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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/arch/x86_64/ia32/ia32_signal.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | * | |
7 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson | |
8 | * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes | |
9 | * 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen | |
1da177e4 LT |
10 | */ |
11 | ||
12 | #include <linux/sched.h> | |
68db0cf1 | 13 | #include <linux/sched/task_stack.h> |
1da177e4 LT |
14 | #include <linux/mm.h> |
15 | #include <linux/smp.h> | |
1da177e4 | 16 | #include <linux/kernel.h> |
1da177e4 LT |
17 | #include <linux/errno.h> |
18 | #include <linux/wait.h> | |
1da177e4 LT |
19 | #include <linux/unistd.h> |
20 | #include <linux/stddef.h> | |
21 | #include <linux/personality.h> | |
22 | #include <linux/compat.h> | |
9fbbd4dd | 23 | #include <linux/binfmts.h> |
1da177e4 | 24 | #include <asm/ucontext.h> |
7c0f6ba6 | 25 | #include <linux/uaccess.h> |
78f7f1e5 | 26 | #include <asm/fpu/internal.h> |
fcbc99c4 | 27 | #include <asm/fpu/signal.h> |
1da177e4 LT |
28 | #include <asm/ptrace.h> |
29 | #include <asm/ia32_unistd.h> | |
30 | #include <asm/user32.h> | |
decb4c41 | 31 | #include <uapi/asm/sigcontext.h> |
1da177e4 | 32 | #include <asm/proto.h> |
af65d648 | 33 | #include <asm/vdso.h> |
d98f9d84 | 34 | #include <asm/sigframe.h> |
f28f0c23 | 35 | #include <asm/sighandling.h> |
2f06de06 | 36 | #include <asm/sys_ia32.h> |
49b8c695 | 37 | #include <asm/smap.h> |
d98f9d84 | 38 | |
1da177e4 LT |
39 | /* |
40 | * Do a signal return; undo the signal stack. | |
41 | */ | |
a967bb3f HS |
42 | #define loadsegment_gs(v) load_gs_index(v) |
43 | #define loadsegment_fs(v) loadsegment(fs, v) | |
44 | #define loadsegment_ds(v) loadsegment(ds, v) | |
45 | #define loadsegment_es(v) loadsegment(es, v) | |
46 | ||
47 | #define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; }) | |
48 | #define set_user_seg(seg, v) loadsegment_##seg(v) | |
49 | ||
b78a5b52 | 50 | #define COPY(x) { \ |
3b4b7570 | 51 | get_user_ex(regs->x, &sc->x); \ |
1da177e4 | 52 | } |
1da177e4 | 53 | |
8801ead4 HS |
54 | #define GET_SEG(seg) ({ \ |
55 | unsigned short tmp; \ | |
56 | get_user_ex(tmp, &sc->seg); \ | |
57 | tmp; \ | |
58 | }) | |
59 | ||
60 | #define COPY_SEG_CPL3(seg) do { \ | |
61 | regs->seg = GET_SEG(seg) | 3; \ | |
62 | } while (0) | |
1da177e4 | 63 | |
8c6e5ce0 | 64 | #define RELOAD_SEG(seg) { \ |
a967bb3f HS |
65 | unsigned int pre = GET_SEG(seg); \ |
66 | unsigned int cur = get_user_seg(seg); \ | |
8c6e5ce0 HS |
67 | pre |= 3; \ |
68 | if (pre != cur) \ | |
a967bb3f | 69 | set_user_seg(seg, pre); \ |
8c6e5ce0 | 70 | } |
99b9cdf7 TG |
71 | |
72 | static int ia32_restore_sigcontext(struct pt_regs *regs, | |
8fcb346b | 73 | struct sigcontext_32 __user *sc) |
99b9cdf7 | 74 | { |
a967bb3f | 75 | unsigned int tmpflags, err = 0; |
ab513701 | 76 | void __user *buf; |
99b9cdf7 TG |
77 | u32 tmp; |
78 | ||
79 | /* Always make any pending restarted system calls return -EINTR */ | |
f56141e3 | 80 | current->restart_block.fn = do_no_restart_syscall; |
99b9cdf7 | 81 | |
3b4b7570 HS |
82 | get_user_try { |
83 | /* | |
84 | * Reload fs and gs if they have changed in the signal | |
85 | * handler. This does not handle long fs/gs base changes in | |
86 | * the handler, but does not clobber them at least in the | |
87 | * normal case. | |
88 | */ | |
a967bb3f | 89 | RELOAD_SEG(gs); |
3b4b7570 HS |
90 | RELOAD_SEG(fs); |
91 | RELOAD_SEG(ds); | |
92 | RELOAD_SEG(es); | |
93 | ||
94 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); | |
6a3713f0 | 95 | COPY(dx); COPY(cx); COPY(ip); COPY(ax); |
3b4b7570 HS |
96 | /* Don't touch extended registers */ |
97 | ||
98 | COPY_SEG_CPL3(cs); | |
99 | COPY_SEG_CPL3(ss); | |
100 | ||
101 | get_user_ex(tmpflags, &sc->flags); | |
102 | regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); | |
103 | /* disable syscall checks */ | |
104 | regs->orig_ax = -1; | |
105 | ||
106 | get_user_ex(tmp, &sc->fpstate); | |
107 | buf = compat_ptr(tmp); | |
3b4b7570 HS |
108 | } get_user_catch(err); |
109 | ||
9dfe99b7 | 110 | err |= fpu__restore_sig(buf, 1); |
5e88353d | 111 | |
1daeaa31 BG |
112 | force_iret(); |
113 | ||
1da177e4 | 114 | return err; |
1da177e4 LT |
115 | } |
116 | ||
3fe26fa3 | 117 | asmlinkage long sys32_sigreturn(void) |
1da177e4 | 118 | { |
3fe26fa3 | 119 | struct pt_regs *regs = current_pt_regs(); |
3b0d29ee | 120 | struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8); |
1da177e4 | 121 | sigset_t set; |
1da177e4 LT |
122 | |
123 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
124 | goto badframe; | |
125 | if (__get_user(set.sig[0], &frame->sc.oldmask) | |
126 | || (_COMPAT_NSIG_WORDS > 1 | |
99b9cdf7 TG |
127 | && __copy_from_user((((char *) &set.sig) + 4), |
128 | &frame->extramask, | |
1da177e4 LT |
129 | sizeof(frame->extramask)))) |
130 | goto badframe; | |
131 | ||
905f29e2 | 132 | set_current_blocked(&set); |
99b9cdf7 | 133 | |
6a3713f0 | 134 | if (ia32_restore_sigcontext(regs, &frame->sc)) |
1da177e4 | 135 | goto badframe; |
6a3713f0 | 136 | return regs->ax; |
1da177e4 LT |
137 | |
138 | badframe: | |
139 | signal_fault(regs, frame, "32bit sigreturn"); | |
140 | return 0; | |
99b9cdf7 | 141 | } |
1da177e4 | 142 | |
3fe26fa3 | 143 | asmlinkage long sys32_rt_sigreturn(void) |
1da177e4 | 144 | { |
3fe26fa3 | 145 | struct pt_regs *regs = current_pt_regs(); |
3b0d29ee | 146 | struct rt_sigframe_ia32 __user *frame; |
1da177e4 | 147 | sigset_t set; |
1da177e4 | 148 | |
3b0d29ee | 149 | frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4); |
1da177e4 LT |
150 | |
151 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
152 | goto badframe; | |
153 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
154 | goto badframe; | |
155 | ||
905f29e2 | 156 | set_current_blocked(&set); |
99b9cdf7 | 157 | |
6a3713f0 | 158 | if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext)) |
1da177e4 LT |
159 | goto badframe; |
160 | ||
90268439 | 161 | if (compat_restore_altstack(&frame->uc.uc_stack)) |
1da177e4 LT |
162 | goto badframe; |
163 | ||
6a3713f0 | 164 | return regs->ax; |
1da177e4 LT |
165 | |
166 | badframe: | |
99b9cdf7 | 167 | signal_fault(regs, frame, "32bit rt sigreturn"); |
1da177e4 | 168 | return 0; |
99b9cdf7 | 169 | } |
1da177e4 LT |
170 | |
171 | /* | |
172 | * Set up a signal frame. | |
173 | */ | |
174 | ||
8fcb346b | 175 | static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc, |
ab513701 | 176 | void __user *fpstate, |
99b9cdf7 | 177 | struct pt_regs *regs, unsigned int mask) |
1da177e4 | 178 | { |
a967bb3f | 179 | int err = 0; |
1da177e4 | 180 | |
3b4b7570 | 181 | put_user_try { |
a967bb3f HS |
182 | put_user_ex(get_user_seg(gs), (unsigned int __user *)&sc->gs); |
183 | put_user_ex(get_user_seg(fs), (unsigned int __user *)&sc->fs); | |
184 | put_user_ex(get_user_seg(ds), (unsigned int __user *)&sc->ds); | |
185 | put_user_ex(get_user_seg(es), (unsigned int __user *)&sc->es); | |
3b4b7570 HS |
186 | |
187 | put_user_ex(regs->di, &sc->di); | |
188 | put_user_ex(regs->si, &sc->si); | |
189 | put_user_ex(regs->bp, &sc->bp); | |
190 | put_user_ex(regs->sp, &sc->sp); | |
191 | put_user_ex(regs->bx, &sc->bx); | |
192 | put_user_ex(regs->dx, &sc->dx); | |
193 | put_user_ex(regs->cx, &sc->cx); | |
194 | put_user_ex(regs->ax, &sc->ax); | |
51e7dc70 | 195 | put_user_ex(current->thread.trap_nr, &sc->trapno); |
3b4b7570 HS |
196 | put_user_ex(current->thread.error_code, &sc->err); |
197 | put_user_ex(regs->ip, &sc->ip); | |
198 | put_user_ex(regs->cs, (unsigned int __user *)&sc->cs); | |
199 | put_user_ex(regs->flags, &sc->flags); | |
200 | put_user_ex(regs->sp, &sc->sp_at_signal); | |
201 | put_user_ex(regs->ss, (unsigned int __user *)&sc->ss); | |
202 | ||
203 | put_user_ex(ptr_to_compat(fpstate), &sc->fpstate); | |
204 | ||
205 | /* non-iBCS2 extensions.. */ | |
206 | put_user_ex(mask, &sc->oldmask); | |
207 | put_user_ex(current->thread.cr2, &sc->cr2); | |
208 | } put_user_catch(err); | |
1da177e4 LT |
209 | |
210 | return err; | |
211 | } | |
212 | ||
213 | /* | |
214 | * Determine which stack to use.. | |
215 | */ | |
235b8022 | 216 | static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, |
3c1c7f10 | 217 | size_t frame_size, |
0ff8fef4 | 218 | void __user **fpstate) |
1da177e4 | 219 | { |
c5bedc68 | 220 | struct fpu *fpu = ¤t->thread.fpu; |
65ea5b03 | 221 | unsigned long sp; |
1da177e4 LT |
222 | |
223 | /* Default to using normal stack */ | |
65ea5b03 | 224 | sp = regs->sp; |
1da177e4 LT |
225 | |
226 | /* This is the X/Open sanctioned signal stack switching. */ | |
235b8022 AV |
227 | if (ksig->ka.sa.sa_flags & SA_ONSTACK) |
228 | sp = sigsp(sp, ksig); | |
1da177e4 | 229 | /* This is the legacy signal stack switching. */ |
99504819 | 230 | else if (regs->ss != __USER32_DS && |
235b8022 AV |
231 | !(ksig->ka.sa.sa_flags & SA_RESTORER) && |
232 | ksig->ka.sa.sa_restorer) | |
233 | sp = (unsigned long) ksig->ka.sa.sa_restorer; | |
1da177e4 | 234 | |
e4a81bfc | 235 | if (fpu->initialized) { |
72a671ce SS |
236 | unsigned long fx_aligned, math_size; |
237 | ||
82c0e45e | 238 | sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size); |
86e9fc3a | 239 | *fpstate = (struct _fpstate_32 __user *) sp; |
c8e14041 | 240 | if (copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned, |
72a671ce | 241 | math_size) < 0) |
99ea1b93 | 242 | return (void __user *) -1L; |
3c1c7f10 SS |
243 | } |
244 | ||
65ea5b03 | 245 | sp -= frame_size; |
d347f372 MO |
246 | /* Align the stack pointer according to the i386 ABI, |
247 | * i.e. so that on function entry ((sp + 4) & 15) == 0. */ | |
65ea5b03 PA |
248 | sp = ((sp + 4) & -16ul) - 4; |
249 | return (void __user *) sp; | |
1da177e4 LT |
250 | } |
251 | ||
235b8022 | 252 | int ia32_setup_frame(int sig, struct ksignal *ksig, |
99b9cdf7 | 253 | compat_sigset_t *set, struct pt_regs *regs) |
1da177e4 | 254 | { |
3b0d29ee | 255 | struct sigframe_ia32 __user *frame; |
99b9cdf7 | 256 | void __user *restorer; |
1da177e4 | 257 | int err = 0; |
ab513701 | 258 | void __user *fpstate = NULL; |
1da177e4 | 259 | |
99b9cdf7 TG |
260 | /* copy_to_user optimizes that into a single 8 byte store */ |
261 | static const struct { | |
262 | u16 poplmovl; | |
263 | u32 val; | |
264 | u16 int80; | |
99b9cdf7 TG |
265 | } __attribute__((packed)) code = { |
266 | 0xb858, /* popl %eax ; movl $...,%eax */ | |
267 | __NR_ia32_sigreturn, | |
268 | 0x80cd, /* int $0x80 */ | |
99b9cdf7 TG |
269 | }; |
270 | ||
235b8022 | 271 | frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
272 | |
273 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 274 | return -EFAULT; |
1da177e4 | 275 | |
2ba48e16 | 276 | if (__put_user(sig, &frame->sig)) |
3d0aedd9 | 277 | return -EFAULT; |
1da177e4 | 278 | |
2ba48e16 | 279 | if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) |
3d0aedd9 | 280 | return -EFAULT; |
1da177e4 LT |
281 | |
282 | if (_COMPAT_NSIG_WORDS > 1) { | |
2ba48e16 HS |
283 | if (__copy_to_user(frame->extramask, &set->sig[1], |
284 | sizeof(frame->extramask))) | |
3d0aedd9 | 285 | return -EFAULT; |
1da177e4 | 286 | } |
1da177e4 | 287 | |
235b8022 AV |
288 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
289 | restorer = ksig->ka.sa.sa_restorer; | |
af65d648 RM |
290 | } else { |
291 | /* Return stub is in 32bit vsyscall page */ | |
1a3e4ca4 | 292 | if (current->mm->context.vdso) |
6f121e54 | 293 | restorer = current->mm->context.vdso + |
0a6d1fa0 | 294 | vdso_image_32.sym___kernel_sigreturn; |
af65d648 | 295 | else |
ade1af77 | 296 | restorer = &frame->retcode; |
af65d648 | 297 | } |
99b9cdf7 | 298 | |
3b4b7570 HS |
299 | put_user_try { |
300 | put_user_ex(ptr_to_compat(restorer), &frame->pretcode); | |
301 | ||
302 | /* | |
303 | * These are actually not used anymore, but left because some | |
304 | * gdb versions depend on them as a marker. | |
305 | */ | |
0ff8fef4 | 306 | put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode); |
3b4b7570 HS |
307 | } put_user_catch(err); |
308 | ||
1da177e4 | 309 | if (err) |
3d0aedd9 | 310 | return -EFAULT; |
1da177e4 LT |
311 | |
312 | /* Set up registers for signal handler */ | |
65ea5b03 | 313 | regs->sp = (unsigned long) frame; |
235b8022 | 314 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
1da177e4 | 315 | |
536e3ee4 | 316 | /* Make -mregparm=3 work */ |
65ea5b03 PA |
317 | regs->ax = sig; |
318 | regs->dx = 0; | |
319 | regs->cx = 0; | |
536e3ee4 | 320 | |
b6edbb1e JF |
321 | loadsegment(ds, __USER32_DS); |
322 | loadsegment(es, __USER32_DS); | |
1da177e4 | 323 | |
99b9cdf7 TG |
324 | regs->cs = __USER32_CS; |
325 | regs->ss = __USER32_DS; | |
1da177e4 | 326 | |
1d001df1 | 327 | return 0; |
1da177e4 LT |
328 | } |
329 | ||
235b8022 | 330 | int ia32_setup_rt_frame(int sig, struct ksignal *ksig, |
99b9cdf7 | 331 | compat_sigset_t *set, struct pt_regs *regs) |
1da177e4 | 332 | { |
3b0d29ee | 333 | struct rt_sigframe_ia32 __user *frame; |
af65d648 | 334 | void __user *restorer; |
1da177e4 | 335 | int err = 0; |
ab513701 | 336 | void __user *fpstate = NULL; |
1da177e4 | 337 | |
99b9cdf7 TG |
338 | /* __copy_to_user optimizes that into a single 8 byte store */ |
339 | static const struct { | |
340 | u8 movl; | |
341 | u32 val; | |
342 | u16 int80; | |
9cc3c49e | 343 | u8 pad; |
99b9cdf7 TG |
344 | } __attribute__((packed)) code = { |
345 | 0xb8, | |
346 | __NR_ia32_rt_sigreturn, | |
347 | 0x80cd, | |
348 | 0, | |
349 | }; | |
350 | ||
235b8022 | 351 | frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
352 | |
353 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 354 | return -EFAULT; |
1da177e4 | 355 | |
3b4b7570 HS |
356 | put_user_try { |
357 | put_user_ex(sig, &frame->sig); | |
358 | put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo); | |
359 | put_user_ex(ptr_to_compat(&frame->uc), &frame->puc); | |
1da177e4 | 360 | |
3b4b7570 | 361 | /* Create the ucontext. */ |
d366bf7e | 362 | if (boot_cpu_has(X86_FEATURE_XSAVE)) |
3b4b7570 HS |
363 | put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); |
364 | else | |
365 | put_user_ex(0, &frame->uc.uc_flags); | |
366 | put_user_ex(0, &frame->uc.uc_link); | |
bd1c149a | 367 | compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); |
3b4b7570 | 368 | |
235b8022 AV |
369 | if (ksig->ka.sa.sa_flags & SA_RESTORER) |
370 | restorer = ksig->ka.sa.sa_restorer; | |
3b4b7570 | 371 | else |
6f121e54 | 372 | restorer = current->mm->context.vdso + |
0a6d1fa0 | 373 | vdso_image_32.sym___kernel_rt_sigreturn; |
3b4b7570 HS |
374 | put_user_ex(ptr_to_compat(restorer), &frame->pretcode); |
375 | ||
376 | /* | |
377 | * Not actually used anymore, but left because some gdb | |
378 | * versions need it. | |
379 | */ | |
0ff8fef4 | 380 | put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode); |
3b4b7570 | 381 | } put_user_catch(err); |
1da177e4 | 382 | |
68463510 | 383 | err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false); |
5e88353d PA |
384 | err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
385 | regs, set->sig[0]); | |
386 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
387 | ||
1da177e4 | 388 | if (err) |
3d0aedd9 | 389 | return -EFAULT; |
1da177e4 LT |
390 | |
391 | /* Set up registers for signal handler */ | |
65ea5b03 | 392 | regs->sp = (unsigned long) frame; |
235b8022 | 393 | regs->ip = (unsigned long) ksig->ka.sa.sa_handler; |
1da177e4 | 394 | |
a7aacdf9 | 395 | /* Make -mregparm=3 work */ |
65ea5b03 PA |
396 | regs->ax = sig; |
397 | regs->dx = (unsigned long) &frame->info; | |
398 | regs->cx = (unsigned long) &frame->uc; | |
a7aacdf9 | 399 | |
b6edbb1e JF |
400 | loadsegment(ds, __USER32_DS); |
401 | loadsegment(es, __USER32_DS); | |
99b9cdf7 TG |
402 | |
403 | regs->cs = __USER32_CS; | |
404 | regs->ss = __USER32_DS; | |
1da177e4 | 405 | |
1d001df1 | 406 | return 0; |
1da177e4 | 407 | } |