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 | |
85139422 PA |
64 | int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, |
65 | unsigned long *pax) | |
2601657d HS |
66 | { |
67 | void __user *buf; | |
68 | unsigned int tmpflags; | |
69 | unsigned int err = 0; | |
70 | ||
71 | /* Always make any pending restarted system calls return -EINTR */ | |
f56141e3 | 72 | current->restart_block.fn = do_no_restart_syscall; |
2601657d | 73 | |
98e3d45e HS |
74 | get_user_try { |
75 | ||
2601657d | 76 | #ifdef CONFIG_X86_32 |
d9a89a26 | 77 | set_user_gs(regs, GET_SEG(gs)); |
98e3d45e HS |
78 | COPY_SEG(fs); |
79 | COPY_SEG(es); | |
80 | COPY_SEG(ds); | |
2601657d HS |
81 | #endif /* CONFIG_X86_32 */ |
82 | ||
98e3d45e HS |
83 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
84 | COPY(dx); COPY(cx); COPY(ip); | |
2601657d HS |
85 | |
86 | #ifdef CONFIG_X86_64 | |
98e3d45e HS |
87 | COPY(r8); |
88 | COPY(r9); | |
89 | COPY(r10); | |
90 | COPY(r11); | |
91 | COPY(r12); | |
92 | COPY(r13); | |
93 | COPY(r14); | |
94 | COPY(r15); | |
2601657d HS |
95 | #endif /* CONFIG_X86_64 */ |
96 | ||
98e3d45e HS |
97 | COPY_SEG_CPL3(cs); |
98 | COPY_SEG_CPL3(ss); | |
2601657d | 99 | |
98e3d45e HS |
100 | get_user_ex(tmpflags, &sc->flags); |
101 | regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); | |
102 | regs->orig_ax = -1; /* disable syscall checks */ | |
103 | ||
104 | get_user_ex(buf, &sc->fpstate); | |
2601657d | 105 | |
98e3d45e HS |
106 | get_user_ex(*pax, &sc->ax); |
107 | } get_user_catch(err); | |
2601657d | 108 | |
49b8c695 | 109 | err |= restore_xstate_sig(buf, config_enabled(CONFIG_X86_32)); |
5e88353d | 110 | |
1daeaa31 BG |
111 | force_iret(); |
112 | ||
2601657d HS |
113 | return err; |
114 | } | |
115 | ||
85139422 PA |
116 | int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, |
117 | struct pt_regs *regs, unsigned long mask) | |
2601657d HS |
118 | { |
119 | int err = 0; | |
120 | ||
98e3d45e | 121 | put_user_try { |
2601657d | 122 | |
98e3d45e | 123 | #ifdef CONFIG_X86_32 |
d9a89a26 | 124 | put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs); |
98e3d45e HS |
125 | put_user_ex(regs->fs, (unsigned int __user *)&sc->fs); |
126 | put_user_ex(regs->es, (unsigned int __user *)&sc->es); | |
127 | put_user_ex(regs->ds, (unsigned int __user *)&sc->ds); | |
2601657d HS |
128 | #endif /* CONFIG_X86_32 */ |
129 | ||
98e3d45e HS |
130 | put_user_ex(regs->di, &sc->di); |
131 | put_user_ex(regs->si, &sc->si); | |
132 | put_user_ex(regs->bp, &sc->bp); | |
133 | put_user_ex(regs->sp, &sc->sp); | |
134 | put_user_ex(regs->bx, &sc->bx); | |
135 | put_user_ex(regs->dx, &sc->dx); | |
136 | put_user_ex(regs->cx, &sc->cx); | |
137 | put_user_ex(regs->ax, &sc->ax); | |
2601657d | 138 | #ifdef CONFIG_X86_64 |
98e3d45e HS |
139 | put_user_ex(regs->r8, &sc->r8); |
140 | put_user_ex(regs->r9, &sc->r9); | |
141 | put_user_ex(regs->r10, &sc->r10); | |
142 | put_user_ex(regs->r11, &sc->r11); | |
143 | put_user_ex(regs->r12, &sc->r12); | |
144 | put_user_ex(regs->r13, &sc->r13); | |
145 | put_user_ex(regs->r14, &sc->r14); | |
146 | put_user_ex(regs->r15, &sc->r15); | |
2601657d HS |
147 | #endif /* CONFIG_X86_64 */ |
148 | ||
51e7dc70 | 149 | put_user_ex(current->thread.trap_nr, &sc->trapno); |
98e3d45e HS |
150 | put_user_ex(current->thread.error_code, &sc->err); |
151 | put_user_ex(regs->ip, &sc->ip); | |
2601657d | 152 | #ifdef CONFIG_X86_32 |
98e3d45e HS |
153 | put_user_ex(regs->cs, (unsigned int __user *)&sc->cs); |
154 | put_user_ex(regs->flags, &sc->flags); | |
155 | put_user_ex(regs->sp, &sc->sp_at_signal); | |
156 | put_user_ex(regs->ss, (unsigned int __user *)&sc->ss); | |
2601657d | 157 | #else /* !CONFIG_X86_32 */ |
98e3d45e HS |
158 | put_user_ex(regs->flags, &sc->flags); |
159 | put_user_ex(regs->cs, &sc->cs); | |
9a036b93 AL |
160 | put_user_ex(0, &sc->__pad2); |
161 | put_user_ex(0, &sc->__pad1); | |
c6f20629 | 162 | put_user_ex(regs->ss, &sc->ss); |
2601657d HS |
163 | #endif /* CONFIG_X86_32 */ |
164 | ||
98e3d45e | 165 | put_user_ex(fpstate, &sc->fpstate); |
2601657d | 166 | |
98e3d45e HS |
167 | /* non-iBCS2 extensions.. */ |
168 | put_user_ex(mask, &sc->oldmask); | |
169 | put_user_ex(current->thread.cr2, &sc->cr2); | |
170 | } put_user_catch(err); | |
2601657d HS |
171 | |
172 | return err; | |
173 | } | |
174 | ||
1da177e4 | 175 | /* |
bfeb91a9 | 176 | * Set up a signal frame. |
1da177e4 | 177 | */ |
1da177e4 LT |
178 | |
179 | /* | |
180 | * Determine which stack to use.. | |
181 | */ | |
1fae0279 HS |
182 | static unsigned long align_sigframe(unsigned long sp) |
183 | { | |
184 | #ifdef CONFIG_X86_32 | |
185 | /* | |
186 | * Align the stack pointer according to the i386 ABI, | |
187 | * i.e. so that on function entry ((sp + 4) & 15) == 0. | |
188 | */ | |
189 | sp = ((sp + 4) & -16ul) - 4; | |
190 | #else /* !CONFIG_X86_32 */ | |
191 | sp = round_down(sp, 16) - 8; | |
192 | #endif | |
193 | return sp; | |
194 | } | |
195 | ||
1da177e4 | 196 | static inline void __user * |
3c1c7f10 | 197 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, |
144b0712 | 198 | void __user **fpstate) |
1da177e4 | 199 | { |
1da177e4 | 200 | /* Default to using normal stack */ |
72a671ce | 201 | unsigned long math_size = 0; |
75779f05 | 202 | unsigned long sp = regs->sp; |
72a671ce | 203 | unsigned long buf_fx = 0; |
14fc9fbc | 204 | int onsigstack = on_sig_stack(sp); |
75779f05 | 205 | |
75779f05 | 206 | /* redzone */ |
050902c0 SS |
207 | if (config_enabled(CONFIG_X86_64)) |
208 | sp -= 128; | |
1da177e4 | 209 | |
14fc9fbc HS |
210 | if (!onsigstack) { |
211 | /* This is the X/Open sanctioned signal stack switching. */ | |
212 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
0f8f3089 | 213 | if (current->sas_ss_size) |
14fc9fbc | 214 | sp = current->sas_ss_sp + current->sas_ss_size; |
050902c0 SS |
215 | } else if (config_enabled(CONFIG_X86_32) && |
216 | (regs->ss & 0xffff) != __USER_DS && | |
217 | !(ka->sa.sa_flags & SA_RESTORER) && | |
218 | ka->sa.sa_restorer) { | |
219 | /* This is the legacy signal stack switching. */ | |
14fc9fbc | 220 | sp = (unsigned long) ka->sa.sa_restorer; |
14fc9fbc | 221 | } |
1da177e4 LT |
222 | } |
223 | ||
3c1c7f10 | 224 | if (used_math()) { |
72a671ce SS |
225 | sp = alloc_mathframe(sp, config_enabled(CONFIG_X86_32), |
226 | &buf_fx, &math_size); | |
25051702 | 227 | *fpstate = (void __user *)sp; |
3c1c7f10 SS |
228 | } |
229 | ||
14fc9fbc HS |
230 | sp = align_sigframe(sp - frame_size); |
231 | ||
232 | /* | |
233 | * If we are on the alternate signal stack and would overflow it, don't. | |
234 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
235 | */ | |
236 | if (onsigstack && !likely(on_sig_stack(sp))) | |
237 | return (void __user *)-1L; | |
238 | ||
72a671ce SS |
239 | /* save i387 and extended state */ |
240 | if (used_math() && | |
241 | save_xstate_sig(*fpstate, (void __user *)buf_fx, math_size) < 0) | |
14fc9fbc HS |
242 | return (void __user *)-1L; |
243 | ||
244 | return (void __user *)sp; | |
1da177e4 LT |
245 | } |
246 | ||
75779f05 HS |
247 | #ifdef CONFIG_X86_32 |
248 | static const struct { | |
249 | u16 poplmovl; | |
250 | u32 val; | |
251 | u16 int80; | |
252 | } __attribute__((packed)) retcode = { | |
253 | 0xb858, /* popl %eax; movl $..., %eax */ | |
254 | __NR_sigreturn, | |
255 | 0x80cd, /* int $0x80 */ | |
256 | }; | |
257 | ||
258 | static const struct { | |
259 | u8 movl; | |
260 | u32 val; | |
261 | u16 int80; | |
262 | u8 pad; | |
263 | } __attribute__((packed)) rt_retcode = { | |
264 | 0xb8, /* movl $..., %eax */ | |
265 | __NR_rt_sigreturn, | |
266 | 0x80cd, /* int $0x80 */ | |
267 | 0 | |
268 | }; | |
269 | ||
7e907f48 | 270 | static int |
235b8022 | 271 | __setup_frame(int sig, struct ksignal *ksig, sigset_t *set, |
1d13024e | 272 | struct pt_regs *regs) |
1da177e4 | 273 | { |
1da177e4 | 274 | struct sigframe __user *frame; |
7e907f48 | 275 | void __user *restorer; |
1da177e4 | 276 | int err = 0; |
ab513701 | 277 | void __user *fpstate = NULL; |
1da177e4 | 278 | |
235b8022 | 279 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
280 | |
281 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 282 | return -EFAULT; |
1da177e4 | 283 | |
2ba48e16 | 284 | if (__put_user(sig, &frame->sig)) |
3d0aedd9 | 285 | return -EFAULT; |
1da177e4 | 286 | |
2ba48e16 | 287 | if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) |
3d0aedd9 | 288 | return -EFAULT; |
1da177e4 LT |
289 | |
290 | if (_NSIG_WORDS > 1) { | |
2ba48e16 HS |
291 | if (__copy_to_user(&frame->extramask, &set->sig[1], |
292 | sizeof(frame->extramask))) | |
3d0aedd9 | 293 | return -EFAULT; |
1da177e4 LT |
294 | } |
295 | ||
1a3e4ca4 | 296 | if (current->mm->context.vdso) |
6f121e54 AL |
297 | restorer = current->mm->context.vdso + |
298 | selected_vdso32->sym___kernel_sigreturn; | |
9fbbd4dd | 299 | else |
ade1af77 | 300 | restorer = &frame->retcode; |
235b8022 AV |
301 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
302 | restorer = ksig->ka.sa.sa_restorer; | |
1da177e4 LT |
303 | |
304 | /* Set up to return from userspace. */ | |
305 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 306 | |
1da177e4 | 307 | /* |
7e907f48 | 308 | * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
1da177e4 LT |
309 | * |
310 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
311 | * reasons and because gdb uses it as a signature to notice | |
312 | * signal handler stack frames. | |
313 | */ | |
4a612048 | 314 | err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode); |
1da177e4 LT |
315 | |
316 | if (err) | |
3d0aedd9 | 317 | return -EFAULT; |
1da177e4 LT |
318 | |
319 | /* Set up registers for signal handler */ | |
7e907f48 | 320 | regs->sp = (unsigned long)frame; |
235b8022 | 321 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
7e907f48 | 322 | regs->ax = (unsigned long)sig; |
92bc2056 HH |
323 | regs->dx = 0; |
324 | regs->cx = 0; | |
1da177e4 | 325 | |
65ea5b03 PA |
326 | regs->ds = __USER_DS; |
327 | regs->es = __USER_DS; | |
328 | regs->ss = __USER_DS; | |
329 | regs->cs = __USER_CS; | |
1da177e4 | 330 | |
283828f3 | 331 | return 0; |
1da177e4 LT |
332 | } |
333 | ||
235b8022 | 334 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
1d13024e | 335 | sigset_t *set, struct pt_regs *regs) |
1da177e4 | 336 | { |
1da177e4 | 337 | struct rt_sigframe __user *frame; |
7e907f48 | 338 | void __user *restorer; |
1da177e4 | 339 | int err = 0; |
ab513701 | 340 | void __user *fpstate = NULL; |
1da177e4 | 341 | |
235b8022 | 342 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
343 | |
344 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 345 | return -EFAULT; |
1da177e4 | 346 | |
98e3d45e HS |
347 | put_user_try { |
348 | put_user_ex(sig, &frame->sig); | |
349 | put_user_ex(&frame->info, &frame->pinfo); | |
350 | put_user_ex(&frame->uc, &frame->puc); | |
98e3d45e HS |
351 | |
352 | /* Create the ucontext. */ | |
353 | if (cpu_has_xsave) | |
354 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | |
355 | else | |
356 | put_user_ex(0, &frame->uc.uc_flags); | |
357 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 358 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
359 | |
360 | /* Set up to return from userspace. */ | |
6f121e54 | 361 | restorer = current->mm->context.vdso + |
6ba19a67 | 362 | selected_vdso32->sym___kernel_rt_sigreturn; |
235b8022 AV |
363 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
364 | restorer = ksig->ka.sa.sa_restorer; | |
98e3d45e HS |
365 | put_user_ex(restorer, &frame->pretcode); |
366 | ||
367 | /* | |
368 | * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 | |
369 | * | |
370 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
371 | * reasons and because gdb uses it as a signature to notice | |
372 | * signal handler stack frames. | |
373 | */ | |
374 | put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode); | |
375 | } put_user_catch(err); | |
49b8c695 | 376 | |
235b8022 | 377 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
5e88353d PA |
378 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
379 | regs, set->sig[0]); | |
380 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
1da177e4 LT |
381 | |
382 | if (err) | |
3d0aedd9 | 383 | return -EFAULT; |
1da177e4 LT |
384 | |
385 | /* Set up registers for signal handler */ | |
7e907f48 | 386 | regs->sp = (unsigned long)frame; |
235b8022 | 387 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
13ad7725 | 388 | regs->ax = (unsigned long)sig; |
7e907f48 IM |
389 | regs->dx = (unsigned long)&frame->info; |
390 | regs->cx = (unsigned long)&frame->uc; | |
1da177e4 | 391 | |
65ea5b03 PA |
392 | regs->ds = __USER_DS; |
393 | regs->es = __USER_DS; | |
394 | regs->ss = __USER_DS; | |
395 | regs->cs = __USER_CS; | |
1da177e4 | 396 | |
283828f3 | 397 | return 0; |
1da177e4 | 398 | } |
bfeb91a9 | 399 | #else /* !CONFIG_X86_32 */ |
235b8022 | 400 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
bfeb91a9 HS |
401 | sigset_t *set, struct pt_regs *regs) |
402 | { | |
403 | struct rt_sigframe __user *frame; | |
404 | void __user *fp = NULL; | |
405 | int err = 0; | |
bfeb91a9 | 406 | |
235b8022 | 407 | frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp); |
bfeb91a9 HS |
408 | |
409 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
410 | return -EFAULT; | |
411 | ||
235b8022 AV |
412 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
413 | if (copy_siginfo_to_user(&frame->info, &ksig->info)) | |
bfeb91a9 HS |
414 | return -EFAULT; |
415 | } | |
416 | ||
98e3d45e HS |
417 | put_user_try { |
418 | /* Create the ucontext. */ | |
419 | if (cpu_has_xsave) | |
420 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | |
421 | else | |
422 | put_user_ex(0, &frame->uc.uc_flags); | |
423 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 424 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
425 | |
426 | /* Set up to return from userspace. If provided, use a stub | |
427 | already in userspace. */ | |
428 | /* x86-64 should always use SA_RESTORER. */ | |
235b8022 AV |
429 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
430 | put_user_ex(ksig->ka.sa.sa_restorer, &frame->pretcode); | |
98e3d45e HS |
431 | } else { |
432 | /* could use a vstub here */ | |
433 | err |= -EFAULT; | |
434 | } | |
435 | } put_user_catch(err); | |
bfeb91a9 | 436 | |
5e88353d PA |
437 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]); |
438 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
439 | ||
bfeb91a9 HS |
440 | if (err) |
441 | return -EFAULT; | |
442 | ||
443 | /* Set up registers for signal handler */ | |
444 | regs->di = sig; | |
445 | /* In case the signal handler was declared without prototypes */ | |
446 | regs->ax = 0; | |
447 | ||
448 | /* This also works for non SA_SIGINFO handlers because they expect the | |
449 | next argument after the signal number on the stack. */ | |
450 | regs->si = (unsigned long)&frame->info; | |
451 | regs->dx = (unsigned long)&frame->uc; | |
235b8022 | 452 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
bfeb91a9 HS |
453 | |
454 | regs->sp = (unsigned long)frame; | |
455 | ||
c6f20629 AL |
456 | /* |
457 | * Set up the CS and SS registers to run signal handlers in | |
458 | * 64-bit mode, even if the handler happens to be interrupting | |
459 | * 32-bit or 16-bit code. | |
460 | * | |
461 | * SS is subtle. In 64-bit mode, we don't need any particular | |
462 | * SS descriptor, but we do need SS to be valid. It's possible | |
463 | * that the old SS is entirely bogus -- this can happen if the | |
464 | * signal we're trying to deliver is #GP or #SS caused by a bad | |
465 | * SS value. | |
466 | */ | |
bfeb91a9 | 467 | regs->cs = __USER_CS; |
c6f20629 | 468 | regs->ss = __USER_DS; |
bfeb91a9 HS |
469 | |
470 | return 0; | |
471 | } | |
472 | #endif /* CONFIG_X86_32 */ | |
473 | ||
235b8022 AV |
474 | static int x32_setup_rt_frame(struct ksignal *ksig, |
475 | compat_sigset_t *set, | |
050902c0 SS |
476 | struct pt_regs *regs) |
477 | { | |
478 | #ifdef CONFIG_X86_X32_ABI | |
479 | struct rt_sigframe_x32 __user *frame; | |
480 | void __user *restorer; | |
481 | int err = 0; | |
482 | void __user *fpstate = NULL; | |
483 | ||
235b8022 | 484 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
050902c0 SS |
485 | |
486 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
487 | return -EFAULT; | |
488 | ||
235b8022 AV |
489 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
490 | if (copy_siginfo_to_user32(&frame->info, &ksig->info)) | |
050902c0 SS |
491 | return -EFAULT; |
492 | } | |
493 | ||
494 | put_user_try { | |
495 | /* Create the ucontext. */ | |
496 | if (cpu_has_xsave) | |
497 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | |
498 | else | |
499 | put_user_ex(0, &frame->uc.uc_flags); | |
500 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 501 | compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
050902c0 | 502 | put_user_ex(0, &frame->uc.uc__pad0); |
050902c0 | 503 | |
235b8022 AV |
504 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
505 | restorer = ksig->ka.sa.sa_restorer; | |
050902c0 SS |
506 | } else { |
507 | /* could use a vstub here */ | |
508 | restorer = NULL; | |
509 | err |= -EFAULT; | |
510 | } | |
511 | put_user_ex(restorer, &frame->pretcode); | |
512 | } put_user_catch(err); | |
513 | ||
49b8c695 PA |
514 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
515 | regs, set->sig[0]); | |
516 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
517 | ||
050902c0 SS |
518 | if (err) |
519 | return -EFAULT; | |
520 | ||
521 | /* Set up registers for signal handler */ | |
522 | regs->sp = (unsigned long) frame; | |
235b8022 | 523 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
050902c0 SS |
524 | |
525 | /* We use the x32 calling convention here... */ | |
235b8022 | 526 | regs->di = ksig->sig; |
050902c0 SS |
527 | regs->si = (unsigned long) &frame->info; |
528 | regs->dx = (unsigned long) &frame->uc; | |
529 | ||
530 | loadsegment(ds, __USER_DS); | |
531 | loadsegment(es, __USER_DS); | |
532 | ||
533 | regs->cs = __USER_CS; | |
534 | regs->ss = __USER_DS; | |
535 | #endif /* CONFIG_X86_X32_ABI */ | |
536 | ||
537 | return 0; | |
538 | } | |
539 | ||
bfeb91a9 HS |
540 | /* |
541 | * Do a signal return; undo the signal stack. | |
542 | */ | |
e5fa2d06 | 543 | #ifdef CONFIG_X86_32 |
ff49103f | 544 | asmlinkage unsigned long sys_sigreturn(void) |
bfeb91a9 | 545 | { |
3fe26fa3 | 546 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 | 547 | struct sigframe __user *frame; |
bfeb91a9 HS |
548 | unsigned long ax; |
549 | sigset_t set; | |
550 | ||
bfeb91a9 HS |
551 | frame = (struct sigframe __user *)(regs->sp - 8); |
552 | ||
553 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
554 | goto badframe; | |
555 | if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 | |
556 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
557 | sizeof(frame->extramask)))) | |
558 | goto badframe; | |
559 | ||
3982294b | 560 | set_current_blocked(&set); |
bfeb91a9 HS |
561 | |
562 | if (restore_sigcontext(regs, &frame->sc, &ax)) | |
563 | goto badframe; | |
564 | return ax; | |
565 | ||
566 | badframe: | |
ae417bb4 | 567 | signal_fault(regs, frame, "sigreturn"); |
bfeb91a9 HS |
568 | |
569 | return 0; | |
570 | } | |
e5fa2d06 | 571 | #endif /* CONFIG_X86_32 */ |
bfeb91a9 | 572 | |
ff49103f | 573 | asmlinkage long sys_rt_sigreturn(void) |
bfeb91a9 | 574 | { |
3fe26fa3 | 575 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 HS |
576 | struct rt_sigframe __user *frame; |
577 | unsigned long ax; | |
578 | sigset_t set; | |
579 | ||
580 | frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); | |
581 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
582 | goto badframe; | |
583 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
584 | goto badframe; | |
585 | ||
e9bd3f0f | 586 | set_current_blocked(&set); |
bfeb91a9 HS |
587 | |
588 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) | |
589 | goto badframe; | |
590 | ||
c40702c4 | 591 | if (restore_altstack(&frame->uc.uc_stack)) |
bfeb91a9 HS |
592 | goto badframe; |
593 | ||
594 | return ax; | |
595 | ||
596 | badframe: | |
597 | signal_fault(regs, frame, "rt_sigreturn"); | |
598 | return 0; | |
599 | } | |
600 | ||
1da177e4 | 601 | /* |
7e907f48 IM |
602 | * OK, we're invoking a handler: |
603 | */ | |
8d8c13bd HS |
604 | static int signr_convert(int sig) |
605 | { | |
96bf84b7 | 606 | #ifdef CONFIG_X86_32 |
8d8c13bd HS |
607 | struct thread_info *info = current_thread_info(); |
608 | ||
609 | if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32) | |
610 | return info->exec_domain->signal_invmap[sig]; | |
96bf84b7 | 611 | #endif /* CONFIG_X86_32 */ |
8d8c13bd HS |
612 | return sig; |
613 | } | |
614 | ||
1d13024e | 615 | static int |
235b8022 | 616 | setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) |
1d13024e | 617 | { |
235b8022 | 618 | int usig = signr_convert(ksig->sig); |
b7f9a11a | 619 | sigset_t *set = sigmask_to_save(); |
050902c0 | 620 | compat_sigset_t *cset = (compat_sigset_t *) set; |
1d13024e HS |
621 | |
622 | /* Set up the stack frame */ | |
050902c0 | 623 | if (is_ia32_frame()) { |
235b8022 AV |
624 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
625 | return ia32_setup_rt_frame(usig, ksig, cset, regs); | |
455edbc4 | 626 | else |
235b8022 | 627 | return ia32_setup_frame(usig, ksig, cset, regs); |
050902c0 | 628 | } else if (is_x32_frame()) { |
235b8022 | 629 | return x32_setup_rt_frame(ksig, cset, regs); |
c5a37394 | 630 | } else { |
235b8022 | 631 | return __setup_rt_frame(ksig->sig, ksig, set, regs); |
c5a37394 | 632 | } |
1d13024e HS |
633 | } |
634 | ||
a610d6e6 | 635 | static void |
235b8022 | 636 | handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 637 | { |
235b8022 | 638 | bool failed; |
1da177e4 | 639 | /* Are we from a system call? */ |
bb57925f | 640 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 641 | /* If so, check system call restarting.. */ |
bb57925f | 642 | switch (syscall_get_error(current, regs)) { |
ac66f3fd HH |
643 | case -ERESTART_RESTARTBLOCK: |
644 | case -ERESTARTNOHAND: | |
645 | regs->ax = -EINTR; | |
646 | break; | |
647 | ||
648 | case -ERESTARTSYS: | |
235b8022 | 649 | if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
65ea5b03 | 650 | regs->ax = -EINTR; |
1da177e4 | 651 | break; |
ac66f3fd HH |
652 | } |
653 | /* fallthrough */ | |
654 | case -ERESTARTNOINTR: | |
655 | regs->ax = regs->orig_ax; | |
656 | regs->ip -= 2; | |
657 | break; | |
1da177e4 LT |
658 | } |
659 | } | |
660 | ||
661 | /* | |
e1f28773 RM |
662 | * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF |
663 | * flag so that register information in the sigcontext is correct. | |
1da177e4 | 664 | */ |
65ea5b03 | 665 | if (unlikely(regs->flags & X86_EFLAGS_TF) && |
e1f28773 | 666 | likely(test_and_clear_thread_flag(TIF_FORCED_TF))) |
65ea5b03 | 667 | regs->flags &= ~X86_EFLAGS_TF; |
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 | * |
235b8022 AV |
678 | * Clear TF when entering the signal handler, but |
679 | * notify any tracer that was single-stepping it. | |
680 | * The tracer may want to single-step inside the | |
681 | * handler too. | |
682 | */ | |
ddd40da4 | 683 | regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF); |
66463db4 ON |
684 | /* |
685 | * Ensure the signal handler starts with the new fpu state. | |
686 | */ | |
687 | if (used_math()) | |
688 | drop_init_fpu(current); | |
a610d6e6 | 689 | } |
235b8022 | 690 | signal_setup_done(failed, ksig, test_thread_flag(TIF_SINGLESTEP)); |
1da177e4 LT |
691 | } |
692 | ||
57917752 | 693 | #ifdef CONFIG_X86_32 |
8fcd8e20 | 694 | #define NR_restart_syscall __NR_restart_syscall |
57917752 HS |
695 | #else /* !CONFIG_X86_32 */ |
696 | #define NR_restart_syscall \ | |
697 | test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall | |
698 | #endif /* CONFIG_X86_32 */ | |
699 | ||
1da177e4 LT |
700 | /* |
701 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
702 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
703 | * mistake. | |
704 | */ | |
75604d7f | 705 | static void do_signal(struct pt_regs *regs) |
1da177e4 | 706 | { |
235b8022 | 707 | struct ksignal ksig; |
1da177e4 | 708 | |
235b8022 | 709 | if (get_signal(&ksig)) { |
7e907f48 | 710 | /* Whee! Actually deliver the signal. */ |
235b8022 | 711 | handle_signal(&ksig, regs); |
283828f3 | 712 | return; |
1da177e4 LT |
713 | } |
714 | ||
1da177e4 | 715 | /* Did we come from a system call? */ |
bb57925f | 716 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 717 | /* Restart the system call - no handlers present */ |
bb57925f | 718 | switch (syscall_get_error(current, regs)) { |
283828f3 DH |
719 | case -ERESTARTNOHAND: |
720 | case -ERESTARTSYS: | |
721 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
722 | regs->ax = regs->orig_ax; |
723 | regs->ip -= 2; | |
283828f3 DH |
724 | break; |
725 | ||
726 | case -ERESTART_RESTARTBLOCK: | |
8fcd8e20 | 727 | regs->ax = NR_restart_syscall; |
65ea5b03 | 728 | regs->ip -= 2; |
283828f3 | 729 | break; |
1da177e4 LT |
730 | } |
731 | } | |
283828f3 | 732 | |
ac66f3fd HH |
733 | /* |
734 | * If there's no signal to deliver, we just put the saved sigmask | |
735 | * back. | |
736 | */ | |
51a7b448 | 737 | restore_saved_sigmask(); |
1da177e4 LT |
738 | } |
739 | ||
740 | /* | |
741 | * notification of userspace execution resumption | |
283828f3 | 742 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 | 743 | */ |
277d5b40 | 744 | __visible void |
7e907f48 | 745 | do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) |
1da177e4 | 746 | { |
91d1aa43 | 747 | user_exit(); |
edf55fda | 748 | |
db023ea5 | 749 | if (thread_info_flags & _TIF_UPROBE) |
0326f5a9 | 750 | uprobe_notify_resume(regs); |
0326f5a9 | 751 | |
1da177e4 | 752 | /* deal with pending signal delivery */ |
5a8da0ea | 753 | if (thread_info_flags & _TIF_SIGPENDING) |
283828f3 | 754 | do_signal(regs); |
8f4d37ec | 755 | |
59e52130 RM |
756 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
757 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
758 | tracehook_notify_resume(regs); | |
759 | } | |
7c68af6e AK |
760 | if (thread_info_flags & _TIF_USER_RETURN_NOTIFY) |
761 | fire_user_return_notifiers(); | |
59e52130 | 762 | |
91d1aa43 | 763 | user_enter(); |
1da177e4 | 764 | } |
72fa50f4 HS |
765 | |
766 | void signal_fault(struct pt_regs *regs, void __user *frame, char *where) | |
767 | { | |
768 | struct task_struct *me = current; | |
769 | ||
770 | if (show_unhandled_signals && printk_ratelimit()) { | |
ae417bb4 | 771 | printk("%s" |
72fa50f4 | 772 | "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", |
ae417bb4 | 773 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
72fa50f4 HS |
774 | me->comm, me->pid, where, frame, |
775 | regs->ip, regs->sp, regs->orig_ax); | |
776 | print_vma_addr(" in ", regs->ip); | |
c767a54b | 777 | pr_cont("\n"); |
72fa50f4 HS |
778 | } |
779 | ||
780 | force_sig(SIGSEGV, me); | |
781 | } | |
c5a37394 PA |
782 | |
783 | #ifdef CONFIG_X86_X32_ABI | |
3fe26fa3 | 784 | asmlinkage long sys32_x32_rt_sigreturn(void) |
c5a37394 | 785 | { |
3fe26fa3 | 786 | struct pt_regs *regs = current_pt_regs(); |
c5a37394 PA |
787 | struct rt_sigframe_x32 __user *frame; |
788 | sigset_t set; | |
789 | unsigned long ax; | |
c5a37394 PA |
790 | |
791 | frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8); | |
792 | ||
793 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
794 | goto badframe; | |
795 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
796 | goto badframe; | |
797 | ||
c5a37394 PA |
798 | set_current_blocked(&set); |
799 | ||
800 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) | |
801 | goto badframe; | |
802 | ||
90268439 | 803 | if (compat_restore_altstack(&frame->uc.uc_stack)) |
c5a37394 PA |
804 | goto badframe; |
805 | ||
806 | return ax; | |
807 | ||
808 | badframe: | |
809 | signal_fault(regs, frame, "x32 rt_sigreturn"); | |
810 | return 0; | |
811 | } | |
812 | #endif |