframe __user *)(regs->sp - 8); |
548 | ||
549 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
550 | goto badframe; | |
551 | if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 | |
552 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
553 | sizeof(frame->extramask)))) | |
554 | goto badframe; | |
555 | ||
3982294b | 556 | set_current_blocked(&set); |
bfeb91a9 | 557 | |
6a3713f0 | 558 | if (restore_sigcontext(regs, &frame->sc)) |
bfeb91a9 | 559 | goto badframe; |
6a3713f0 | 560 | return regs->ax; |
bfeb91a9 HS |
561 | |
562 | badframe: | |
ae417bb4 | 563 | signal_fault(regs, frame, "sigreturn"); |
bfeb91a9 HS |
564 | |
565 | return 0; | |
566 | } | |
e5fa2d06 | 567 | #endif /* CONFIG_X86_32 */ |
bfeb91a9 | 568 | |
ff49103f | 569 | asmlinkage long sys_rt_sigreturn(void) |
bfeb91a9 | 570 | { |
3fe26fa3 | 571 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 | 572 | struct rt_sigframe __user *frame; |
bfeb91a9 HS |
573 | sigset_t set; |
574 | ||
575 | frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); | |
576 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
577 | goto badframe; | |
578 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
579 | goto badframe; | |
580 | ||
e9bd3f0f | 581 | set_current_blocked(&set); |
bfeb91a9 | 582 | |
6a3713f0 | 583 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) |
bfeb91a9 HS |
584 | goto badframe; |
585 | ||
c40702c4 | 586 | if (restore_altstack(&frame->uc.uc_stack)) |
bfeb91a9 HS |
587 | goto badframe; |
588 | ||
6a3713f0 | 589 | return regs->ax; |
bfeb91a9 HS |
590 | |
591 | badframe: | |
592 | signal_fault(regs, frame, "rt_sigreturn"); | |
593 | return 0; | |
594 | } | |
595 | ||
1d13024e | 596 | static int |
235b8022 | 597 | setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) |
1d13024e | 598 | { |
3050a35f | 599 | int usig = ksig->sig; |
b7f9a11a | 600 | sigset_t *set = sigmask_to_save(); |
050902c0 | 601 | compat_sigset_t *cset = (compat_sigset_t *) set; |
1d13024e HS |
602 | |
603 | /* Set up the stack frame */ | |
050902c0 | 604 | if (is_ia32_frame()) { |
235b8022 AV |
605 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
606 | return ia32_setup_rt_frame(usig, ksig, cset, regs); | |
455edbc4 | 607 | else |
235b8022 | 608 | return ia32_setup_frame(usig, ksig, cset, regs); |
050902c0 | 609 | } else if (is_x32_frame()) { |
235b8022 | 610 | return x32_setup_rt_frame(ksig, cset, regs); |
c5a37394 | 611 | } else { |
235b8022 | 612 | return __setup_rt_frame(ksig->sig, ksig, set, regs); |
c5a37394 | 613 | } |
1d13024e HS |
614 | } |
615 | ||
a610d6e6 | 616 | static void |
235b8022 | 617 | handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 618 | { |
fd0f86b6 ON |
619 | bool stepping, failed; |
620 | ||
1da177e4 | 621 | /* Are we from a system call? */ |
bb57925f | 622 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 623 | /* If so, check system call restarting.. */ |
bb57925f | 624 | switch (syscall_get_error(current, regs)) { |
ac66f3fd HH |
625 | case -ERESTART_RESTARTBLOCK: |
626 | case -ERESTARTNOHAND: | |
627 | regs->ax = -EINTR; | |
628 | break; | |
629 | ||
630 | case -ERESTARTSYS: | |
235b8022 | 631 | if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
65ea5b03 | 632 | regs->ax = -EINTR; |
1da177e4 | 633 | break; |
ac66f3fd HH |
634 | } |
635 | /* fallthrough */ | |
636 | case -ERESTARTNOINTR: | |
637 | regs->ax = regs->orig_ax; | |
638 | regs->ip -= 2; | |
639 | break; | |
1da177e4 LT |
640 | } |
641 | } | |
642 | ||
643 | /* | |
fd0f86b6 ON |
644 | * If TF is set due to a debugger (TIF_FORCED_TF), clear TF now |
645 | * so that register information in the sigcontext is correct and | |
646 | * then notify the tracer before entering the signal handler. | |
1da177e4 | 647 | */ |
fd0f86b6 ON |
648 | stepping = test_thread_flag(TIF_SINGLESTEP); |
649 | if (stepping) | |
650 | user_disable_single_step(current); | |
1da177e4 | 651 | |
235b8022 AV |
652 | failed = (setup_rt_frame(ksig, regs) < 0); |
653 | if (!failed) { | |
654 | /* | |
655 | * Clear the direction flag as per the ABI for function entry. | |
ddd40da4 | 656 | * |
24cda109 JO |
657 | * Clear RF when entering the signal handler, because |
658 | * it might disable possible debug exception from the | |
659 | * signal handler. | |
ddd40da4 | 660 | * |
fd0f86b6 ON |
661 | * Clear TF for the case when it wasn't set by debugger to |
662 | * avoid the recursive send_sigtrap() in SIGTRAP handler. | |
235b8022 | 663 | */ |
ddd40da4 | 664 | regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF); |
66463db4 ON |
665 | /* |
666 | * Ensure the signal handler starts with the new fpu state. | |
667 | */ | |
668 | if (used_math()) | |
b85e67d1 | 669 | fpu_reset_state(current); |
a610d6e6 | 670 | } |
fd0f86b6 | 671 | signal_setup_done(failed, ksig, stepping); |
1da177e4 LT |
672 | } |
673 | ||
57917752 | 674 | #ifdef CONFIG_X86_32 |
8fcd8e20 | 675 | #define NR_restart_syscall __NR_restart_syscall |
57917752 HS |
676 | #else /* !CONFIG_X86_32 */ |
677 | #define NR_restart_syscall \ | |
678 | test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall | |
679 | #endif /* CONFIG_X86_32 */ | |
680 | ||
1da177e4 LT |
681 | /* |
682 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
683 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
684 | * mistake. | |
685 | */ | |
75604d7f | 686 | static void do_signal(struct pt_regs *regs) |
1da177e4 | 687 | { |
235b8022 | 688 | struct ksignal ksig; |
1da177e4 | 689 | |
235b8022 | 690 | if (get_signal(&ksig)) { |
7e907f48 | 691 | /* Whee! Actually deliver the signal. */ |
235b8022 | 692 | handle_signal(&ksig, regs); |
283828f3 | 693 | return; |
1da177e4 LT |
694 | } |
695 | ||
1da177e4 | 696 | /* Did we come from a system call? */ |
bb57925f | 697 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 698 | /* Restart the system call - no handlers present */ |
bb57925f | 699 | switch (syscall_get_error(current, regs)) { |
283828f3 DH |
700 | case -ERESTARTNOHAND: |
701 | case -ERESTARTSYS: | |
702 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
703 | regs->ax = regs->orig_ax; |
704 | regs->ip -= 2; | |
283828f3 DH |
705 | break; |
706 | ||
707 | case -ERESTART_RESTARTBLOCK: | |
8fcd8e20 | 708 | regs->ax = NR_restart_syscall; |
65ea5b03 | 709 | regs->ip -= 2; |
283828f3 | 710 | break; |
1da177e4 LT |
711 | } |
712 | } | |
283828f3 | 713 | |
ac66f3fd HH |
714 | /* |
715 | * If there's no signal to deliver, we just put the saved sigmask | |
716 | * back. | |
717 | */ | |
51a7b448 | 718 | restore_saved_sigmask(); |
1da177e4 LT |
719 | } |
720 | ||
721 | /* | |
722 | * notification of userspace execution resumption | |
283828f3 | 723 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 | 724 | */ |
277d5b40 | 725 | __visible void |
7e907f48 | 726 | do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) |
1da177e4 | 727 | { |
91d1aa43 | 728 | user_exit(); |
edf55fda | 729 | |
db023ea5 | 730 | if (thread_info_flags & _TIF_UPROBE) |
0326f5a9 | 731 | uprobe_notify_resume(regs); |
0326f5a9 | 732 | |
1da177e4 | 733 | /* deal with pending signal delivery */ |
5a8da0ea | 734 | if (thread_info_flags & _TIF_SIGPENDING) |
283828f3 | 735 | do_signal(regs); |
8f4d37ec | 736 | |
59e52130 RM |
737 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
738 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
739 | tracehook_notify_resume(regs); | |
740 | } | |
7c68af6e AK |
741 | if (thread_info_flags & _TIF_USER_RETURN_NOTIFY) |
742 | fire_user_return_notifiers(); | |
59e52130 | 743 | |
91d1aa43 | 744 | user_enter(); |
1da177e4 | 745 | } |
72fa50f4 HS |
746 | |
747 | void signal_fault(struct pt_regs *regs, void __user *frame, char *where) | |
748 | { | |
749 | struct task_struct *me = current; | |
750 | ||
751 | if (show_unhandled_signals && printk_ratelimit()) { | |
ae417bb4 | 752 | printk("%s" |
72fa50f4 | 753 | "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", |
ae417bb4 | 754 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
72fa50f4 HS |
755 | me->comm, me->pid, where, frame, |
756 | regs->ip, regs->sp, regs->orig_ax); | |
757 | print_vma_addr(" in ", regs->ip); | |
c767a54b | 758 | pr_cont("\n"); |
72fa50f4 HS |
759 | } |
760 | ||
761 | force_sig(SIGSEGV, me); | |
762 | } | |
c5a37394 PA |
763 | |
764 | #ifdef CONFIG_X86_X32_ABI | |
3fe26fa3 | 765 | asmlinkage long sys32_x32_rt_sigreturn(void) |
c5a37394 | 766 | { |
3fe26fa3 | 767 | struct pt_regs *regs = current_pt_regs(); |
c5a37394 PA |
768 | struct rt_sigframe_x32 __user *frame; |
769 | sigset_t set; | |
c5a37394 PA |
770 | |
771 | frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8); | |
772 | ||
773 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
774 | goto badframe; | |
775 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
776 | goto badframe; | |
777 | ||
c5a37394 PA |
778 | set_current_blocked(&set); |
779 | ||
6a3713f0 | 780 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) |
c5a37394 PA |
781 | goto badframe; |
782 | ||
90268439 | 783 | if (compat_restore_altstack(&frame->uc.uc_stack)) |
c5a37394 PA |
784 | goto badframe; |
785 | ||
6a3713f0 | 786 | return regs->ax; |
c5a37394 PA |
787 | |
788 | badframe: | |
789 | signal_fault(regs, frame, "x32 rt_sigreturn"); | |
790 | return 0; | |
791 | } | |
792 | #endif |