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linux-user: i386/signal: move fpstate at the end of the 32-bit frames
[qemu.git] / linux-user / i386 / signal.c
blob76317a3d1648fa2dd0b05a2c1bfabe3205b96623
1 /*
2 * Emulation of Linux signals
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 */
19 #include "qemu/osdep.h"
20 #include "qemu.h"
21 #include "user-internals.h"
22 #include "signal-common.h"
23 #include "linux-user/trace.h"
24
25 /* from the Linux kernel - /arch/x86/include/uapi/asm/sigcontext.h */
26
27 struct target_fpreg {
28 uint16_t significand[4];
29 uint16_t exponent;
30 };
31
32 struct target_fpxreg {
33 uint16_t significand[4];
34 uint16_t exponent;
35 uint16_t padding[3];
36 };
37
38 struct target_xmmreg {
39 uint32_t element[4];
40 };
41
42 struct target_fpstate_32 {
43 /* Regular FPU environment */
44 uint32_t cw;
45 uint32_t sw;
46 uint32_t tag;
47 uint32_t ipoff;
48 uint32_t cssel;
49 uint32_t dataoff;
50 uint32_t datasel;
51 struct target_fpreg st[8];
52 uint16_t status;
53 uint16_t magic; /* 0xffff = regular FPU data only */
54
55 /* FXSR FPU environment */
56 uint32_t _fxsr_env[6]; /* FXSR FPU env is ignored */
57 uint32_t mxcsr;
58 uint32_t reserved;
59 struct target_fpxreg fxsr_st[8]; /* FXSR FPU reg data is ignored */
60 struct target_xmmreg xmm[8];
61 uint32_t padding[56];
62 };
63
64 struct target_fpstate_64 {
65 /* FXSAVE format */
66 uint16_t cw;
67 uint16_t sw;
68 uint16_t twd;
69 uint16_t fop;
70 uint64_t rip;
71 uint64_t rdp;
72 uint32_t mxcsr;
73 uint32_t mxcsr_mask;
74 uint32_t st_space[32];
75 uint32_t xmm_space[64];
76 uint32_t reserved[24];
77 };
78
79 #ifndef TARGET_X86_64
80 # define target_fpstate target_fpstate_32
81 #else
82 # define target_fpstate target_fpstate_64
83 #endif
84
85 struct target_sigcontext_32 {
86 uint16_t gs, __gsh;
87 uint16_t fs, __fsh;
88 uint16_t es, __esh;
89 uint16_t ds, __dsh;
90 uint32_t edi;
91 uint32_t esi;
92 uint32_t ebp;
93 uint32_t esp;
94 uint32_t ebx;
95 uint32_t edx;
96 uint32_t ecx;
97 uint32_t eax;
98 uint32_t trapno;
99 uint32_t err;
100 uint32_t eip;
101 uint16_t cs, __csh;
102 uint32_t eflags;
103 uint32_t esp_at_signal;
104 uint16_t ss, __ssh;
105 uint32_t fpstate; /* pointer */
106 uint32_t oldmask;
107 uint32_t cr2;
108 };
109
110 struct target_sigcontext_64 {
111 uint64_t r8;
112 uint64_t r9;
113 uint64_t r10;
114 uint64_t r11;
115 uint64_t r12;
116 uint64_t r13;
117 uint64_t r14;
118 uint64_t r15;
119
120 uint64_t rdi;
121 uint64_t rsi;
122 uint64_t rbp;
123 uint64_t rbx;
124 uint64_t rdx;
125 uint64_t rax;
126 uint64_t rcx;
127 uint64_t rsp;
128 uint64_t rip;
129
130 uint64_t eflags;
131
132 uint16_t cs;
133 uint16_t gs;
134 uint16_t fs;
135 uint16_t ss;
136
137 uint64_t err;
138 uint64_t trapno;
139 uint64_t oldmask;
140 uint64_t cr2;
141
142 uint64_t fpstate; /* pointer */
143 uint64_t padding[8];
144 };
145
146 #ifndef TARGET_X86_64
147 # define target_sigcontext target_sigcontext_32
148 #else
149 # define target_sigcontext target_sigcontext_64
150 #endif
151
152 /* see Linux/include/uapi/asm-generic/ucontext.h */
153 struct target_ucontext {
154 abi_ulong tuc_flags;
155 abi_ulong tuc_link;
156 target_stack_t tuc_stack;
157 struct target_sigcontext tuc_mcontext;
158 target_sigset_t tuc_sigmask; /* mask last for extensibility */
159 };
160
161 #ifndef TARGET_X86_64
162 struct sigframe {
163 abi_ulong pretcode;
164 int sig;
165 struct target_sigcontext sc;
166 /*
167 * The actual fpstate is placed after retcode[] below, to make
168 * room for the variable-sized xsave data. The older unused fpstate
169 * has to be kept to avoid changing the offset of extramask[], which
170 * is part of the ABI.
171 */
172 struct target_fpstate fpstate_unused;
173 abi_ulong extramask[TARGET_NSIG_WORDS-1];
174 char retcode[8];
175 struct target_fpstate fpstate;
176 };
177
178 struct rt_sigframe {
179 abi_ulong pretcode;
180 int sig;
181 abi_ulong pinfo;
182 abi_ulong puc;
183 struct target_siginfo info;
184 struct target_ucontext uc;
185 char retcode[8];
186 struct target_fpstate fpstate;
187 };
188
189 #else
190
191 struct rt_sigframe {
192 abi_ulong pretcode;
193 struct target_ucontext uc;
194 struct target_siginfo info;
195 struct target_fpstate fpstate;
196 };
197
198 #endif
199
200 /*
201 * Set up a signal frame.
202 */
203
204 /* XXX: save x87 state */
205 static void setup_sigcontext(struct target_sigcontext *sc,
206 struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask,
207 abi_ulong fpstate_addr)
208 {
209 CPUState *cs = env_cpu(env);
210 #ifndef TARGET_X86_64
211 uint16_t magic;
212
213 /* already locked in setup_frame() */
214 __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
215 __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
216 __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
217 __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
218 __put_user(env->regs[R_EDI], &sc->edi);
219 __put_user(env->regs[R_ESI], &sc->esi);
220 __put_user(env->regs[R_EBP], &sc->ebp);
221 __put_user(env->regs[R_ESP], &sc->esp);
222 __put_user(env->regs[R_EBX], &sc->ebx);
223 __put_user(env->regs[R_EDX], &sc->edx);
224 __put_user(env->regs[R_ECX], &sc->ecx);
225 __put_user(env->regs[R_EAX], &sc->eax);
226 __put_user(cs->exception_index, &sc->trapno);
227 __put_user(env->error_code, &sc->err);
228 __put_user(env->eip, &sc->eip);
229 __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
230 __put_user(env->eflags, &sc->eflags);
231 __put_user(env->regs[R_ESP], &sc->esp_at_signal);
232 __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
233
234 cpu_x86_fsave(env, fpstate_addr, 1);
235 fpstate->status = fpstate->sw;
236 magic = 0xffff;
237 __put_user(magic, &fpstate->magic);
238 __put_user(fpstate_addr, &sc->fpstate);
239
240 /* non-iBCS2 extensions.. */
241 __put_user(mask, &sc->oldmask);
242 __put_user(env->cr[2], &sc->cr2);
243 #else
244 __put_user(env->regs[R_EDI], &sc->rdi);
245 __put_user(env->regs[R_ESI], &sc->rsi);
246 __put_user(env->regs[R_EBP], &sc->rbp);
247 __put_user(env->regs[R_ESP], &sc->rsp);
248 __put_user(env->regs[R_EBX], &sc->rbx);
249 __put_user(env->regs[R_EDX], &sc->rdx);
250 __put_user(env->regs[R_ECX], &sc->rcx);
251 __put_user(env->regs[R_EAX], &sc->rax);
252
253 __put_user(env->regs[8], &sc->r8);
254 __put_user(env->regs[9], &sc->r9);
255 __put_user(env->regs[10], &sc->r10);
256 __put_user(env->regs[11], &sc->r11);
257 __put_user(env->regs[12], &sc->r12);
258 __put_user(env->regs[13], &sc->r13);
259 __put_user(env->regs[14], &sc->r14);
260 __put_user(env->regs[15], &sc->r15);
261
262 __put_user(cs->exception_index, &sc->trapno);
263 __put_user(env->error_code, &sc->err);
264 __put_user(env->eip, &sc->rip);
265
266 __put_user(env->eflags, &sc->eflags);
267 __put_user(env->segs[R_CS].selector, &sc->cs);
268 __put_user((uint16_t)0, &sc->gs);
269 __put_user((uint16_t)0, &sc->fs);
270 __put_user(env->segs[R_SS].selector, &sc->ss);
271
272 __put_user(mask, &sc->oldmask);
273 __put_user(env->cr[2], &sc->cr2);
274
275 /* fpstate_addr must be 16 byte aligned for fxsave */
276 assert(!(fpstate_addr & 0xf));
277
278 cpu_x86_fxsave(env, fpstate_addr);
279 __put_user(fpstate_addr, &sc->fpstate);
280 #endif
281 }
282
283 /*
284 * Determine which stack to use..
285 */
286
287 static inline abi_ulong
288 get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t frame_size)
289 {
290 unsigned long esp;
291
292 /* Default to using normal stack */
293 esp = get_sp_from_cpustate(env);
294 #ifdef TARGET_X86_64
295 esp -= 128; /* this is the redzone */
296 #endif
297
298 /* This is the X/Open sanctioned signal stack switching. */
299 if (ka->sa_flags & TARGET_SA_ONSTACK) {
300 esp = target_sigsp(esp, ka);
301 } else {
302 #ifndef TARGET_X86_64
303 /* This is the legacy signal stack switching. */
304 if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
305 !(ka->sa_flags & TARGET_SA_RESTORER) &&
306 ka->sa_restorer) {
307 esp = (unsigned long) ka->sa_restorer;
308 }
309 #endif
310 }
311
312 #ifndef TARGET_X86_64
313 return (esp - frame_size) & -8ul;
314 #else
315 return ((esp - frame_size) & (~15ul)) - 8;
316 #endif
317 }
318
319 #ifndef TARGET_X86_64
320 static void install_sigtramp(void *tramp)
321 {
322 /* This is popl %eax ; movl $syscall,%eax ; int $0x80 */
323 __put_user(0xb858, (uint16_t *)(tramp + 0));
324 __put_user(TARGET_NR_sigreturn, (int32_t *)(tramp + 2));
325 __put_user(0x80cd, (uint16_t *)(tramp + 6));
326 }
327
328 static void install_rt_sigtramp(void *tramp)
329 {
330 /* This is movl $syscall,%eax ; int $0x80 */
331 __put_user(0xb8, (uint8_t *)(tramp + 0));
332 __put_user(TARGET_NR_rt_sigreturn, (int32_t *)(tramp + 1));
333 __put_user(0x80cd, (uint16_t *)(tramp + 5));
334 }
335
336 /* compare linux/arch/i386/kernel/signal.c:setup_frame() */
337 void setup_frame(int sig, struct target_sigaction *ka,
338 target_sigset_t *set, CPUX86State *env)
339 {
340 abi_ulong frame_addr;
341 struct sigframe *frame;
342 int i;
343
344 frame_addr = get_sigframe(ka, env, sizeof(*frame));
345 trace_user_setup_frame(env, frame_addr);
346
347 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
348 goto give_sigsegv;
349
350 __put_user(sig, &frame->sig);
351
352 setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0],
353 frame_addr + offsetof(struct sigframe, fpstate));
354
355 for(i = 1; i < TARGET_NSIG_WORDS; i++) {
356 __put_user(set->sig[i], &frame->extramask[i - 1]);
357 }
358
359 /* Set up to return from userspace. If provided, use a stub
360 already in userspace. */
361 if (ka->sa_flags & TARGET_SA_RESTORER) {
362 __put_user(ka->sa_restorer, &frame->pretcode);
363 } else {
364 /* This is no longer used, but is retained for ABI compatibility. */
365 install_sigtramp(frame->retcode);
366 __put_user(default_sigreturn, &frame->pretcode);
367 }
368
369 /* Set up registers for signal handler */
370 env->regs[R_ESP] = frame_addr;
371 env->eip = ka->_sa_handler;
372
373 cpu_x86_load_seg(env, R_DS, __USER_DS);
374 cpu_x86_load_seg(env, R_ES, __USER_DS);
375 cpu_x86_load_seg(env, R_SS, __USER_DS);
376 cpu_x86_load_seg(env, R_CS, __USER_CS);
377 env->eflags &= ~TF_MASK;
378
379 unlock_user_struct(frame, frame_addr, 1);
380
381 return;
382
383 give_sigsegv:
384 force_sigsegv(sig);
385 }
386 #endif
387
388 /* compare linux/arch/x86/kernel/signal.c:setup_rt_frame() */
389 void setup_rt_frame(int sig, struct target_sigaction *ka,
390 target_siginfo_t *info,
391 target_sigset_t *set, CPUX86State *env)
392 {
393 abi_ulong frame_addr;
394 #ifndef TARGET_X86_64
395 abi_ulong addr;
396 #endif
397 struct rt_sigframe *frame;
398 int i;
399
400 frame_addr = get_sigframe(ka, env, sizeof(*frame));
401 trace_user_setup_rt_frame(env, frame_addr);
402
403 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
404 goto give_sigsegv;
405
406 /* These fields are only in rt_sigframe on 32 bit */
407 #ifndef TARGET_X86_64
408 __put_user(sig, &frame->sig);
409 addr = frame_addr + offsetof(struct rt_sigframe, info);
410 __put_user(addr, &frame->pinfo);
411 addr = frame_addr + offsetof(struct rt_sigframe, uc);
412 __put_user(addr, &frame->puc);
413 #endif
414 if (ka->sa_flags & TARGET_SA_SIGINFO) {
415 tswap_siginfo(&frame->info, info);
416 }
417
418 /* Create the ucontext. */
419 __put_user(0, &frame->uc.tuc_flags);
420 __put_user(0, &frame->uc.tuc_link);
421 target_save_altstack(&frame->uc.tuc_stack, env);
422 setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env,
423 set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate));
424
425 for(i = 0; i < TARGET_NSIG_WORDS; i++) {
426 __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
427 }
428
429 /* Set up to return from userspace. If provided, use a stub
430 already in userspace. */
431 if (ka->sa_flags & TARGET_SA_RESTORER) {
432 __put_user(ka->sa_restorer, &frame->pretcode);
433 } else {
434 #ifdef TARGET_X86_64
435 /* For x86_64, SA_RESTORER is required ABI. */
436 goto give_sigsegv;
437 #else
438 /* This is no longer used, but is retained for ABI compatibility. */
439 install_rt_sigtramp(frame->retcode);
440 __put_user(default_rt_sigreturn, &frame->pretcode);
441 #endif
442 }
443
444 /* Set up registers for signal handler */
445 env->regs[R_ESP] = frame_addr;
446 env->eip = ka->_sa_handler;
447
448 #ifndef TARGET_X86_64
449 env->regs[R_EAX] = sig;
450 env->regs[R_EDX] = frame_addr + offsetof(struct rt_sigframe, info);
451 env->regs[R_ECX] = frame_addr + offsetof(struct rt_sigframe, uc);
452 #else
453 env->regs[R_EAX] = 0;
454 env->regs[R_EDI] = sig;
455 env->regs[R_ESI] = frame_addr + offsetof(struct rt_sigframe, info);
456 env->regs[R_EDX] = frame_addr + offsetof(struct rt_sigframe, uc);
457 #endif
458
459 cpu_x86_load_seg(env, R_DS, __USER_DS);
460 cpu_x86_load_seg(env, R_ES, __USER_DS);
461 cpu_x86_load_seg(env, R_CS, __USER_CS);
462 cpu_x86_load_seg(env, R_SS, __USER_DS);
463 env->eflags &= ~TF_MASK;
464
465 unlock_user_struct(frame, frame_addr, 1);
466
467 return;
468
469 give_sigsegv:
470 force_sigsegv(sig);
471 }
472
473 static int
474 restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc)
475 {
476 unsigned int err = 0;
477 abi_ulong fpstate_addr;
478 unsigned int tmpflags;
479
480 #ifndef TARGET_X86_64
481 cpu_x86_load_seg(env, R_GS, tswap16(sc->gs));
482 cpu_x86_load_seg(env, R_FS, tswap16(sc->fs));
483 cpu_x86_load_seg(env, R_ES, tswap16(sc->es));
484 cpu_x86_load_seg(env, R_DS, tswap16(sc->ds));
485
486 env->regs[R_EDI] = tswapl(sc->edi);
487 env->regs[R_ESI] = tswapl(sc->esi);
488 env->regs[R_EBP] = tswapl(sc->ebp);
489 env->regs[R_ESP] = tswapl(sc->esp);
490 env->regs[R_EBX] = tswapl(sc->ebx);
491 env->regs[R_EDX] = tswapl(sc->edx);
492 env->regs[R_ECX] = tswapl(sc->ecx);
493 env->regs[R_EAX] = tswapl(sc->eax);
494
495 env->eip = tswapl(sc->eip);
496 #else
497 env->regs[8] = tswapl(sc->r8);
498 env->regs[9] = tswapl(sc->r9);
499 env->regs[10] = tswapl(sc->r10);
500 env->regs[11] = tswapl(sc->r11);
501 env->regs[12] = tswapl(sc->r12);
502 env->regs[13] = tswapl(sc->r13);
503 env->regs[14] = tswapl(sc->r14);
504 env->regs[15] = tswapl(sc->r15);
505
506 env->regs[R_EDI] = tswapl(sc->rdi);
507 env->regs[R_ESI] = tswapl(sc->rsi);
508 env->regs[R_EBP] = tswapl(sc->rbp);
509 env->regs[R_EBX] = tswapl(sc->rbx);
510 env->regs[R_EDX] = tswapl(sc->rdx);
511 env->regs[R_EAX] = tswapl(sc->rax);
512 env->regs[R_ECX] = tswapl(sc->rcx);
513 env->regs[R_ESP] = tswapl(sc->rsp);
514
515 env->eip = tswapl(sc->rip);
516 #endif
517
518 cpu_x86_load_seg(env, R_CS, lduw_p(&sc->cs) | 3);
519 cpu_x86_load_seg(env, R_SS, lduw_p(&sc->ss) | 3);
520
521 tmpflags = tswapl(sc->eflags);
522 env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
523 // regs->orig_eax = -1; /* disable syscall checks */
524
525 fpstate_addr = tswapl(sc->fpstate);
526 if (fpstate_addr != 0) {
527 if (!access_ok(env_cpu(env), VERIFY_READ, fpstate_addr,
528 sizeof(struct target_fpstate))) {
529 goto badframe;
530 }
531 #ifndef TARGET_X86_64
532 cpu_x86_frstor(env, fpstate_addr, 1);
533 #else
534 cpu_x86_fxrstor(env, fpstate_addr);
535 #endif
536 }
537
538 return err;
539 badframe:
540 return 1;
541 }
542
543 /* Note: there is no sigreturn on x86_64, there is only rt_sigreturn */
544 #ifndef TARGET_X86_64
545 long do_sigreturn(CPUX86State *env)
546 {
547 struct sigframe *frame;
548 abi_ulong frame_addr = env->regs[R_ESP] - 8;
549 target_sigset_t target_set;
550 sigset_t set;
551 int i;
552
553 trace_user_do_sigreturn(env, frame_addr);
554 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
555 goto badframe;
556 /* set blocked signals */
557 __get_user(target_set.sig[0], &frame->sc.oldmask);
558 for(i = 1; i < TARGET_NSIG_WORDS; i++) {
559 __get_user(target_set.sig[i], &frame->extramask[i - 1]);
560 }
561
562 target_to_host_sigset_internal(&set, &target_set);
563 set_sigmask(&set);
564
565 /* restore registers */
566 if (restore_sigcontext(env, &frame->sc))
567 goto badframe;
568 unlock_user_struct(frame, frame_addr, 0);
569 return -QEMU_ESIGRETURN;
570
571 badframe:
572 unlock_user_struct(frame, frame_addr, 0);
573 force_sig(TARGET_SIGSEGV);
574 return -QEMU_ESIGRETURN;
575 }
576 #endif
577
578 long do_rt_sigreturn(CPUX86State *env)
579 {
580 abi_ulong frame_addr;
581 struct rt_sigframe *frame;
582 sigset_t set;
583
584 frame_addr = env->regs[R_ESP] - sizeof(abi_ulong);
585 trace_user_do_rt_sigreturn(env, frame_addr);
586 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
587 goto badframe;
588 target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
589 set_sigmask(&set);
590
591 if (restore_sigcontext(env, &frame->uc.tuc_mcontext)) {
592 goto badframe;
593 }
594
595 target_restore_altstack(&frame->uc.tuc_stack, env);
596
597 unlock_user_struct(frame, frame_addr, 0);
598 return -QEMU_ESIGRETURN;
599
600 badframe:
601 unlock_user_struct(frame, frame_addr, 0);
602 force_sig(TARGET_SIGSEGV);
603 return -QEMU_ESIGRETURN;
604 }
605
606 #ifndef TARGET_X86_64
607 void setup_sigtramp(abi_ulong sigtramp_page)
608 {
609 uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0);
610 assert(tramp != NULL);
611
612 default_sigreturn = sigtramp_page;
613 install_sigtramp(tramp);
614
615 default_rt_sigreturn = sigtramp_page + 8;
616 install_rt_sigtramp(tramp + 8);
617
618 unlock_user(tramp, sigtramp_page, 2 * 8);
619 }
620 #endif
QEmu