xref: /qemu/linux-user/signal.c (revision 58fe2f10f0e9ddd63bc6004776ef6e874101e9c5)
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 | ((unsigned long)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 static void host_signal_handler(int host_signum, siginfo_t *info,
374                                 void *puc)
375 {
376     int sig;
377     target_siginfo_t tinfo;
378 
379     /* the CPU emulator uses some host signals to detect exceptions,
380        we we forward to it some signals */
381     if (host_signum == SIGSEGV || host_signum == SIGBUS
382 #if defined(TARGET_I386) && defined(USE_CODE_COPY)
383         || host_signum == SIGFPE
384 #endif
385         ) {
386         if (cpu_signal_handler(host_signum, info, puc))
387             return;
388     }
389 
390     /* get target signal number */
391     sig = host_to_target_signal(host_signum);
392     if (sig < 1 || sig > TARGET_NSIG)
393         return;
394 #if defined(DEBUG_SIGNAL)
395     fprintf(stderr, "qemu: got signal %d\n", sig);
396 #endif
397     host_to_target_siginfo_noswap(&tinfo, info);
398     if (queue_signal(sig, &tinfo) == 1) {
399         /* interrupt the virtual CPU as soon as possible */
400         cpu_interrupt(global_env, CPU_INTERRUPT_EXIT);
401     }
402 }
403 
404 int do_sigaction(int sig, const struct target_sigaction *act,
405                  struct target_sigaction *oact)
406 {
407     struct emulated_sigaction *k;
408     struct sigaction act1;
409     int host_sig;
410 
411     if (sig < 1 || sig > TARGET_NSIG)
412         return -EINVAL;
413     k = &sigact_table[sig - 1];
414 #if defined(DEBUG_SIGNAL)
415     fprintf(stderr, "sigaction sig=%d act=0x%08x, oact=0x%08x\n",
416             sig, (int)act, (int)oact);
417 #endif
418     if (oact) {
419         oact->_sa_handler = tswapl(k->sa._sa_handler);
420         oact->sa_flags = tswapl(k->sa.sa_flags);
421         oact->sa_restorer = tswapl(k->sa.sa_restorer);
422         oact->sa_mask = k->sa.sa_mask;
423     }
424     if (act) {
425         k->sa._sa_handler = tswapl(act->_sa_handler);
426         k->sa.sa_flags = tswapl(act->sa_flags);
427         k->sa.sa_restorer = tswapl(act->sa_restorer);
428         k->sa.sa_mask = act->sa_mask;
429 
430         /* we update the host linux signal state */
431         host_sig = target_to_host_signal(sig);
432         if (host_sig != SIGSEGV && host_sig != SIGBUS) {
433             sigfillset(&act1.sa_mask);
434             act1.sa_flags = SA_SIGINFO;
435             if (k->sa.sa_flags & TARGET_SA_RESTART)
436                 act1.sa_flags |= SA_RESTART;
437             /* NOTE: it is important to update the host kernel signal
438                ignore state to avoid getting unexpected interrupted
439                syscalls */
440             if (k->sa._sa_handler == TARGET_SIG_IGN) {
441                 act1.sa_sigaction = (void *)SIG_IGN;
442             } else if (k->sa._sa_handler == TARGET_SIG_DFL) {
443                 act1.sa_sigaction = (void *)SIG_DFL;
444             } else {
445                 act1.sa_sigaction = host_signal_handler;
446             }
447             sigaction(host_sig, &act1, NULL);
448         }
449     }
450     return 0;
451 }
452 
453 #define __put_user(x,ptr)\
454 ({\
455     int size = sizeof(*ptr);\
456     switch(size) {\
457     case 1:\
458         stb(ptr, (typeof(*ptr))(x));\
459         break;\
460     case 2:\
461         stw(ptr, (typeof(*ptr))(x));\
462         break;\
463     case 4:\
464         stl(ptr, (typeof(*ptr))(x));\
465         break;\
466     case 8:\
467         stq(ptr, (typeof(*ptr))(x));\
468         break;\
469     default:\
470         abort();\
471     }\
472     0;\
473 })
474 
475 #define __get_user(x, ptr) \
476 ({\
477     int size = sizeof(*ptr);\
478     switch(size) {\
479     case 1:\
480         x = (typeof(*ptr))ldub(ptr);\
481         break;\
482     case 2:\
483         x = (typeof(*ptr))lduw(ptr);\
484         break;\
485     case 4:\
486         x = (typeof(*ptr))ldl(ptr);\
487         break;\
488     case 8:\
489         x = (typeof(*ptr))ldq(ptr);\
490         break;\
491     default:\
492         abort();\
493     }\
494     0;\
495 })
496 
497 
498 #define __copy_to_user(dst, src, size)\
499 ({\
500     memcpy(dst, src, size);\
501     0;\
502 })
503 
504 #define __copy_from_user(dst, src, size)\
505 ({\
506     memcpy(dst, src, size);\
507     0;\
508 })
509 
510 #define __clear_user(dst, size)\
511 ({\
512     memset(dst, 0, size);\
513     0;\
514 })
515 
516 #ifndef offsetof
517 #define offsetof(type, field) ((size_t) &((type *)0)->field)
518 #endif
519 
520 static inline int copy_siginfo_to_user(target_siginfo_t *tinfo,
521                                        const target_siginfo_t *info)
522 {
523     tswap_siginfo(tinfo, info);
524     return 0;
525 }
526 
527 #ifdef TARGET_I386
528 
529 /* from the Linux kernel */
530 
531 struct target_fpreg {
532 	uint16_t significand[4];
533 	uint16_t exponent;
534 };
535 
536 struct target_fpxreg {
537 	uint16_t significand[4];
538 	uint16_t exponent;
539 	uint16_t padding[3];
540 };
541 
542 struct target_xmmreg {
543 	target_ulong element[4];
544 };
545 
546 struct target_fpstate {
547 	/* Regular FPU environment */
548 	target_ulong 	cw;
549 	target_ulong	sw;
550 	target_ulong	tag;
551 	target_ulong	ipoff;
552 	target_ulong	cssel;
553 	target_ulong	dataoff;
554 	target_ulong	datasel;
555 	struct target_fpreg	_st[8];
556 	uint16_t	status;
557 	uint16_t	magic;		/* 0xffff = regular FPU data only */
558 
559 	/* FXSR FPU environment */
560 	target_ulong	_fxsr_env[6];	/* FXSR FPU env is ignored */
561 	target_ulong	mxcsr;
562 	target_ulong	reserved;
563 	struct target_fpxreg	_fxsr_st[8];	/* FXSR FPU reg data is ignored */
564 	struct target_xmmreg	_xmm[8];
565 	target_ulong	padding[56];
566 };
567 
568 #define X86_FXSR_MAGIC		0x0000
569 
570 struct target_sigcontext {
571 	uint16_t gs, __gsh;
572 	uint16_t fs, __fsh;
573 	uint16_t es, __esh;
574 	uint16_t ds, __dsh;
575 	target_ulong edi;
576 	target_ulong esi;
577 	target_ulong ebp;
578 	target_ulong esp;
579 	target_ulong ebx;
580 	target_ulong edx;
581 	target_ulong ecx;
582 	target_ulong eax;
583 	target_ulong trapno;
584 	target_ulong err;
585 	target_ulong eip;
586 	uint16_t cs, __csh;
587 	target_ulong eflags;
588 	target_ulong esp_at_signal;
589 	uint16_t ss, __ssh;
590         target_ulong fpstate; /* pointer */
591 	target_ulong oldmask;
592 	target_ulong cr2;
593 };
594 
595 typedef struct target_sigaltstack {
596 	target_ulong ss_sp;
597 	int ss_flags;
598 	target_ulong ss_size;
599 } target_stack_t;
600 
601 struct target_ucontext {
602         target_ulong	  uc_flags;
603 	target_ulong      uc_link;
604 	target_stack_t	  uc_stack;
605 	struct target_sigcontext uc_mcontext;
606 	target_sigset_t	  uc_sigmask;	/* mask last for extensibility */
607 };
608 
609 struct sigframe
610 {
611     target_ulong pretcode;
612     int sig;
613     struct target_sigcontext sc;
614     struct target_fpstate fpstate;
615     target_ulong extramask[TARGET_NSIG_WORDS-1];
616     char retcode[8];
617 };
618 
619 struct rt_sigframe
620 {
621     target_ulong pretcode;
622     int sig;
623     target_ulong pinfo;
624     target_ulong puc;
625     struct target_siginfo info;
626     struct target_ucontext uc;
627     struct target_fpstate fpstate;
628     char retcode[8];
629 };
630 
631 /*
632  * Set up a signal frame.
633  */
634 
635 /* XXX: save x87 state */
636 static int
637 setup_sigcontext(struct target_sigcontext *sc, struct target_fpstate *fpstate,
638 		 CPUX86State *env, unsigned long mask)
639 {
640 	int err = 0;
641 
642 	err |= __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
643 	err |= __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
644 	err |= __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
645 	err |= __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
646 	err |= __put_user(env->regs[R_EDI], &sc->edi);
647 	err |= __put_user(env->regs[R_ESI], &sc->esi);
648 	err |= __put_user(env->regs[R_EBP], &sc->ebp);
649 	err |= __put_user(env->regs[R_ESP], &sc->esp);
650 	err |= __put_user(env->regs[R_EBX], &sc->ebx);
651 	err |= __put_user(env->regs[R_EDX], &sc->edx);
652 	err |= __put_user(env->regs[R_ECX], &sc->ecx);
653 	err |= __put_user(env->regs[R_EAX], &sc->eax);
654 	err |= __put_user(env->exception_index, &sc->trapno);
655 	err |= __put_user(env->error_code, &sc->err);
656 	err |= __put_user(env->eip, &sc->eip);
657 	err |= __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
658 	err |= __put_user(env->eflags, &sc->eflags);
659 	err |= __put_user(env->regs[R_ESP], &sc->esp_at_signal);
660 	err |= __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
661 
662         cpu_x86_fsave(env, (void *)fpstate, 1);
663         fpstate->status = fpstate->sw;
664         err |= __put_user(0xffff, &fpstate->magic);
665         err |= __put_user(fpstate, &sc->fpstate);
666 
667 	/* non-iBCS2 extensions.. */
668 	err |= __put_user(mask, &sc->oldmask);
669 	err |= __put_user(env->cr[2], &sc->cr2);
670 	return err;
671 }
672 
673 /*
674  * Determine which stack to use..
675  */
676 
677 static inline void *
678 get_sigframe(struct emulated_sigaction *ka, CPUX86State *env, size_t frame_size)
679 {
680 	unsigned long esp;
681 
682 	/* Default to using normal stack */
683 	esp = env->regs[R_ESP];
684 #if 0
685 	/* This is the X/Open sanctioned signal stack switching.  */
686 	if (ka->sa.sa_flags & SA_ONSTACK) {
687 		if (sas_ss_flags(esp) == 0)
688 			esp = current->sas_ss_sp + current->sas_ss_size;
689 	}
690 
691 	/* This is the legacy signal stack switching. */
692 	else
693 #endif
694         if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
695             !(ka->sa.sa_flags & TARGET_SA_RESTORER) &&
696             ka->sa.sa_restorer) {
697             esp = (unsigned long) ka->sa.sa_restorer;
698 	}
699         return (void *)((esp - frame_size) & -8ul);
700 }
701 
702 static void setup_frame(int sig, struct emulated_sigaction *ka,
703 			target_sigset_t *set, CPUX86State *env)
704 {
705 	struct sigframe *frame;
706 	int err = 0;
707 
708 	frame = get_sigframe(ka, env, sizeof(*frame));
709 
710 #if 0
711 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
712 		goto give_sigsegv;
713 #endif
714 	err |= __put_user((/*current->exec_domain
715 		           && current->exec_domain->signal_invmap
716 		           && sig < 32
717 		           ? current->exec_domain->signal_invmap[sig]
718 		           : */ sig),
719 		          &frame->sig);
720 	if (err)
721 		goto give_sigsegv;
722 
723 	setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0]);
724 	if (err)
725 		goto give_sigsegv;
726 
727 	if (TARGET_NSIG_WORDS > 1) {
728 		err |= __copy_to_user(frame->extramask, &set->sig[1],
729 				      sizeof(frame->extramask));
730 	}
731 	if (err)
732 		goto give_sigsegv;
733 
734 	/* Set up to return from userspace.  If provided, use a stub
735 	   already in userspace.  */
736 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
737 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
738 	} else {
739 		err |= __put_user(frame->retcode, &frame->pretcode);
740 		/* This is popl %eax ; movl $,%eax ; int $0x80 */
741 		err |= __put_user(0xb858, (short *)(frame->retcode+0));
742 		err |= __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2));
743 		err |= __put_user(0x80cd, (short *)(frame->retcode+6));
744 	}
745 
746 	if (err)
747 		goto give_sigsegv;
748 
749 	/* Set up registers for signal handler */
750 	env->regs[R_ESP] = (unsigned long) frame;
751 	env->eip = (unsigned long) ka->sa._sa_handler;
752 
753         cpu_x86_load_seg(env, R_DS, __USER_DS);
754         cpu_x86_load_seg(env, R_ES, __USER_DS);
755         cpu_x86_load_seg(env, R_SS, __USER_DS);
756         cpu_x86_load_seg(env, R_CS, __USER_CS);
757 	env->eflags &= ~TF_MASK;
758 
759 	return;
760 
761 give_sigsegv:
762 	if (sig == TARGET_SIGSEGV)
763 		ka->sa._sa_handler = TARGET_SIG_DFL;
764 	force_sig(TARGET_SIGSEGV /* , current */);
765 }
766 
767 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
768                            target_siginfo_t *info,
769 			   target_sigset_t *set, CPUX86State *env)
770 {
771 	struct rt_sigframe *frame;
772 	int err = 0;
773 
774 	frame = get_sigframe(ka, env, sizeof(*frame));
775 
776 #if 0
777 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
778 		goto give_sigsegv;
779 #endif
780 
781 	err |= __put_user((/*current->exec_domain
782 		    	   && current->exec_domain->signal_invmap
783 		    	   && sig < 32
784 		    	   ? current->exec_domain->signal_invmap[sig]
785 			   : */sig),
786 			  &frame->sig);
787 	err |= __put_user((target_ulong)&frame->info, &frame->pinfo);
788 	err |= __put_user((target_ulong)&frame->uc, &frame->puc);
789 	err |= copy_siginfo_to_user(&frame->info, info);
790 	if (err)
791 		goto give_sigsegv;
792 
793 	/* Create the ucontext.  */
794 	err |= __put_user(0, &frame->uc.uc_flags);
795 	err |= __put_user(0, &frame->uc.uc_link);
796 	err |= __put_user(/*current->sas_ss_sp*/ 0, &frame->uc.uc_stack.ss_sp);
797 	err |= __put_user(/* sas_ss_flags(regs->esp) */ 0,
798 			  &frame->uc.uc_stack.ss_flags);
799 	err |= __put_user(/* current->sas_ss_size */ 0, &frame->uc.uc_stack.ss_size);
800 	err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
801 			        env, set->sig[0]);
802 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
803 	if (err)
804 		goto give_sigsegv;
805 
806 	/* Set up to return from userspace.  If provided, use a stub
807 	   already in userspace.  */
808 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
809 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
810 	} else {
811 		err |= __put_user(frame->retcode, &frame->pretcode);
812 		/* This is movl $,%eax ; int $0x80 */
813 		err |= __put_user(0xb8, (char *)(frame->retcode+0));
814 		err |= __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1));
815 		err |= __put_user(0x80cd, (short *)(frame->retcode+5));
816 	}
817 
818 	if (err)
819 		goto give_sigsegv;
820 
821 	/* Set up registers for signal handler */
822 	env->regs[R_ESP] = (unsigned long) frame;
823 	env->eip = (unsigned long) ka->sa._sa_handler;
824 
825         cpu_x86_load_seg(env, R_DS, __USER_DS);
826         cpu_x86_load_seg(env, R_ES, __USER_DS);
827         cpu_x86_load_seg(env, R_SS, __USER_DS);
828         cpu_x86_load_seg(env, R_CS, __USER_CS);
829 	env->eflags &= ~TF_MASK;
830 
831 	return;
832 
833 give_sigsegv:
834 	if (sig == TARGET_SIGSEGV)
835 		ka->sa._sa_handler = TARGET_SIG_DFL;
836 	force_sig(TARGET_SIGSEGV /* , current */);
837 }
838 
839 static int
840 restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax)
841 {
842 	unsigned int err = 0;
843 
844         cpu_x86_load_seg(env, R_GS, lduw(&sc->gs));
845         cpu_x86_load_seg(env, R_FS, lduw(&sc->fs));
846         cpu_x86_load_seg(env, R_ES, lduw(&sc->es));
847         cpu_x86_load_seg(env, R_DS, lduw(&sc->ds));
848 
849         env->regs[R_EDI] = ldl(&sc->edi);
850         env->regs[R_ESI] = ldl(&sc->esi);
851         env->regs[R_EBP] = ldl(&sc->ebp);
852         env->regs[R_ESP] = ldl(&sc->esp);
853         env->regs[R_EBX] = ldl(&sc->ebx);
854         env->regs[R_EDX] = ldl(&sc->edx);
855         env->regs[R_ECX] = ldl(&sc->ecx);
856         env->eip = ldl(&sc->eip);
857 
858         cpu_x86_load_seg(env, R_CS, lduw(&sc->cs) | 3);
859         cpu_x86_load_seg(env, R_SS, lduw(&sc->ss) | 3);
860 
861 	{
862 		unsigned int tmpflags;
863                 tmpflags = ldl(&sc->eflags);
864 		env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
865                 //		regs->orig_eax = -1;		/* disable syscall checks */
866 	}
867 
868 	{
869 		struct _fpstate * buf;
870                 buf = (void *)ldl(&sc->fpstate);
871 		if (buf) {
872 #if 0
873 			if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
874 				goto badframe;
875 #endif
876                         cpu_x86_frstor(env, (void *)buf, 1);
877 		}
878 	}
879 
880         *peax = ldl(&sc->eax);
881 	return err;
882 #if 0
883 badframe:
884 	return 1;
885 #endif
886 }
887 
888 long do_sigreturn(CPUX86State *env)
889 {
890     struct sigframe *frame = (struct sigframe *)(env->regs[R_ESP] - 8);
891     target_sigset_t target_set;
892     sigset_t set;
893     int eax, i;
894 
895 #if defined(DEBUG_SIGNAL)
896     fprintf(stderr, "do_sigreturn\n");
897 #endif
898     /* set blocked signals */
899     target_set.sig[0] = frame->sc.oldmask;
900     for(i = 1; i < TARGET_NSIG_WORDS; i++)
901         target_set.sig[i] = frame->extramask[i - 1];
902 
903     target_to_host_sigset(&set, &target_set);
904     sigprocmask(SIG_SETMASK, &set, NULL);
905 
906     /* restore registers */
907     if (restore_sigcontext(env, &frame->sc, &eax))
908         goto badframe;
909     return eax;
910 
911 badframe:
912     force_sig(TARGET_SIGSEGV);
913     return 0;
914 }
915 
916 long do_rt_sigreturn(CPUX86State *env)
917 {
918 	struct rt_sigframe *frame = (struct rt_sigframe *)(env->regs[R_ESP] - 4);
919 	target_sigset_t target_set;
920         sigset_t set;
921         //	stack_t st;
922 	int eax;
923 
924 #if 0
925 	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
926 		goto badframe;
927 #endif
928         memcpy(&target_set, &frame->uc.uc_sigmask, sizeof(target_sigset_t));
929 
930         target_to_host_sigset(&set, &target_set);
931         sigprocmask(SIG_SETMASK, &set, NULL);
932 
933 	if (restore_sigcontext(env, &frame->uc.uc_mcontext, &eax))
934 		goto badframe;
935 
936 #if 0
937 	if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
938 		goto badframe;
939 	/* It is more difficult to avoid calling this function than to
940 	   call it and ignore errors.  */
941 	do_sigaltstack(&st, NULL, regs->esp);
942 #endif
943 	return eax;
944 
945 badframe:
946 	force_sig(TARGET_SIGSEGV);
947 	return 0;
948 }
949 
950 #elif defined(TARGET_ARM)
951 
952 struct target_sigcontext {
953 	target_ulong trap_no;
954 	target_ulong error_code;
955 	target_ulong oldmask;
956 	target_ulong arm_r0;
957 	target_ulong arm_r1;
958 	target_ulong arm_r2;
959 	target_ulong arm_r3;
960 	target_ulong arm_r4;
961 	target_ulong arm_r5;
962 	target_ulong arm_r6;
963 	target_ulong arm_r7;
964 	target_ulong arm_r8;
965 	target_ulong arm_r9;
966 	target_ulong arm_r10;
967 	target_ulong arm_fp;
968 	target_ulong arm_ip;
969 	target_ulong arm_sp;
970 	target_ulong arm_lr;
971 	target_ulong arm_pc;
972 	target_ulong arm_cpsr;
973 	target_ulong fault_address;
974 };
975 
976 typedef struct target_sigaltstack {
977 	target_ulong ss_sp;
978 	int ss_flags;
979 	target_ulong ss_size;
980 } target_stack_t;
981 
982 struct target_ucontext {
983     target_ulong uc_flags;
984     target_ulong uc_link;
985     target_stack_t uc_stack;
986     struct target_sigcontext uc_mcontext;
987     target_sigset_t  uc_sigmask;	/* mask last for extensibility */
988 };
989 
990 struct sigframe
991 {
992     struct target_sigcontext sc;
993     target_ulong extramask[TARGET_NSIG_WORDS-1];
994     target_ulong retcode;
995 };
996 
997 struct rt_sigframe
998 {
999     struct target_siginfo *pinfo;
1000     void *puc;
1001     struct target_siginfo info;
1002     struct target_ucontext uc;
1003     target_ulong retcode;
1004 };
1005 
1006 #define TARGET_CONFIG_CPU_32 1
1007 
1008 /*
1009  * For ARM syscalls, we encode the syscall number into the instruction.
1010  */
1011 #define SWI_SYS_SIGRETURN	(0xef000000|(TARGET_NR_sigreturn + ARM_SYSCALL_BASE))
1012 #define SWI_SYS_RT_SIGRETURN	(0xef000000|(TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE))
1013 
1014 /*
1015  * For Thumb syscalls, we pass the syscall number via r7.  We therefore
1016  * need two 16-bit instructions.
1017  */
1018 #define SWI_THUMB_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_sigreturn))
1019 #define SWI_THUMB_RT_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_rt_sigreturn))
1020 
1021 static const target_ulong retcodes[4] = {
1022 	SWI_SYS_SIGRETURN,	SWI_THUMB_SIGRETURN,
1023 	SWI_SYS_RT_SIGRETURN,	SWI_THUMB_RT_SIGRETURN
1024 };
1025 
1026 
1027 #define __put_user_error(x,p,e) __put_user(x, p)
1028 #define __get_user_error(x,p,e) __get_user(x, p)
1029 
1030 static inline int valid_user_regs(CPUState *regs)
1031 {
1032     return 1;
1033 }
1034 
1035 static int
1036 setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
1037 		 CPUState *env, unsigned long mask)
1038 {
1039 	int err = 0;
1040 
1041 	__put_user_error(env->regs[0], &sc->arm_r0, err);
1042 	__put_user_error(env->regs[1], &sc->arm_r1, err);
1043 	__put_user_error(env->regs[2], &sc->arm_r2, err);
1044 	__put_user_error(env->regs[3], &sc->arm_r3, err);
1045 	__put_user_error(env->regs[4], &sc->arm_r4, err);
1046 	__put_user_error(env->regs[5], &sc->arm_r5, err);
1047 	__put_user_error(env->regs[6], &sc->arm_r6, err);
1048 	__put_user_error(env->regs[7], &sc->arm_r7, err);
1049 	__put_user_error(env->regs[8], &sc->arm_r8, err);
1050 	__put_user_error(env->regs[9], &sc->arm_r9, err);
1051 	__put_user_error(env->regs[10], &sc->arm_r10, err);
1052 	__put_user_error(env->regs[11], &sc->arm_fp, err);
1053 	__put_user_error(env->regs[12], &sc->arm_ip, err);
1054 	__put_user_error(env->regs[13], &sc->arm_sp, err);
1055 	__put_user_error(env->regs[14], &sc->arm_lr, err);
1056 	__put_user_error(env->regs[15], &sc->arm_pc, err);
1057 #ifdef TARGET_CONFIG_CPU_32
1058 	__put_user_error(env->cpsr, &sc->arm_cpsr, err);
1059 #endif
1060 
1061 	__put_user_error(/* current->thread.trap_no */ 0, &sc->trap_no, err);
1062 	__put_user_error(/* current->thread.error_code */ 0, &sc->error_code, err);
1063 	__put_user_error(/* current->thread.address */ 0, &sc->fault_address, err);
1064 	__put_user_error(mask, &sc->oldmask, err);
1065 
1066 	return err;
1067 }
1068 
1069 static inline void *
1070 get_sigframe(struct emulated_sigaction *ka, CPUState *regs, int framesize)
1071 {
1072 	unsigned long sp = regs->regs[13];
1073 
1074 #if 0
1075 	/*
1076 	 * This is the X/Open sanctioned signal stack switching.
1077 	 */
1078 	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
1079 		sp = current->sas_ss_sp + current->sas_ss_size;
1080 #endif
1081 	/*
1082 	 * ATPCS B01 mandates 8-byte alignment
1083 	 */
1084 	return (void *)((sp - framesize) & ~7);
1085 }
1086 
1087 static int
1088 setup_return(CPUState *env, struct emulated_sigaction *ka,
1089 	     target_ulong *rc, void *frame, int usig)
1090 {
1091 	target_ulong handler = (target_ulong)ka->sa._sa_handler;
1092 	target_ulong retcode;
1093 	int thumb = 0;
1094 #if defined(TARGET_CONFIG_CPU_32)
1095 	target_ulong cpsr = env->cpsr;
1096 
1097 #if 0
1098 	/*
1099 	 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
1100 	 */
1101 	if (ka->sa.sa_flags & SA_THIRTYTWO)
1102 		cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
1103 
1104 #ifdef CONFIG_ARM_THUMB
1105 	if (elf_hwcap & HWCAP_THUMB) {
1106 		/*
1107 		 * The LSB of the handler determines if we're going to
1108 		 * be using THUMB or ARM mode for this signal handler.
1109 		 */
1110 		thumb = handler & 1;
1111 
1112 		if (thumb)
1113 			cpsr |= T_BIT;
1114 		else
1115 			cpsr &= ~T_BIT;
1116 	}
1117 #endif
1118 #endif
1119 #endif /* TARGET_CONFIG_CPU_32 */
1120 
1121 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
1122 		retcode = (target_ulong)ka->sa.sa_restorer;
1123 	} else {
1124 		unsigned int idx = thumb;
1125 
1126 		if (ka->sa.sa_flags & TARGET_SA_SIGINFO)
1127 			idx += 2;
1128 
1129 		if (__put_user(retcodes[idx], rc))
1130 			return 1;
1131 #if 0
1132 		flush_icache_range((target_ulong)rc,
1133 				   (target_ulong)(rc + 1));
1134 #endif
1135 		retcode = ((target_ulong)rc) + thumb;
1136 	}
1137 
1138 	env->regs[0] = usig;
1139 	env->regs[13] = (target_ulong)frame;
1140 	env->regs[14] = retcode;
1141 	env->regs[15] = handler & (thumb ? ~1 : ~3);
1142 
1143 #ifdef TARGET_CONFIG_CPU_32
1144 	env->cpsr = cpsr;
1145 #endif
1146 
1147 	return 0;
1148 }
1149 
1150 static void setup_frame(int usig, struct emulated_sigaction *ka,
1151 			target_sigset_t *set, CPUState *regs)
1152 {
1153 	struct sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
1154 	int err = 0;
1155 
1156 	err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);
1157 
1158 	if (TARGET_NSIG_WORDS > 1) {
1159 		err |= __copy_to_user(frame->extramask, &set->sig[1],
1160 				      sizeof(frame->extramask));
1161 	}
1162 
1163 	if (err == 0)
1164             err = setup_return(regs, ka, &frame->retcode, frame, usig);
1165         //	return err;
1166 }
1167 
1168 static void setup_rt_frame(int usig, struct emulated_sigaction *ka,
1169                            target_siginfo_t *info,
1170 			   target_sigset_t *set, CPUState *env)
1171 {
1172 	struct rt_sigframe *frame = get_sigframe(ka, env, sizeof(*frame));
1173 	int err = 0;
1174 
1175 #if 0
1176 	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
1177             return 1;
1178 #endif
1179 	__put_user_error(&frame->info, (target_ulong *)&frame->pinfo, err);
1180 	__put_user_error(&frame->uc, (target_ulong *)&frame->puc, err);
1181 	err |= copy_siginfo_to_user(&frame->info, info);
1182 
1183 	/* Clear all the bits of the ucontext we don't use.  */
1184 	err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
1185 
1186 	err |= setup_sigcontext(&frame->uc.uc_mcontext, /*&frame->fpstate,*/
1187 				env, set->sig[0]);
1188 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
1189 
1190 	if (err == 0)
1191 		err = setup_return(env, ka, &frame->retcode, frame, usig);
1192 
1193 	if (err == 0) {
1194 		/*
1195 		 * For realtime signals we must also set the second and third
1196 		 * arguments for the signal handler.
1197 		 *   -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
1198 		 */
1199             env->regs[1] = (target_ulong)frame->pinfo;
1200             env->regs[2] = (target_ulong)frame->puc;
1201 	}
1202 
1203         //	return err;
1204 }
1205 
1206 static int
1207 restore_sigcontext(CPUState *env, struct target_sigcontext *sc)
1208 {
1209 	int err = 0;
1210 
1211 	__get_user_error(env->regs[0], &sc->arm_r0, err);
1212 	__get_user_error(env->regs[1], &sc->arm_r1, err);
1213 	__get_user_error(env->regs[2], &sc->arm_r2, err);
1214 	__get_user_error(env->regs[3], &sc->arm_r3, err);
1215 	__get_user_error(env->regs[4], &sc->arm_r4, err);
1216 	__get_user_error(env->regs[5], &sc->arm_r5, err);
1217 	__get_user_error(env->regs[6], &sc->arm_r6, err);
1218 	__get_user_error(env->regs[7], &sc->arm_r7, err);
1219 	__get_user_error(env->regs[8], &sc->arm_r8, err);
1220 	__get_user_error(env->regs[9], &sc->arm_r9, err);
1221 	__get_user_error(env->regs[10], &sc->arm_r10, err);
1222 	__get_user_error(env->regs[11], &sc->arm_fp, err);
1223 	__get_user_error(env->regs[12], &sc->arm_ip, err);
1224 	__get_user_error(env->regs[13], &sc->arm_sp, err);
1225 	__get_user_error(env->regs[14], &sc->arm_lr, err);
1226 	__get_user_error(env->regs[15], &sc->arm_pc, err);
1227 #ifdef TARGET_CONFIG_CPU_32
1228 	__get_user_error(env->cpsr, &sc->arm_cpsr, err);
1229 #endif
1230 
1231 	err |= !valid_user_regs(env);
1232 
1233 	return err;
1234 }
1235 
1236 long do_sigreturn(CPUState *env)
1237 {
1238 	struct sigframe *frame;
1239 	target_sigset_t set;
1240         sigset_t host_set;
1241 
1242 	/*
1243 	 * Since we stacked the signal on a 64-bit boundary,
1244 	 * then 'sp' should be word aligned here.  If it's
1245 	 * not, then the user is trying to mess with us.
1246 	 */
1247 	if (env->regs[13] & 7)
1248 		goto badframe;
1249 
1250 	frame = (struct sigframe *)env->regs[13];
1251 
1252 #if 0
1253 	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
1254 		goto badframe;
1255 #endif
1256 	if (__get_user(set.sig[0], &frame->sc.oldmask)
1257 	    || (TARGET_NSIG_WORDS > 1
1258 	        && __copy_from_user(&set.sig[1], &frame->extramask,
1259 				    sizeof(frame->extramask))))
1260 		goto badframe;
1261 
1262         target_to_host_sigset(&host_set, &set);
1263         sigprocmask(SIG_SETMASK, &host_set, NULL);
1264 
1265 	if (restore_sigcontext(env, &frame->sc))
1266 		goto badframe;
1267 
1268 #if 0
1269 	/* Send SIGTRAP if we're single-stepping */
1270 	if (ptrace_cancel_bpt(current))
1271 		send_sig(SIGTRAP, current, 1);
1272 #endif
1273 	return env->regs[0];
1274 
1275 badframe:
1276         force_sig(SIGSEGV /* , current */);
1277 	return 0;
1278 }
1279 
1280 long do_rt_sigreturn(CPUState *env)
1281 {
1282 	struct rt_sigframe *frame;
1283 	target_sigset_t set;
1284         sigset_t host_set;
1285 
1286 	/*
1287 	 * Since we stacked the signal on a 64-bit boundary,
1288 	 * then 'sp' should be word aligned here.  If it's
1289 	 * not, then the user is trying to mess with us.
1290 	 */
1291 	if (env->regs[13] & 7)
1292 		goto badframe;
1293 
1294 	frame = (struct rt_sigframe *)env->regs[13];
1295 
1296 #if 0
1297 	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
1298 		goto badframe;
1299 #endif
1300 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
1301 		goto badframe;
1302 
1303         target_to_host_sigset(&host_set, &set);
1304         sigprocmask(SIG_SETMASK, &host_set, NULL);
1305 
1306 	if (restore_sigcontext(env, &frame->uc.uc_mcontext))
1307 		goto badframe;
1308 
1309 #if 0
1310 	/* Send SIGTRAP if we're single-stepping */
1311 	if (ptrace_cancel_bpt(current))
1312 		send_sig(SIGTRAP, current, 1);
1313 #endif
1314 	return env->regs[0];
1315 
1316 badframe:
1317         force_sig(SIGSEGV /* , current */);
1318 	return 0;
1319 }
1320 
1321 #else
1322 
1323 static void setup_frame(int sig, struct emulated_sigaction *ka,
1324 			target_sigset_t *set, CPUState *env)
1325 {
1326     fprintf(stderr, "setup_frame: not implemented\n");
1327 }
1328 
1329 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
1330                            target_siginfo_t *info,
1331 			   target_sigset_t *set, CPUState *env)
1332 {
1333     fprintf(stderr, "setup_rt_frame: not implemented\n");
1334 }
1335 
1336 long do_sigreturn(CPUState *env)
1337 {
1338     fprintf(stderr, "do_sigreturn: not implemented\n");
1339     return -ENOSYS;
1340 }
1341 
1342 long do_rt_sigreturn(CPUState *env)
1343 {
1344     fprintf(stderr, "do_rt_sigreturn: not implemented\n");
1345     return -ENOSYS;
1346 }
1347 
1348 #endif
1349 
1350 void process_pending_signals(void *cpu_env)
1351 {
1352     int sig;
1353     target_ulong handler;
1354     sigset_t set, old_set;
1355     target_sigset_t target_old_set;
1356     struct emulated_sigaction *k;
1357     struct sigqueue *q;
1358 
1359     if (!signal_pending)
1360         return;
1361 
1362     k = sigact_table;
1363     for(sig = 1; sig <= TARGET_NSIG; sig++) {
1364         if (k->pending)
1365             goto handle_signal;
1366         k++;
1367     }
1368     /* if no signal is pending, just return */
1369     signal_pending = 0;
1370     return;
1371 
1372  handle_signal:
1373 #ifdef DEBUG_SIGNAL
1374     fprintf(stderr, "qemu: process signal %d\n", sig);
1375 #endif
1376     /* dequeue signal */
1377     q = k->first;
1378     k->first = q->next;
1379     if (!k->first)
1380         k->pending = 0;
1381 
1382     handler = k->sa._sa_handler;
1383     if (handler == TARGET_SIG_DFL) {
1384         /* default handler : ignore some signal. The other are fatal */
1385         if (sig != TARGET_SIGCHLD &&
1386             sig != TARGET_SIGURG &&
1387             sig != TARGET_SIGWINCH) {
1388             force_sig(sig);
1389         }
1390     } else if (handler == TARGET_SIG_IGN) {
1391         /* ignore sig */
1392     } else if (handler == TARGET_SIG_ERR) {
1393         force_sig(sig);
1394     } else {
1395         /* compute the blocked signals during the handler execution */
1396         target_to_host_sigset(&set, &k->sa.sa_mask);
1397         /* SA_NODEFER indicates that the current signal should not be
1398            blocked during the handler */
1399         if (!(k->sa.sa_flags & TARGET_SA_NODEFER))
1400             sigaddset(&set, target_to_host_signal(sig));
1401 
1402         /* block signals in the handler using Linux */
1403         sigprocmask(SIG_BLOCK, &set, &old_set);
1404         /* save the previous blocked signal state to restore it at the
1405            end of the signal execution (see do_sigreturn) */
1406         host_to_target_sigset(&target_old_set, &old_set);
1407 
1408         /* if the CPU is in VM86 mode, we restore the 32 bit values */
1409 #ifdef TARGET_I386
1410         {
1411             CPUX86State *env = cpu_env;
1412             if (env->eflags & VM_MASK)
1413                 save_v86_state(env);
1414         }
1415 #endif
1416         /* prepare the stack frame of the virtual CPU */
1417         if (k->sa.sa_flags & TARGET_SA_SIGINFO)
1418             setup_rt_frame(sig, k, &q->info, &target_old_set, cpu_env);
1419         else
1420             setup_frame(sig, k, &target_old_set, cpu_env);
1421 	if (k->sa.sa_flags & TARGET_SA_RESETHAND)
1422             k->sa._sa_handler = TARGET_SIG_DFL;
1423     }
1424     if (q != &k->info)
1425         free_sigqueue(q);
1426 }
1427 
1428 
1429