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Commit | Line | Data |
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1da177e4 | 1 | /* |
1da177e4 | 2 | * Copyright (C) 1991, 1992 Linus Torvalds |
e5fa2d06 | 3 | * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs |
1da177e4 LT |
4 | * |
5 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson | |
6 | * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes | |
e5fa2d06 | 7 | * 2000-2002 x86-64 support by Andi Kleen |
1da177e4 | 8 | */ |
c767a54b JP |
9 | |
10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
11 | ||
5c9b3a0c HS |
12 | #include <linux/sched.h> |
13 | #include <linux/mm.h> | |
14 | #include <linux/smp.h> | |
1da177e4 | 15 | #include <linux/kernel.h> |
1da177e4 LT |
16 | #include <linux/errno.h> |
17 | #include <linux/wait.h> | |
36a03308 | 18 | #include <linux/tracehook.h> |
5c9b3a0c HS |
19 | #include <linux/unistd.h> |
20 | #include <linux/stddef.h> | |
21 | #include <linux/personality.h> | |
22 | #include <linux/uaccess.h> | |
7c68af6e | 23 | #include <linux/user-return-notifier.h> |
0326f5a9 | 24 | #include <linux/uprobes.h> |
91d1aa43 | 25 | #include <linux/context_tracking.h> |
7e907f48 | 26 | |
1da177e4 LT |
27 | #include <asm/processor.h> |
28 | #include <asm/ucontext.h> | |
78f7f1e5 | 29 | #include <asm/fpu/internal.h> |
fcbc99c4 | 30 | #include <asm/fpu/signal.h> |
6c3652ef | 31 | #include <asm/vdso.h> |
4efc0670 | 32 | #include <asm/mce.h> |
f28f0c23 | 33 | #include <asm/sighandling.h> |
ba3e127e | 34 | #include <asm/vm86.h> |
5c9b3a0c HS |
35 | |
36 | #ifdef CONFIG_X86_64 | |
37 | #include <asm/proto.h> | |
38 | #include <asm/ia32_unistd.h> | |
5c9b3a0c HS |
39 | #endif /* CONFIG_X86_64 */ |
40 | ||
bb57925f | 41 | #include <asm/syscall.h> |
bbc1f698 | 42 | #include <asm/syscalls.h> |
7e907f48 | 43 | |
41af86fa | 44 | #include <asm/sigframe.h> |
1da177e4 | 45 | |
d9a89a26 TH |
46 | #define COPY(x) do { \ |
47 | get_user_ex(regs->x, &sc->x); \ | |
48 | } while (0) | |
2601657d | 49 | |
d9a89a26 TH |
50 | #define GET_SEG(seg) ({ \ |
51 | unsigned short tmp; \ | |
52 | get_user_ex(tmp, &sc->seg); \ | |
53 | tmp; \ | |
54 | }) | |
2601657d | 55 | |
d9a89a26 TH |
56 | #define COPY_SEG(seg) do { \ |
57 | regs->seg = GET_SEG(seg); \ | |
58 | } while (0) | |
2601657d | 59 | |
d9a89a26 TH |
60 | #define COPY_SEG_CPL3(seg) do { \ |
61 | regs->seg = GET_SEG(seg) | 3; \ | |
62 | } while (0) | |
2601657d | 63 | |
8ff5bd2e AL |
64 | #ifdef CONFIG_X86_64 |
65 | /* | |
66 | * If regs->ss will cause an IRET fault, change it. Otherwise leave it | |
67 | * alone. Using this generally makes no sense unless | |
68 | * user_64bit_mode(regs) would return true. | |
69 | */ | |
70 | static void force_valid_ss(struct pt_regs *regs) | |
71 | { | |
72 | u32 ar; | |
73 | asm volatile ("lar %[old_ss], %[ar]\n\t" | |
74 | "jz 1f\n\t" /* If invalid: */ | |
75 | "xorl %[ar], %[ar]\n\t" /* set ar = 0 */ | |
76 | "1:" | |
77 | : [ar] "=r" (ar) | |
78 | : [old_ss] "rm" ((u16)regs->ss)); | |
79 | ||
80 | /* | |
81 | * For a valid 64-bit user context, we need DPL 3, type | |
82 | * read-write data or read-write exp-down data, and S and P | |
83 | * set. We can't use VERW because VERW doesn't check the | |
84 | * P bit. | |
85 | */ | |
86 | ar &= AR_DPL_MASK | AR_S | AR_P | AR_TYPE_MASK; | |
87 | if (ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA) && | |
88 | ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN)) | |
89 | regs->ss = __USER_DS; | |
90 | } | |
91 | #endif | |
92 | ||
6a3713f0 | 93 | int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) |
2601657d | 94 | { |
530e5c82 | 95 | unsigned long buf_val; |
2601657d HS |
96 | void __user *buf; |
97 | unsigned int tmpflags; | |
98 | unsigned int err = 0; | |
99 | ||
100 | /* Always make any pending restarted system calls return -EINTR */ | |
f56141e3 | 101 | current->restart_block.fn = do_no_restart_syscall; |
2601657d | 102 | |
98e3d45e HS |
103 | get_user_try { |
104 | ||
2601657d | 105 | #ifdef CONFIG_X86_32 |
d9a89a26 | 106 | set_user_gs(regs, GET_SEG(gs)); |
98e3d45e HS |
107 | COPY_SEG(fs); |
108 | COPY_SEG(es); | |
109 | COPY_SEG(ds); | |
2601657d HS |
110 | #endif /* CONFIG_X86_32 */ |
111 | ||
98e3d45e | 112 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
6a3713f0 | 113 | COPY(dx); COPY(cx); COPY(ip); COPY(ax); |
2601657d HS |
114 | |
115 | #ifdef CONFIG_X86_64 | |
98e3d45e HS |
116 | COPY(r8); |
117 | COPY(r9); | |
118 | COPY(r10); | |
119 | COPY(r11); | |
120 | COPY(r12); | |
121 | COPY(r13); | |
122 | COPY(r14); | |
123 | COPY(r15); | |
2601657d HS |
124 | #endif /* CONFIG_X86_64 */ |
125 | ||
ed596cde | 126 | #ifdef CONFIG_X86_32 |
98e3d45e HS |
127 | COPY_SEG_CPL3(cs); |
128 | COPY_SEG_CPL3(ss); | |
ed596cde LT |
129 | #else /* !CONFIG_X86_32 */ |
130 | /* Kernel saves and restores only the CS segment register on signals, | |
131 | * which is the bare minimum needed to allow mixed 32/64-bit code. | |
132 | * App's signal handler can save/restore other segments if needed. */ | |
133 | COPY_SEG_CPL3(cs); | |
134 | #endif /* CONFIG_X86_32 */ | |
2601657d | 135 | |
98e3d45e HS |
136 | get_user_ex(tmpflags, &sc->flags); |
137 | regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); | |
138 | regs->orig_ax = -1; /* disable syscall checks */ | |
139 | ||
530e5c82 IM |
140 | get_user_ex(buf_val, &sc->fpstate); |
141 | buf = (void __user *)buf_val; | |
98e3d45e | 142 | } get_user_catch(err); |
2601657d | 143 | |
9dfe99b7 | 144 | err |= fpu__restore_sig(buf, config_enabled(CONFIG_X86_32)); |
5e88353d | 145 | |
1daeaa31 BG |
146 | force_iret(); |
147 | ||
2601657d HS |
148 | return err; |
149 | } | |
150 | ||
85139422 PA |
151 | int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, |
152 | struct pt_regs *regs, unsigned long mask) | |
2601657d HS |
153 | { |
154 | int err = 0; | |
155 | ||
98e3d45e | 156 | put_user_try { |
2601657d | 157 | |
98e3d45e | 158 | #ifdef CONFIG_X86_32 |
d9a89a26 | 159 | put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs); |
98e3d45e HS |
160 | put_user_ex(regs->fs, (unsigned int __user *)&sc->fs); |
161 | put_user_ex(regs->es, (unsigned int __user *)&sc->es); | |
162 | put_user_ex(regs->ds, (unsigned int __user *)&sc->ds); | |
2601657d HS |
163 | #endif /* CONFIG_X86_32 */ |
164 | ||
98e3d45e HS |
165 | put_user_ex(regs->di, &sc->di); |
166 | put_user_ex(regs->si, &sc->si); | |
167 | put_user_ex(regs->bp, &sc->bp); | |
168 | put_user_ex(regs->sp, &sc->sp); | |
169 | put_user_ex(regs->bx, &sc->bx); | |
170 | put_user_ex(regs->dx, &sc->dx); | |
171 | put_user_ex(regs->cx, &sc->cx); | |
172 | put_user_ex(regs->ax, &sc->ax); | |
2601657d | 173 | #ifdef CONFIG_X86_64 |
98e3d45e HS |
174 | put_user_ex(regs->r8, &sc->r8); |
175 | put_user_ex(regs->r9, &sc->r9); | |
176 | put_user_ex(regs->r10, &sc->r10); | |
177 | put_user_ex(regs->r11, &sc->r11); | |
178 | put_user_ex(regs->r12, &sc->r12); | |
179 | put_user_ex(regs->r13, &sc->r13); | |
180 | put_user_ex(regs->r14, &sc->r14); | |
181 | put_user_ex(regs->r15, &sc->r15); | |
2601657d HS |
182 | #endif /* CONFIG_X86_64 */ |
183 | ||
51e7dc70 | 184 | put_user_ex(current->thread.trap_nr, &sc->trapno); |
98e3d45e HS |
185 | put_user_ex(current->thread.error_code, &sc->err); |
186 | put_user_ex(regs->ip, &sc->ip); | |
2601657d | 187 | #ifdef CONFIG_X86_32 |
98e3d45e HS |
188 | put_user_ex(regs->cs, (unsigned int __user *)&sc->cs); |
189 | put_user_ex(regs->flags, &sc->flags); | |
190 | put_user_ex(regs->sp, &sc->sp_at_signal); | |
191 | put_user_ex(regs->ss, (unsigned int __user *)&sc->ss); | |
2601657d | 192 | #else /* !CONFIG_X86_32 */ |
98e3d45e HS |
193 | put_user_ex(regs->flags, &sc->flags); |
194 | put_user_ex(regs->cs, &sc->cs); | |
ed596cde LT |
195 | put_user_ex(0, &sc->gs); |
196 | put_user_ex(0, &sc->fs); | |
2601657d HS |
197 | #endif /* CONFIG_X86_32 */ |
198 | ||
98e3d45e | 199 | put_user_ex(fpstate, &sc->fpstate); |
2601657d | 200 | |
98e3d45e HS |
201 | /* non-iBCS2 extensions.. */ |
202 | put_user_ex(mask, &sc->oldmask); | |
203 | put_user_ex(current->thread.cr2, &sc->cr2); | |
204 | } put_user_catch(err); | |
2601657d HS |
205 | |
206 | return err; | |
207 | } | |
208 | ||
1da177e4 | 209 | /* |
bfeb91a9 | 210 | * Set up a signal frame. |
1da177e4 | 211 | */ |
1da177e4 LT |
212 | |
213 | /* | |
214 | * Determine which stack to use.. | |
215 | */ | |
1fae0279 HS |
216 | static unsigned long align_sigframe(unsigned long sp) |
217 | { | |
218 | #ifdef CONFIG_X86_32 | |
219 | /* | |
220 | * Align the stack pointer according to the i386 ABI, | |
221 | * i.e. so that on function entry ((sp + 4) & 15) == 0. | |
222 | */ | |
223 | sp = ((sp + 4) & -16ul) - 4; | |
224 | #else /* !CONFIG_X86_32 */ | |
225 | sp = round_down(sp, 16) - 8; | |
226 | #endif | |
227 | return sp; | |
228 | } | |
229 | ||
dae0f305 | 230 | static void __user * |
3c1c7f10 | 231 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, |
144b0712 | 232 | void __user **fpstate) |
1da177e4 | 233 | { |
1da177e4 | 234 | /* Default to using normal stack */ |
72a671ce | 235 | unsigned long math_size = 0; |
75779f05 | 236 | unsigned long sp = regs->sp; |
72a671ce | 237 | unsigned long buf_fx = 0; |
14fc9fbc | 238 | int onsigstack = on_sig_stack(sp); |
c5bedc68 | 239 | struct fpu *fpu = ¤t->thread.fpu; |
75779f05 | 240 | |
75779f05 | 241 | /* redzone */ |
050902c0 SS |
242 | if (config_enabled(CONFIG_X86_64)) |
243 | sp -= 128; | |
1da177e4 | 244 | |
14fc9fbc HS |
245 | if (!onsigstack) { |
246 | /* This is the X/Open sanctioned signal stack switching. */ | |
247 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
0f8f3089 | 248 | if (current->sas_ss_size) |
14fc9fbc | 249 | sp = current->sas_ss_sp + current->sas_ss_size; |
050902c0 SS |
250 | } else if (config_enabled(CONFIG_X86_32) && |
251 | (regs->ss & 0xffff) != __USER_DS && | |
252 | !(ka->sa.sa_flags & SA_RESTORER) && | |
253 | ka->sa.sa_restorer) { | |
254 | /* This is the legacy signal stack switching. */ | |
14fc9fbc | 255 | sp = (unsigned long) ka->sa.sa_restorer; |
14fc9fbc | 256 | } |
1da177e4 LT |
257 | } |
258 | ||
c5bedc68 | 259 | if (fpu->fpstate_active) { |
82c0e45e IM |
260 | sp = fpu__alloc_mathframe(sp, config_enabled(CONFIG_X86_32), |
261 | &buf_fx, &math_size); | |
25051702 | 262 | *fpstate = (void __user *)sp; |
3c1c7f10 SS |
263 | } |
264 | ||
14fc9fbc HS |
265 | sp = align_sigframe(sp - frame_size); |
266 | ||
267 | /* | |
268 | * If we are on the alternate signal stack and would overflow it, don't. | |
269 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
270 | */ | |
271 | if (onsigstack && !likely(on_sig_stack(sp))) | |
272 | return (void __user *)-1L; | |
273 | ||
72a671ce | 274 | /* save i387 and extended state */ |
c5bedc68 | 275 | if (fpu->fpstate_active && |
c8e14041 | 276 | copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size) < 0) |
14fc9fbc HS |
277 | return (void __user *)-1L; |
278 | ||
279 | return (void __user *)sp; | |
1da177e4 LT |
280 | } |
281 | ||
75779f05 HS |
282 | #ifdef CONFIG_X86_32 |
283 | static const struct { | |
284 | u16 poplmovl; | |
285 | u32 val; | |
286 | u16 int80; | |
287 | } __attribute__((packed)) retcode = { | |
288 | 0xb858, /* popl %eax; movl $..., %eax */ | |
289 | __NR_sigreturn, | |
290 | 0x80cd, /* int $0x80 */ | |
291 | }; | |
292 | ||
293 | static const struct { | |
294 | u8 movl; | |
295 | u32 val; | |
296 | u16 int80; | |
297 | u8 pad; | |
298 | } __attribute__((packed)) rt_retcode = { | |
299 | 0xb8, /* movl $..., %eax */ | |
300 | __NR_rt_sigreturn, | |
301 | 0x80cd, /* int $0x80 */ | |
302 | 0 | |
303 | }; | |
304 | ||
7e907f48 | 305 | static int |
235b8022 | 306 | __setup_frame(int sig, struct ksignal *ksig, sigset_t *set, |
1d13024e | 307 | struct pt_regs *regs) |
1da177e4 | 308 | { |
1da177e4 | 309 | struct sigframe __user *frame; |
7e907f48 | 310 | void __user *restorer; |
1da177e4 | 311 | int err = 0; |
ab513701 | 312 | void __user *fpstate = NULL; |
1da177e4 | 313 | |
235b8022 | 314 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
315 | |
316 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 317 | return -EFAULT; |
1da177e4 | 318 | |
2ba48e16 | 319 | if (__put_user(sig, &frame->sig)) |
3d0aedd9 | 320 | return -EFAULT; |
1da177e4 | 321 | |
2ba48e16 | 322 | if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) |
3d0aedd9 | 323 | return -EFAULT; |
1da177e4 LT |
324 | |
325 | if (_NSIG_WORDS > 1) { | |
2ba48e16 HS |
326 | if (__copy_to_user(&frame->extramask, &set->sig[1], |
327 | sizeof(frame->extramask))) | |
3d0aedd9 | 328 | return -EFAULT; |
1da177e4 LT |
329 | } |
330 | ||
1a3e4ca4 | 331 | if (current->mm->context.vdso) |
6f121e54 | 332 | restorer = current->mm->context.vdso + |
0a6d1fa0 | 333 | vdso_image_32.sym___kernel_sigreturn; |
9fbbd4dd | 334 | else |
ade1af77 | 335 | restorer = &frame->retcode; |
235b8022 AV |
336 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
337 | restorer = ksig->ka.sa.sa_restorer; | |
1da177e4 LT |
338 | |
339 | /* Set up to return from userspace. */ | |
340 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 341 | |
1da177e4 | 342 | /* |
7e907f48 | 343 | * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
1da177e4 LT |
344 | * |
345 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
346 | * reasons and because gdb uses it as a signature to notice | |
347 | * signal handler stack frames. | |
348 | */ | |
4a612048 | 349 | err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode); |
1da177e4 LT |
350 | |
351 | if (err) | |
3d0aedd9 | 352 | return -EFAULT; |
1da177e4 LT |
353 | |
354 | /* Set up registers for signal handler */ | |
7e907f48 | 355 | regs->sp = (unsigned long)frame; |
235b8022 | 356 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
7e907f48 | 357 | regs->ax = (unsigned long)sig; |
92bc2056 HH |
358 | regs->dx = 0; |
359 | regs->cx = 0; | |
1da177e4 | 360 | |
65ea5b03 PA |
361 | regs->ds = __USER_DS; |
362 | regs->es = __USER_DS; | |
363 | regs->ss = __USER_DS; | |
364 | regs->cs = __USER_CS; | |
1da177e4 | 365 | |
283828f3 | 366 | return 0; |
1da177e4 LT |
367 | } |
368 | ||
235b8022 | 369 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
1d13024e | 370 | sigset_t *set, struct pt_regs *regs) |
1da177e4 | 371 | { |
1da177e4 | 372 | struct rt_sigframe __user *frame; |
7e907f48 | 373 | void __user *restorer; |
1da177e4 | 374 | int err = 0; |
ab513701 | 375 | void __user *fpstate = NULL; |
1da177e4 | 376 | |
235b8022 | 377 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
378 | |
379 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 380 | return -EFAULT; |
1da177e4 | 381 | |
98e3d45e HS |
382 | put_user_try { |
383 | put_user_ex(sig, &frame->sig); | |
384 | put_user_ex(&frame->info, &frame->pinfo); | |
385 | put_user_ex(&frame->uc, &frame->puc); | |
98e3d45e HS |
386 | |
387 | /* Create the ucontext. */ | |
388 | if (cpu_has_xsave) | |
389 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | |
390 | else | |
391 | put_user_ex(0, &frame->uc.uc_flags); | |
392 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 393 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
394 | |
395 | /* Set up to return from userspace. */ | |
6f121e54 | 396 | restorer = current->mm->context.vdso + |
0a6d1fa0 | 397 | vdso_image_32.sym___kernel_rt_sigreturn; |
235b8022 AV |
398 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
399 | restorer = ksig->ka.sa.sa_restorer; | |
98e3d45e HS |
400 | put_user_ex(restorer, &frame->pretcode); |
401 | ||
402 | /* | |
403 | * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 | |
404 | * | |
405 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
406 | * reasons and because gdb uses it as a signature to notice | |
407 | * signal handler stack frames. | |
408 | */ | |
409 | put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode); | |
410 | } put_user_catch(err); | |
49b8c695 | 411 | |
235b8022 | 412 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
5e88353d PA |
413 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
414 | regs, set->sig[0]); | |
415 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
1da177e4 LT |
416 | |
417 | if (err) | |
3d0aedd9 | 418 | return -EFAULT; |
1da177e4 LT |
419 | |
420 | /* Set up registers for signal handler */ | |
7e907f48 | 421 | regs->sp = (unsigned long)frame; |
235b8022 | 422 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
13ad7725 | 423 | regs->ax = (unsigned long)sig; |
7e907f48 IM |
424 | regs->dx = (unsigned long)&frame->info; |
425 | regs->cx = (unsigned long)&frame->uc; | |
1da177e4 | 426 | |
65ea5b03 PA |
427 | regs->ds = __USER_DS; |
428 | regs->es = __USER_DS; | |
429 | regs->ss = __USER_DS; | |
430 | regs->cs = __USER_CS; | |
1da177e4 | 431 | |
283828f3 | 432 | return 0; |
1da177e4 | 433 | } |
bfeb91a9 | 434 | #else /* !CONFIG_X86_32 */ |
235b8022 | 435 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
bfeb91a9 HS |
436 | sigset_t *set, struct pt_regs *regs) |
437 | { | |
438 | struct rt_sigframe __user *frame; | |
439 | void __user *fp = NULL; | |
440 | int err = 0; | |
bfeb91a9 | 441 | |
235b8022 | 442 | frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp); |
bfeb91a9 HS |
443 | |
444 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
445 | return -EFAULT; | |
446 | ||
235b8022 AV |
447 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
448 | if (copy_siginfo_to_user(&frame->info, &ksig->info)) | |
bfeb91a9 HS |
449 | return -EFAULT; |
450 | } | |
451 | ||
98e3d45e HS |
452 | put_user_try { |
453 | /* Create the ucontext. */ | |
454 | if (cpu_has_xsave) | |
455 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | |
456 | else | |
457 | put_user_ex(0, &frame->uc.uc_flags); | |
458 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 459 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
460 | |
461 | /* Set up to return from userspace. If provided, use a stub | |
462 | already in userspace. */ | |
463 | /* x86-64 should always use SA_RESTORER. */ | |
235b8022 AV |
464 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
465 | put_user_ex(ksig->ka.sa.sa_restorer, &frame->pretcode); | |
98e3d45e HS |
466 | } else { |
467 | /* could use a vstub here */ | |
468 | err |= -EFAULT; | |
469 | } | |
470 | } put_user_catch(err); | |
bfeb91a9 | 471 | |
5e88353d PA |
472 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]); |
473 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
474 | ||
bfeb91a9 HS |
475 | if (err) |
476 | return -EFAULT; | |
477 | ||
478 | /* Set up registers for signal handler */ | |
479 | regs->di = sig; | |
480 | /* In case the signal handler was declared without prototypes */ | |
481 | regs->ax = 0; | |
482 | ||
483 | /* This also works for non SA_SIGINFO handlers because they expect the | |
484 | next argument after the signal number on the stack. */ | |
485 | regs->si = (unsigned long)&frame->info; | |
486 | regs->dx = (unsigned long)&frame->uc; | |
235b8022 | 487 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
bfeb91a9 HS |
488 | |
489 | regs->sp = (unsigned long)frame; | |
490 | ||
8ff5bd2e AL |
491 | /* |
492 | * Set up the CS and SS registers to run signal handlers in | |
493 | * 64-bit mode, even if the handler happens to be interrupting | |
494 | * 32-bit or 16-bit code. | |
495 | * | |
496 | * SS is subtle. In 64-bit mode, we don't need any particular | |
497 | * SS descriptor, but we do need SS to be valid. It's possible | |
498 | * that the old SS is entirely bogus -- this can happen if the | |
499 | * signal we're trying to deliver is #GP or #SS caused by a bad | |
500 | * SS value. We also have a compatbility issue here: DOSEMU | |
501 | * relies on the contents of the SS register indicating the | |
502 | * SS value at the time of the signal, even though that code in | |
503 | * DOSEMU predates sigreturn's ability to restore SS. (DOSEMU | |
504 | * avoids relying on sigreturn to restore SS; instead it uses | |
505 | * a trampoline.) So we do our best: if the old SS was valid, | |
506 | * we keep it. Otherwise we replace it. | |
507 | */ | |
bfeb91a9 HS |
508 | regs->cs = __USER_CS; |
509 | ||
8ff5bd2e AL |
510 | if (unlikely(regs->ss != __USER_DS)) |
511 | force_valid_ss(regs); | |
512 | ||
bfeb91a9 HS |
513 | return 0; |
514 | } | |
515 | #endif /* CONFIG_X86_32 */ | |
516 | ||
235b8022 AV |
517 | static int x32_setup_rt_frame(struct ksignal *ksig, |
518 | compat_sigset_t *set, | |
050902c0 SS |
519 | struct pt_regs *regs) |
520 | { | |
521 | #ifdef CONFIG_X86_X32_ABI | |
522 | struct rt_sigframe_x32 __user *frame; | |
523 | void __user *restorer; | |
524 | int err = 0; | |
525 | void __user *fpstate = NULL; | |
526 | ||
235b8022 | 527 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
050902c0 SS |
528 | |
529 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
530 | return -EFAULT; | |
531 | ||
235b8022 AV |
532 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
533 | if (copy_siginfo_to_user32(&frame->info, &ksig->info)) | |
050902c0 SS |
534 | return -EFAULT; |
535 | } | |
536 | ||
537 | put_user_try { | |
538 | /* Create the ucontext. */ | |
539 | if (cpu_has_xsave) | |
540 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); | |
541 | else | |
542 | put_user_ex(0, &frame->uc.uc_flags); | |
543 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 544 | compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
050902c0 | 545 | put_user_ex(0, &frame->uc.uc__pad0); |
050902c0 | 546 | |
235b8022 AV |
547 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
548 | restorer = ksig->ka.sa.sa_restorer; | |
050902c0 SS |
549 | } else { |
550 | /* could use a vstub here */ | |
551 | restorer = NULL; | |
552 | err |= -EFAULT; | |
553 | } | |
554 | put_user_ex(restorer, &frame->pretcode); | |
555 | } put_user_catch(err); | |
556 | ||
49b8c695 PA |
557 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
558 | regs, set->sig[0]); | |
559 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
560 | ||
050902c0 SS |
561 | if (err) |
562 | return -EFAULT; | |
563 | ||
564 | /* Set up registers for signal handler */ | |
565 | regs->sp = (unsigned long) frame; | |
235b8022 | 566 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
050902c0 SS |
567 | |
568 | /* We use the x32 calling convention here... */ | |
235b8022 | 569 | regs->di = ksig->sig; |
050902c0 SS |
570 | regs->si = (unsigned long) &frame->info; |
571 | regs->dx = (unsigned long) &frame->uc; | |
572 | ||
573 | loadsegment(ds, __USER_DS); | |
574 | loadsegment(es, __USER_DS); | |
575 | ||
576 | regs->cs = __USER_CS; | |
577 | regs->ss = __USER_DS; | |
578 | #endif /* CONFIG_X86_X32_ABI */ | |
579 | ||
580 | return 0; | |
581 | } | |
582 | ||
bfeb91a9 HS |
583 | /* |
584 | * Do a signal return; undo the signal stack. | |
585 | */ | |
e5fa2d06 | 586 | #ifdef CONFIG_X86_32 |
ff49103f | 587 | asmlinkage unsigned long sys_sigreturn(void) |
bfeb91a9 | 588 | { |
3fe26fa3 | 589 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 | 590 | struct sigframe __user *frame; |
bfeb91a9 HS |
591 | sigset_t set; |
592 | ||
bfeb91a9 HS |
593 | frame = (struct sigframe __user *)(regs->sp - 8); |
594 | ||
595 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
596 | goto badframe; | |
597 | if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 | |
598 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
599 | sizeof(frame->extramask)))) | |
600 | goto badframe; | |
601 | ||
3982294b | 602 | set_current_blocked(&set); |
bfeb91a9 | 603 | |
6a3713f0 | 604 | if (restore_sigcontext(regs, &frame->sc)) |
bfeb91a9 | 605 | goto badframe; |
6a3713f0 | 606 | return regs->ax; |
bfeb91a9 HS |
607 | |
608 | badframe: | |
ae417bb4 | 609 | signal_fault(regs, frame, "sigreturn"); |
bfeb91a9 HS |
610 | |
611 | return 0; | |
612 | } | |
e5fa2d06 | 613 | #endif /* CONFIG_X86_32 */ |
bfeb91a9 | 614 | |
ff49103f | 615 | asmlinkage long sys_rt_sigreturn(void) |
bfeb91a9 | 616 | { |
3fe26fa3 | 617 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 | 618 | struct rt_sigframe __user *frame; |
bfeb91a9 HS |
619 | sigset_t set; |
620 | ||
621 | frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); | |
622 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
623 | goto badframe; | |
624 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
625 | goto badframe; | |
626 | ||
e9bd3f0f | 627 | set_current_blocked(&set); |
bfeb91a9 | 628 | |
6a3713f0 | 629 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) |
bfeb91a9 HS |
630 | goto badframe; |
631 | ||
c40702c4 | 632 | if (restore_altstack(&frame->uc.uc_stack)) |
bfeb91a9 HS |
633 | goto badframe; |
634 | ||
6a3713f0 | 635 | return regs->ax; |
bfeb91a9 HS |
636 | |
637 | badframe: | |
638 | signal_fault(regs, frame, "rt_sigreturn"); | |
639 | return 0; | |
640 | } | |
641 | ||
05012c13 IM |
642 | static inline int is_ia32_compat_frame(void) |
643 | { | |
644 | return config_enabled(CONFIG_IA32_EMULATION) && | |
645 | test_thread_flag(TIF_IA32); | |
646 | } | |
647 | ||
648 | static inline int is_ia32_frame(void) | |
649 | { | |
650 | return config_enabled(CONFIG_X86_32) || is_ia32_compat_frame(); | |
651 | } | |
652 | ||
653 | static inline int is_x32_frame(void) | |
654 | { | |
655 | return config_enabled(CONFIG_X86_X32_ABI) && test_thread_flag(TIF_X32); | |
656 | } | |
657 | ||
1d13024e | 658 | static int |
235b8022 | 659 | setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) |
1d13024e | 660 | { |
3050a35f | 661 | int usig = ksig->sig; |
b7f9a11a | 662 | sigset_t *set = sigmask_to_save(); |
050902c0 | 663 | compat_sigset_t *cset = (compat_sigset_t *) set; |
1d13024e HS |
664 | |
665 | /* Set up the stack frame */ | |
050902c0 | 666 | if (is_ia32_frame()) { |
235b8022 AV |
667 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
668 | return ia32_setup_rt_frame(usig, ksig, cset, regs); | |
455edbc4 | 669 | else |
235b8022 | 670 | return ia32_setup_frame(usig, ksig, cset, regs); |
050902c0 | 671 | } else if (is_x32_frame()) { |
235b8022 | 672 | return x32_setup_rt_frame(ksig, cset, regs); |
c5a37394 | 673 | } else { |
235b8022 | 674 | return __setup_rt_frame(ksig->sig, ksig, set, regs); |
c5a37394 | 675 | } |
1d13024e HS |
676 | } |
677 | ||
a610d6e6 | 678 | static void |
235b8022 | 679 | handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 680 | { |
fd0f86b6 | 681 | bool stepping, failed; |
c5bedc68 | 682 | struct fpu *fpu = ¤t->thread.fpu; |
fd0f86b6 | 683 | |
5ed92a8a BG |
684 | if (v8086_mode(regs)) |
685 | save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL); | |
686 | ||
1da177e4 | 687 | /* Are we from a system call? */ |
bb57925f | 688 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 689 | /* If so, check system call restarting.. */ |
bb57925f | 690 | switch (syscall_get_error(current, regs)) { |
ac66f3fd HH |
691 | case -ERESTART_RESTARTBLOCK: |
692 | case -ERESTARTNOHAND: | |
693 | regs->ax = -EINTR; | |
694 | break; | |
695 | ||
696 | case -ERESTARTSYS: | |
235b8022 | 697 | if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
65ea5b03 | 698 | regs->ax = -EINTR; |
1da177e4 | 699 | break; |
ac66f3fd HH |
700 | } |
701 | /* fallthrough */ | |
702 | case -ERESTARTNOINTR: | |
703 | regs->ax = regs->orig_ax; | |
704 | regs->ip -= 2; | |
705 | break; | |
1da177e4 LT |
706 | } |
707 | } | |
708 | ||
709 | /* | |
fd0f86b6 ON |
710 | * If TF is set due to a debugger (TIF_FORCED_TF), clear TF now |
711 | * so that register information in the sigcontext is correct and | |
712 | * then notify the tracer before entering the signal handler. | |
1da177e4 | 713 | */ |
fd0f86b6 ON |
714 | stepping = test_thread_flag(TIF_SINGLESTEP); |
715 | if (stepping) | |
716 | user_disable_single_step(current); | |
1da177e4 | 717 | |
235b8022 AV |
718 | failed = (setup_rt_frame(ksig, regs) < 0); |
719 | if (!failed) { | |
720 | /* | |
721 | * Clear the direction flag as per the ABI for function entry. | |
ddd40da4 | 722 | * |
24cda109 JO |
723 | * Clear RF when entering the signal handler, because |
724 | * it might disable possible debug exception from the | |
725 | * signal handler. | |
ddd40da4 | 726 | * |
fd0f86b6 ON |
727 | * Clear TF for the case when it wasn't set by debugger to |
728 | * avoid the recursive send_sigtrap() in SIGTRAP handler. | |
235b8022 | 729 | */ |
ddd40da4 | 730 | regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF); |
66463db4 ON |
731 | /* |
732 | * Ensure the signal handler starts with the new fpu state. | |
733 | */ | |
c5bedc68 | 734 | if (fpu->fpstate_active) |
fbce7782 | 735 | fpu__clear(fpu); |
a610d6e6 | 736 | } |
fd0f86b6 | 737 | signal_setup_done(failed, ksig, stepping); |
1da177e4 LT |
738 | } |
739 | ||
22eab110 DL |
740 | static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs) |
741 | { | |
95d97adb DL |
742 | #ifdef CONFIG_X86_64 |
743 | if (is_ia32_task()) | |
744 | return __NR_ia32_restart_syscall; | |
745 | #endif | |
746 | #ifdef CONFIG_X86_X32_ABI | |
747 | return __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT); | |
748 | #else | |
22eab110 | 749 | return __NR_restart_syscall; |
95d97adb | 750 | #endif |
22eab110 | 751 | } |
57917752 | 752 | |
1da177e4 LT |
753 | /* |
754 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
755 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
756 | * mistake. | |
757 | */ | |
1f484aa6 | 758 | void do_signal(struct pt_regs *regs) |
1da177e4 | 759 | { |
235b8022 | 760 | struct ksignal ksig; |
1da177e4 | 761 | |
235b8022 | 762 | if (get_signal(&ksig)) { |
7e907f48 | 763 | /* Whee! Actually deliver the signal. */ |
235b8022 | 764 | handle_signal(&ksig, regs); |
283828f3 | 765 | return; |
1da177e4 LT |
766 | } |
767 | ||
1da177e4 | 768 | /* Did we come from a system call? */ |
bb57925f | 769 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 770 | /* Restart the system call - no handlers present */ |
bb57925f | 771 | switch (syscall_get_error(current, regs)) { |
283828f3 DH |
772 | case -ERESTARTNOHAND: |
773 | case -ERESTARTSYS: | |
774 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
775 | regs->ax = regs->orig_ax; |
776 | regs->ip -= 2; | |
283828f3 DH |
777 | break; |
778 | ||
779 | case -ERESTART_RESTARTBLOCK: | |
22eab110 | 780 | regs->ax = get_nr_restart_syscall(regs); |
65ea5b03 | 781 | regs->ip -= 2; |
283828f3 | 782 | break; |
1da177e4 LT |
783 | } |
784 | } | |
283828f3 | 785 | |
ac66f3fd HH |
786 | /* |
787 | * If there's no signal to deliver, we just put the saved sigmask | |
788 | * back. | |
789 | */ | |
51a7b448 | 790 | restore_saved_sigmask(); |
1da177e4 LT |
791 | } |
792 | ||
72fa50f4 HS |
793 | void signal_fault(struct pt_regs *regs, void __user *frame, char *where) |
794 | { | |
795 | struct task_struct *me = current; | |
796 | ||
797 | if (show_unhandled_signals && printk_ratelimit()) { | |
ae417bb4 | 798 | printk("%s" |
72fa50f4 | 799 | "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", |
ae417bb4 | 800 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
72fa50f4 HS |
801 | me->comm, me->pid, where, frame, |
802 | regs->ip, regs->sp, regs->orig_ax); | |
803 | print_vma_addr(" in ", regs->ip); | |
c767a54b | 804 | pr_cont("\n"); |
72fa50f4 HS |
805 | } |
806 | ||
807 | force_sig(SIGSEGV, me); | |
808 | } | |
c5a37394 PA |
809 | |
810 | #ifdef CONFIG_X86_X32_ABI | |
3fe26fa3 | 811 | asmlinkage long sys32_x32_rt_sigreturn(void) |
c5a37394 | 812 | { |
3fe26fa3 | 813 | struct pt_regs *regs = current_pt_regs(); |
c5a37394 PA |
814 | struct rt_sigframe_x32 __user *frame; |
815 | sigset_t set; | |
c5a37394 PA |
816 | |
817 | frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8); | |
818 | ||
819 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
820 | goto badframe; | |
821 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
822 | goto badframe; | |
823 | ||
c5a37394 PA |
824 | set_current_blocked(&set); |
825 | ||
6a3713f0 | 826 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) |
c5a37394 PA |
827 | goto badframe; |
828 | ||
90268439 | 829 | if (compat_restore_altstack(&frame->uc.uc_stack)) |
c5a37394 PA |
830 | goto badframe; |
831 | ||
6a3713f0 | 832 | return regs->ax; |
c5a37394 PA |
833 | |
834 | badframe: | |
835 | signal_fault(regs, frame, "x32 rt_sigreturn"); | |
836 | return 0; | |
837 | } | |
838 | #endif |