xref: /qemu/linux-user/signal.c (revision 9e5f5284b3b452ace0097c5171d369be46847e74)
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, write to the Free Software
18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 #include <stdlib.h>
21 #include <stdio.h>
22 #include <string.h>
23 #include <stdarg.h>
24 #include <unistd.h>
25 #include <signal.h>
26 #include <errno.h>
27 #include <sys/ucontext.h>
28 
29 #ifdef __ia64__
30 #undef uc_mcontext
31 #undef uc_sigmask
32 #undef uc_stack
33 #undef uc_link
34 #endif
35 
36 #include "qemu.h"
37 
38 //#define DEBUG_SIGNAL
39 
40 #define MAX_SIGQUEUE_SIZE 1024
41 
42 struct sigqueue {
43     struct sigqueue *next;
44     target_siginfo_t info;
45 };
46 
47 struct emulated_sigaction {
48     struct target_sigaction sa;
49     int pending; /* true if signal is pending */
50     struct sigqueue *first;
51     struct sigqueue info; /* in order to always have memory for the
52                              first signal, we put it here */
53 };
54 
55 static struct emulated_sigaction sigact_table[TARGET_NSIG];
56 static struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
57 static struct sigqueue *first_free; /* first free siginfo queue entry */
58 static int signal_pending; /* non zero if a signal may be pending */
59 
60 static void host_signal_handler(int host_signum, siginfo_t *info,
61                                 void *puc);
62 
63 static uint8_t host_to_target_signal_table[65] = {
64     [SIGHUP] = TARGET_SIGHUP,
65     [SIGINT] = TARGET_SIGINT,
66     [SIGQUIT] = TARGET_SIGQUIT,
67     [SIGILL] = TARGET_SIGILL,
68     [SIGTRAP] = TARGET_SIGTRAP,
69     [SIGABRT] = TARGET_SIGABRT,
70     [SIGIOT] = TARGET_SIGIOT,
71     [SIGBUS] = TARGET_SIGBUS,
72     [SIGFPE] = TARGET_SIGFPE,
73     [SIGKILL] = TARGET_SIGKILL,
74     [SIGUSR1] = TARGET_SIGUSR1,
75     [SIGSEGV] = TARGET_SIGSEGV,
76     [SIGUSR2] = TARGET_SIGUSR2,
77     [SIGPIPE] = TARGET_SIGPIPE,
78     [SIGALRM] = TARGET_SIGALRM,
79     [SIGTERM] = TARGET_SIGTERM,
80 #ifdef SIGSTKFLT
81     [SIGSTKFLT] = TARGET_SIGSTKFLT,
82 #endif
83     [SIGCHLD] = TARGET_SIGCHLD,
84     [SIGCONT] = TARGET_SIGCONT,
85     [SIGSTOP] = TARGET_SIGSTOP,
86     [SIGTSTP] = TARGET_SIGTSTP,
87     [SIGTTIN] = TARGET_SIGTTIN,
88     [SIGTTOU] = TARGET_SIGTTOU,
89     [SIGURG] = TARGET_SIGURG,
90     [SIGXCPU] = TARGET_SIGXCPU,
91     [SIGXFSZ] = TARGET_SIGXFSZ,
92     [SIGVTALRM] = TARGET_SIGVTALRM,
93     [SIGPROF] = TARGET_SIGPROF,
94     [SIGWINCH] = TARGET_SIGWINCH,
95     [SIGIO] = TARGET_SIGIO,
96     [SIGPWR] = TARGET_SIGPWR,
97     [SIGSYS] = TARGET_SIGSYS,
98     /* next signals stay the same */
99 };
100 static uint8_t target_to_host_signal_table[65];
101 
102 static inline int host_to_target_signal(int sig)
103 {
104     return host_to_target_signal_table[sig];
105 }
106 
107 static inline int target_to_host_signal(int sig)
108 {
109     return target_to_host_signal_table[sig];
110 }
111 
112 void host_to_target_sigset(target_sigset_t *d, const sigset_t *s)
113 {
114     int i;
115     unsigned long sigmask;
116     uint32_t target_sigmask;
117 
118     sigmask = ((unsigned long *)s)[0];
119     target_sigmask = 0;
120     for(i = 0; i < 32; i++) {
121         if (sigmask & (1 << i))
122             target_sigmask |= 1 << (host_to_target_signal(i + 1) - 1);
123     }
124 #if TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 32
125     d->sig[0] = tswapl(target_sigmask);
126     for(i = 1;i < TARGET_NSIG_WORDS; i++) {
127         d->sig[i] = tswapl(((unsigned long *)s)[i]);
128     }
129 #elif TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 64 && TARGET_NSIG_WORDS == 2
130     d->sig[0] = tswapl(target_sigmask);
131     d->sig[1] = tswapl(sigmask >> 32);
132 #else
133 #error host_to_target_sigset
134 #endif
135 }
136 
137 void target_to_host_sigset(sigset_t *d, const target_sigset_t *s)
138 {
139     int i;
140     unsigned long sigmask;
141     target_ulong target_sigmask;
142 
143     target_sigmask = tswapl(s->sig[0]);
144     sigmask = 0;
145     for(i = 0; i < 32; i++) {
146         if (target_sigmask & (1 << i))
147             sigmask |= 1 << (target_to_host_signal(i + 1) - 1);
148     }
149 #if TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 32
150     ((unsigned long *)d)[0] = sigmask;
151     for(i = 1;i < TARGET_NSIG_WORDS; i++) {
152         ((unsigned long *)d)[i] = tswapl(s->sig[i]);
153     }
154 #elif TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 64 && TARGET_NSIG_WORDS == 2
155     ((unsigned long *)d)[0] = sigmask | (tswapl(s->sig[1]) << 32);
156 #else
157 #error target_to_host_sigset
158 #endif /* TARGET_LONG_BITS */
159 }
160 
161 void host_to_target_old_sigset(target_ulong *old_sigset,
162                                const sigset_t *sigset)
163 {
164     target_sigset_t d;
165     host_to_target_sigset(&d, sigset);
166     *old_sigset = d.sig[0];
167 }
168 
169 void target_to_host_old_sigset(sigset_t *sigset,
170                                const target_ulong *old_sigset)
171 {
172     target_sigset_t d;
173     int i;
174 
175     d.sig[0] = *old_sigset;
176     for(i = 1;i < TARGET_NSIG_WORDS; i++)
177         d.sig[i] = 0;
178     target_to_host_sigset(sigset, &d);
179 }
180 
181 /* siginfo conversion */
182 
183 static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
184                                                  const siginfo_t *info)
185 {
186     int sig;
187     sig = host_to_target_signal(info->si_signo);
188     tinfo->si_signo = sig;
189     tinfo->si_errno = 0;
190     tinfo->si_code = 0;
191     if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV ||
192         sig == SIGBUS || sig == SIGTRAP) {
193         /* should never come here, but who knows. The information for
194            the target is irrelevant */
195         tinfo->_sifields._sigfault._addr = 0;
196     } else if (sig >= TARGET_SIGRTMIN) {
197         tinfo->_sifields._rt._pid = info->si_pid;
198         tinfo->_sifields._rt._uid = info->si_uid;
199         /* XXX: potential problem if 64 bit */
200         tinfo->_sifields._rt._sigval.sival_ptr =
201             (target_ulong)info->si_value.sival_ptr;
202     }
203 }
204 
205 static void tswap_siginfo(target_siginfo_t *tinfo,
206                           const target_siginfo_t *info)
207 {
208     int sig;
209     sig = info->si_signo;
210     tinfo->si_signo = tswap32(sig);
211     tinfo->si_errno = tswap32(info->si_errno);
212     tinfo->si_code = tswap32(info->si_code);
213     if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV ||
214         sig == SIGBUS || sig == SIGTRAP) {
215         tinfo->_sifields._sigfault._addr =
216             tswapl(info->_sifields._sigfault._addr);
217     } else if (sig >= TARGET_SIGRTMIN) {
218         tinfo->_sifields._rt._pid = tswap32(info->_sifields._rt._pid);
219         tinfo->_sifields._rt._uid = tswap32(info->_sifields._rt._uid);
220         tinfo->_sifields._rt._sigval.sival_ptr =
221             tswapl(info->_sifields._rt._sigval.sival_ptr);
222     }
223 }
224 
225 
226 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
227 {
228     host_to_target_siginfo_noswap(tinfo, info);
229     tswap_siginfo(tinfo, tinfo);
230 }
231 
232 /* XXX: we support only POSIX RT signals are used. */
233 /* XXX: find a solution for 64 bit (additionnal malloced data is needed) */
234 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
235 {
236     info->si_signo = tswap32(tinfo->si_signo);
237     info->si_errno = tswap32(tinfo->si_errno);
238     info->si_code = tswap32(tinfo->si_code);
239     info->si_pid = tswap32(tinfo->_sifields._rt._pid);
240     info->si_uid = tswap32(tinfo->_sifields._rt._uid);
241     info->si_value.sival_ptr =
242         (void *)tswapl(tinfo->_sifields._rt._sigval.sival_ptr);
243 }
244 
245 void signal_init(void)
246 {
247     struct sigaction act;
248     int i, j;
249 
250     /* generate signal conversion tables */
251     for(i = 1; i <= 64; i++) {
252         if (host_to_target_signal_table[i] == 0)
253             host_to_target_signal_table[i] = i;
254     }
255     for(i = 1; i <= 64; i++) {
256         j = host_to_target_signal_table[i];
257         target_to_host_signal_table[j] = i;
258     }
259 
260     /* set all host signal handlers. ALL signals are blocked during
261        the handlers to serialize them. */
262     sigfillset(&act.sa_mask);
263     act.sa_flags = SA_SIGINFO;
264     act.sa_sigaction = host_signal_handler;
265     for(i = 1; i < NSIG; i++) {
266         sigaction(i, &act, NULL);
267     }
268 
269     memset(sigact_table, 0, sizeof(sigact_table));
270 
271     first_free = &sigqueue_table[0];
272     for(i = 0; i < MAX_SIGQUEUE_SIZE - 1; i++)
273         sigqueue_table[i].next = &sigqueue_table[i + 1];
274     sigqueue_table[MAX_SIGQUEUE_SIZE - 1].next = NULL;
275 }
276 
277 /* signal queue handling */
278 
279 static inline struct sigqueue *alloc_sigqueue(void)
280 {
281     struct sigqueue *q = first_free;
282     if (!q)
283         return NULL;
284     first_free = q->next;
285     return q;
286 }
287 
288 static inline void free_sigqueue(struct sigqueue *q)
289 {
290     q->next = first_free;
291     first_free = q;
292 }
293 
294 /* abort execution with signal */
295 void __attribute((noreturn)) force_sig(int sig)
296 {
297     int host_sig;
298     host_sig = target_to_host_signal(sig);
299     fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n",
300             sig, strsignal(host_sig));
301 #if 1
302     _exit(-host_sig);
303 #else
304     {
305         struct sigaction act;
306         sigemptyset(&act.sa_mask);
307         act.sa_flags = SA_SIGINFO;
308         act.sa_sigaction = SIG_DFL;
309         sigaction(SIGABRT, &act, NULL);
310         abort();
311     }
312 #endif
313 }
314 
315 /* queue a signal so that it will be send to the virtual CPU as soon
316    as possible */
317 int queue_signal(int sig, target_siginfo_t *info)
318 {
319     struct emulated_sigaction *k;
320     struct sigqueue *q, **pq;
321     target_ulong handler;
322 
323 #if defined(DEBUG_SIGNAL)
324     fprintf(stderr, "queue_signal: sig=%d\n",
325             sig);
326 #endif
327     k = &sigact_table[sig - 1];
328     handler = k->sa._sa_handler;
329     if (handler == TARGET_SIG_DFL) {
330         /* default handler : ignore some signal. The other are fatal */
331         if (sig != TARGET_SIGCHLD &&
332             sig != TARGET_SIGURG &&
333             sig != TARGET_SIGWINCH) {
334             force_sig(sig);
335         } else {
336             return 0; /* indicate ignored */
337         }
338     } else if (handler == TARGET_SIG_IGN) {
339         /* ignore signal */
340         return 0;
341     } else if (handler == TARGET_SIG_ERR) {
342         force_sig(sig);
343     } else {
344         pq = &k->first;
345         if (sig < TARGET_SIGRTMIN) {
346             /* if non real time signal, we queue exactly one signal */
347             if (!k->pending)
348                 q = &k->info;
349             else
350                 return 0;
351         } else {
352             if (!k->pending) {
353                 /* first signal */
354                 q = &k->info;
355             } else {
356                 q = alloc_sigqueue();
357                 if (!q)
358                     return -EAGAIN;
359                 while (*pq != NULL)
360                     pq = &(*pq)->next;
361             }
362         }
363         *pq = q;
364         q->info = *info;
365         q->next = NULL;
366         k->pending = 1;
367         /* signal that a new signal is pending */
368         signal_pending = 1;
369         return 1; /* indicates that the signal was queued */
370     }
371 }
372 
373 #if defined(DEBUG_SIGNAL)
374 #ifdef __i386__
375 static void dump_regs(struct ucontext *uc)
376 {
377     fprintf(stderr,
378             "EAX=%08x EBX=%08x ECX=%08x EDX=%08x\n"
379             "ESI=%08x EDI=%08x EBP=%08x ESP=%08x\n"
380             "EFL=%08x EIP=%08x\n",
381             uc->uc_mcontext.gregs[EAX],
382             uc->uc_mcontext.gregs[EBX],
383             uc->uc_mcontext.gregs[ECX],
384             uc->uc_mcontext.gregs[EDX],
385             uc->uc_mcontext.gregs[ESI],
386             uc->uc_mcontext.gregs[EDI],
387             uc->uc_mcontext.gregs[EBP],
388             uc->uc_mcontext.gregs[ESP],
389             uc->uc_mcontext.gregs[EFL],
390             uc->uc_mcontext.gregs[EIP]);
391 }
392 #else
393 static void dump_regs(struct ucontext *uc)
394 {
395 }
396 #endif
397 
398 #endif
399 
400 static void host_signal_handler(int host_signum, siginfo_t *info,
401                                 void *puc)
402 {
403     int sig;
404     target_siginfo_t tinfo;
405 
406     /* the CPU emulator uses some host signals to detect exceptions,
407        we we forward to it some signals */
408     if (host_signum == SIGSEGV || host_signum == SIGBUS) {
409         if (cpu_signal_handler(host_signum, info, puc))
410             return;
411     }
412 
413     /* get target signal number */
414     sig = host_to_target_signal(host_signum);
415     if (sig < 1 || sig > TARGET_NSIG)
416         return;
417 #if defined(DEBUG_SIGNAL)
418     fprintf(stderr, "qemu: got signal %d\n", sig);
419     dump_regs(puc);
420 #endif
421     host_to_target_siginfo_noswap(&tinfo, info);
422     if (queue_signal(sig, &tinfo) == 1) {
423         /* interrupt the virtual CPU as soon as possible */
424         cpu_interrupt(global_env, CPU_INTERRUPT_EXIT);
425     }
426 }
427 
428 int do_sigaction(int sig, const struct target_sigaction *act,
429                  struct target_sigaction *oact)
430 {
431     struct emulated_sigaction *k;
432 
433     if (sig < 1 || sig > TARGET_NSIG)
434         return -EINVAL;
435     k = &sigact_table[sig - 1];
436 #if defined(DEBUG_SIGNAL) && 0
437     fprintf(stderr, "sigaction sig=%d act=0x%08x, oact=0x%08x\n",
438             sig, (int)act, (int)oact);
439 #endif
440     if (oact) {
441         oact->_sa_handler = tswapl(k->sa._sa_handler);
442         oact->sa_flags = tswapl(k->sa.sa_flags);
443         oact->sa_restorer = tswapl(k->sa.sa_restorer);
444         oact->sa_mask = k->sa.sa_mask;
445     }
446     if (act) {
447         k->sa._sa_handler = tswapl(act->_sa_handler);
448         k->sa.sa_flags = tswapl(act->sa_flags);
449         k->sa.sa_restorer = tswapl(act->sa_restorer);
450         k->sa.sa_mask = act->sa_mask;
451     }
452     return 0;
453 }
454 
455 #define __put_user(x,ptr)\
456 ({\
457     int size = sizeof(*ptr);\
458     switch(size) {\
459     case 1:\
460         stb(ptr, (typeof(*ptr))(x));\
461         break;\
462     case 2:\
463         stw(ptr, (typeof(*ptr))(x));\
464         break;\
465     case 4:\
466         stl(ptr, (typeof(*ptr))(x));\
467         break;\
468     case 8:\
469         stq(ptr, (typeof(*ptr))(x));\
470         break;\
471     default:\
472         abort();\
473     }\
474     0;\
475 })
476 
477 #define __get_user(x, ptr) \
478 ({\
479     int size = sizeof(*ptr);\
480     switch(size) {\
481     case 1:\
482         x = (typeof(*ptr))ldub(ptr);\
483         break;\
484     case 2:\
485         x = (typeof(*ptr))lduw(ptr);\
486         break;\
487     case 4:\
488         x = (typeof(*ptr))ldl(ptr);\
489         break;\
490     case 8:\
491         x = (typeof(*ptr))ldq(ptr);\
492         break;\
493     default:\
494         abort();\
495     }\
496     0;\
497 })
498 
499 
500 #define __copy_to_user(dst, src, size)\
501 ({\
502     memcpy(dst, src, size);\
503     0;\
504 })
505 
506 #define __copy_from_user(dst, src, size)\
507 ({\
508     memcpy(dst, src, size);\
509     0;\
510 })
511 
512 #define __clear_user(dst, size)\
513 ({\
514     memset(dst, 0, size);\
515     0;\
516 })
517 
518 #ifndef offsetof
519 #define offsetof(type, field) ((size_t) &((type *)0)->field)
520 #endif
521 
522 static inline int copy_siginfo_to_user(target_siginfo_t *tinfo,
523                                        const target_siginfo_t *info)
524 {
525     tswap_siginfo(tinfo, info);
526     return 0;
527 }
528 
529 #ifdef TARGET_I386
530 
531 /* from the Linux kernel */
532 
533 struct target_fpreg {
534 	uint16_t significand[4];
535 	uint16_t exponent;
536 };
537 
538 struct target_fpxreg {
539 	uint16_t significand[4];
540 	uint16_t exponent;
541 	uint16_t padding[3];
542 };
543 
544 struct target_xmmreg {
545 	target_ulong element[4];
546 };
547 
548 struct target_fpstate {
549 	/* Regular FPU environment */
550 	target_ulong 	cw;
551 	target_ulong	sw;
552 	target_ulong	tag;
553 	target_ulong	ipoff;
554 	target_ulong	cssel;
555 	target_ulong	dataoff;
556 	target_ulong	datasel;
557 	struct target_fpreg	_st[8];
558 	uint16_t	status;
559 	uint16_t	magic;		/* 0xffff = regular FPU data only */
560 
561 	/* FXSR FPU environment */
562 	target_ulong	_fxsr_env[6];	/* FXSR FPU env is ignored */
563 	target_ulong	mxcsr;
564 	target_ulong	reserved;
565 	struct target_fpxreg	_fxsr_st[8];	/* FXSR FPU reg data is ignored */
566 	struct target_xmmreg	_xmm[8];
567 	target_ulong	padding[56];
568 };
569 
570 #define X86_FXSR_MAGIC		0x0000
571 
572 struct target_sigcontext {
573 	uint16_t gs, __gsh;
574 	uint16_t fs, __fsh;
575 	uint16_t es, __esh;
576 	uint16_t ds, __dsh;
577 	target_ulong edi;
578 	target_ulong esi;
579 	target_ulong ebp;
580 	target_ulong esp;
581 	target_ulong ebx;
582 	target_ulong edx;
583 	target_ulong ecx;
584 	target_ulong eax;
585 	target_ulong trapno;
586 	target_ulong err;
587 	target_ulong eip;
588 	uint16_t cs, __csh;
589 	target_ulong eflags;
590 	target_ulong esp_at_signal;
591 	uint16_t ss, __ssh;
592         target_ulong fpstate; /* pointer */
593 	target_ulong oldmask;
594 	target_ulong cr2;
595 };
596 
597 typedef struct target_sigaltstack {
598 	target_ulong ss_sp;
599 	int ss_flags;
600 	target_ulong ss_size;
601 } target_stack_t;
602 
603 struct target_ucontext {
604         target_ulong	  uc_flags;
605 	target_ulong      uc_link;
606 	target_stack_t	  uc_stack;
607 	struct target_sigcontext uc_mcontext;
608 	target_sigset_t	  uc_sigmask;	/* mask last for extensibility */
609 };
610 
611 struct sigframe
612 {
613     target_ulong pretcode;
614     int sig;
615     struct target_sigcontext sc;
616     struct target_fpstate fpstate;
617     target_ulong extramask[TARGET_NSIG_WORDS-1];
618     char retcode[8];
619 };
620 
621 struct rt_sigframe
622 {
623     target_ulong pretcode;
624     int sig;
625     target_ulong pinfo;
626     target_ulong puc;
627     struct target_siginfo info;
628     struct target_ucontext uc;
629     struct target_fpstate fpstate;
630     char retcode[8];
631 };
632 
633 /*
634  * Set up a signal frame.
635  */
636 
637 /* XXX: save x87 state */
638 static int
639 setup_sigcontext(struct target_sigcontext *sc, struct target_fpstate *fpstate,
640 		 CPUX86State *env, unsigned long mask)
641 {
642 	int err = 0;
643 
644 	err |= __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
645 	err |= __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
646 	err |= __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
647 	err |= __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
648 	err |= __put_user(env->regs[R_EDI], &sc->edi);
649 	err |= __put_user(env->regs[R_ESI], &sc->esi);
650 	err |= __put_user(env->regs[R_EBP], &sc->ebp);
651 	err |= __put_user(env->regs[R_ESP], &sc->esp);
652 	err |= __put_user(env->regs[R_EBX], &sc->ebx);
653 	err |= __put_user(env->regs[R_EDX], &sc->edx);
654 	err |= __put_user(env->regs[R_ECX], &sc->ecx);
655 	err |= __put_user(env->regs[R_EAX], &sc->eax);
656 	err |= __put_user(env->exception_index, &sc->trapno);
657 	err |= __put_user(env->error_code, &sc->err);
658 	err |= __put_user(env->eip, &sc->eip);
659 	err |= __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
660 	err |= __put_user(env->eflags, &sc->eflags);
661 	err |= __put_user(env->regs[R_ESP], &sc->esp_at_signal);
662 	err |= __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
663 
664         cpu_x86_fsave(env, (void *)fpstate, 1);
665         fpstate->status = fpstate->sw;
666         err |= __put_user(0xffff, &fpstate->magic);
667         err |= __put_user(fpstate, &sc->fpstate);
668 
669 	/* non-iBCS2 extensions.. */
670 	err |= __put_user(mask, &sc->oldmask);
671 	err |= __put_user(env->cr[2], &sc->cr2);
672 	return err;
673 }
674 
675 /*
676  * Determine which stack to use..
677  */
678 
679 static inline void *
680 get_sigframe(struct emulated_sigaction *ka, CPUX86State *env, size_t frame_size)
681 {
682 	unsigned long esp;
683 
684 	/* Default to using normal stack */
685 	esp = env->regs[R_ESP];
686 #if 0
687 	/* This is the X/Open sanctioned signal stack switching.  */
688 	if (ka->sa.sa_flags & SA_ONSTACK) {
689 		if (sas_ss_flags(esp) == 0)
690 			esp = current->sas_ss_sp + current->sas_ss_size;
691 	}
692 
693 	/* This is the legacy signal stack switching. */
694 	else
695 #endif
696         if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
697             !(ka->sa.sa_flags & TARGET_SA_RESTORER) &&
698             ka->sa.sa_restorer) {
699             esp = (unsigned long) ka->sa.sa_restorer;
700 	}
701         return (void *)((esp - frame_size) & -8ul);
702 }
703 
704 static void setup_frame(int sig, struct emulated_sigaction *ka,
705 			target_sigset_t *set, CPUX86State *env)
706 {
707 	struct sigframe *frame;
708 	int err = 0;
709 
710 	frame = get_sigframe(ka, env, sizeof(*frame));
711 
712 #if 0
713 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
714 		goto give_sigsegv;
715 #endif
716 	err |= __put_user((/*current->exec_domain
717 		           && current->exec_domain->signal_invmap
718 		           && sig < 32
719 		           ? current->exec_domain->signal_invmap[sig]
720 		           : */ sig),
721 		          &frame->sig);
722 	if (err)
723 		goto give_sigsegv;
724 
725 	setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0]);
726 	if (err)
727 		goto give_sigsegv;
728 
729 	if (TARGET_NSIG_WORDS > 1) {
730 		err |= __copy_to_user(frame->extramask, &set->sig[1],
731 				      sizeof(frame->extramask));
732 	}
733 	if (err)
734 		goto give_sigsegv;
735 
736 	/* Set up to return from userspace.  If provided, use a stub
737 	   already in userspace.  */
738 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
739 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
740 	} else {
741 		err |= __put_user(frame->retcode, &frame->pretcode);
742 		/* This is popl %eax ; movl $,%eax ; int $0x80 */
743 		err |= __put_user(0xb858, (short *)(frame->retcode+0));
744 		err |= __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2));
745 		err |= __put_user(0x80cd, (short *)(frame->retcode+6));
746 	}
747 
748 	if (err)
749 		goto give_sigsegv;
750 
751 	/* Set up registers for signal handler */
752 	env->regs[R_ESP] = (unsigned long) frame;
753 	env->eip = (unsigned long) ka->sa._sa_handler;
754 
755         cpu_x86_load_seg(env, R_DS, __USER_DS);
756         cpu_x86_load_seg(env, R_ES, __USER_DS);
757         cpu_x86_load_seg(env, R_SS, __USER_DS);
758         cpu_x86_load_seg(env, R_CS, __USER_CS);
759 	env->eflags &= ~TF_MASK;
760 
761 	return;
762 
763 give_sigsegv:
764 	if (sig == TARGET_SIGSEGV)
765 		ka->sa._sa_handler = TARGET_SIG_DFL;
766 	force_sig(TARGET_SIGSEGV /* , current */);
767 }
768 
769 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
770                            target_siginfo_t *info,
771 			   target_sigset_t *set, CPUX86State *env)
772 {
773 	struct rt_sigframe *frame;
774 	int err = 0;
775 
776 	frame = get_sigframe(ka, env, sizeof(*frame));
777 
778 #if 0
779 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
780 		goto give_sigsegv;
781 #endif
782 
783 	err |= __put_user((/*current->exec_domain
784 		    	   && current->exec_domain->signal_invmap
785 		    	   && sig < 32
786 		    	   ? current->exec_domain->signal_invmap[sig]
787 			   : */sig),
788 			  &frame->sig);
789 	err |= __put_user((target_ulong)&frame->info, &frame->pinfo);
790 	err |= __put_user((target_ulong)&frame->uc, &frame->puc);
791 	err |= copy_siginfo_to_user(&frame->info, info);
792 	if (err)
793 		goto give_sigsegv;
794 
795 	/* Create the ucontext.  */
796 	err |= __put_user(0, &frame->uc.uc_flags);
797 	err |= __put_user(0, &frame->uc.uc_link);
798 	err |= __put_user(/*current->sas_ss_sp*/ 0, &frame->uc.uc_stack.ss_sp);
799 	err |= __put_user(/* sas_ss_flags(regs->esp) */ 0,
800 			  &frame->uc.uc_stack.ss_flags);
801 	err |= __put_user(/* current->sas_ss_size */ 0, &frame->uc.uc_stack.ss_size);
802 	err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
803 			        env, set->sig[0]);
804 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
805 	if (err)
806 		goto give_sigsegv;
807 
808 	/* Set up to return from userspace.  If provided, use a stub
809 	   already in userspace.  */
810 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
811 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
812 	} else {
813 		err |= __put_user(frame->retcode, &frame->pretcode);
814 		/* This is movl $,%eax ; int $0x80 */
815 		err |= __put_user(0xb8, (char *)(frame->retcode+0));
816 		err |= __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1));
817 		err |= __put_user(0x80cd, (short *)(frame->retcode+5));
818 	}
819 
820 	if (err)
821 		goto give_sigsegv;
822 
823 	/* Set up registers for signal handler */
824 	env->regs[R_ESP] = (unsigned long) frame;
825 	env->eip = (unsigned long) ka->sa._sa_handler;
826 
827         cpu_x86_load_seg(env, R_DS, __USER_DS);
828         cpu_x86_load_seg(env, R_ES, __USER_DS);
829         cpu_x86_load_seg(env, R_SS, __USER_DS);
830         cpu_x86_load_seg(env, R_CS, __USER_CS);
831 	env->eflags &= ~TF_MASK;
832 
833 	return;
834 
835 give_sigsegv:
836 	if (sig == TARGET_SIGSEGV)
837 		ka->sa._sa_handler = TARGET_SIG_DFL;
838 	force_sig(TARGET_SIGSEGV /* , current */);
839 }
840 
841 static int
842 restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax)
843 {
844 	unsigned int err = 0;
845 
846         cpu_x86_load_seg(env, R_GS, lduw(&sc->gs));
847         cpu_x86_load_seg(env, R_FS, lduw(&sc->fs));
848         cpu_x86_load_seg(env, R_ES, lduw(&sc->es));
849         cpu_x86_load_seg(env, R_DS, lduw(&sc->ds));
850 
851         env->regs[R_EDI] = ldl(&sc->edi);
852         env->regs[R_ESI] = ldl(&sc->esi);
853         env->regs[R_EBP] = ldl(&sc->ebp);
854         env->regs[R_ESP] = ldl(&sc->esp);
855         env->regs[R_EBX] = ldl(&sc->ebx);
856         env->regs[R_EDX] = ldl(&sc->edx);
857         env->regs[R_ECX] = ldl(&sc->ecx);
858         env->eip = ldl(&sc->eip);
859 
860         cpu_x86_load_seg(env, R_CS, lduw(&sc->cs) | 3);
861         cpu_x86_load_seg(env, R_SS, lduw(&sc->ss) | 3);
862 
863 	{
864 		unsigned int tmpflags;
865                 tmpflags = ldl(&sc->eflags);
866 		env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
867                 //		regs->orig_eax = -1;		/* disable syscall checks */
868 	}
869 
870 	{
871 		struct _fpstate * buf;
872                 buf = (void *)ldl(&sc->fpstate);
873 		if (buf) {
874 #if 0
875 			if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
876 				goto badframe;
877 #endif
878                         cpu_x86_frstor(env, (void *)buf, 1);
879 		}
880 	}
881 
882         *peax = ldl(&sc->eax);
883 	return err;
884 #if 0
885 badframe:
886 	return 1;
887 #endif
888 }
889 
890 long do_sigreturn(CPUX86State *env)
891 {
892     struct sigframe *frame = (struct sigframe *)(env->regs[R_ESP] - 8);
893     target_sigset_t target_set;
894     sigset_t set;
895     int eax, i;
896 
897 #if defined(DEBUG_SIGNAL)
898     fprintf(stderr, "do_sigreturn\n");
899 #endif
900     /* set blocked signals */
901     target_set.sig[0] = frame->sc.oldmask;
902     for(i = 1; i < TARGET_NSIG_WORDS; i++)
903         target_set.sig[i] = frame->extramask[i - 1];
904 
905     target_to_host_sigset(&set, &target_set);
906     sigprocmask(SIG_SETMASK, &set, NULL);
907 
908     /* restore registers */
909     if (restore_sigcontext(env, &frame->sc, &eax))
910         goto badframe;
911     return eax;
912 
913 badframe:
914     force_sig(TARGET_SIGSEGV);
915     return 0;
916 }
917 
918 long do_rt_sigreturn(CPUX86State *env)
919 {
920 	struct rt_sigframe *frame = (struct rt_sigframe *)(env->regs[R_ESP] - 4);
921 	target_sigset_t target_set;
922         sigset_t set;
923         //	stack_t st;
924 	int eax;
925 
926 #if 0
927 	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
928 		goto badframe;
929 #endif
930         memcpy(&target_set, &frame->uc.uc_sigmask, sizeof(target_sigset_t));
931 
932         target_to_host_sigset(&set, &target_set);
933         sigprocmask(SIG_SETMASK, &set, NULL);
934 
935 	if (restore_sigcontext(env, &frame->uc.uc_mcontext, &eax))
936 		goto badframe;
937 
938 #if 0
939 	if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
940 		goto badframe;
941 	/* It is more difficult to avoid calling this function than to
942 	   call it and ignore errors.  */
943 	do_sigaltstack(&st, NULL, regs->esp);
944 #endif
945 	return eax;
946 
947 badframe:
948 	force_sig(TARGET_SIGSEGV);
949 	return 0;
950 }
951 
952 #elif defined(TARGET_ARM)
953 
954 struct target_sigcontext {
955 	target_ulong trap_no;
956 	target_ulong error_code;
957 	target_ulong oldmask;
958 	target_ulong arm_r0;
959 	target_ulong arm_r1;
960 	target_ulong arm_r2;
961 	target_ulong arm_r3;
962 	target_ulong arm_r4;
963 	target_ulong arm_r5;
964 	target_ulong arm_r6;
965 	target_ulong arm_r7;
966 	target_ulong arm_r8;
967 	target_ulong arm_r9;
968 	target_ulong arm_r10;
969 	target_ulong arm_fp;
970 	target_ulong arm_ip;
971 	target_ulong arm_sp;
972 	target_ulong arm_lr;
973 	target_ulong arm_pc;
974 	target_ulong arm_cpsr;
975 	target_ulong fault_address;
976 };
977 
978 typedef struct target_sigaltstack {
979 	target_ulong ss_sp;
980 	int ss_flags;
981 	target_ulong ss_size;
982 } target_stack_t;
983 
984 struct target_ucontext {
985     target_ulong uc_flags;
986     target_ulong uc_link;
987     target_stack_t uc_stack;
988     struct target_sigcontext uc_mcontext;
989     target_sigset_t  uc_sigmask;	/* mask last for extensibility */
990 };
991 
992 struct sigframe
993 {
994     struct target_sigcontext sc;
995     target_ulong extramask[TARGET_NSIG_WORDS-1];
996     target_ulong retcode;
997 };
998 
999 struct rt_sigframe
1000 {
1001     struct target_siginfo *pinfo;
1002     void *puc;
1003     struct target_siginfo info;
1004     struct target_ucontext uc;
1005     target_ulong retcode;
1006 };
1007 
1008 #define TARGET_CONFIG_CPU_32 1
1009 
1010 /*
1011  * For ARM syscalls, we encode the syscall number into the instruction.
1012  */
1013 #define SWI_SYS_SIGRETURN	(0xef000000|(TARGET_NR_sigreturn + ARM_SYSCALL_BASE))
1014 #define SWI_SYS_RT_SIGRETURN	(0xef000000|(TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE))
1015 
1016 /*
1017  * For Thumb syscalls, we pass the syscall number via r7.  We therefore
1018  * need two 16-bit instructions.
1019  */
1020 #define SWI_THUMB_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_sigreturn))
1021 #define SWI_THUMB_RT_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_rt_sigreturn))
1022 
1023 static const target_ulong retcodes[4] = {
1024 	SWI_SYS_SIGRETURN,	SWI_THUMB_SIGRETURN,
1025 	SWI_SYS_RT_SIGRETURN,	SWI_THUMB_RT_SIGRETURN
1026 };
1027 
1028 
1029 #define __put_user_error(x,p,e) __put_user(x, p)
1030 #define __get_user_error(x,p,e) __get_user(x, p)
1031 
1032 static inline int valid_user_regs(CPUState *regs)
1033 {
1034     return 1;
1035 }
1036 
1037 static int
1038 setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
1039 		 CPUState *env, unsigned long mask)
1040 {
1041 	int err = 0;
1042 
1043 	__put_user_error(env->regs[0], &sc->arm_r0, err);
1044 	__put_user_error(env->regs[1], &sc->arm_r1, err);
1045 	__put_user_error(env->regs[2], &sc->arm_r2, err);
1046 	__put_user_error(env->regs[3], &sc->arm_r3, err);
1047 	__put_user_error(env->regs[4], &sc->arm_r4, err);
1048 	__put_user_error(env->regs[5], &sc->arm_r5, err);
1049 	__put_user_error(env->regs[6], &sc->arm_r6, err);
1050 	__put_user_error(env->regs[7], &sc->arm_r7, err);
1051 	__put_user_error(env->regs[8], &sc->arm_r8, err);
1052 	__put_user_error(env->regs[9], &sc->arm_r9, err);
1053 	__put_user_error(env->regs[10], &sc->arm_r10, err);
1054 	__put_user_error(env->regs[11], &sc->arm_fp, err);
1055 	__put_user_error(env->regs[12], &sc->arm_ip, err);
1056 	__put_user_error(env->regs[13], &sc->arm_sp, err);
1057 	__put_user_error(env->regs[14], &sc->arm_lr, err);
1058 	__put_user_error(env->regs[15], &sc->arm_pc, err);
1059 #ifdef TARGET_CONFIG_CPU_32
1060 	__put_user_error(env->cpsr, &sc->arm_cpsr, err);
1061 #endif
1062 
1063 	__put_user_error(/* current->thread.trap_no */ 0, &sc->trap_no, err);
1064 	__put_user_error(/* current->thread.error_code */ 0, &sc->error_code, err);
1065 	__put_user_error(/* current->thread.address */ 0, &sc->fault_address, err);
1066 	__put_user_error(mask, &sc->oldmask, err);
1067 
1068 	return err;
1069 }
1070 
1071 static inline void *
1072 get_sigframe(struct emulated_sigaction *ka, CPUState *regs, int framesize)
1073 {
1074 	unsigned long sp = regs->regs[13];
1075 
1076 #if 0
1077 	/*
1078 	 * This is the X/Open sanctioned signal stack switching.
1079 	 */
1080 	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
1081 		sp = current->sas_ss_sp + current->sas_ss_size;
1082 #endif
1083 	/*
1084 	 * ATPCS B01 mandates 8-byte alignment
1085 	 */
1086 	return (void *)((sp - framesize) & ~7);
1087 }
1088 
1089 static int
1090 setup_return(CPUState *env, struct emulated_sigaction *ka,
1091 	     target_ulong *rc, void *frame, int usig)
1092 {
1093 	target_ulong handler = (target_ulong)ka->sa._sa_handler;
1094 	target_ulong retcode;
1095 	int thumb = 0;
1096 #if defined(TARGET_CONFIG_CPU_32)
1097 	target_ulong cpsr = env->cpsr;
1098 
1099 #if 0
1100 	/*
1101 	 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
1102 	 */
1103 	if (ka->sa.sa_flags & SA_THIRTYTWO)
1104 		cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
1105 
1106 #ifdef CONFIG_ARM_THUMB
1107 	if (elf_hwcap & HWCAP_THUMB) {
1108 		/*
1109 		 * The LSB of the handler determines if we're going to
1110 		 * be using THUMB or ARM mode for this signal handler.
1111 		 */
1112 		thumb = handler & 1;
1113 
1114 		if (thumb)
1115 			cpsr |= T_BIT;
1116 		else
1117 			cpsr &= ~T_BIT;
1118 	}
1119 #endif
1120 #endif
1121 #endif /* TARGET_CONFIG_CPU_32 */
1122 
1123 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
1124 		retcode = (target_ulong)ka->sa.sa_restorer;
1125 	} else {
1126 		unsigned int idx = thumb;
1127 
1128 		if (ka->sa.sa_flags & TARGET_SA_SIGINFO)
1129 			idx += 2;
1130 
1131 		if (__put_user(retcodes[idx], rc))
1132 			return 1;
1133 #if 0
1134 		flush_icache_range((target_ulong)rc,
1135 				   (target_ulong)(rc + 1));
1136 #endif
1137 		retcode = ((target_ulong)rc) + thumb;
1138 	}
1139 
1140 	env->regs[0] = usig;
1141 	env->regs[13] = (target_ulong)frame;
1142 	env->regs[14] = retcode;
1143 	env->regs[15] = handler & (thumb ? ~1 : ~3);
1144 
1145 #ifdef TARGET_CONFIG_CPU_32
1146 	env->cpsr = cpsr;
1147 #endif
1148 
1149 	return 0;
1150 }
1151 
1152 static void setup_frame(int usig, struct emulated_sigaction *ka,
1153 			target_sigset_t *set, CPUState *regs)
1154 {
1155 	struct sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
1156 	int err = 0;
1157 
1158 	err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);
1159 
1160 	if (TARGET_NSIG_WORDS > 1) {
1161 		err |= __copy_to_user(frame->extramask, &set->sig[1],
1162 				      sizeof(frame->extramask));
1163 	}
1164 
1165 	if (err == 0)
1166             err = setup_return(regs, ka, &frame->retcode, frame, usig);
1167         //	return err;
1168 }
1169 
1170 static void setup_rt_frame(int usig, struct emulated_sigaction *ka,
1171                            target_siginfo_t *info,
1172 			   target_sigset_t *set, CPUState *env)
1173 {
1174 	struct rt_sigframe *frame = get_sigframe(ka, env, sizeof(*frame));
1175 	int err = 0;
1176 
1177 #if 0
1178 	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
1179             return 1;
1180 #endif
1181 	__put_user_error(&frame->info, (target_ulong *)&frame->pinfo, err);
1182 	__put_user_error(&frame->uc, (target_ulong *)&frame->puc, err);
1183 	err |= copy_siginfo_to_user(&frame->info, info);
1184 
1185 	/* Clear all the bits of the ucontext we don't use.  */
1186 	err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
1187 
1188 	err |= setup_sigcontext(&frame->uc.uc_mcontext, /*&frame->fpstate,*/
1189 				env, set->sig[0]);
1190 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
1191 
1192 	if (err == 0)
1193 		err = setup_return(env, ka, &frame->retcode, frame, usig);
1194 
1195 	if (err == 0) {
1196 		/*
1197 		 * For realtime signals we must also set the second and third
1198 		 * arguments for the signal handler.
1199 		 *   -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
1200 		 */
1201             env->regs[1] = (target_ulong)frame->pinfo;
1202             env->regs[2] = (target_ulong)frame->puc;
1203 	}
1204 
1205         //	return err;
1206 }
1207 
1208 static int
1209 restore_sigcontext(CPUState *env, struct target_sigcontext *sc)
1210 {
1211 	int err = 0;
1212 
1213 	__get_user_error(env->regs[0], &sc->arm_r0, err);
1214 	__get_user_error(env->regs[1], &sc->arm_r1, err);
1215 	__get_user_error(env->regs[2], &sc->arm_r2, err);
1216 	__get_user_error(env->regs[3], &sc->arm_r3, err);
1217 	__get_user_error(env->regs[4], &sc->arm_r4, err);
1218 	__get_user_error(env->regs[5], &sc->arm_r5, err);
1219 	__get_user_error(env->regs[6], &sc->arm_r6, err);
1220 	__get_user_error(env->regs[7], &sc->arm_r7, err);
1221 	__get_user_error(env->regs[8], &sc->arm_r8, err);
1222 	__get_user_error(env->regs[9], &sc->arm_r9, err);
1223 	__get_user_error(env->regs[10], &sc->arm_r10, err);
1224 	__get_user_error(env->regs[11], &sc->arm_fp, err);
1225 	__get_user_error(env->regs[12], &sc->arm_ip, err);
1226 	__get_user_error(env->regs[13], &sc->arm_sp, err);
1227 	__get_user_error(env->regs[14], &sc->arm_lr, err);
1228 	__get_user_error(env->regs[15], &sc->arm_pc, err);
1229 #ifdef TARGET_CONFIG_CPU_32
1230 	__get_user_error(env->cpsr, &sc->arm_cpsr, err);
1231 #endif
1232 
1233 	err |= !valid_user_regs(env);
1234 
1235 	return err;
1236 }
1237 
1238 long do_sigreturn(CPUState *env)
1239 {
1240 	struct sigframe *frame;
1241 	target_sigset_t set;
1242         sigset_t host_set;
1243 
1244 	/*
1245 	 * Since we stacked the signal on a 64-bit boundary,
1246 	 * then 'sp' should be word aligned here.  If it's
1247 	 * not, then the user is trying to mess with us.
1248 	 */
1249 	if (env->regs[13] & 7)
1250 		goto badframe;
1251 
1252 	frame = (struct sigframe *)env->regs[13];
1253 
1254 #if 0
1255 	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
1256 		goto badframe;
1257 #endif
1258 	if (__get_user(set.sig[0], &frame->sc.oldmask)
1259 	    || (TARGET_NSIG_WORDS > 1
1260 	        && __copy_from_user(&set.sig[1], &frame->extramask,
1261 				    sizeof(frame->extramask))))
1262 		goto badframe;
1263 
1264         target_to_host_sigset(&host_set, &set);
1265         sigprocmask(SIG_SETMASK, &host_set, NULL);
1266 
1267 	if (restore_sigcontext(env, &frame->sc))
1268 		goto badframe;
1269 
1270 #if 0
1271 	/* Send SIGTRAP if we're single-stepping */
1272 	if (ptrace_cancel_bpt(current))
1273 		send_sig(SIGTRAP, current, 1);
1274 #endif
1275 	return env->regs[0];
1276 
1277 badframe:
1278         force_sig(SIGSEGV /* , current */);
1279 	return 0;
1280 }
1281 
1282 long do_rt_sigreturn(CPUState *env)
1283 {
1284 	struct rt_sigframe *frame;
1285 	target_sigset_t set;
1286         sigset_t host_set;
1287 
1288 	/*
1289 	 * Since we stacked the signal on a 64-bit boundary,
1290 	 * then 'sp' should be word aligned here.  If it's
1291 	 * not, then the user is trying to mess with us.
1292 	 */
1293 	if (env->regs[13] & 7)
1294 		goto badframe;
1295 
1296 	frame = (struct rt_sigframe *)env->regs[13];
1297 
1298 #if 0
1299 	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
1300 		goto badframe;
1301 #endif
1302 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
1303 		goto badframe;
1304 
1305         target_to_host_sigset(&host_set, &set);
1306         sigprocmask(SIG_SETMASK, &host_set, NULL);
1307 
1308 	if (restore_sigcontext(env, &frame->uc.uc_mcontext))
1309 		goto badframe;
1310 
1311 #if 0
1312 	/* Send SIGTRAP if we're single-stepping */
1313 	if (ptrace_cancel_bpt(current))
1314 		send_sig(SIGTRAP, current, 1);
1315 #endif
1316 	return env->regs[0];
1317 
1318 badframe:
1319         force_sig(SIGSEGV /* , current */);
1320 	return 0;
1321 }
1322 
1323 #else
1324 
1325 static void setup_frame(int sig, struct emulated_sigaction *ka,
1326 			target_sigset_t *set, CPUState *env)
1327 {
1328     fprintf(stderr, "setup_frame: not implemented\n");
1329 }
1330 
1331 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
1332                            target_siginfo_t *info,
1333 			   target_sigset_t *set, CPUState *env)
1334 {
1335     fprintf(stderr, "setup_rt_frame: not implemented\n");
1336 }
1337 
1338 long do_sigreturn(CPUState *env)
1339 {
1340     fprintf(stderr, "do_sigreturn: not implemented\n");
1341     return -ENOSYS;
1342 }
1343 
1344 long do_rt_sigreturn(CPUState *env)
1345 {
1346     fprintf(stderr, "do_rt_sigreturn: not implemented\n");
1347     return -ENOSYS;
1348 }
1349 
1350 #endif
1351 
1352 void process_pending_signals(void *cpu_env)
1353 {
1354     int sig;
1355     target_ulong handler;
1356     sigset_t set, old_set;
1357     target_sigset_t target_old_set;
1358     struct emulated_sigaction *k;
1359     struct sigqueue *q;
1360 
1361     if (!signal_pending)
1362         return;
1363 
1364     k = sigact_table;
1365     for(sig = 1; sig <= TARGET_NSIG; sig++) {
1366         if (k->pending)
1367             goto handle_signal;
1368         k++;
1369     }
1370     /* if no signal is pending, just return */
1371     signal_pending = 0;
1372     return;
1373 
1374  handle_signal:
1375 #ifdef DEBUG_SIGNAL
1376     fprintf(stderr, "qemu: process signal %d\n", sig);
1377 #endif
1378     /* dequeue signal */
1379     q = k->first;
1380     k->first = q->next;
1381     if (!k->first)
1382         k->pending = 0;
1383 
1384     handler = k->sa._sa_handler;
1385     if (handler == TARGET_SIG_DFL) {
1386         /* default handler : ignore some signal. The other are fatal */
1387         if (sig != TARGET_SIGCHLD &&
1388             sig != TARGET_SIGURG &&
1389             sig != TARGET_SIGWINCH) {
1390             force_sig(sig);
1391         }
1392     } else if (handler == TARGET_SIG_IGN) {
1393         /* ignore sig */
1394     } else if (handler == TARGET_SIG_ERR) {
1395         force_sig(sig);
1396     } else {
1397         /* compute the blocked signals during the handler execution */
1398         target_to_host_sigset(&set, &k->sa.sa_mask);
1399         /* SA_NODEFER indicates that the current signal should not be
1400            blocked during the handler */
1401         if (!(k->sa.sa_flags & TARGET_SA_NODEFER))
1402             sigaddset(&set, target_to_host_signal(sig));
1403 
1404         /* block signals in the handler using Linux */
1405         sigprocmask(SIG_BLOCK, &set, &old_set);
1406         /* save the previous blocked signal state to restore it at the
1407            end of the signal execution (see do_sigreturn) */
1408         host_to_target_sigset(&target_old_set, &old_set);
1409 
1410         /* if the CPU is in VM86 mode, we restore the 32 bit values */
1411 #ifdef TARGET_I386
1412         {
1413             CPUX86State *env = cpu_env;
1414             if (env->eflags & VM_MASK)
1415                 save_v86_state(env);
1416         }
1417 #endif
1418         /* prepare the stack frame of the virtual CPU */
1419         if (k->sa.sa_flags & TARGET_SA_SIGINFO)
1420             setup_rt_frame(sig, k, &q->info, &target_old_set, cpu_env);
1421         else
1422             setup_frame(sig, k, &target_old_set, cpu_env);
1423 	if (k->sa.sa_flags & TARGET_SA_RESETHAND)
1424             k->sa._sa_handler = TARGET_SIG_DFL;
1425     }
1426     if (q != &k->info)
1427         free_sigqueue(q);
1428 }
1429 
1430 
1431