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> | |
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> |
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 | |
9dfe99b7 | 106 | err |= fpu__restore_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); |
c5bedc68 | 202 | struct fpu *fpu = ¤t->thread.fpu; |
75779f05 | 203 | |
75779f05 | 204 | /* redzone */ |
050902c0 SS |
205 | if (config_enabled(CONFIG_X86_64)) |
206 | sp -= 128; | |
1da177e4 | 207 | |
14fc9fbc HS |
208 | if (!onsigstack) { |
209 | /* This is the X/Open sanctioned signal stack switching. */ | |
210 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
0f8f3089 | 211 | if (current->sas_ss_size) |
14fc9fbc | 212 | sp = current->sas_ss_sp + current->sas_ss_size; |
050902c0 SS |
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. */ | |
14fc9fbc | 218 | sp = (unsigned long) ka->sa.sa_restorer; |
14fc9fbc | 219 | } |
1da177e4 LT |
220 | } |
221 | ||
c5bedc68 | 222 | if (fpu->fpstate_active) { |
82c0e45e IM |
223 | sp = fpu__alloc_mathframe(sp, config_enabled(CONFIG_X86_32), |
224 | &buf_fx, &math_size); | |
25051702 | 225 | *fpstate = (void __user *)sp; |
3c1c7f10 SS |
226 | } |
227 | ||
14fc9fbc HS |
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 | ||
72a671ce | 237 | /* save i387 and extended state */ |
c5bedc68 | 238 | if (fpu->fpstate_active && |
c8e14041 | 239 | copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size) < 0) |
14fc9fbc HS |
240 | return (void __user *)-1L; |
241 | ||
242 | return (void __user *)sp; | |
1da177e4 LT |
243 | } |
244 | ||
75779f05 HS |
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 | ||
7e907f48 | 268 | static int |
235b8022 | 269 | __setup_frame(int sig, struct ksignal *ksig, sigset_t *set, |
1d13024e | 270 | struct pt_regs *regs) |
1da177e4 | 271 | { |
1da177e4 | 272 | struct sigframe __user *frame; |
7e907f48 | 273 | void __user *restorer; |
1da177e4 | 274 | int err = 0; |
ab513701 | 275 | void __user *fpstate = NULL; |
1da177e4 | 276 | |
235b8022 | 277 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
278 | |
279 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 280 | return -EFAULT; |
1da177e4 | 281 | |
2ba48e16 | 282 | if (__put_user(sig, &frame->sig)) |
3d0aedd9 | 283 | return -EFAULT; |
1da177e4 | 284 | |
2ba48e16 | 285 | if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) |
3d0aedd9 | 286 | return -EFAULT; |
1da177e4 LT |
287 | |
288 | if (_NSIG_WORDS > 1) { | |
2ba48e16 HS |
289 | if (__copy_to_user(&frame->extramask, &set->sig[1], |
290 | sizeof(frame->extramask))) | |
3d0aedd9 | 291 | return -EFAULT; |
1da177e4 LT |
292 | } |
293 | ||
1a3e4ca4 | 294 | if (current->mm->context.vdso) |
6f121e54 AL |
295 | restorer = current->mm->context.vdso + |
296 | selected_vdso32->sym___kernel_sigreturn; | |
9fbbd4dd | 297 | else |
ade1af77 | 298 | restorer = &frame->retcode; |
235b8022 AV |
299 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
300 | restorer = ksig->ka.sa.sa_restorer; | |
1da177e4 LT |
301 | |
302 | /* Set up to return from userspace. */ | |
303 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 304 | |
1da177e4 | 305 | /* |
7e907f48 | 306 | * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
1da177e4 LT |
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 | */ | |
4a612048 | 312 | err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode); |
1da177e4 LT |
313 | |
314 | if (err) | |
3d0aedd9 | 315 | return -EFAULT; |
1da177e4 LT |
316 | |
317 | /* Set up registers for signal handler */ | |
7e907f48 | 318 | regs->sp = (unsigned long)frame; |
235b8022 | 319 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
7e907f48 | 320 | regs->ax = (unsigned long)sig; |
92bc2056 HH |
321 | regs->dx = 0; |
322 | regs->cx = 0; | |
1da177e4 | 323 | |
65ea5b03 PA |
324 | regs->ds = __USER_DS; |
325 | regs->es = __USER_DS; | |
326 | regs->ss = __USER_DS; | |
327 | regs->cs = __USER_CS; | |
1da177e4 | 328 | |
283828f3 | 329 | return 0; |
1da177e4 LT |
330 | } |
331 | ||
235b8022 | 332 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
1d13024e | 333 | sigset_t *set, struct pt_regs *regs) |
1da177e4 | 334 | { |
1da177e4 | 335 | struct rt_sigframe __user *frame; |
7e907f48 | 336 | void __user *restorer; |
1da177e4 | 337 | int err = 0; |
ab513701 | 338 | void __user *fpstate = NULL; |
1da177e4 | 339 | |
235b8022 | 340 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
341 | |
342 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 343 | return -EFAULT; |
1da177e4 | 344 | |
98e3d45e HS |
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); | |
98e3d45e HS |
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); | |
bd1c149a | 356 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
357 | |
358 | /* Set up to return from userspace. */ | |
6f121e54 | 359 | restorer = current->mm->context.vdso + |
6ba19a67 | 360 | selected_vdso32->sym___kernel_rt_sigreturn; |
235b8022 AV |
361 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
362 | restorer = ksig->ka.sa.sa_restorer; | |
98e3d45e HS |
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); | |
49b8c695 | 374 | |
235b8022 | 375 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
5e88353d PA |
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)); | |
1da177e4 LT |
379 | |
380 | if (err) | |
3d0aedd9 | 381 | return -EFAULT; |
1da177e4 LT |
382 | |
383 | /* Set up registers for signal handler */ | |
7e907f48 | 384 | regs->sp = (unsigned long)frame; |
235b8022 | 385 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
13ad7725 | 386 | regs->ax = (unsigned long)sig; |
7e907f48 IM |
387 | regs->dx = (unsigned long)&frame->info; |
388 | regs->cx = (unsigned long)&frame->uc; | |
1da177e4 | 389 | |
65ea5b03 PA |
390 | regs->ds = __USER_DS; |
391 | regs->es = __USER_DS; | |
392 | regs->ss = __USER_DS; | |
393 | regs->cs = __USER_CS; | |
1da177e4 | 394 | |
283828f3 | 395 | return 0; |
1da177e4 | 396 | } |
bfeb91a9 | 397 | #else /* !CONFIG_X86_32 */ |
235b8022 | 398 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
bfeb91a9 HS |
399 | sigset_t *set, struct pt_regs *regs) |
400 | { | |
401 | struct rt_sigframe __user *frame; | |
402 | void __user *fp = NULL; | |
403 | int err = 0; | |
bfeb91a9 | 404 | |
235b8022 | 405 | frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp); |
bfeb91a9 HS |
406 | |
407 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
408 | return -EFAULT; | |
409 | ||
235b8022 AV |
410 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
411 | if (copy_siginfo_to_user(&frame->info, &ksig->info)) | |
bfeb91a9 HS |
412 | return -EFAULT; |
413 | } | |
414 | ||
98e3d45e HS |
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); | |
bd1c149a | 422 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
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. */ | |
235b8022 AV |
427 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
428 | put_user_ex(ksig->ka.sa.sa_restorer, &frame->pretcode); | |
98e3d45e HS |
429 | } else { |
430 | /* could use a vstub here */ | |
431 | err |= -EFAULT; | |
432 | } | |
433 | } put_user_catch(err); | |
bfeb91a9 | 434 | |
5e88353d PA |
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 | ||
bfeb91a9 HS |
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; | |
235b8022 | 450 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
bfeb91a9 HS |
451 | |
452 | regs->sp = (unsigned long)frame; | |
453 | ||
c6f20629 AL |
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 | */ | |
bfeb91a9 | 465 | regs->cs = __USER_CS; |
c6f20629 | 466 | regs->ss = __USER_DS; |
bfeb91a9 HS |
467 | |
468 | return 0; | |
469 | } | |
470 | #endif /* CONFIG_X86_32 */ | |
471 | ||
235b8022 AV |
472 | static int x32_setup_rt_frame(struct ksignal *ksig, |
473 | compat_sigset_t *set, | |
050902c0 SS |
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 | ||
235b8022 | 482 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
050902c0 SS |
483 | |
484 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
485 | return -EFAULT; | |
486 | ||
235b8022 AV |
487 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
488 | if (copy_siginfo_to_user32(&frame->info, &ksig->info)) | |
050902c0 SS |
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); | |
bd1c149a | 499 | compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
050902c0 | 500 | put_user_ex(0, &frame->uc.uc__pad0); |
050902c0 | 501 | |
235b8022 AV |
502 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
503 | restorer = ksig->ka.sa.sa_restorer; | |
050902c0 SS |
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 | ||
49b8c695 PA |
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 | ||
050902c0 SS |
516 | if (err) |
517 | return -EFAULT; | |
518 | ||
519 | /* Set up registers for signal handler */ | |
520 | regs->sp = (unsigned long) frame; | |
235b8022 | 521 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
050902c0 SS |
522 | |
523 | /* We use the x32 calling convention here... */ | |
235b8022 | 524 | regs->di = ksig->sig; |
050902c0 SS |
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 | ||
bfeb91a9 HS |
538 | /* |
539 | * Do a signal return; undo the signal stack. | |
540 | */ | |
e5fa2d06 | 541 | #ifdef CONFIG_X86_32 |
ff49103f | 542 | asmlinkage unsigned long sys_sigreturn(void) |
bfeb91a9 | 543 | { |
3fe26fa3 | 544 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 | 545 | struct sigframe __user *frame; |
bfeb91a9 HS |
546 | sigset_t set; |
547 | ||
bfeb91a9 HS |
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 | ||
3982294b | 557 | set_current_blocked(&set); |
bfeb91a9 | 558 | |
6a3713f0 | 559 | if (restore_sigcontext(regs, &frame->sc)) |
bfeb91a9 | 560 | goto badframe; |
6a3713f0 | 561 | return regs->ax; |
bfeb91a9 HS |
562 | |
563 | badframe: | |
ae417bb4 | 564 | signal_fault(regs, frame, "sigreturn"); |
bfeb91a9 HS |
565 | |
566 | return 0; | |
567 | } | |
e5fa2d06 | 568 | #endif /* CONFIG_X86_32 */ |
bfeb91a9 | 569 | |
ff49103f | 570 | asmlinkage long sys_rt_sigreturn(void) |
bfeb91a9 | 571 | { |
3fe26fa3 | 572 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 | 573 | struct rt_sigframe __user *frame; |
bfeb91a9 HS |
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 | ||
e9bd3f0f | 582 | set_current_blocked(&set); |
bfeb91a9 | 583 | |
6a3713f0 | 584 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) |
bfeb91a9 HS |
585 | goto badframe; |
586 | ||
c40702c4 | 587 | if (restore_altstack(&frame->uc.uc_stack)) |
bfeb91a9 HS |
588 | goto badframe; |
589 | ||
6a3713f0 | 590 | return regs->ax; |
bfeb91a9 HS |
591 | |
592 | badframe: | |
593 | signal_fault(regs, frame, "rt_sigreturn"); | |
594 | return 0; | |
595 | } | |
596 | ||
05012c13 IM |
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 | ||
1d13024e | 613 | static int |
235b8022 | 614 | setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) |
1d13024e | 615 | { |
3050a35f | 616 | int usig = ksig->sig; |
b7f9a11a | 617 | sigset_t *set = sigmask_to_save(); |
050902c0 | 618 | compat_sigset_t *cset = (compat_sigset_t *) set; |
1d13024e HS |
619 | |
620 | /* Set up the stack frame */ | |
050902c0 | 621 | if (is_ia32_frame()) { |
235b8022 AV |
622 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
623 | return ia32_setup_rt_frame(usig, ksig, cset, regs); | |
455edbc4 | 624 | else |
235b8022 | 625 | return ia32_setup_frame(usig, ksig, cset, regs); |
050902c0 | 626 | } else if (is_x32_frame()) { |
235b8022 | 627 | return x32_setup_rt_frame(ksig, cset, regs); |
c5a37394 | 628 | } else { |
235b8022 | 629 | return __setup_rt_frame(ksig->sig, ksig, set, regs); |
c5a37394 | 630 | } |
1d13024e HS |
631 | } |
632 | ||
a610d6e6 | 633 | static void |
235b8022 | 634 | handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 635 | { |
fd0f86b6 | 636 | bool stepping, failed; |
c5bedc68 | 637 | struct fpu *fpu = ¤t->thread.fpu; |
fd0f86b6 | 638 | |
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 | /* | |
fd0f86b6 ON |
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. | |
1da177e4 | 665 | */ |
fd0f86b6 ON |
666 | stepping = test_thread_flag(TIF_SINGLESTEP); |
667 | if (stepping) | |
668 | user_disable_single_step(current); | |
1da177e4 | 669 | |
235b8022 AV |
670 | failed = (setup_rt_frame(ksig, regs) < 0); |
671 | if (!failed) { | |
672 | /* | |
673 | * Clear the direction flag as per the ABI for function entry. | |
ddd40da4 | 674 | * |
24cda109 JO |
675 | * Clear RF when entering the signal handler, because |
676 | * it might disable possible debug exception from the | |
677 | * signal handler. | |
ddd40da4 | 678 | * |
fd0f86b6 ON |
679 | * Clear TF for the case when it wasn't set by debugger to |
680 | * avoid the recursive send_sigtrap() in SIGTRAP handler. | |
235b8022 | 681 | */ |
ddd40da4 | 682 | regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF); |
66463db4 ON |
683 | /* |
684 | * Ensure the signal handler starts with the new fpu state. | |
685 | */ | |
c5bedc68 | 686 | if (fpu->fpstate_active) |
fbce7782 | 687 | fpu__clear(fpu); |
a610d6e6 | 688 | } |
fd0f86b6 | 689 | signal_setup_done(failed, ksig, stepping); |
1da177e4 LT |
690 | } |
691 | ||
57917752 | 692 | #ifdef CONFIG_X86_32 |
8fcd8e20 | 693 | #define NR_restart_syscall __NR_restart_syscall |
57917752 HS |
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 | ||
1da177e4 LT |
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 | */ | |
75604d7f | 704 | static void do_signal(struct pt_regs *regs) |
1da177e4 | 705 | { |
235b8022 | 706 | struct ksignal ksig; |
1da177e4 | 707 | |
235b8022 | 708 | if (get_signal(&ksig)) { |
7e907f48 | 709 | /* Whee! Actually deliver the signal. */ |
235b8022 | 710 | handle_signal(&ksig, regs); |
283828f3 | 711 | return; |
1da177e4 LT |
712 | } |
713 | ||
1da177e4 | 714 | /* Did we come from a system call? */ |
bb57925f | 715 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 716 | /* Restart the system call - no handlers present */ |
bb57925f | 717 | switch (syscall_get_error(current, regs)) { |
283828f3 DH |
718 | case -ERESTARTNOHAND: |
719 | case -ERESTARTSYS: | |
720 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
721 | regs->ax = regs->orig_ax; |
722 | regs->ip -= 2; | |
283828f3 DH |
723 | break; |
724 | ||
725 | case -ERESTART_RESTARTBLOCK: | |
8fcd8e20 | 726 | regs->ax = NR_restart_syscall; |
65ea5b03 | 727 | regs->ip -= 2; |
283828f3 | 728 | break; |
1da177e4 LT |
729 | } |
730 | } | |
283828f3 | 731 | |
ac66f3fd HH |
732 | /* |
733 | * If there's no signal to deliver, we just put the saved sigmask | |
734 | * back. | |
735 | */ | |
51a7b448 | 736 | restore_saved_sigmask(); |
1da177e4 LT |
737 | } |
738 | ||
739 | /* | |
740 | * notification of userspace execution resumption | |
283828f3 | 741 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 | 742 | */ |
277d5b40 | 743 | __visible void |
7e907f48 | 744 | do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) |
1da177e4 | 745 | { |
91d1aa43 | 746 | user_exit(); |
edf55fda | 747 | |
db023ea5 | 748 | if (thread_info_flags & _TIF_UPROBE) |
0326f5a9 | 749 | uprobe_notify_resume(regs); |
0326f5a9 | 750 | |
1da177e4 | 751 | /* deal with pending signal delivery */ |
5a8da0ea | 752 | if (thread_info_flags & _TIF_SIGPENDING) |
283828f3 | 753 | do_signal(regs); |
8f4d37ec | 754 | |
59e52130 RM |
755 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
756 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
757 | tracehook_notify_resume(regs); | |
758 | } | |
7c68af6e AK |
759 | if (thread_info_flags & _TIF_USER_RETURN_NOTIFY) |
760 | fire_user_return_notifiers(); | |
59e52130 | 761 | |
91d1aa43 | 762 | user_enter(); |
1da177e4 | 763 | } |
72fa50f4 HS |
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()) { | |
ae417bb4 | 770 | printk("%s" |
72fa50f4 | 771 | "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", |
ae417bb4 | 772 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
72fa50f4 HS |
773 | me->comm, me->pid, where, frame, |
774 | regs->ip, regs->sp, regs->orig_ax); | |
775 | print_vma_addr(" in ", regs->ip); | |
c767a54b | 776 | pr_cont("\n"); |
72fa50f4 HS |
777 | } |
778 | ||
779 | force_sig(SIGSEGV, me); | |
780 | } | |
c5a37394 PA |
781 | |
782 | #ifdef CONFIG_X86_X32_ABI | |
3fe26fa3 | 783 | asmlinkage long sys32_x32_rt_sigreturn(void) |
c5a37394 | 784 | { |
3fe26fa3 | 785 | struct pt_regs *regs = current_pt_regs(); |
c5a37394 PA |
786 | struct rt_sigframe_x32 __user *frame; |
787 | sigset_t set; | |
c5a37394 PA |
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 | ||
c5a37394 PA |
796 | set_current_blocked(&set); |
797 | ||
6a3713f0 | 798 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) |
c5a37394 PA |
799 | goto badframe; |
800 | ||
90268439 | 801 | if (compat_restore_altstack(&frame->uc.uc_stack)) |
c5a37394 PA |
802 | goto badframe; |
803 | ||
6a3713f0 | 804 | return regs->ax; |
c5a37394 PA |
805 | |
806 | badframe: | |
807 | signal_fault(regs, frame, "x32 rt_sigreturn"); | |
808 | return 0; | |
809 | } | |
810 | #endif |