xref: /openbmc/qemu/linux-user/i386/signal.c (revision 259ebed4)
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 
218 /*
219  * Verify that vdso-asmoffset.h constants match.
220  */
221 #include "i386/vdso-asmoffset.h"
222 
223 QEMU_BUILD_BUG_ON(offsetof(struct sigframe, sc.eip)
224                   != SIGFRAME_SIGCONTEXT_eip);
225 QEMU_BUILD_BUG_ON(offsetof(struct rt_sigframe, uc.tuc_mcontext.eip)
226                   != RT_SIGFRAME_SIGCONTEXT_eip);
227 
228 #else
229 
230 struct rt_sigframe {
231     abi_ulong pretcode;
232     struct target_ucontext uc;
233     struct target_siginfo info;
234     struct target_fpstate fpstate QEMU_ALIGNED(16);
235 };
236 #define TARGET_RT_SIGFRAME_FXSAVE_OFFSET (                                 \
237     offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET)
238 #endif
239 
240 /*
241  * Set up a signal frame.
242  */
243 
244 static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave,
245                              abi_ulong fxsave_addr)
246 {
247     if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) {
248         /* fxsave_addr must be 16 byte aligned for fxsave */
249         assert(!(fxsave_addr & 0xf));
250 
251         cpu_x86_fxsave(env, fxsave_addr);
252         __put_user(0, &fxsave->sw_reserved.magic1);
253     } else {
254         uint32_t xstate_size = xsave_area_size(env->xcr0, false);
255         uint32_t xfeatures_size = xstate_size - TARGET_FXSAVE_SIZE;
256 
257         /*
258          * extended_size is the offset from fpstate_addr to right after the end
259          * of the extended save states.  On 32-bit that includes the legacy
260          * FSAVE area.
261          */
262         uint32_t extended_size = TARGET_FPSTATE_FXSAVE_OFFSET
263             + xstate_size + TARGET_FP_XSTATE_MAGIC2_SIZE;
264 
265         /* fxsave_addr must be 64 byte aligned for xsave */
266         assert(!(fxsave_addr & 0x3f));
267 
268         /* Zero the header, XSAVE *adds* features to an existing save state.  */
269         memset(fxsave->xfeatures, 0, 64);
270         cpu_x86_xsave(env, fxsave_addr);
271         __put_user(TARGET_FP_XSTATE_MAGIC1, &fxsave->sw_reserved.magic1);
272         __put_user(extended_size, &fxsave->sw_reserved.extended_size);
273         __put_user(env->xcr0, &fxsave->sw_reserved.xfeatures);
274         __put_user(xstate_size, &fxsave->sw_reserved.xstate_size);
275         __put_user(TARGET_FP_XSTATE_MAGIC2, (uint32_t *) &fxsave->xfeatures[xfeatures_size]);
276     }
277 }
278 
279 static void setup_sigcontext(struct target_sigcontext *sc,
280         struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask,
281         abi_ulong fpstate_addr)
282 {
283     CPUState *cs = env_cpu(env);
284 #ifndef TARGET_X86_64
285     uint16_t magic;
286 
287     /* already locked in setup_frame() */
288     __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
289     __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
290     __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
291     __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
292     __put_user(env->regs[R_EDI], &sc->edi);
293     __put_user(env->regs[R_ESI], &sc->esi);
294     __put_user(env->regs[R_EBP], &sc->ebp);
295     __put_user(env->regs[R_ESP], &sc->esp);
296     __put_user(env->regs[R_EBX], &sc->ebx);
297     __put_user(env->regs[R_EDX], &sc->edx);
298     __put_user(env->regs[R_ECX], &sc->ecx);
299     __put_user(env->regs[R_EAX], &sc->eax);
300     __put_user(cs->exception_index, &sc->trapno);
301     __put_user(env->error_code, &sc->err);
302     __put_user(env->eip, &sc->eip);
303     __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
304     __put_user(env->eflags, &sc->eflags);
305     __put_user(env->regs[R_ESP], &sc->esp_at_signal);
306     __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
307 
308     cpu_x86_fsave(env, fpstate_addr, 1);
309     fpstate->status = fpstate->sw;
310     if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) {
311         magic = 0xffff;
312     } else {
313         xsave_sigcontext(env, &fpstate->fxsave,
314                          fpstate_addr + TARGET_FPSTATE_FXSAVE_OFFSET);
315         magic = 0;
316     }
317     __put_user(magic, &fpstate->magic);
318 #else
319     __put_user(env->regs[R_EDI], &sc->rdi);
320     __put_user(env->regs[R_ESI], &sc->rsi);
321     __put_user(env->regs[R_EBP], &sc->rbp);
322     __put_user(env->regs[R_ESP], &sc->rsp);
323     __put_user(env->regs[R_EBX], &sc->rbx);
324     __put_user(env->regs[R_EDX], &sc->rdx);
325     __put_user(env->regs[R_ECX], &sc->rcx);
326     __put_user(env->regs[R_EAX], &sc->rax);
327 
328     __put_user(env->regs[8], &sc->r8);
329     __put_user(env->regs[9], &sc->r9);
330     __put_user(env->regs[10], &sc->r10);
331     __put_user(env->regs[11], &sc->r11);
332     __put_user(env->regs[12], &sc->r12);
333     __put_user(env->regs[13], &sc->r13);
334     __put_user(env->regs[14], &sc->r14);
335     __put_user(env->regs[15], &sc->r15);
336 
337     __put_user(cs->exception_index, &sc->trapno);
338     __put_user(env->error_code, &sc->err);
339     __put_user(env->eip, &sc->rip);
340 
341     __put_user(env->eflags, &sc->eflags);
342     __put_user(env->segs[R_CS].selector, &sc->cs);
343     __put_user((uint16_t)0, &sc->gs);
344     __put_user((uint16_t)0, &sc->fs);
345     __put_user(env->segs[R_SS].selector, &sc->ss);
346 
347     xsave_sigcontext(env, fpstate, fpstate_addr);
348 #endif
349 
350     __put_user(fpstate_addr, &sc->fpstate);
351 
352     /* non-iBCS2 extensions.. */
353     __put_user(mask, &sc->oldmask);
354     __put_user(env->cr[2], &sc->cr2);
355 }
356 
357 /*
358  * Determine which stack to use..
359  */
360 
361 static inline abi_ulong
362 get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset)
363 {
364     unsigned long esp;
365 
366     /* Default to using normal stack */
367     esp = get_sp_from_cpustate(env);
368 #ifdef TARGET_X86_64
369     esp -= 128; /* this is the redzone */
370 #endif
371 
372     /* This is the X/Open sanctioned signal stack switching.  */
373     if (ka->sa_flags & TARGET_SA_ONSTACK) {
374         esp = target_sigsp(esp, ka);
375     } else {
376 #ifndef TARGET_X86_64
377         /* This is the legacy signal stack switching. */
378         if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
379                 !(ka->sa_flags & TARGET_SA_RESTORER) &&
380                 ka->sa_restorer) {
381             esp = (unsigned long) ka->sa_restorer;
382         }
383 #endif
384     }
385 
386     if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) {
387         return (esp - (fxsave_offset + TARGET_FXSAVE_SIZE)) & -8ul;
388     } else if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) {
389         return ((esp - TARGET_FXSAVE_SIZE) & -16ul) - fxsave_offset;
390     } else {
391         size_t xstate_size =
392                xsave_area_size(env->xcr0, false) + TARGET_FP_XSTATE_MAGIC2_SIZE;
393         return ((esp - xstate_size) & -64ul) - fxsave_offset;
394     }
395 }
396 
397 #ifndef TARGET_X86_64
398 static void install_sigtramp(void *tramp)
399 {
400     /* This is popl %eax ; movl $syscall,%eax ; int $0x80 */
401     __put_user(0xb858, (uint16_t *)(tramp + 0));
402     __put_user(TARGET_NR_sigreturn, (int32_t *)(tramp + 2));
403     __put_user(0x80cd, (uint16_t *)(tramp + 6));
404 }
405 
406 static void install_rt_sigtramp(void *tramp)
407 {
408     /* This is movl $syscall,%eax ; int $0x80 */
409     __put_user(0xb8, (uint8_t *)(tramp + 0));
410     __put_user(TARGET_NR_rt_sigreturn, (int32_t *)(tramp + 1));
411     __put_user(0x80cd, (uint16_t *)(tramp + 5));
412 }
413 
414 /* compare linux/arch/i386/kernel/signal.c:setup_frame() */
415 void setup_frame(int sig, struct target_sigaction *ka,
416                  target_sigset_t *set, CPUX86State *env)
417 {
418     abi_ulong frame_addr;
419     struct sigframe *frame;
420     int i;
421 
422     frame_addr = get_sigframe(ka, env, TARGET_SIGFRAME_FXSAVE_OFFSET);
423     trace_user_setup_frame(env, frame_addr);
424 
425     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
426         goto give_sigsegv;
427 
428     __put_user(sig, &frame->sig);
429 
430     setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0],
431             frame_addr + offsetof(struct sigframe, fpstate));
432 
433     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
434         __put_user(set->sig[i], &frame->extramask[i - 1]);
435     }
436 
437     /* Set up to return from userspace.  If provided, use a stub
438        already in userspace.  */
439     if (ka->sa_flags & TARGET_SA_RESTORER) {
440         __put_user(ka->sa_restorer, &frame->pretcode);
441     } else {
442         /* This is no longer used, but is retained for ABI compatibility. */
443         install_sigtramp(frame->retcode);
444         __put_user(default_sigreturn, &frame->pretcode);
445     }
446 
447     /* Set up registers for signal handler */
448     env->regs[R_ESP] = frame_addr;
449     env->eip = ka->_sa_handler;
450 
451     cpu_x86_load_seg(env, R_DS, __USER_DS);
452     cpu_x86_load_seg(env, R_ES, __USER_DS);
453     cpu_x86_load_seg(env, R_SS, __USER_DS);
454     cpu_x86_load_seg(env, R_CS, __USER_CS);
455     env->eflags &= ~TF_MASK;
456 
457     unlock_user_struct(frame, frame_addr, 1);
458 
459     return;
460 
461 give_sigsegv:
462     force_sigsegv(sig);
463 }
464 #endif
465 
466 /* compare linux/arch/x86/kernel/signal.c:setup_rt_frame() */
467 void setup_rt_frame(int sig, struct target_sigaction *ka,
468                     target_siginfo_t *info,
469                     target_sigset_t *set, CPUX86State *env)
470 {
471     abi_ulong frame_addr;
472 #ifndef TARGET_X86_64
473     abi_ulong addr;
474 #endif
475     struct rt_sigframe *frame;
476     int i;
477 
478     frame_addr = get_sigframe(ka, env, TARGET_RT_SIGFRAME_FXSAVE_OFFSET);
479     trace_user_setup_rt_frame(env, frame_addr);
480 
481     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
482         goto give_sigsegv;
483 
484     /* These fields are only in rt_sigframe on 32 bit */
485 #ifndef TARGET_X86_64
486     __put_user(sig, &frame->sig);
487     addr = frame_addr + offsetof(struct rt_sigframe, info);
488     __put_user(addr, &frame->pinfo);
489     addr = frame_addr + offsetof(struct rt_sigframe, uc);
490     __put_user(addr, &frame->puc);
491 #endif
492     if (ka->sa_flags & TARGET_SA_SIGINFO) {
493         tswap_siginfo(&frame->info, info);
494     }
495 
496     /* Create the ucontext.  */
497     if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) {
498         __put_user(1, &frame->uc.tuc_flags);
499     } else {
500         __put_user(0, &frame->uc.tuc_flags);
501     }
502     __put_user(0, &frame->uc.tuc_link);
503     target_save_altstack(&frame->uc.tuc_stack, env);
504     setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env,
505             set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate));
506 
507     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
508         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
509     }
510 
511     /* Set up to return from userspace.  If provided, use a stub
512        already in userspace.  */
513     if (ka->sa_flags & TARGET_SA_RESTORER) {
514         __put_user(ka->sa_restorer, &frame->pretcode);
515     } else {
516 #ifdef TARGET_X86_64
517         /* For x86_64, SA_RESTORER is required ABI.  */
518         goto give_sigsegv;
519 #else
520         /* This is no longer used, but is retained for ABI compatibility. */
521         install_rt_sigtramp(frame->retcode);
522         __put_user(default_rt_sigreturn, &frame->pretcode);
523 #endif
524     }
525 
526     /* Set up registers for signal handler */
527     env->regs[R_ESP] = frame_addr;
528     env->eip = ka->_sa_handler;
529 
530 #ifndef TARGET_X86_64
531     env->regs[R_EAX] = sig;
532     env->regs[R_EDX] = frame_addr + offsetof(struct rt_sigframe, info);
533     env->regs[R_ECX] = frame_addr + offsetof(struct rt_sigframe, uc);
534 #else
535     env->regs[R_EAX] = 0;
536     env->regs[R_EDI] = sig;
537     env->regs[R_ESI] = frame_addr + offsetof(struct rt_sigframe, info);
538     env->regs[R_EDX] = frame_addr + offsetof(struct rt_sigframe, uc);
539 #endif
540 
541     cpu_x86_load_seg(env, R_DS, __USER_DS);
542     cpu_x86_load_seg(env, R_ES, __USER_DS);
543     cpu_x86_load_seg(env, R_CS, __USER_CS);
544     cpu_x86_load_seg(env, R_SS, __USER_DS);
545     env->eflags &= ~TF_MASK;
546 
547     unlock_user_struct(frame, frame_addr, 1);
548 
549     return;
550 
551 give_sigsegv:
552     force_sigsegv(sig);
553 }
554 
555 static int xrstor_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave,
556                              abi_ulong fxsave_addr)
557 {
558     if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) {
559         uint32_t extended_size = tswapl(fxsave->sw_reserved.extended_size);
560         uint32_t xstate_size = tswapl(fxsave->sw_reserved.xstate_size);
561         uint32_t xfeatures_size = xstate_size - TARGET_FXSAVE_SIZE;
562 
563         /* Linux checks MAGIC2 using xstate_size, not extended_size.  */
564         if (tswapl(fxsave->sw_reserved.magic1) == TARGET_FP_XSTATE_MAGIC1 &&
565             extended_size >= TARGET_FPSTATE_FXSAVE_OFFSET + xstate_size + TARGET_FP_XSTATE_MAGIC2_SIZE) {
566             if (!access_ok(env_cpu(env), VERIFY_READ, fxsave_addr,
567                            extended_size - TARGET_FPSTATE_FXSAVE_OFFSET)) {
568                 return 1;
569             }
570             if (tswapl(*(uint32_t *) &fxsave->xfeatures[xfeatures_size]) == TARGET_FP_XSTATE_MAGIC2) {
571                 cpu_x86_xrstor(env, fxsave_addr);
572                 return 0;
573             }
574         }
575         /* fall through to fxrstor */
576     }
577 
578     cpu_x86_fxrstor(env, fxsave_addr);
579     return 0;
580 }
581 
582 static int
583 restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc)
584 {
585     int err = 1;
586     abi_ulong fpstate_addr;
587     unsigned int tmpflags;
588 
589 #ifndef TARGET_X86_64
590     cpu_x86_load_seg(env, R_GS, tswap16(sc->gs));
591     cpu_x86_load_seg(env, R_FS, tswap16(sc->fs));
592     cpu_x86_load_seg(env, R_ES, tswap16(sc->es));
593     cpu_x86_load_seg(env, R_DS, tswap16(sc->ds));
594 
595     env->regs[R_EDI] = tswapl(sc->edi);
596     env->regs[R_ESI] = tswapl(sc->esi);
597     env->regs[R_EBP] = tswapl(sc->ebp);
598     env->regs[R_ESP] = tswapl(sc->esp);
599     env->regs[R_EBX] = tswapl(sc->ebx);
600     env->regs[R_EDX] = tswapl(sc->edx);
601     env->regs[R_ECX] = tswapl(sc->ecx);
602     env->regs[R_EAX] = tswapl(sc->eax);
603 
604     env->eip = tswapl(sc->eip);
605 #else
606     env->regs[8] = tswapl(sc->r8);
607     env->regs[9] = tswapl(sc->r9);
608     env->regs[10] = tswapl(sc->r10);
609     env->regs[11] = tswapl(sc->r11);
610     env->regs[12] = tswapl(sc->r12);
611     env->regs[13] = tswapl(sc->r13);
612     env->regs[14] = tswapl(sc->r14);
613     env->regs[15] = tswapl(sc->r15);
614 
615     env->regs[R_EDI] = tswapl(sc->rdi);
616     env->regs[R_ESI] = tswapl(sc->rsi);
617     env->regs[R_EBP] = tswapl(sc->rbp);
618     env->regs[R_EBX] = tswapl(sc->rbx);
619     env->regs[R_EDX] = tswapl(sc->rdx);
620     env->regs[R_EAX] = tswapl(sc->rax);
621     env->regs[R_ECX] = tswapl(sc->rcx);
622     env->regs[R_ESP] = tswapl(sc->rsp);
623 
624     env->eip = tswapl(sc->rip);
625 #endif
626 
627     cpu_x86_load_seg(env, R_CS, lduw_p(&sc->cs) | 3);
628     cpu_x86_load_seg(env, R_SS, lduw_p(&sc->ss) | 3);
629 
630     tmpflags = tswapl(sc->eflags);
631     env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
632     //          regs->orig_eax = -1;            /* disable syscall checks */
633 
634     fpstate_addr = tswapl(sc->fpstate);
635     if (fpstate_addr != 0) {
636         struct target_fpstate *fpstate;
637         if (!lock_user_struct(VERIFY_READ, fpstate, fpstate_addr,
638                               sizeof(struct target_fpstate))) {
639             return err;
640         }
641 #ifndef TARGET_X86_64
642         if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) {
643             cpu_x86_frstor(env, fpstate_addr, 1);
644             err = 0;
645         } else {
646             err = xrstor_sigcontext(env, &fpstate->fxsave,
647                                     fpstate_addr + TARGET_FPSTATE_FXSAVE_OFFSET);
648         }
649 #else
650         err = xrstor_sigcontext(env, fpstate, fpstate_addr);
651 #endif
652         unlock_user_struct(fpstate, fpstate_addr, 0);
653     } else {
654         err = 0;
655     }
656 
657     return err;
658 }
659 
660 /* Note: there is no sigreturn on x86_64, there is only rt_sigreturn */
661 #ifndef TARGET_X86_64
662 long do_sigreturn(CPUX86State *env)
663 {
664     struct sigframe *frame;
665     abi_ulong frame_addr = env->regs[R_ESP] - 8;
666     target_sigset_t target_set;
667     sigset_t set;
668     int i;
669 
670     trace_user_do_sigreturn(env, frame_addr);
671     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
672         goto badframe;
673     /* set blocked signals */
674     __get_user(target_set.sig[0], &frame->sc.oldmask);
675     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
676         __get_user(target_set.sig[i], &frame->extramask[i - 1]);
677     }
678 
679     target_to_host_sigset_internal(&set, &target_set);
680     set_sigmask(&set);
681 
682     /* restore registers */
683     if (restore_sigcontext(env, &frame->sc))
684         goto badframe;
685     unlock_user_struct(frame, frame_addr, 0);
686     return -QEMU_ESIGRETURN;
687 
688 badframe:
689     unlock_user_struct(frame, frame_addr, 0);
690     force_sig(TARGET_SIGSEGV);
691     return -QEMU_ESIGRETURN;
692 }
693 #endif
694 
695 long do_rt_sigreturn(CPUX86State *env)
696 {
697     abi_ulong frame_addr;
698     struct rt_sigframe *frame;
699     sigset_t set;
700 
701     frame_addr = env->regs[R_ESP] - sizeof(abi_ulong);
702     trace_user_do_rt_sigreturn(env, frame_addr);
703     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
704         goto badframe;
705     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
706     set_sigmask(&set);
707 
708     if (restore_sigcontext(env, &frame->uc.tuc_mcontext)) {
709         goto badframe;
710     }
711 
712     target_restore_altstack(&frame->uc.tuc_stack, env);
713 
714     unlock_user_struct(frame, frame_addr, 0);
715     return -QEMU_ESIGRETURN;
716 
717 badframe:
718     unlock_user_struct(frame, frame_addr, 0);
719     force_sig(TARGET_SIGSEGV);
720     return -QEMU_ESIGRETURN;
721 }
722 
723 #ifndef TARGET_X86_64
724 void setup_sigtramp(abi_ulong sigtramp_page)
725 {
726     uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0);
727     assert(tramp != NULL);
728 
729     default_sigreturn = sigtramp_page;
730     install_sigtramp(tramp);
731 
732     default_rt_sigreturn = sigtramp_page + 8;
733     install_rt_sigtramp(tramp + 8);
734 
735     unlock_user(tramp, sigtramp_page, 2 * 8);
736 }
737 #endif
738