]>
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> |
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> |
68463510 | 45 | #include <asm/signal.h> |
1da177e4 | 46 | |
d9a89a26 TH |
47 | #define COPY(x) do { \ |
48 | get_user_ex(regs->x, &sc->x); \ | |
49 | } while (0) | |
2601657d | 50 | |
d9a89a26 TH |
51 | #define GET_SEG(seg) ({ \ |
52 | unsigned short tmp; \ | |
53 | get_user_ex(tmp, &sc->seg); \ | |
54 | tmp; \ | |
55 | }) | |
2601657d | 56 | |
d9a89a26 TH |
57 | #define COPY_SEG(seg) do { \ |
58 | regs->seg = GET_SEG(seg); \ | |
59 | } while (0) | |
2601657d | 60 | |
d9a89a26 TH |
61 | #define COPY_SEG_CPL3(seg) do { \ |
62 | regs->seg = GET_SEG(seg) | 3; \ | |
63 | } while (0) | |
2601657d | 64 | |
8ff5bd2e AL |
65 | #ifdef CONFIG_X86_64 |
66 | /* | |
67 | * If regs->ss will cause an IRET fault, change it. Otherwise leave it | |
68 | * alone. Using this generally makes no sense unless | |
69 | * user_64bit_mode(regs) would return true. | |
70 | */ | |
71 | static void force_valid_ss(struct pt_regs *regs) | |
72 | { | |
73 | u32 ar; | |
74 | asm volatile ("lar %[old_ss], %[ar]\n\t" | |
75 | "jz 1f\n\t" /* If invalid: */ | |
76 | "xorl %[ar], %[ar]\n\t" /* set ar = 0 */ | |
77 | "1:" | |
78 | : [ar] "=r" (ar) | |
79 | : [old_ss] "rm" ((u16)regs->ss)); | |
80 | ||
81 | /* | |
82 | * For a valid 64-bit user context, we need DPL 3, type | |
83 | * read-write data or read-write exp-down data, and S and P | |
84 | * set. We can't use VERW because VERW doesn't check the | |
85 | * P bit. | |
86 | */ | |
87 | ar &= AR_DPL_MASK | AR_S | AR_P | AR_TYPE_MASK; | |
88 | if (ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA) && | |
89 | ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN)) | |
90 | regs->ss = __USER_DS; | |
91 | } | |
92 | #endif | |
93 | ||
6c25da5a AL |
94 | static int restore_sigcontext(struct pt_regs *regs, |
95 | struct sigcontext __user *sc, | |
96 | unsigned long uc_flags) | |
2601657d | 97 | { |
530e5c82 | 98 | unsigned long buf_val; |
2601657d HS |
99 | void __user *buf; |
100 | unsigned int tmpflags; | |
101 | unsigned int err = 0; | |
102 | ||
103 | /* Always make any pending restarted system calls return -EINTR */ | |
f56141e3 | 104 | current->restart_block.fn = do_no_restart_syscall; |
2601657d | 105 | |
98e3d45e HS |
106 | get_user_try { |
107 | ||
2601657d | 108 | #ifdef CONFIG_X86_32 |
d9a89a26 | 109 | set_user_gs(regs, GET_SEG(gs)); |
98e3d45e HS |
110 | COPY_SEG(fs); |
111 | COPY_SEG(es); | |
112 | COPY_SEG(ds); | |
2601657d HS |
113 | #endif /* CONFIG_X86_32 */ |
114 | ||
98e3d45e | 115 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
6a3713f0 | 116 | COPY(dx); COPY(cx); COPY(ip); COPY(ax); |
2601657d HS |
117 | |
118 | #ifdef CONFIG_X86_64 | |
98e3d45e HS |
119 | COPY(r8); |
120 | COPY(r9); | |
121 | COPY(r10); | |
122 | COPY(r11); | |
123 | COPY(r12); | |
124 | COPY(r13); | |
125 | COPY(r14); | |
126 | COPY(r15); | |
2601657d HS |
127 | #endif /* CONFIG_X86_64 */ |
128 | ||
98e3d45e HS |
129 | COPY_SEG_CPL3(cs); |
130 | COPY_SEG_CPL3(ss); | |
6c25da5a AL |
131 | |
132 | #ifdef CONFIG_X86_64 | |
133 | /* | |
134 | * Fix up SS if needed for the benefit of old DOSEMU and | |
135 | * CRIU. | |
136 | */ | |
137 | if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && | |
138 | user_64bit_mode(regs))) | |
139 | force_valid_ss(regs); | |
140 | #endif | |
2601657d | 141 | |
98e3d45e HS |
142 | get_user_ex(tmpflags, &sc->flags); |
143 | regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); | |
144 | regs->orig_ax = -1; /* disable syscall checks */ | |
145 | ||
530e5c82 IM |
146 | get_user_ex(buf_val, &sc->fpstate); |
147 | buf = (void __user *)buf_val; | |
98e3d45e | 148 | } get_user_catch(err); |
2601657d | 149 | |
97f2645f | 150 | err |= fpu__restore_sig(buf, IS_ENABLED(CONFIG_X86_32)); |
5e88353d | 151 | |
1daeaa31 BG |
152 | force_iret(); |
153 | ||
2601657d HS |
154 | return err; |
155 | } | |
156 | ||
85139422 PA |
157 | int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, |
158 | struct pt_regs *regs, unsigned long mask) | |
2601657d HS |
159 | { |
160 | int err = 0; | |
161 | ||
98e3d45e | 162 | put_user_try { |
2601657d | 163 | |
98e3d45e | 164 | #ifdef CONFIG_X86_32 |
d9a89a26 | 165 | put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs); |
98e3d45e HS |
166 | put_user_ex(regs->fs, (unsigned int __user *)&sc->fs); |
167 | put_user_ex(regs->es, (unsigned int __user *)&sc->es); | |
168 | put_user_ex(regs->ds, (unsigned int __user *)&sc->ds); | |
2601657d HS |
169 | #endif /* CONFIG_X86_32 */ |
170 | ||
98e3d45e HS |
171 | put_user_ex(regs->di, &sc->di); |
172 | put_user_ex(regs->si, &sc->si); | |
173 | put_user_ex(regs->bp, &sc->bp); | |
174 | put_user_ex(regs->sp, &sc->sp); | |
175 | put_user_ex(regs->bx, &sc->bx); | |
176 | put_user_ex(regs->dx, &sc->dx); | |
177 | put_user_ex(regs->cx, &sc->cx); | |
178 | put_user_ex(regs->ax, &sc->ax); | |
2601657d | 179 | #ifdef CONFIG_X86_64 |
98e3d45e HS |
180 | put_user_ex(regs->r8, &sc->r8); |
181 | put_user_ex(regs->r9, &sc->r9); | |
182 | put_user_ex(regs->r10, &sc->r10); | |
183 | put_user_ex(regs->r11, &sc->r11); | |
184 | put_user_ex(regs->r12, &sc->r12); | |
185 | put_user_ex(regs->r13, &sc->r13); | |
186 | put_user_ex(regs->r14, &sc->r14); | |
187 | put_user_ex(regs->r15, &sc->r15); | |
2601657d HS |
188 | #endif /* CONFIG_X86_64 */ |
189 | ||
51e7dc70 | 190 | put_user_ex(current->thread.trap_nr, &sc->trapno); |
98e3d45e HS |
191 | put_user_ex(current->thread.error_code, &sc->err); |
192 | put_user_ex(regs->ip, &sc->ip); | |
2601657d | 193 | #ifdef CONFIG_X86_32 |
98e3d45e HS |
194 | put_user_ex(regs->cs, (unsigned int __user *)&sc->cs); |
195 | put_user_ex(regs->flags, &sc->flags); | |
196 | put_user_ex(regs->sp, &sc->sp_at_signal); | |
197 | put_user_ex(regs->ss, (unsigned int __user *)&sc->ss); | |
2601657d | 198 | #else /* !CONFIG_X86_32 */ |
98e3d45e HS |
199 | put_user_ex(regs->flags, &sc->flags); |
200 | put_user_ex(regs->cs, &sc->cs); | |
ed596cde LT |
201 | put_user_ex(0, &sc->gs); |
202 | put_user_ex(0, &sc->fs); | |
6c25da5a | 203 | put_user_ex(regs->ss, &sc->ss); |
2601657d HS |
204 | #endif /* CONFIG_X86_32 */ |
205 | ||
98e3d45e | 206 | put_user_ex(fpstate, &sc->fpstate); |
2601657d | 207 | |
98e3d45e HS |
208 | /* non-iBCS2 extensions.. */ |
209 | put_user_ex(mask, &sc->oldmask); | |
210 | put_user_ex(current->thread.cr2, &sc->cr2); | |
211 | } put_user_catch(err); | |
2601657d HS |
212 | |
213 | return err; | |
214 | } | |
215 | ||
1da177e4 | 216 | /* |
bfeb91a9 | 217 | * Set up a signal frame. |
1da177e4 | 218 | */ |
1da177e4 LT |
219 | |
220 | /* | |
221 | * Determine which stack to use.. | |
222 | */ | |
1fae0279 HS |
223 | static unsigned long align_sigframe(unsigned long sp) |
224 | { | |
225 | #ifdef CONFIG_X86_32 | |
226 | /* | |
227 | * Align the stack pointer according to the i386 ABI, | |
228 | * i.e. so that on function entry ((sp + 4) & 15) == 0. | |
229 | */ | |
230 | sp = ((sp + 4) & -16ul) - 4; | |
231 | #else /* !CONFIG_X86_32 */ | |
232 | sp = round_down(sp, 16) - 8; | |
233 | #endif | |
234 | return sp; | |
235 | } | |
236 | ||
dae0f305 | 237 | static void __user * |
3c1c7f10 | 238 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, |
144b0712 | 239 | void __user **fpstate) |
1da177e4 | 240 | { |
1da177e4 | 241 | /* Default to using normal stack */ |
72a671ce | 242 | unsigned long math_size = 0; |
75779f05 | 243 | unsigned long sp = regs->sp; |
72a671ce | 244 | unsigned long buf_fx = 0; |
14fc9fbc | 245 | int onsigstack = on_sig_stack(sp); |
c5bedc68 | 246 | struct fpu *fpu = ¤t->thread.fpu; |
75779f05 | 247 | |
75779f05 | 248 | /* redzone */ |
97f2645f | 249 | if (IS_ENABLED(CONFIG_X86_64)) |
050902c0 | 250 | sp -= 128; |
1da177e4 | 251 | |
0b4521e8 SS |
252 | /* This is the X/Open sanctioned signal stack switching. */ |
253 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
254 | if (sas_ss_flags(sp) == 0) | |
255 | sp = current->sas_ss_sp + current->sas_ss_size; | |
97f2645f | 256 | } else if (IS_ENABLED(CONFIG_X86_32) && |
0b4521e8 SS |
257 | !onsigstack && |
258 | (regs->ss & 0xffff) != __USER_DS && | |
259 | !(ka->sa.sa_flags & SA_RESTORER) && | |
260 | ka->sa.sa_restorer) { | |
261 | /* This is the legacy signal stack switching. */ | |
262 | sp = (unsigned long) ka->sa.sa_restorer; | |
1da177e4 LT |
263 | } |
264 | ||
c5bedc68 | 265 | if (fpu->fpstate_active) { |
97f2645f | 266 | sp = fpu__alloc_mathframe(sp, IS_ENABLED(CONFIG_X86_32), |
82c0e45e | 267 | &buf_fx, &math_size); |
25051702 | 268 | *fpstate = (void __user *)sp; |
3c1c7f10 SS |
269 | } |
270 | ||
14fc9fbc HS |
271 | sp = align_sigframe(sp - frame_size); |
272 | ||
273 | /* | |
274 | * If we are on the alternate signal stack and would overflow it, don't. | |
275 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
276 | */ | |
277 | if (onsigstack && !likely(on_sig_stack(sp))) | |
278 | return (void __user *)-1L; | |
279 | ||
72a671ce | 280 | /* save i387 and extended state */ |
c5bedc68 | 281 | if (fpu->fpstate_active && |
c8e14041 | 282 | copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size) < 0) |
14fc9fbc HS |
283 | return (void __user *)-1L; |
284 | ||
285 | return (void __user *)sp; | |
1da177e4 LT |
286 | } |
287 | ||
75779f05 HS |
288 | #ifdef CONFIG_X86_32 |
289 | static const struct { | |
290 | u16 poplmovl; | |
291 | u32 val; | |
292 | u16 int80; | |
293 | } __attribute__((packed)) retcode = { | |
294 | 0xb858, /* popl %eax; movl $..., %eax */ | |
295 | __NR_sigreturn, | |
296 | 0x80cd, /* int $0x80 */ | |
297 | }; | |
298 | ||
299 | static const struct { | |
300 | u8 movl; | |
301 | u32 val; | |
302 | u16 int80; | |
303 | u8 pad; | |
304 | } __attribute__((packed)) rt_retcode = { | |
305 | 0xb8, /* movl $..., %eax */ | |
306 | __NR_rt_sigreturn, | |
307 | 0x80cd, /* int $0x80 */ | |
308 | 0 | |
309 | }; | |
310 | ||
7e907f48 | 311 | static int |
235b8022 | 312 | __setup_frame(int sig, struct ksignal *ksig, sigset_t *set, |
1d13024e | 313 | struct pt_regs *regs) |
1da177e4 | 314 | { |
1da177e4 | 315 | struct sigframe __user *frame; |
7e907f48 | 316 | void __user *restorer; |
1da177e4 | 317 | int err = 0; |
ab513701 | 318 | void __user *fpstate = NULL; |
1da177e4 | 319 | |
235b8022 | 320 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
321 | |
322 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 323 | return -EFAULT; |
1da177e4 | 324 | |
2ba48e16 | 325 | if (__put_user(sig, &frame->sig)) |
3d0aedd9 | 326 | return -EFAULT; |
1da177e4 | 327 | |
2ba48e16 | 328 | if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) |
3d0aedd9 | 329 | return -EFAULT; |
1da177e4 LT |
330 | |
331 | if (_NSIG_WORDS > 1) { | |
2ba48e16 HS |
332 | if (__copy_to_user(&frame->extramask, &set->sig[1], |
333 | sizeof(frame->extramask))) | |
3d0aedd9 | 334 | return -EFAULT; |
1da177e4 LT |
335 | } |
336 | ||
1a3e4ca4 | 337 | if (current->mm->context.vdso) |
6f121e54 | 338 | restorer = current->mm->context.vdso + |
0a6d1fa0 | 339 | vdso_image_32.sym___kernel_sigreturn; |
9fbbd4dd | 340 | else |
ade1af77 | 341 | restorer = &frame->retcode; |
235b8022 AV |
342 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
343 | restorer = ksig->ka.sa.sa_restorer; | |
1da177e4 LT |
344 | |
345 | /* Set up to return from userspace. */ | |
346 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 347 | |
1da177e4 | 348 | /* |
7e907f48 | 349 | * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
1da177e4 LT |
350 | * |
351 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
352 | * reasons and because gdb uses it as a signature to notice | |
353 | * signal handler stack frames. | |
354 | */ | |
4a612048 | 355 | err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode); |
1da177e4 LT |
356 | |
357 | if (err) | |
3d0aedd9 | 358 | return -EFAULT; |
1da177e4 LT |
359 | |
360 | /* Set up registers for signal handler */ | |
7e907f48 | 361 | regs->sp = (unsigned long)frame; |
235b8022 | 362 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
7e907f48 | 363 | regs->ax = (unsigned long)sig; |
92bc2056 HH |
364 | regs->dx = 0; |
365 | regs->cx = 0; | |
1da177e4 | 366 | |
65ea5b03 PA |
367 | regs->ds = __USER_DS; |
368 | regs->es = __USER_DS; | |
369 | regs->ss = __USER_DS; | |
370 | regs->cs = __USER_CS; | |
1da177e4 | 371 | |
283828f3 | 372 | return 0; |
1da177e4 LT |
373 | } |
374 | ||
235b8022 | 375 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
1d13024e | 376 | sigset_t *set, struct pt_regs *regs) |
1da177e4 | 377 | { |
1da177e4 | 378 | struct rt_sigframe __user *frame; |
7e907f48 | 379 | void __user *restorer; |
1da177e4 | 380 | int err = 0; |
ab513701 | 381 | void __user *fpstate = NULL; |
1da177e4 | 382 | |
235b8022 | 383 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
384 | |
385 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 386 | return -EFAULT; |
1da177e4 | 387 | |
98e3d45e HS |
388 | put_user_try { |
389 | put_user_ex(sig, &frame->sig); | |
390 | put_user_ex(&frame->info, &frame->pinfo); | |
391 | put_user_ex(&frame->uc, &frame->puc); | |
98e3d45e HS |
392 | |
393 | /* Create the ucontext. */ | |
d366bf7e | 394 | if (boot_cpu_has(X86_FEATURE_XSAVE)) |
98e3d45e HS |
395 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); |
396 | else | |
397 | put_user_ex(0, &frame->uc.uc_flags); | |
398 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 399 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
400 | |
401 | /* Set up to return from userspace. */ | |
6f121e54 | 402 | restorer = current->mm->context.vdso + |
0a6d1fa0 | 403 | vdso_image_32.sym___kernel_rt_sigreturn; |
235b8022 AV |
404 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
405 | restorer = ksig->ka.sa.sa_restorer; | |
98e3d45e HS |
406 | put_user_ex(restorer, &frame->pretcode); |
407 | ||
408 | /* | |
409 | * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 | |
410 | * | |
411 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
412 | * reasons and because gdb uses it as a signature to notice | |
413 | * signal handler stack frames. | |
414 | */ | |
415 | put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode); | |
416 | } put_user_catch(err); | |
49b8c695 | 417 | |
235b8022 | 418 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
5e88353d PA |
419 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
420 | regs, set->sig[0]); | |
421 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
1da177e4 LT |
422 | |
423 | if (err) | |
3d0aedd9 | 424 | return -EFAULT; |
1da177e4 LT |
425 | |
426 | /* Set up registers for signal handler */ | |
7e907f48 | 427 | regs->sp = (unsigned long)frame; |
235b8022 | 428 | regs->ip = (unsigned long)ksig->ka.sa.sa_handler; |
13ad7725 | 429 | regs->ax = (unsigned long)sig; |
7e907f48 IM |
430 | regs->dx = (unsigned long)&frame->info; |
431 | regs->cx = (unsigned long)&frame->uc; | |
1da177e4 | 432 | |
65ea5b03 PA |
433 | regs->ds = __USER_DS; |
434 | regs->es = __USER_DS; | |
435 | regs->ss = __USER_DS; | |
436 | regs->cs = __USER_CS; | |
1da177e4 | 437 | |
283828f3 | 438 | return 0; |
1da177e4 | 439 | } |
bfeb91a9 | 440 | #else /* !CONFIG_X86_32 */ |
6c25da5a AL |
441 | static unsigned long frame_uc_flags(struct pt_regs *regs) |
442 | { | |
443 | unsigned long flags; | |
444 | ||
d366bf7e | 445 | if (boot_cpu_has(X86_FEATURE_XSAVE)) |
6c25da5a AL |
446 | flags = UC_FP_XSTATE | UC_SIGCONTEXT_SS; |
447 | else | |
448 | flags = UC_SIGCONTEXT_SS; | |
449 | ||
450 | if (likely(user_64bit_mode(regs))) | |
451 | flags |= UC_STRICT_RESTORE_SS; | |
452 | ||
453 | return flags; | |
454 | } | |
455 | ||
235b8022 | 456 | static int __setup_rt_frame(int sig, struct ksignal *ksig, |
bfeb91a9 HS |
457 | sigset_t *set, struct pt_regs *regs) |
458 | { | |
459 | struct rt_sigframe __user *frame; | |
460 | void __user *fp = NULL; | |
461 | int err = 0; | |
bfeb91a9 | 462 | |
235b8022 | 463 | frame = get_sigframe(&ksig->ka, regs, sizeof(struct rt_sigframe), &fp); |
bfeb91a9 HS |
464 | |
465 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
466 | return -EFAULT; | |
467 | ||
235b8022 AV |
468 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
469 | if (copy_siginfo_to_user(&frame->info, &ksig->info)) | |
bfeb91a9 HS |
470 | return -EFAULT; |
471 | } | |
472 | ||
98e3d45e HS |
473 | put_user_try { |
474 | /* Create the ucontext. */ | |
6c25da5a | 475 | put_user_ex(frame_uc_flags(regs), &frame->uc.uc_flags); |
98e3d45e | 476 | put_user_ex(0, &frame->uc.uc_link); |
bd1c149a | 477 | save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
98e3d45e HS |
478 | |
479 | /* Set up to return from userspace. If provided, use a stub | |
480 | already in userspace. */ | |
481 | /* x86-64 should always use SA_RESTORER. */ | |
235b8022 AV |
482 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
483 | put_user_ex(ksig->ka.sa.sa_restorer, &frame->pretcode); | |
98e3d45e HS |
484 | } else { |
485 | /* could use a vstub here */ | |
486 | err |= -EFAULT; | |
487 | } | |
488 | } put_user_catch(err); | |
bfeb91a9 | 489 | |
5e88353d PA |
490 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]); |
491 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
492 | ||
bfeb91a9 HS |
493 | if (err) |
494 | return -EFAULT; | |
495 | ||
496 | /* Set up registers for signal handler */ | |
497 | regs->di = sig; | |
498 | /* In case the signal handler was declared without prototypes */ | |
499 | regs->ax = 0; | |
500 | ||
501 | /* This also works for non SA_SIGINFO handlers because they expect the | |
502 | next argument after the signal number on the stack. */ | |
503 | regs->si = (unsigned long)&frame->info; | |
504 | regs->dx = (unsigned long)&frame->uc; | |
235b8022 | 505 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
bfeb91a9 HS |
506 | |
507 | regs->sp = (unsigned long)frame; | |
508 | ||
8ff5bd2e AL |
509 | /* |
510 | * Set up the CS and SS registers to run signal handlers in | |
511 | * 64-bit mode, even if the handler happens to be interrupting | |
512 | * 32-bit or 16-bit code. | |
513 | * | |
514 | * SS is subtle. In 64-bit mode, we don't need any particular | |
515 | * SS descriptor, but we do need SS to be valid. It's possible | |
516 | * that the old SS is entirely bogus -- this can happen if the | |
517 | * signal we're trying to deliver is #GP or #SS caused by a bad | |
518 | * SS value. We also have a compatbility issue here: DOSEMU | |
519 | * relies on the contents of the SS register indicating the | |
520 | * SS value at the time of the signal, even though that code in | |
521 | * DOSEMU predates sigreturn's ability to restore SS. (DOSEMU | |
522 | * avoids relying on sigreturn to restore SS; instead it uses | |
523 | * a trampoline.) So we do our best: if the old SS was valid, | |
524 | * we keep it. Otherwise we replace it. | |
525 | */ | |
bfeb91a9 HS |
526 | regs->cs = __USER_CS; |
527 | ||
8ff5bd2e AL |
528 | if (unlikely(regs->ss != __USER_DS)) |
529 | force_valid_ss(regs); | |
530 | ||
bfeb91a9 HS |
531 | return 0; |
532 | } | |
533 | #endif /* CONFIG_X86_32 */ | |
534 | ||
235b8022 AV |
535 | static int x32_setup_rt_frame(struct ksignal *ksig, |
536 | compat_sigset_t *set, | |
050902c0 SS |
537 | struct pt_regs *regs) |
538 | { | |
539 | #ifdef CONFIG_X86_X32_ABI | |
540 | struct rt_sigframe_x32 __user *frame; | |
541 | void __user *restorer; | |
542 | int err = 0; | |
543 | void __user *fpstate = NULL; | |
544 | ||
235b8022 | 545 | frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); |
050902c0 SS |
546 | |
547 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
548 | return -EFAULT; | |
549 | ||
235b8022 | 550 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
68463510 | 551 | if (__copy_siginfo_to_user32(&frame->info, &ksig->info, true)) |
050902c0 SS |
552 | return -EFAULT; |
553 | } | |
554 | ||
555 | put_user_try { | |
556 | /* Create the ucontext. */ | |
6c25da5a | 557 | put_user_ex(frame_uc_flags(regs), &frame->uc.uc_flags); |
050902c0 | 558 | put_user_ex(0, &frame->uc.uc_link); |
bd1c149a | 559 | compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
050902c0 | 560 | put_user_ex(0, &frame->uc.uc__pad0); |
050902c0 | 561 | |
235b8022 AV |
562 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
563 | restorer = ksig->ka.sa.sa_restorer; | |
050902c0 SS |
564 | } else { |
565 | /* could use a vstub here */ | |
566 | restorer = NULL; | |
567 | err |= -EFAULT; | |
568 | } | |
569 | put_user_ex(restorer, &frame->pretcode); | |
570 | } put_user_catch(err); | |
571 | ||
49b8c695 PA |
572 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
573 | regs, set->sig[0]); | |
574 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
575 | ||
050902c0 SS |
576 | if (err) |
577 | return -EFAULT; | |
578 | ||
579 | /* Set up registers for signal handler */ | |
580 | regs->sp = (unsigned long) frame; | |
235b8022 | 581 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
050902c0 SS |
582 | |
583 | /* We use the x32 calling convention here... */ | |
235b8022 | 584 | regs->di = ksig->sig; |
050902c0 SS |
585 | regs->si = (unsigned long) &frame->info; |
586 | regs->dx = (unsigned long) &frame->uc; | |
587 | ||
588 | loadsegment(ds, __USER_DS); | |
589 | loadsegment(es, __USER_DS); | |
590 | ||
591 | regs->cs = __USER_CS; | |
592 | regs->ss = __USER_DS; | |
593 | #endif /* CONFIG_X86_X32_ABI */ | |
594 | ||
595 | return 0; | |
596 | } | |
597 | ||
bfeb91a9 HS |
598 | /* |
599 | * Do a signal return; undo the signal stack. | |
600 | */ | |
e5fa2d06 | 601 | #ifdef CONFIG_X86_32 |
ff49103f | 602 | asmlinkage unsigned long sys_sigreturn(void) |
bfeb91a9 | 603 | { |
3fe26fa3 | 604 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 | 605 | struct sigframe __user *frame; |
bfeb91a9 HS |
606 | sigset_t set; |
607 | ||
bfeb91a9 HS |
608 | frame = (struct sigframe __user *)(regs->sp - 8); |
609 | ||
610 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
611 | goto badframe; | |
612 | if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 | |
613 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
614 | sizeof(frame->extramask)))) | |
615 | goto badframe; | |
616 | ||
3982294b | 617 | set_current_blocked(&set); |
bfeb91a9 | 618 | |
6c25da5a AL |
619 | /* |
620 | * x86_32 has no uc_flags bits relevant to restore_sigcontext. | |
621 | * Save a few cycles by skipping the __get_user. | |
622 | */ | |
623 | if (restore_sigcontext(regs, &frame->sc, 0)) | |
bfeb91a9 | 624 | goto badframe; |
6a3713f0 | 625 | return regs->ax; |
bfeb91a9 HS |
626 | |
627 | badframe: | |
ae417bb4 | 628 | signal_fault(regs, frame, "sigreturn"); |
bfeb91a9 HS |
629 | |
630 | return 0; | |
631 | } | |
e5fa2d06 | 632 | #endif /* CONFIG_X86_32 */ |
bfeb91a9 | 633 | |
ff49103f | 634 | asmlinkage long sys_rt_sigreturn(void) |
bfeb91a9 | 635 | { |
3fe26fa3 | 636 | struct pt_regs *regs = current_pt_regs(); |
bfeb91a9 | 637 | struct rt_sigframe __user *frame; |
bfeb91a9 | 638 | sigset_t set; |
6c25da5a | 639 | unsigned long uc_flags; |
bfeb91a9 HS |
640 | |
641 | frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); | |
642 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
643 | goto badframe; | |
644 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
645 | goto badframe; | |
6c25da5a AL |
646 | if (__get_user(uc_flags, &frame->uc.uc_flags)) |
647 | goto badframe; | |
bfeb91a9 | 648 | |
e9bd3f0f | 649 | set_current_blocked(&set); |
bfeb91a9 | 650 | |
6c25da5a | 651 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags)) |
bfeb91a9 HS |
652 | goto badframe; |
653 | ||
c40702c4 | 654 | if (restore_altstack(&frame->uc.uc_stack)) |
bfeb91a9 HS |
655 | goto badframe; |
656 | ||
6a3713f0 | 657 | return regs->ax; |
bfeb91a9 HS |
658 | |
659 | badframe: | |
660 | signal_fault(regs, frame, "rt_sigreturn"); | |
661 | return 0; | |
662 | } | |
663 | ||
68463510 | 664 | static inline int is_ia32_compat_frame(struct ksignal *ksig) |
05012c13 | 665 | { |
97f2645f | 666 | return IS_ENABLED(CONFIG_IA32_EMULATION) && |
68463510 | 667 | ksig->ka.sa.sa_flags & SA_IA32_ABI; |
05012c13 IM |
668 | } |
669 | ||
68463510 | 670 | static inline int is_ia32_frame(struct ksignal *ksig) |
05012c13 | 671 | { |
68463510 | 672 | return IS_ENABLED(CONFIG_X86_32) || is_ia32_compat_frame(ksig); |
05012c13 IM |
673 | } |
674 | ||
68463510 | 675 | static inline int is_x32_frame(struct ksignal *ksig) |
05012c13 | 676 | { |
68463510 DS |
677 | return IS_ENABLED(CONFIG_X86_X32_ABI) && |
678 | ksig->ka.sa.sa_flags & SA_X32_ABI; | |
05012c13 IM |
679 | } |
680 | ||
1d13024e | 681 | static int |
235b8022 | 682 | setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) |
1d13024e | 683 | { |
3050a35f | 684 | int usig = ksig->sig; |
b7f9a11a | 685 | sigset_t *set = sigmask_to_save(); |
050902c0 | 686 | compat_sigset_t *cset = (compat_sigset_t *) set; |
1d13024e HS |
687 | |
688 | /* Set up the stack frame */ | |
68463510 | 689 | if (is_ia32_frame(ksig)) { |
235b8022 AV |
690 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
691 | return ia32_setup_rt_frame(usig, ksig, cset, regs); | |
455edbc4 | 692 | else |
235b8022 | 693 | return ia32_setup_frame(usig, ksig, cset, regs); |
68463510 | 694 | } else if (is_x32_frame(ksig)) { |
235b8022 | 695 | return x32_setup_rt_frame(ksig, cset, regs); |
c5a37394 | 696 | } else { |
235b8022 | 697 | return __setup_rt_frame(ksig->sig, ksig, set, regs); |
c5a37394 | 698 | } |
1d13024e HS |
699 | } |
700 | ||
a610d6e6 | 701 | static void |
235b8022 | 702 | handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 703 | { |
fd0f86b6 | 704 | bool stepping, failed; |
c5bedc68 | 705 | struct fpu *fpu = ¤t->thread.fpu; |
fd0f86b6 | 706 | |
5ed92a8a BG |
707 | if (v8086_mode(regs)) |
708 | save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL); | |
709 | ||
1da177e4 | 710 | /* Are we from a system call? */ |
bb57925f | 711 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 712 | /* If so, check system call restarting.. */ |
bb57925f | 713 | switch (syscall_get_error(current, regs)) { |
ac66f3fd HH |
714 | case -ERESTART_RESTARTBLOCK: |
715 | case -ERESTARTNOHAND: | |
716 | regs->ax = -EINTR; | |
717 | break; | |
718 | ||
719 | case -ERESTARTSYS: | |
235b8022 | 720 | if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
65ea5b03 | 721 | regs->ax = -EINTR; |
1da177e4 | 722 | break; |
ac66f3fd HH |
723 | } |
724 | /* fallthrough */ | |
725 | case -ERESTARTNOINTR: | |
726 | regs->ax = regs->orig_ax; | |
727 | regs->ip -= 2; | |
728 | break; | |
1da177e4 LT |
729 | } |
730 | } | |
731 | ||
732 | /* | |
fd0f86b6 ON |
733 | * If TF is set due to a debugger (TIF_FORCED_TF), clear TF now |
734 | * so that register information in the sigcontext is correct and | |
735 | * then notify the tracer before entering the signal handler. | |
1da177e4 | 736 | */ |
fd0f86b6 ON |
737 | stepping = test_thread_flag(TIF_SINGLESTEP); |
738 | if (stepping) | |
739 | user_disable_single_step(current); | |
1da177e4 | 740 | |
235b8022 AV |
741 | failed = (setup_rt_frame(ksig, regs) < 0); |
742 | if (!failed) { | |
743 | /* | |
744 | * Clear the direction flag as per the ABI for function entry. | |
ddd40da4 | 745 | * |
24cda109 JO |
746 | * Clear RF when entering the signal handler, because |
747 | * it might disable possible debug exception from the | |
748 | * signal handler. | |
ddd40da4 | 749 | * |
fd0f86b6 ON |
750 | * Clear TF for the case when it wasn't set by debugger to |
751 | * avoid the recursive send_sigtrap() in SIGTRAP handler. | |
235b8022 | 752 | */ |
ddd40da4 | 753 | regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF); |
66463db4 ON |
754 | /* |
755 | * Ensure the signal handler starts with the new fpu state. | |
756 | */ | |
c5bedc68 | 757 | if (fpu->fpstate_active) |
fbce7782 | 758 | fpu__clear(fpu); |
a610d6e6 | 759 | } |
fd0f86b6 | 760 | signal_setup_done(failed, ksig, stepping); |
1da177e4 LT |
761 | } |
762 | ||
22eab110 DL |
763 | static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs) |
764 | { | |
609c19a3 AL |
765 | /* |
766 | * This function is fundamentally broken as currently | |
767 | * implemented. | |
768 | * | |
769 | * The idea is that we want to trigger a call to the | |
770 | * restart_block() syscall and that we want in_ia32_syscall(), | |
771 | * in_x32_syscall(), etc. to match whatever they were in the | |
772 | * syscall being restarted. We assume that the syscall | |
773 | * instruction at (regs->ip - 2) matches whatever syscall | |
774 | * instruction we used to enter in the first place. | |
775 | * | |
776 | * The problem is that we can get here when ptrace pokes | |
777 | * syscall-like values into regs even if we're not in a syscall | |
778 | * at all. | |
779 | * | |
780 | * For now, we maintain historical behavior and guess based on | |
781 | * stored state. We could do better by saving the actual | |
782 | * syscall arch in restart_block or (with caveats on x32) by | |
783 | * checking if regs->ip points to 'int $0x80'. The current | |
784 | * behavior is incorrect if a tracer has a different bitness | |
785 | * than the tracee. | |
786 | */ | |
787 | #ifdef CONFIG_IA32_EMULATION | |
b9d989c7 | 788 | if (current->thread.status & (TS_COMPAT|TS_I386_REGS_POKED)) |
95d97adb DL |
789 | return __NR_ia32_restart_syscall; |
790 | #endif | |
791 | #ifdef CONFIG_X86_X32_ABI | |
792 | return __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT); | |
793 | #else | |
22eab110 | 794 | return __NR_restart_syscall; |
95d97adb | 795 | #endif |
22eab110 | 796 | } |
57917752 | 797 | |
1da177e4 LT |
798 | /* |
799 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
800 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
801 | * mistake. | |
802 | */ | |
1f484aa6 | 803 | void do_signal(struct pt_regs *regs) |
1da177e4 | 804 | { |
235b8022 | 805 | struct ksignal ksig; |
1da177e4 | 806 | |
235b8022 | 807 | if (get_signal(&ksig)) { |
7e907f48 | 808 | /* Whee! Actually deliver the signal. */ |
235b8022 | 809 | handle_signal(&ksig, regs); |
283828f3 | 810 | return; |
1da177e4 LT |
811 | } |
812 | ||
1da177e4 | 813 | /* Did we come from a system call? */ |
bb57925f | 814 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 815 | /* Restart the system call - no handlers present */ |
bb57925f | 816 | switch (syscall_get_error(current, regs)) { |
283828f3 DH |
817 | case -ERESTARTNOHAND: |
818 | case -ERESTARTSYS: | |
819 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
820 | regs->ax = regs->orig_ax; |
821 | regs->ip -= 2; | |
283828f3 DH |
822 | break; |
823 | ||
824 | case -ERESTART_RESTARTBLOCK: | |
22eab110 | 825 | regs->ax = get_nr_restart_syscall(regs); |
65ea5b03 | 826 | regs->ip -= 2; |
283828f3 | 827 | break; |
1da177e4 LT |
828 | } |
829 | } | |
283828f3 | 830 | |
ac66f3fd HH |
831 | /* |
832 | * If there's no signal to deliver, we just put the saved sigmask | |
833 | * back. | |
834 | */ | |
51a7b448 | 835 | restore_saved_sigmask(); |
1da177e4 LT |
836 | } |
837 | ||
72fa50f4 HS |
838 | void signal_fault(struct pt_regs *regs, void __user *frame, char *where) |
839 | { | |
840 | struct task_struct *me = current; | |
841 | ||
842 | if (show_unhandled_signals && printk_ratelimit()) { | |
ae417bb4 | 843 | printk("%s" |
72fa50f4 | 844 | "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", |
ae417bb4 | 845 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
72fa50f4 HS |
846 | me->comm, me->pid, where, frame, |
847 | regs->ip, regs->sp, regs->orig_ax); | |
848 | print_vma_addr(" in ", regs->ip); | |
c767a54b | 849 | pr_cont("\n"); |
72fa50f4 HS |
850 | } |
851 | ||
852 | force_sig(SIGSEGV, me); | |
853 | } | |
c5a37394 PA |
854 | |
855 | #ifdef CONFIG_X86_X32_ABI | |
3fe26fa3 | 856 | asmlinkage long sys32_x32_rt_sigreturn(void) |
c5a37394 | 857 | { |
3fe26fa3 | 858 | struct pt_regs *regs = current_pt_regs(); |
c5a37394 PA |
859 | struct rt_sigframe_x32 __user *frame; |
860 | sigset_t set; | |
6c25da5a | 861 | unsigned long uc_flags; |
c5a37394 PA |
862 | |
863 | frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8); | |
864 | ||
865 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
866 | goto badframe; | |
867 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
868 | goto badframe; | |
6c25da5a AL |
869 | if (__get_user(uc_flags, &frame->uc.uc_flags)) |
870 | goto badframe; | |
c5a37394 | 871 | |
c5a37394 PA |
872 | set_current_blocked(&set); |
873 | ||
6c25da5a | 874 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, uc_flags)) |
c5a37394 PA |
875 | goto badframe; |
876 | ||
90268439 | 877 | if (compat_restore_altstack(&frame->uc.uc_stack)) |
c5a37394 PA |
878 | goto badframe; |
879 | ||
6a3713f0 | 880 | return regs->ax; |
c5a37394 PA |
881 | |
882 | badframe: | |
883 | signal_fault(regs, frame, "x32 rt_sigreturn"); | |
884 | return 0; | |
885 | } | |
886 | #endif |