xref: /openbmc/qemu/linux-user/i386/signal.c (revision 93e0932b)
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 #define TARGET_FP_XSTATE_MAGIC1         0x46505853U /* FPXS */
28 #define TARGET_FP_XSTATE_MAGIC2         0x46505845U /* FPXE */
29 #define TARGET_FP_XSTATE_MAGIC2_SIZE    4
30 
31 struct target_fpreg {
32     uint16_t significand[4];
33     uint16_t exponent;
34 };
35 
36 struct target_fpxreg {
37     uint16_t significand[4];
38     uint16_t exponent;
39     uint16_t padding[3];
40 };
41 
42 struct target_xmmreg {
43     uint32_t element[4];
44 };
45 
46 struct target_fpx_sw_bytes {
47     uint32_t magic1;
48     uint32_t extended_size;
49     uint64_t xfeatures;
50     uint32_t xstate_size;
51     uint32_t reserved[7];
52 };
53 QEMU_BUILD_BUG_ON(sizeof(struct target_fpx_sw_bytes) != 12*4);
54 
55 struct target_fpstate_fxsave {
56     /* FXSAVE format */
57     uint16_t cw;
58     uint16_t sw;
59     uint16_t twd;
60     uint16_t fop;
61     uint64_t rip;
62     uint64_t rdp;
63     uint32_t mxcsr;
64     uint32_t mxcsr_mask;
65     uint32_t st_space[32];
66     uint32_t xmm_space[64];
67     uint32_t hw_reserved[12];
68     struct target_fpx_sw_bytes sw_reserved;
69     uint8_t xfeatures[];
70 };
71 #define TARGET_FXSAVE_SIZE   sizeof(struct target_fpstate_fxsave)
72 QEMU_BUILD_BUG_ON(TARGET_FXSAVE_SIZE != 512);
73 QEMU_BUILD_BUG_ON(offsetof(struct target_fpstate_fxsave, sw_reserved) != 464);
74 
75 struct target_fpstate_32 {
76     /* Regular FPU environment */
77     uint32_t cw;
78     uint32_t sw;
79     uint32_t tag;
80     uint32_t ipoff;
81     uint32_t cssel;
82     uint32_t dataoff;
83     uint32_t datasel;
84     struct target_fpreg st[8];
85     uint16_t  status;
86     uint16_t  magic;          /* 0xffff = regular FPU data only */
87     struct target_fpstate_fxsave fxsave;
88 };
89 
90 /*
91  * For simplicity, setup_frame aligns struct target_fpstate_32 to
92  * 16 bytes, so ensure that the FXSAVE area is also aligned.
93  */
94 QEMU_BUILD_BUG_ON(offsetof(struct target_fpstate_32, fxsave) & 15);
95 
96 #ifndef TARGET_X86_64
97 # define target_fpstate target_fpstate_32
98 # define TARGET_FPSTATE_FXSAVE_OFFSET offsetof(struct target_fpstate_32, fxsave)
99 #else
100 # define target_fpstate target_fpstate_fxsave
101 # define TARGET_FPSTATE_FXSAVE_OFFSET 0
102 #endif
103 
104 struct target_sigcontext_32 {
105     uint16_t gs, __gsh;
106     uint16_t fs, __fsh;
107     uint16_t es, __esh;
108     uint16_t ds, __dsh;
109     uint32_t edi;
110     uint32_t esi;
111     uint32_t ebp;
112     uint32_t esp;
113     uint32_t ebx;
114     uint32_t edx;
115     uint32_t ecx;
116     uint32_t eax;
117     uint32_t trapno;
118     uint32_t err;
119     uint32_t eip;
120     uint16_t cs, __csh;
121     uint32_t eflags;
122     uint32_t esp_at_signal;
123     uint16_t ss, __ssh;
124     uint32_t fpstate; /* pointer */
125     uint32_t oldmask;
126     uint32_t cr2;
127 };
128 
129 struct target_sigcontext_64 {
130     uint64_t r8;
131     uint64_t r9;
132     uint64_t r10;
133     uint64_t r11;
134     uint64_t r12;
135     uint64_t r13;
136     uint64_t r14;
137     uint64_t r15;
138 
139     uint64_t rdi;
140     uint64_t rsi;
141     uint64_t rbp;
142     uint64_t rbx;
143     uint64_t rdx;
144     uint64_t rax;
145     uint64_t rcx;
146     uint64_t rsp;
147     uint64_t rip;
148 
149     uint64_t eflags;
150 
151     uint16_t cs;
152     uint16_t gs;
153     uint16_t fs;
154     uint16_t ss;
155 
156     uint64_t err;
157     uint64_t trapno;
158     uint64_t oldmask;
159     uint64_t cr2;
160 
161     uint64_t fpstate; /* pointer */
162     uint64_t padding[8];
163 };
164 
165 #ifndef TARGET_X86_64
166 # define target_sigcontext target_sigcontext_32
167 #else
168 # define target_sigcontext target_sigcontext_64
169 #endif
170 
171 /* see Linux/include/uapi/asm-generic/ucontext.h */
172 struct target_ucontext {
173     abi_ulong         tuc_flags;
174     abi_ulong         tuc_link;
175     target_stack_t    tuc_stack;
176     struct target_sigcontext tuc_mcontext;
177     target_sigset_t   tuc_sigmask;  /* mask last for extensibility */
178 };
179 
180 #ifndef TARGET_X86_64
181 struct sigframe {
182     abi_ulong pretcode;
183     int sig;
184     struct target_sigcontext sc;
185     /*
186      * The actual fpstate is placed after retcode[] below, to make
187      * room for the variable-sized xsave data.  The older unused fpstate
188      * has to be kept to avoid changing the offset of extramask[], which
189      * is part of the ABI.
190      */
191     struct target_fpstate fpstate_unused;
192     abi_ulong extramask[TARGET_NSIG_WORDS-1];
193     char retcode[8];
194 
195     /*
196      * This field will be 16-byte aligned in memory.  Applying QEMU_ALIGNED
197      * to it ensures that the base of the frame has an appropriate alignment
198      * too.
199      */
200     struct target_fpstate fpstate QEMU_ALIGNED(8);
201 };
202 #define TARGET_SIGFRAME_FXSAVE_OFFSET (                                    \
203     offsetof(struct sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET)
204 
205 struct rt_sigframe {
206     abi_ulong pretcode;
207     int sig;
208     abi_ulong pinfo;
209     abi_ulong puc;
210     struct target_siginfo info;
211     struct target_ucontext uc;
212     char retcode[8];
213     struct target_fpstate fpstate QEMU_ALIGNED(8);
214 };
215 #define TARGET_RT_SIGFRAME_FXSAVE_OFFSET (                                 \
216     offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET)
217 #else
218 
219 struct rt_sigframe {
220     abi_ulong pretcode;
221     struct target_ucontext uc;
222     struct target_siginfo info;
223     struct target_fpstate fpstate QEMU_ALIGNED(16);
224 };
225 #define TARGET_RT_SIGFRAME_FXSAVE_OFFSET (                                 \
226     offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET)
227 #endif
228 
229 /*
230  * Set up a signal frame.
231  */
232 
233 static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave,
234                              abi_ulong fxsave_addr)
235 {
236     if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) {
237         /* fxsave_addr must be 16 byte aligned for fxsave */
238         assert(!(fxsave_addr & 0xf));
239 
240         cpu_x86_fxsave(env, fxsave_addr);
241         __put_user(0, &fxsave->sw_reserved.magic1);
242     } else {
243         uint32_t xstate_size = xsave_area_size(env->xcr0, false);
244         uint32_t xfeatures_size = xstate_size - TARGET_FXSAVE_SIZE;
245 
246         /*
247          * extended_size is the offset from fpstate_addr to right after the end
248          * of the extended save states.  On 32-bit that includes the legacy
249          * FSAVE area.
250          */
251         uint32_t extended_size = TARGET_FPSTATE_FXSAVE_OFFSET
252             + xstate_size + TARGET_FP_XSTATE_MAGIC2_SIZE;
253 
254         /* fxsave_addr must be 64 byte aligned for xsave */
255         assert(!(fxsave_addr & 0x3f));
256 
257         /* Zero the header, XSAVE *adds* features to an existing save state.  */
258         memset(fxsave->xfeatures, 0, 64);
259         cpu_x86_xsave(env, fxsave_addr);
260         __put_user(TARGET_FP_XSTATE_MAGIC1, &fxsave->sw_reserved.magic1);
261         __put_user(extended_size, &fxsave->sw_reserved.extended_size);
262         __put_user(env->xcr0, &fxsave->sw_reserved.xfeatures);
263         __put_user(xstate_size, &fxsave->sw_reserved.xstate_size);
264         __put_user(TARGET_FP_XSTATE_MAGIC2, (uint32_t *) &fxsave->xfeatures[xfeatures_size]);
265     }
266 }
267 
268 static void setup_sigcontext(struct target_sigcontext *sc,
269         struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask,
270         abi_ulong fpstate_addr)
271 {
272     CPUState *cs = env_cpu(env);
273 #ifndef TARGET_X86_64
274     uint16_t magic;
275 
276     /* already locked in setup_frame() */
277     __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
278     __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
279     __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
280     __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
281     __put_user(env->regs[R_EDI], &sc->edi);
282     __put_user(env->regs[R_ESI], &sc->esi);
283     __put_user(env->regs[R_EBP], &sc->ebp);
284     __put_user(env->regs[R_ESP], &sc->esp);
285     __put_user(env->regs[R_EBX], &sc->ebx);
286     __put_user(env->regs[R_EDX], &sc->edx);
287     __put_user(env->regs[R_ECX], &sc->ecx);
288     __put_user(env->regs[R_EAX], &sc->eax);
289     __put_user(cs->exception_index, &sc->trapno);
290     __put_user(env->error_code, &sc->err);
291     __put_user(env->eip, &sc->eip);
292     __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
293     __put_user(env->eflags, &sc->eflags);
294     __put_user(env->regs[R_ESP], &sc->esp_at_signal);
295     __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
296 
297     cpu_x86_fsave(env, fpstate_addr, 1);
298     fpstate->status = fpstate->sw;
299     if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) {
300         magic = 0xffff;
301     } else {
302         xsave_sigcontext(env, &fpstate->fxsave,
303                          fpstate_addr + TARGET_FPSTATE_FXSAVE_OFFSET);
304         magic = 0;
305     }
306     __put_user(magic, &fpstate->magic);
307 #else
308     __put_user(env->regs[R_EDI], &sc->rdi);
309     __put_user(env->regs[R_ESI], &sc->rsi);
310     __put_user(env->regs[R_EBP], &sc->rbp);
311     __put_user(env->regs[R_ESP], &sc->rsp);
312     __put_user(env->regs[R_EBX], &sc->rbx);
313     __put_user(env->regs[R_EDX], &sc->rdx);
314     __put_user(env->regs[R_ECX], &sc->rcx);
315     __put_user(env->regs[R_EAX], &sc->rax);
316 
317     __put_user(env->regs[8], &sc->r8);
318     __put_user(env->regs[9], &sc->r9);
319     __put_user(env->regs[10], &sc->r10);
320     __put_user(env->regs[11], &sc->r11);
321     __put_user(env->regs[12], &sc->r12);
322     __put_user(env->regs[13], &sc->r13);
323     __put_user(env->regs[14], &sc->r14);
324     __put_user(env->regs[15], &sc->r15);
325 
326     __put_user(cs->exception_index, &sc->trapno);
327     __put_user(env->error_code, &sc->err);
328     __put_user(env->eip, &sc->rip);
329 
330     __put_user(env->eflags, &sc->eflags);
331     __put_user(env->segs[R_CS].selector, &sc->cs);
332     __put_user((uint16_t)0, &sc->gs);
333     __put_user((uint16_t)0, &sc->fs);
334     __put_user(env->segs[R_SS].selector, &sc->ss);
335 
336     xsave_sigcontext(env, fpstate, fpstate_addr);
337 #endif
338 
339     __put_user(fpstate_addr, &sc->fpstate);
340 
341     /* non-iBCS2 extensions.. */
342     __put_user(mask, &sc->oldmask);
343     __put_user(env->cr[2], &sc->cr2);
344 }
345 
346 /*
347  * Determine which stack to use..
348  */
349 
350 static inline abi_ulong
351 get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset)
352 {
353     unsigned long esp;
354 
355     /* Default to using normal stack */
356     esp = get_sp_from_cpustate(env);
357 #ifdef TARGET_X86_64
358     esp -= 128; /* this is the redzone */
359 #endif
360 
361     /* This is the X/Open sanctioned signal stack switching.  */
362     if (ka->sa_flags & TARGET_SA_ONSTACK) {
363         esp = target_sigsp(esp, ka);
364     } else {
365 #ifndef TARGET_X86_64
366         /* This is the legacy signal stack switching. */
367         if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
368                 !(ka->sa_flags & TARGET_SA_RESTORER) &&
369                 ka->sa_restorer) {
370             esp = (unsigned long) ka->sa_restorer;
371         }
372 #endif
373     }
374 
375     if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) {
376         return (esp - (fxsave_offset + TARGET_FXSAVE_SIZE)) & -8ul;
377     } else if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) {
378         return ((esp - TARGET_FXSAVE_SIZE) & -16ul) - fxsave_offset;
379     } else {
380         size_t xstate_size =
381                xsave_area_size(env->xcr0, false) + TARGET_FP_XSTATE_MAGIC2_SIZE;
382         return ((esp - xstate_size) & -64ul) - fxsave_offset;
383     }
384 }
385 
386 #ifndef TARGET_X86_64
387 static void install_sigtramp(void *tramp)
388 {
389     /* This is popl %eax ; movl $syscall,%eax ; int $0x80 */
390     __put_user(0xb858, (uint16_t *)(tramp + 0));
391     __put_user(TARGET_NR_sigreturn, (int32_t *)(tramp + 2));
392     __put_user(0x80cd, (uint16_t *)(tramp + 6));
393 }
394 
395 static void install_rt_sigtramp(void *tramp)
396 {
397     /* This is movl $syscall,%eax ; int $0x80 */
398     __put_user(0xb8, (uint8_t *)(tramp + 0));
399     __put_user(TARGET_NR_rt_sigreturn, (int32_t *)(tramp + 1));
400     __put_user(0x80cd, (uint16_t *)(tramp + 5));
401 }
402 
403 /* compare linux/arch/i386/kernel/signal.c:setup_frame() */
404 void setup_frame(int sig, struct target_sigaction *ka,
405                  target_sigset_t *set, CPUX86State *env)
406 {
407     abi_ulong frame_addr;
408     struct sigframe *frame;
409     int i;
410 
411     frame_addr = get_sigframe(ka, env, TARGET_SIGFRAME_FXSAVE_OFFSET);
412     trace_user_setup_frame(env, frame_addr);
413 
414     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
415         goto give_sigsegv;
416 
417     __put_user(sig, &frame->sig);
418 
419     setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0],
420             frame_addr + offsetof(struct sigframe, fpstate));
421 
422     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
423         __put_user(set->sig[i], &frame->extramask[i - 1]);
424     }
425 
426     /* Set up to return from userspace.  If provided, use a stub
427        already in userspace.  */
428     if (ka->sa_flags & TARGET_SA_RESTORER) {
429         __put_user(ka->sa_restorer, &frame->pretcode);
430     } else {
431         /* This is no longer used, but is retained for ABI compatibility. */
432         install_sigtramp(frame->retcode);
433         __put_user(default_sigreturn, &frame->pretcode);
434     }
435 
436     /* Set up registers for signal handler */
437     env->regs[R_ESP] = frame_addr;
438     env->eip = ka->_sa_handler;
439 
440     cpu_x86_load_seg(env, R_DS, __USER_DS);
441     cpu_x86_load_seg(env, R_ES, __USER_DS);
442     cpu_x86_load_seg(env, R_SS, __USER_DS);
443     cpu_x86_load_seg(env, R_CS, __USER_CS);
444     env->eflags &= ~TF_MASK;
445 
446     unlock_user_struct(frame, frame_addr, 1);
447 
448     return;
449 
450 give_sigsegv:
451     force_sigsegv(sig);
452 }
453 #endif
454 
455 /* compare linux/arch/x86/kernel/signal.c:setup_rt_frame() */
456 void setup_rt_frame(int sig, struct target_sigaction *ka,
457                     target_siginfo_t *info,
458                     target_sigset_t *set, CPUX86State *env)
459 {
460     abi_ulong frame_addr;
461 #ifndef TARGET_X86_64
462     abi_ulong addr;
463 #endif
464     struct rt_sigframe *frame;
465     int i;
466 
467     frame_addr = get_sigframe(ka, env, TARGET_RT_SIGFRAME_FXSAVE_OFFSET);
468     trace_user_setup_rt_frame(env, frame_addr);
469 
470     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
471         goto give_sigsegv;
472 
473     /* These fields are only in rt_sigframe on 32 bit */
474 #ifndef TARGET_X86_64
475     __put_user(sig, &frame->sig);
476     addr = frame_addr + offsetof(struct rt_sigframe, info);
477     __put_user(addr, &frame->pinfo);
478     addr = frame_addr + offsetof(struct rt_sigframe, uc);
479     __put_user(addr, &frame->puc);
480 #endif
481     if (ka->sa_flags & TARGET_SA_SIGINFO) {
482         tswap_siginfo(&frame->info, info);
483     }
484 
485     /* Create the ucontext.  */
486     if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) {
487         __put_user(1, &frame->uc.tuc_flags);
488     } else {
489         __put_user(0, &frame->uc.tuc_flags);
490     }
491     __put_user(0, &frame->uc.tuc_link);
492     target_save_altstack(&frame->uc.tuc_stack, env);
493     setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env,
494             set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate));
495 
496     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
497         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
498     }
499 
500     /* Set up to return from userspace.  If provided, use a stub
501        already in userspace.  */
502     if (ka->sa_flags & TARGET_SA_RESTORER) {
503         __put_user(ka->sa_restorer, &frame->pretcode);
504     } else {
505 #ifdef TARGET_X86_64
506         /* For x86_64, SA_RESTORER is required ABI.  */
507         goto give_sigsegv;
508 #else
509         /* This is no longer used, but is retained for ABI compatibility. */
510         install_rt_sigtramp(frame->retcode);
511         __put_user(default_rt_sigreturn, &frame->pretcode);
512 #endif
513     }
514 
515     /* Set up registers for signal handler */
516     env->regs[R_ESP] = frame_addr;
517     env->eip = ka->_sa_handler;
518 
519 #ifndef TARGET_X86_64
520     env->regs[R_EAX] = sig;
521     env->regs[R_EDX] = frame_addr + offsetof(struct rt_sigframe, info);
522     env->regs[R_ECX] = frame_addr + offsetof(struct rt_sigframe, uc);
523 #else
524     env->regs[R_EAX] = 0;
525     env->regs[R_EDI] = sig;
526     env->regs[R_ESI] = frame_addr + offsetof(struct rt_sigframe, info);
527     env->regs[R_EDX] = frame_addr + offsetof(struct rt_sigframe, uc);
528 #endif
529 
530     cpu_x86_load_seg(env, R_DS, __USER_DS);
531     cpu_x86_load_seg(env, R_ES, __USER_DS);
532     cpu_x86_load_seg(env, R_CS, __USER_CS);
533     cpu_x86_load_seg(env, R_SS, __USER_DS);
534     env->eflags &= ~TF_MASK;
535 
536     unlock_user_struct(frame, frame_addr, 1);
537 
538     return;
539 
540 give_sigsegv:
541     force_sigsegv(sig);
542 }
543 
544 static int xrstor_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave,
545                              abi_ulong fxsave_addr)
546 {
547     if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) {
548         uint32_t extended_size = tswapl(fxsave->sw_reserved.extended_size);
549         uint32_t xstate_size = tswapl(fxsave->sw_reserved.xstate_size);
550         uint32_t xfeatures_size = xstate_size - TARGET_FXSAVE_SIZE;
551 
552         /* Linux checks MAGIC2 using xstate_size, not extended_size.  */
553         if (tswapl(fxsave->sw_reserved.magic1) == TARGET_FP_XSTATE_MAGIC1 &&
554             extended_size >= TARGET_FPSTATE_FXSAVE_OFFSET + xstate_size + TARGET_FP_XSTATE_MAGIC2_SIZE) {
555             if (!access_ok(env_cpu(env), VERIFY_READ, fxsave_addr,
556                            extended_size - TARGET_FPSTATE_FXSAVE_OFFSET)) {
557                 return 1;
558             }
559             if (tswapl(*(uint32_t *) &fxsave->xfeatures[xfeatures_size]) == TARGET_FP_XSTATE_MAGIC2) {
560                 cpu_x86_xrstor(env, fxsave_addr);
561                 return 0;
562             }
563         }
564         /* fall through to fxrstor */
565     }
566 
567     cpu_x86_fxrstor(env, fxsave_addr);
568     return 0;
569 }
570 
571 static int
572 restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc)
573 {
574     int err = 1;
575     abi_ulong fpstate_addr;
576     unsigned int tmpflags;
577 
578 #ifndef TARGET_X86_64
579     cpu_x86_load_seg(env, R_GS, tswap16(sc->gs));
580     cpu_x86_load_seg(env, R_FS, tswap16(sc->fs));
581     cpu_x86_load_seg(env, R_ES, tswap16(sc->es));
582     cpu_x86_load_seg(env, R_DS, tswap16(sc->ds));
583 
584     env->regs[R_EDI] = tswapl(sc->edi);
585     env->regs[R_ESI] = tswapl(sc->esi);
586     env->regs[R_EBP] = tswapl(sc->ebp);
587     env->regs[R_ESP] = tswapl(sc->esp);
588     env->regs[R_EBX] = tswapl(sc->ebx);
589     env->regs[R_EDX] = tswapl(sc->edx);
590     env->regs[R_ECX] = tswapl(sc->ecx);
591     env->regs[R_EAX] = tswapl(sc->eax);
592 
593     env->eip = tswapl(sc->eip);
594 #else
595     env->regs[8] = tswapl(sc->r8);
596     env->regs[9] = tswapl(sc->r9);
597     env->regs[10] = tswapl(sc->r10);
598     env->regs[11] = tswapl(sc->r11);
599     env->regs[12] = tswapl(sc->r12);
600     env->regs[13] = tswapl(sc->r13);
601     env->regs[14] = tswapl(sc->r14);
602     env->regs[15] = tswapl(sc->r15);
603 
604     env->regs[R_EDI] = tswapl(sc->rdi);
605     env->regs[R_ESI] = tswapl(sc->rsi);
606     env->regs[R_EBP] = tswapl(sc->rbp);
607     env->regs[R_EBX] = tswapl(sc->rbx);
608     env->regs[R_EDX] = tswapl(sc->rdx);
609     env->regs[R_EAX] = tswapl(sc->rax);
610     env->regs[R_ECX] = tswapl(sc->rcx);
611     env->regs[R_ESP] = tswapl(sc->rsp);
612 
613     env->eip = tswapl(sc->rip);
614 #endif
615 
616     cpu_x86_load_seg(env, R_CS, lduw_p(&sc->cs) | 3);
617     cpu_x86_load_seg(env, R_SS, lduw_p(&sc->ss) | 3);
618 
619     tmpflags = tswapl(sc->eflags);
620     env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
621     //          regs->orig_eax = -1;            /* disable syscall checks */
622 
623     fpstate_addr = tswapl(sc->fpstate);
624     if (fpstate_addr != 0) {
625         struct target_fpstate *fpstate;
626         if (!lock_user_struct(VERIFY_READ, fpstate, fpstate_addr,
627                               sizeof(struct target_fpstate))) {
628             return err;
629         }
630 #ifndef TARGET_X86_64
631         if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) {
632             cpu_x86_frstor(env, fpstate_addr, 1);
633             err = 0;
634         } else {
635             err = xrstor_sigcontext(env, &fpstate->fxsave,
636                                     fpstate_addr + TARGET_FPSTATE_FXSAVE_OFFSET);
637         }
638 #else
639         err = xrstor_sigcontext(env, fpstate, fpstate_addr);
640 #endif
641         unlock_user_struct(fpstate, fpstate_addr, 0);
642     } else {
643         err = 0;
644     }
645 
646     return err;
647 }
648 
649 /* Note: there is no sigreturn on x86_64, there is only rt_sigreturn */
650 #ifndef TARGET_X86_64
651 long do_sigreturn(CPUX86State *env)
652 {
653     struct sigframe *frame;
654     abi_ulong frame_addr = env->regs[R_ESP] - 8;
655     target_sigset_t target_set;
656     sigset_t set;
657     int i;
658 
659     trace_user_do_sigreturn(env, frame_addr);
660     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
661         goto badframe;
662     /* set blocked signals */
663     __get_user(target_set.sig[0], &frame->sc.oldmask);
664     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
665         __get_user(target_set.sig[i], &frame->extramask[i - 1]);
666     }
667 
668     target_to_host_sigset_internal(&set, &target_set);
669     set_sigmask(&set);
670 
671     /* restore registers */
672     if (restore_sigcontext(env, &frame->sc))
673         goto badframe;
674     unlock_user_struct(frame, frame_addr, 0);
675     return -QEMU_ESIGRETURN;
676 
677 badframe:
678     unlock_user_struct(frame, frame_addr, 0);
679     force_sig(TARGET_SIGSEGV);
680     return -QEMU_ESIGRETURN;
681 }
682 #endif
683 
684 long do_rt_sigreturn(CPUX86State *env)
685 {
686     abi_ulong frame_addr;
687     struct rt_sigframe *frame;
688     sigset_t set;
689 
690     frame_addr = env->regs[R_ESP] - sizeof(abi_ulong);
691     trace_user_do_rt_sigreturn(env, frame_addr);
692     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
693         goto badframe;
694     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
695     set_sigmask(&set);
696 
697     if (restore_sigcontext(env, &frame->uc.tuc_mcontext)) {
698         goto badframe;
699     }
700 
701     target_restore_altstack(&frame->uc.tuc_stack, env);
702 
703     unlock_user_struct(frame, frame_addr, 0);
704     return -QEMU_ESIGRETURN;
705 
706 badframe:
707     unlock_user_struct(frame, frame_addr, 0);
708     force_sig(TARGET_SIGSEGV);
709     return -QEMU_ESIGRETURN;
710 }
711 
712 #ifndef TARGET_X86_64
713 void setup_sigtramp(abi_ulong sigtramp_page)
714 {
715     uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0);
716     assert(tramp != NULL);
717 
718     default_sigreturn = sigtramp_page;
719     install_sigtramp(tramp);
720 
721     default_rt_sigreturn = sigtramp_page + 8;
722     install_rt_sigtramp(tramp + 8);
723 
724     unlock_user(tramp, sigtramp_page, 2 * 8);
725 }
726 #endif
727