xref: /qemu/linux-user/signal.c (revision 74ccb34e6b52d06d577b5e3695d86d7f440431df)
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 #include "qemu.h"
30 
31 //#define DEBUG_SIGNAL
32 
33 #define MAX_SIGQUEUE_SIZE 1024
34 
35 struct sigqueue {
36     struct sigqueue *next;
37     target_siginfo_t info;
38 };
39 
40 struct emulated_sigaction {
41     struct target_sigaction sa;
42     int pending; /* true if signal is pending */
43     struct sigqueue *first;
44     struct sigqueue info; /* in order to always have memory for the
45                              first signal, we put it here */
46 };
47 
48 static struct emulated_sigaction sigact_table[TARGET_NSIG];
49 static struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
50 static struct sigqueue *first_free; /* first free siginfo queue entry */
51 static int signal_pending; /* non zero if a signal may be pending */
52 
53 static void host_signal_handler(int host_signum, siginfo_t *info,
54                                 void *puc);
55 
56 static uint8_t host_to_target_signal_table[65] = {
57     [SIGHUP] = TARGET_SIGHUP,
58     [SIGINT] = TARGET_SIGINT,
59     [SIGQUIT] = TARGET_SIGQUIT,
60     [SIGILL] = TARGET_SIGILL,
61     [SIGTRAP] = TARGET_SIGTRAP,
62     [SIGABRT] = TARGET_SIGABRT,
63 /*    [SIGIOT] = TARGET_SIGIOT,*/
64     [SIGBUS] = TARGET_SIGBUS,
65     [SIGFPE] = TARGET_SIGFPE,
66     [SIGKILL] = TARGET_SIGKILL,
67     [SIGUSR1] = TARGET_SIGUSR1,
68     [SIGSEGV] = TARGET_SIGSEGV,
69     [SIGUSR2] = TARGET_SIGUSR2,
70     [SIGPIPE] = TARGET_SIGPIPE,
71     [SIGALRM] = TARGET_SIGALRM,
72     [SIGTERM] = TARGET_SIGTERM,
73 #ifdef SIGSTKFLT
74     [SIGSTKFLT] = TARGET_SIGSTKFLT,
75 #endif
76     [SIGCHLD] = TARGET_SIGCHLD,
77     [SIGCONT] = TARGET_SIGCONT,
78     [SIGSTOP] = TARGET_SIGSTOP,
79     [SIGTSTP] = TARGET_SIGTSTP,
80     [SIGTTIN] = TARGET_SIGTTIN,
81     [SIGTTOU] = TARGET_SIGTTOU,
82     [SIGURG] = TARGET_SIGURG,
83     [SIGXCPU] = TARGET_SIGXCPU,
84     [SIGXFSZ] = TARGET_SIGXFSZ,
85     [SIGVTALRM] = TARGET_SIGVTALRM,
86     [SIGPROF] = TARGET_SIGPROF,
87     [SIGWINCH] = TARGET_SIGWINCH,
88     [SIGIO] = TARGET_SIGIO,
89     [SIGPWR] = TARGET_SIGPWR,
90     [SIGSYS] = TARGET_SIGSYS,
91     /* next signals stay the same */
92 };
93 static uint8_t target_to_host_signal_table[65];
94 
95 static inline int host_to_target_signal(int sig)
96 {
97     return host_to_target_signal_table[sig];
98 }
99 
100 static inline int target_to_host_signal(int sig)
101 {
102     return target_to_host_signal_table[sig];
103 }
104 
105 static void host_to_target_sigset_internal(target_sigset_t *d,
106                                            const sigset_t *s)
107 {
108     int i;
109     unsigned long sigmask;
110     uint32_t target_sigmask;
111 
112     sigmask = ((unsigned long *)s)[0];
113     target_sigmask = 0;
114     for(i = 0; i < 32; i++) {
115         if (sigmask & (1 << i))
116             target_sigmask |= 1 << (host_to_target_signal(i + 1) - 1);
117     }
118 #if TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 32
119     d->sig[0] = target_sigmask;
120     for(i = 1;i < TARGET_NSIG_WORDS; i++) {
121         d->sig[i] = ((unsigned long *)s)[i];
122     }
123 #elif TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 64 && TARGET_NSIG_WORDS == 2
124     d->sig[0] = target_sigmask;
125     d->sig[1] = sigmask >> 32;
126 #else
127 #warning host_to_target_sigset
128 #endif
129 }
130 
131 void host_to_target_sigset(target_sigset_t *d, const sigset_t *s)
132 {
133     target_sigset_t d1;
134     int i;
135 
136     host_to_target_sigset_internal(&d1, s);
137     for(i = 0;i < TARGET_NSIG_WORDS; i++)
138         d->sig[i] = tswapl(d1.sig[i]);
139 }
140 
141 void target_to_host_sigset_internal(sigset_t *d, const target_sigset_t *s)
142 {
143     int i;
144     unsigned long sigmask;
145     target_ulong target_sigmask;
146 
147     target_sigmask = s->sig[0];
148     sigmask = 0;
149     for(i = 0; i < 32; i++) {
150         if (target_sigmask & (1 << i))
151             sigmask |= 1 << (target_to_host_signal(i + 1) - 1);
152     }
153 #if TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 32
154     ((unsigned long *)d)[0] = sigmask;
155     for(i = 1;i < TARGET_NSIG_WORDS; i++) {
156         ((unsigned long *)d)[i] = s->sig[i];
157     }
158 #elif TARGET_LONG_BITS == 32 && HOST_LONG_BITS == 64 && TARGET_NSIG_WORDS == 2
159     ((unsigned long *)d)[0] = sigmask | ((unsigned long)(s->sig[1]) << 32);
160 #else
161 #warning target_to_host_sigset
162 #endif /* TARGET_LONG_BITS */
163 }
164 
165 void target_to_host_sigset(sigset_t *d, const target_sigset_t *s)
166 {
167     target_sigset_t s1;
168     int i;
169 
170     for(i = 0;i < TARGET_NSIG_WORDS; i++)
171         s1.sig[i] = tswapl(s->sig[i]);
172     target_to_host_sigset_internal(d, &s1);
173 }
174 
175 void host_to_target_old_sigset(target_ulong *old_sigset,
176                                const sigset_t *sigset)
177 {
178     target_sigset_t d;
179     host_to_target_sigset(&d, sigset);
180     *old_sigset = d.sig[0];
181 }
182 
183 void target_to_host_old_sigset(sigset_t *sigset,
184                                const target_ulong *old_sigset)
185 {
186     target_sigset_t d;
187     int i;
188 
189     d.sig[0] = *old_sigset;
190     for(i = 1;i < TARGET_NSIG_WORDS; i++)
191         d.sig[i] = 0;
192     target_to_host_sigset(sigset, &d);
193 }
194 
195 /* siginfo conversion */
196 
197 static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
198                                                  const siginfo_t *info)
199 {
200     int sig;
201     sig = host_to_target_signal(info->si_signo);
202     tinfo->si_signo = sig;
203     tinfo->si_errno = 0;
204     tinfo->si_code = 0;
205     if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV ||
206         sig == SIGBUS || sig == SIGTRAP) {
207         /* should never come here, but who knows. The information for
208            the target is irrelevant */
209         tinfo->_sifields._sigfault._addr = 0;
210     } else if (sig >= TARGET_SIGRTMIN) {
211         tinfo->_sifields._rt._pid = info->si_pid;
212         tinfo->_sifields._rt._uid = info->si_uid;
213         /* XXX: potential problem if 64 bit */
214         tinfo->_sifields._rt._sigval.sival_ptr =
215             (target_ulong)info->si_value.sival_ptr;
216     }
217 }
218 
219 static void tswap_siginfo(target_siginfo_t *tinfo,
220                           const target_siginfo_t *info)
221 {
222     int sig;
223     sig = info->si_signo;
224     tinfo->si_signo = tswap32(sig);
225     tinfo->si_errno = tswap32(info->si_errno);
226     tinfo->si_code = tswap32(info->si_code);
227     if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV ||
228         sig == SIGBUS || sig == SIGTRAP) {
229         tinfo->_sifields._sigfault._addr =
230             tswapl(info->_sifields._sigfault._addr);
231     } else if (sig >= TARGET_SIGRTMIN) {
232         tinfo->_sifields._rt._pid = tswap32(info->_sifields._rt._pid);
233         tinfo->_sifields._rt._uid = tswap32(info->_sifields._rt._uid);
234         tinfo->_sifields._rt._sigval.sival_ptr =
235             tswapl(info->_sifields._rt._sigval.sival_ptr);
236     }
237 }
238 
239 
240 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
241 {
242     host_to_target_siginfo_noswap(tinfo, info);
243     tswap_siginfo(tinfo, tinfo);
244 }
245 
246 /* XXX: we support only POSIX RT signals are used. */
247 /* XXX: find a solution for 64 bit (additionnal malloced data is needed) */
248 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
249 {
250     info->si_signo = tswap32(tinfo->si_signo);
251     info->si_errno = tswap32(tinfo->si_errno);
252     info->si_code = tswap32(tinfo->si_code);
253     info->si_pid = tswap32(tinfo->_sifields._rt._pid);
254     info->si_uid = tswap32(tinfo->_sifields._rt._uid);
255     info->si_value.sival_ptr =
256         (void *)tswapl(tinfo->_sifields._rt._sigval.sival_ptr);
257 }
258 
259 void signal_init(void)
260 {
261     struct sigaction act;
262     int i, j;
263 
264     /* generate signal conversion tables */
265     for(i = 1; i <= 64; i++) {
266         if (host_to_target_signal_table[i] == 0)
267             host_to_target_signal_table[i] = i;
268     }
269     for(i = 1; i <= 64; i++) {
270         j = host_to_target_signal_table[i];
271         target_to_host_signal_table[j] = i;
272     }
273 
274     /* set all host signal handlers. ALL signals are blocked during
275        the handlers to serialize them. */
276     sigfillset(&act.sa_mask);
277     act.sa_flags = SA_SIGINFO;
278     act.sa_sigaction = host_signal_handler;
279     for(i = 1; i < NSIG; i++) {
280         sigaction(i, &act, NULL);
281     }
282 
283     memset(sigact_table, 0, sizeof(sigact_table));
284 
285     first_free = &sigqueue_table[0];
286     for(i = 0; i < MAX_SIGQUEUE_SIZE - 1; i++)
287         sigqueue_table[i].next = &sigqueue_table[i + 1];
288     sigqueue_table[MAX_SIGQUEUE_SIZE - 1].next = NULL;
289 }
290 
291 /* signal queue handling */
292 
293 static inline struct sigqueue *alloc_sigqueue(void)
294 {
295     struct sigqueue *q = first_free;
296     if (!q)
297         return NULL;
298     first_free = q->next;
299     return q;
300 }
301 
302 static inline void free_sigqueue(struct sigqueue *q)
303 {
304     q->next = first_free;
305     first_free = q;
306 }
307 
308 /* abort execution with signal */
309 void __attribute((noreturn)) force_sig(int sig)
310 {
311     int host_sig;
312     host_sig = target_to_host_signal(sig);
313     fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n",
314             sig, strsignal(host_sig));
315 #if 1
316     _exit(-host_sig);
317 #else
318     {
319         struct sigaction act;
320         sigemptyset(&act.sa_mask);
321         act.sa_flags = SA_SIGINFO;
322         act.sa_sigaction = SIG_DFL;
323         sigaction(SIGABRT, &act, NULL);
324         abort();
325     }
326 #endif
327 }
328 
329 /* queue a signal so that it will be send to the virtual CPU as soon
330    as possible */
331 int queue_signal(int sig, target_siginfo_t *info)
332 {
333     struct emulated_sigaction *k;
334     struct sigqueue *q, **pq;
335     target_ulong handler;
336 
337 #if defined(DEBUG_SIGNAL)
338     fprintf(stderr, "queue_signal: sig=%d\n",
339             sig);
340 #endif
341     k = &sigact_table[sig - 1];
342     handler = k->sa._sa_handler;
343     if (handler == TARGET_SIG_DFL) {
344         /* default handler : ignore some signal. The other are fatal */
345         if (sig != TARGET_SIGCHLD &&
346             sig != TARGET_SIGURG &&
347             sig != TARGET_SIGWINCH) {
348             force_sig(sig);
349         } else {
350             return 0; /* indicate ignored */
351         }
352     } else if (handler == TARGET_SIG_IGN) {
353         /* ignore signal */
354         return 0;
355     } else if (handler == TARGET_SIG_ERR) {
356         force_sig(sig);
357     } else {
358         pq = &k->first;
359         if (sig < TARGET_SIGRTMIN) {
360             /* if non real time signal, we queue exactly one signal */
361             if (!k->pending)
362                 q = &k->info;
363             else
364                 return 0;
365         } else {
366             if (!k->pending) {
367                 /* first signal */
368                 q = &k->info;
369             } else {
370                 q = alloc_sigqueue();
371                 if (!q)
372                     return -EAGAIN;
373                 while (*pq != NULL)
374                     pq = &(*pq)->next;
375             }
376         }
377         *pq = q;
378         q->info = *info;
379         q->next = NULL;
380         k->pending = 1;
381         /* signal that a new signal is pending */
382         signal_pending = 1;
383         return 1; /* indicates that the signal was queued */
384     }
385 }
386 
387 static void host_signal_handler(int host_signum, siginfo_t *info,
388                                 void *puc)
389 {
390     int sig;
391     target_siginfo_t tinfo;
392 
393     /* the CPU emulator uses some host signals to detect exceptions,
394        we we forward to it some signals */
395     if (host_signum == SIGSEGV || host_signum == SIGBUS
396 #if defined(TARGET_I386) && defined(USE_CODE_COPY)
397         || host_signum == SIGFPE
398 #endif
399         ) {
400         if (cpu_signal_handler(host_signum, info, puc))
401             return;
402     }
403 
404     /* get target signal number */
405     sig = host_to_target_signal(host_signum);
406     if (sig < 1 || sig > TARGET_NSIG)
407         return;
408 #if defined(DEBUG_SIGNAL)
409     fprintf(stderr, "qemu: got signal %d\n", sig);
410 #endif
411     host_to_target_siginfo_noswap(&tinfo, info);
412     if (queue_signal(sig, &tinfo) == 1) {
413         /* interrupt the virtual CPU as soon as possible */
414         cpu_interrupt(global_env, CPU_INTERRUPT_EXIT);
415     }
416 }
417 
418 int do_sigaction(int sig, const struct target_sigaction *act,
419                  struct target_sigaction *oact)
420 {
421     struct emulated_sigaction *k;
422     struct sigaction act1;
423     int host_sig;
424 
425     if (sig < 1 || sig > TARGET_NSIG)
426         return -EINVAL;
427     k = &sigact_table[sig - 1];
428 #if defined(DEBUG_SIGNAL)
429     fprintf(stderr, "sigaction sig=%d act=0x%08x, oact=0x%08x\n",
430             sig, (int)act, (int)oact);
431 #endif
432     if (oact) {
433         oact->_sa_handler = tswapl(k->sa._sa_handler);
434         oact->sa_flags = tswapl(k->sa.sa_flags);
435 	#if !defined(TARGET_MIPS)
436         	oact->sa_restorer = tswapl(k->sa.sa_restorer);
437 	#endif
438         oact->sa_mask = k->sa.sa_mask;
439     }
440     if (act) {
441         k->sa._sa_handler = tswapl(act->_sa_handler);
442         k->sa.sa_flags = tswapl(act->sa_flags);
443 	#if !defined(TARGET_MIPS)
444         	k->sa.sa_restorer = tswapl(act->sa_restorer);
445 	#endif
446         k->sa.sa_mask = act->sa_mask;
447 
448         /* we update the host linux signal state */
449         host_sig = target_to_host_signal(sig);
450         if (host_sig != SIGSEGV && host_sig != SIGBUS) {
451             sigfillset(&act1.sa_mask);
452             act1.sa_flags = SA_SIGINFO;
453             if (k->sa.sa_flags & TARGET_SA_RESTART)
454                 act1.sa_flags |= SA_RESTART;
455             /* NOTE: it is important to update the host kernel signal
456                ignore state to avoid getting unexpected interrupted
457                syscalls */
458             if (k->sa._sa_handler == TARGET_SIG_IGN) {
459                 act1.sa_sigaction = (void *)SIG_IGN;
460             } else if (k->sa._sa_handler == TARGET_SIG_DFL) {
461                 act1.sa_sigaction = (void *)SIG_DFL;
462             } else {
463                 act1.sa_sigaction = host_signal_handler;
464             }
465             sigaction(host_sig, &act1, NULL);
466         }
467     }
468     return 0;
469 }
470 
471 #ifndef offsetof
472 #define offsetof(type, field) ((size_t) &((type *)0)->field)
473 #endif
474 
475 static inline int copy_siginfo_to_user(target_siginfo_t *tinfo,
476                                        const target_siginfo_t *info)
477 {
478     tswap_siginfo(tinfo, info);
479     return 0;
480 }
481 
482 #ifdef TARGET_I386
483 
484 /* from the Linux kernel */
485 
486 struct target_fpreg {
487 	uint16_t significand[4];
488 	uint16_t exponent;
489 };
490 
491 struct target_fpxreg {
492 	uint16_t significand[4];
493 	uint16_t exponent;
494 	uint16_t padding[3];
495 };
496 
497 struct target_xmmreg {
498 	target_ulong element[4];
499 };
500 
501 struct target_fpstate {
502 	/* Regular FPU environment */
503 	target_ulong 	cw;
504 	target_ulong	sw;
505 	target_ulong	tag;
506 	target_ulong	ipoff;
507 	target_ulong	cssel;
508 	target_ulong	dataoff;
509 	target_ulong	datasel;
510 	struct target_fpreg	_st[8];
511 	uint16_t	status;
512 	uint16_t	magic;		/* 0xffff = regular FPU data only */
513 
514 	/* FXSR FPU environment */
515 	target_ulong	_fxsr_env[6];	/* FXSR FPU env is ignored */
516 	target_ulong	mxcsr;
517 	target_ulong	reserved;
518 	struct target_fpxreg	_fxsr_st[8];	/* FXSR FPU reg data is ignored */
519 	struct target_xmmreg	_xmm[8];
520 	target_ulong	padding[56];
521 };
522 
523 #define X86_FXSR_MAGIC		0x0000
524 
525 struct target_sigcontext {
526 	uint16_t gs, __gsh;
527 	uint16_t fs, __fsh;
528 	uint16_t es, __esh;
529 	uint16_t ds, __dsh;
530 	target_ulong edi;
531 	target_ulong esi;
532 	target_ulong ebp;
533 	target_ulong esp;
534 	target_ulong ebx;
535 	target_ulong edx;
536 	target_ulong ecx;
537 	target_ulong eax;
538 	target_ulong trapno;
539 	target_ulong err;
540 	target_ulong eip;
541 	uint16_t cs, __csh;
542 	target_ulong eflags;
543 	target_ulong esp_at_signal;
544 	uint16_t ss, __ssh;
545         target_ulong fpstate; /* pointer */
546 	target_ulong oldmask;
547 	target_ulong cr2;
548 };
549 
550 typedef struct target_sigaltstack {
551 	target_ulong ss_sp;
552 	int ss_flags;
553 	target_ulong ss_size;
554 } target_stack_t;
555 
556 struct target_ucontext {
557         target_ulong	  tuc_flags;
558 	target_ulong      tuc_link;
559 	target_stack_t	  tuc_stack;
560 	struct target_sigcontext tuc_mcontext;
561 	target_sigset_t	  tuc_sigmask;	/* mask last for extensibility */
562 };
563 
564 struct sigframe
565 {
566     target_ulong pretcode;
567     int sig;
568     struct target_sigcontext sc;
569     struct target_fpstate fpstate;
570     target_ulong extramask[TARGET_NSIG_WORDS-1];
571     char retcode[8];
572 };
573 
574 struct rt_sigframe
575 {
576     target_ulong pretcode;
577     int sig;
578     target_ulong pinfo;
579     target_ulong puc;
580     struct target_siginfo info;
581     struct target_ucontext uc;
582     struct target_fpstate fpstate;
583     char retcode[8];
584 };
585 
586 /*
587  * Set up a signal frame.
588  */
589 
590 /* XXX: save x87 state */
591 static int
592 setup_sigcontext(struct target_sigcontext *sc, struct target_fpstate *fpstate,
593 		 CPUX86State *env, unsigned long mask)
594 {
595 	int err = 0;
596 
597 	err |= __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
598 	err |= __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
599 	err |= __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
600 	err |= __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
601 	err |= __put_user(env->regs[R_EDI], &sc->edi);
602 	err |= __put_user(env->regs[R_ESI], &sc->esi);
603 	err |= __put_user(env->regs[R_EBP], &sc->ebp);
604 	err |= __put_user(env->regs[R_ESP], &sc->esp);
605 	err |= __put_user(env->regs[R_EBX], &sc->ebx);
606 	err |= __put_user(env->regs[R_EDX], &sc->edx);
607 	err |= __put_user(env->regs[R_ECX], &sc->ecx);
608 	err |= __put_user(env->regs[R_EAX], &sc->eax);
609 	err |= __put_user(env->exception_index, &sc->trapno);
610 	err |= __put_user(env->error_code, &sc->err);
611 	err |= __put_user(env->eip, &sc->eip);
612 	err |= __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
613 	err |= __put_user(env->eflags, &sc->eflags);
614 	err |= __put_user(env->regs[R_ESP], &sc->esp_at_signal);
615 	err |= __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
616 
617         cpu_x86_fsave(env, (void *)fpstate, 1);
618         fpstate->status = fpstate->sw;
619         err |= __put_user(0xffff, &fpstate->magic);
620         err |= __put_user(fpstate, &sc->fpstate);
621 
622 	/* non-iBCS2 extensions.. */
623 	err |= __put_user(mask, &sc->oldmask);
624 	err |= __put_user(env->cr[2], &sc->cr2);
625 	return err;
626 }
627 
628 /*
629  * Determine which stack to use..
630  */
631 
632 static inline void *
633 get_sigframe(struct emulated_sigaction *ka, CPUX86State *env, size_t frame_size)
634 {
635 	unsigned long esp;
636 
637 	/* Default to using normal stack */
638 	esp = env->regs[R_ESP];
639 #if 0
640 	/* This is the X/Open sanctioned signal stack switching.  */
641 	if (ka->sa.sa_flags & SA_ONSTACK) {
642 		if (sas_ss_flags(esp) == 0)
643 			esp = current->sas_ss_sp + current->sas_ss_size;
644 	}
645 
646 	/* This is the legacy signal stack switching. */
647 	else
648 #endif
649         if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
650             !(ka->sa.sa_flags & TARGET_SA_RESTORER) &&
651             ka->sa.sa_restorer) {
652             esp = (unsigned long) ka->sa.sa_restorer;
653 	}
654         return g2h((esp - frame_size) & -8ul);
655 }
656 
657 static void setup_frame(int sig, struct emulated_sigaction *ka,
658 			target_sigset_t *set, CPUX86State *env)
659 {
660 	struct sigframe *frame;
661 	int i, err = 0;
662 
663 	frame = get_sigframe(ka, env, sizeof(*frame));
664 
665 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
666 		goto give_sigsegv;
667 	err |= __put_user((/*current->exec_domain
668 		           && current->exec_domain->signal_invmap
669 		           && sig < 32
670 		           ? current->exec_domain->signal_invmap[sig]
671 		           : */ sig),
672 		          &frame->sig);
673 	if (err)
674 		goto give_sigsegv;
675 
676 	setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0]);
677 	if (err)
678 		goto give_sigsegv;
679 
680         for(i = 1; i < TARGET_NSIG_WORDS; i++) {
681             if (__put_user(set->sig[i], &frame->extramask[i - 1]))
682                 goto give_sigsegv;
683         }
684 
685 	/* Set up to return from userspace.  If provided, use a stub
686 	   already in userspace.  */
687 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
688 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
689 	} else {
690 		err |= __put_user(frame->retcode, &frame->pretcode);
691 		/* This is popl %eax ; movl $,%eax ; int $0x80 */
692 		err |= __put_user(0xb858, (short *)(frame->retcode+0));
693 		err |= __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2));
694 		err |= __put_user(0x80cd, (short *)(frame->retcode+6));
695 	}
696 
697 	if (err)
698 		goto give_sigsegv;
699 
700 	/* Set up registers for signal handler */
701 	env->regs[R_ESP] = h2g(frame);
702 	env->eip = (unsigned long) ka->sa._sa_handler;
703 
704         cpu_x86_load_seg(env, R_DS, __USER_DS);
705         cpu_x86_load_seg(env, R_ES, __USER_DS);
706         cpu_x86_load_seg(env, R_SS, __USER_DS);
707         cpu_x86_load_seg(env, R_CS, __USER_CS);
708 	env->eflags &= ~TF_MASK;
709 
710 	return;
711 
712 give_sigsegv:
713 	if (sig == TARGET_SIGSEGV)
714 		ka->sa._sa_handler = TARGET_SIG_DFL;
715 	force_sig(TARGET_SIGSEGV /* , current */);
716 }
717 
718 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
719                            target_siginfo_t *info,
720 			   target_sigset_t *set, CPUX86State *env)
721 {
722 	struct rt_sigframe *frame;
723 	int i, err = 0;
724 
725 	frame = get_sigframe(ka, env, sizeof(*frame));
726 
727 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
728 		goto give_sigsegv;
729 
730 	err |= __put_user((/*current->exec_domain
731 		    	   && current->exec_domain->signal_invmap
732 		    	   && sig < 32
733 		    	   ? current->exec_domain->signal_invmap[sig]
734 			   : */sig),
735 			  &frame->sig);
736 	err |= __put_user((target_ulong)&frame->info, &frame->pinfo);
737 	err |= __put_user((target_ulong)&frame->uc, &frame->puc);
738 	err |= copy_siginfo_to_user(&frame->info, info);
739 	if (err)
740 		goto give_sigsegv;
741 
742 	/* Create the ucontext.  */
743 	err |= __put_user(0, &frame->uc.tuc_flags);
744 	err |= __put_user(0, &frame->uc.tuc_link);
745 	err |= __put_user(/*current->sas_ss_sp*/ 0,
746 			  &frame->uc.tuc_stack.ss_sp);
747 	err |= __put_user(/* sas_ss_flags(regs->esp) */ 0,
748 			  &frame->uc.tuc_stack.ss_flags);
749 	err |= __put_user(/* current->sas_ss_size */ 0,
750 			  &frame->uc.tuc_stack.ss_size);
751 	err |= setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate,
752 			        env, set->sig[0]);
753         for(i = 0; i < TARGET_NSIG_WORDS; i++) {
754             if (__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]))
755                 goto give_sigsegv;
756         }
757 
758 	/* Set up to return from userspace.  If provided, use a stub
759 	   already in userspace.  */
760 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
761 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
762 	} else {
763 		err |= __put_user(frame->retcode, &frame->pretcode);
764 		/* This is movl $,%eax ; int $0x80 */
765 		err |= __put_user(0xb8, (char *)(frame->retcode+0));
766 		err |= __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1));
767 		err |= __put_user(0x80cd, (short *)(frame->retcode+5));
768 	}
769 
770 	if (err)
771 		goto give_sigsegv;
772 
773 	/* Set up registers for signal handler */
774 	env->regs[R_ESP] = (unsigned long) frame;
775 	env->eip = (unsigned long) ka->sa._sa_handler;
776 
777         cpu_x86_load_seg(env, R_DS, __USER_DS);
778         cpu_x86_load_seg(env, R_ES, __USER_DS);
779         cpu_x86_load_seg(env, R_SS, __USER_DS);
780         cpu_x86_load_seg(env, R_CS, __USER_CS);
781 	env->eflags &= ~TF_MASK;
782 
783 	return;
784 
785 give_sigsegv:
786 	if (sig == TARGET_SIGSEGV)
787 		ka->sa._sa_handler = TARGET_SIG_DFL;
788 	force_sig(TARGET_SIGSEGV /* , current */);
789 }
790 
791 static int
792 restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax)
793 {
794 	unsigned int err = 0;
795 
796         cpu_x86_load_seg(env, R_GS, lduw(&sc->gs));
797         cpu_x86_load_seg(env, R_FS, lduw(&sc->fs));
798         cpu_x86_load_seg(env, R_ES, lduw(&sc->es));
799         cpu_x86_load_seg(env, R_DS, lduw(&sc->ds));
800 
801         env->regs[R_EDI] = ldl(&sc->edi);
802         env->regs[R_ESI] = ldl(&sc->esi);
803         env->regs[R_EBP] = ldl(&sc->ebp);
804         env->regs[R_ESP] = ldl(&sc->esp);
805         env->regs[R_EBX] = ldl(&sc->ebx);
806         env->regs[R_EDX] = ldl(&sc->edx);
807         env->regs[R_ECX] = ldl(&sc->ecx);
808         env->eip = ldl(&sc->eip);
809 
810         cpu_x86_load_seg(env, R_CS, lduw(&sc->cs) | 3);
811         cpu_x86_load_seg(env, R_SS, lduw(&sc->ss) | 3);
812 
813 	{
814 		unsigned int tmpflags;
815                 tmpflags = ldl(&sc->eflags);
816 		env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
817                 //		regs->orig_eax = -1;		/* disable syscall checks */
818 	}
819 
820 	{
821 		struct _fpstate * buf;
822                 buf = (void *)ldl(&sc->fpstate);
823 		if (buf) {
824 #if 0
825 			if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
826 				goto badframe;
827 #endif
828                         cpu_x86_frstor(env, (void *)buf, 1);
829 		}
830 	}
831 
832         *peax = ldl(&sc->eax);
833 	return err;
834 #if 0
835 badframe:
836 	return 1;
837 #endif
838 }
839 
840 long do_sigreturn(CPUX86State *env)
841 {
842     struct sigframe *frame = (struct sigframe *)g2h(env->regs[R_ESP] - 8);
843     target_sigset_t target_set;
844     sigset_t set;
845     int eax, i;
846 
847 #if defined(DEBUG_SIGNAL)
848     fprintf(stderr, "do_sigreturn\n");
849 #endif
850     /* set blocked signals */
851     if (__get_user(target_set.sig[0], &frame->sc.oldmask))
852         goto badframe;
853     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
854         if (__get_user(target_set.sig[i], &frame->extramask[i - 1]))
855             goto badframe;
856     }
857 
858     target_to_host_sigset_internal(&set, &target_set);
859     sigprocmask(SIG_SETMASK, &set, NULL);
860 
861     /* restore registers */
862     if (restore_sigcontext(env, &frame->sc, &eax))
863         goto badframe;
864     return eax;
865 
866 badframe:
867     force_sig(TARGET_SIGSEGV);
868     return 0;
869 }
870 
871 long do_rt_sigreturn(CPUX86State *env)
872 {
873 	struct rt_sigframe *frame = (struct rt_sigframe *)g2h(env->regs[R_ESP] - 4);
874         sigset_t set;
875         //	stack_t st;
876 	int eax;
877 
878 #if 0
879 	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
880 		goto badframe;
881 #endif
882         target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
883         sigprocmask(SIG_SETMASK, &set, NULL);
884 
885 	if (restore_sigcontext(env, &frame->uc.tuc_mcontext, &eax))
886 		goto badframe;
887 
888 #if 0
889 	if (__copy_from_user(&st, &frame->uc.tuc_stack, sizeof(st)))
890 		goto badframe;
891 	/* It is more difficult to avoid calling this function than to
892 	   call it and ignore errors.  */
893 	do_sigaltstack(&st, NULL, regs->esp);
894 #endif
895 	return eax;
896 
897 badframe:
898 	force_sig(TARGET_SIGSEGV);
899 	return 0;
900 }
901 
902 #elif defined(TARGET_ARM)
903 
904 struct target_sigcontext {
905 	target_ulong trap_no;
906 	target_ulong error_code;
907 	target_ulong oldmask;
908 	target_ulong arm_r0;
909 	target_ulong arm_r1;
910 	target_ulong arm_r2;
911 	target_ulong arm_r3;
912 	target_ulong arm_r4;
913 	target_ulong arm_r5;
914 	target_ulong arm_r6;
915 	target_ulong arm_r7;
916 	target_ulong arm_r8;
917 	target_ulong arm_r9;
918 	target_ulong arm_r10;
919 	target_ulong arm_fp;
920 	target_ulong arm_ip;
921 	target_ulong arm_sp;
922 	target_ulong arm_lr;
923 	target_ulong arm_pc;
924 	target_ulong arm_cpsr;
925 	target_ulong fault_address;
926 };
927 
928 typedef struct target_sigaltstack {
929 	target_ulong ss_sp;
930 	int ss_flags;
931 	target_ulong ss_size;
932 } target_stack_t;
933 
934 struct target_ucontext {
935     target_ulong tuc_flags;
936     target_ulong tuc_link;
937     target_stack_t tuc_stack;
938     struct target_sigcontext tuc_mcontext;
939     target_sigset_t  tuc_sigmask;	/* mask last for extensibility */
940 };
941 
942 struct sigframe
943 {
944     struct target_sigcontext sc;
945     target_ulong extramask[TARGET_NSIG_WORDS-1];
946     target_ulong retcode;
947 };
948 
949 struct rt_sigframe
950 {
951     struct target_siginfo *pinfo;
952     void *puc;
953     struct target_siginfo info;
954     struct target_ucontext uc;
955     target_ulong retcode;
956 };
957 
958 #define TARGET_CONFIG_CPU_32 1
959 
960 /*
961  * For ARM syscalls, we encode the syscall number into the instruction.
962  */
963 #define SWI_SYS_SIGRETURN	(0xef000000|(TARGET_NR_sigreturn + ARM_SYSCALL_BASE))
964 #define SWI_SYS_RT_SIGRETURN	(0xef000000|(TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE))
965 
966 /*
967  * For Thumb syscalls, we pass the syscall number via r7.  We therefore
968  * need two 16-bit instructions.
969  */
970 #define SWI_THUMB_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_sigreturn))
971 #define SWI_THUMB_RT_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_rt_sigreturn))
972 
973 static const target_ulong retcodes[4] = {
974 	SWI_SYS_SIGRETURN,	SWI_THUMB_SIGRETURN,
975 	SWI_SYS_RT_SIGRETURN,	SWI_THUMB_RT_SIGRETURN
976 };
977 
978 
979 #define __put_user_error(x,p,e) __put_user(x, p)
980 #define __get_user_error(x,p,e) __get_user(x, p)
981 
982 static inline int valid_user_regs(CPUState *regs)
983 {
984     return 1;
985 }
986 
987 static int
988 setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
989 		 CPUState *env, unsigned long mask)
990 {
991 	int err = 0;
992 
993 	__put_user_error(env->regs[0], &sc->arm_r0, err);
994 	__put_user_error(env->regs[1], &sc->arm_r1, err);
995 	__put_user_error(env->regs[2], &sc->arm_r2, err);
996 	__put_user_error(env->regs[3], &sc->arm_r3, err);
997 	__put_user_error(env->regs[4], &sc->arm_r4, err);
998 	__put_user_error(env->regs[5], &sc->arm_r5, err);
999 	__put_user_error(env->regs[6], &sc->arm_r6, err);
1000 	__put_user_error(env->regs[7], &sc->arm_r7, err);
1001 	__put_user_error(env->regs[8], &sc->arm_r8, err);
1002 	__put_user_error(env->regs[9], &sc->arm_r9, err);
1003 	__put_user_error(env->regs[10], &sc->arm_r10, err);
1004 	__put_user_error(env->regs[11], &sc->arm_fp, err);
1005 	__put_user_error(env->regs[12], &sc->arm_ip, err);
1006 	__put_user_error(env->regs[13], &sc->arm_sp, err);
1007 	__put_user_error(env->regs[14], &sc->arm_lr, err);
1008 	__put_user_error(env->regs[15], &sc->arm_pc, err);
1009 #ifdef TARGET_CONFIG_CPU_32
1010 	__put_user_error(cpsr_read(env), &sc->arm_cpsr, err);
1011 #endif
1012 
1013 	__put_user_error(/* current->thread.trap_no */ 0, &sc->trap_no, err);
1014 	__put_user_error(/* current->thread.error_code */ 0, &sc->error_code, err);
1015 	__put_user_error(/* current->thread.address */ 0, &sc->fault_address, err);
1016 	__put_user_error(mask, &sc->oldmask, err);
1017 
1018 	return err;
1019 }
1020 
1021 static inline void *
1022 get_sigframe(struct emulated_sigaction *ka, CPUState *regs, int framesize)
1023 {
1024 	unsigned long sp = regs->regs[13];
1025 
1026 #if 0
1027 	/*
1028 	 * This is the X/Open sanctioned signal stack switching.
1029 	 */
1030 	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
1031 		sp = current->sas_ss_sp + current->sas_ss_size;
1032 #endif
1033 	/*
1034 	 * ATPCS B01 mandates 8-byte alignment
1035 	 */
1036 	return g2h((sp - framesize) & ~7);
1037 }
1038 
1039 static int
1040 setup_return(CPUState *env, struct emulated_sigaction *ka,
1041 	     target_ulong *rc, void *frame, int usig)
1042 {
1043 	target_ulong handler = (target_ulong)ka->sa._sa_handler;
1044 	target_ulong retcode;
1045 	int thumb = 0;
1046 #if defined(TARGET_CONFIG_CPU_32)
1047 #if 0
1048 	target_ulong cpsr = env->cpsr;
1049 
1050 	/*
1051 	 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
1052 	 */
1053 	if (ka->sa.sa_flags & SA_THIRTYTWO)
1054 		cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
1055 
1056 #ifdef CONFIG_ARM_THUMB
1057 	if (elf_hwcap & HWCAP_THUMB) {
1058 		/*
1059 		 * The LSB of the handler determines if we're going to
1060 		 * be using THUMB or ARM mode for this signal handler.
1061 		 */
1062 		thumb = handler & 1;
1063 
1064 		if (thumb)
1065 			cpsr |= T_BIT;
1066 		else
1067 			cpsr &= ~T_BIT;
1068 	}
1069 #endif
1070 #endif
1071 #endif /* TARGET_CONFIG_CPU_32 */
1072 
1073 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
1074 		retcode = (target_ulong)ka->sa.sa_restorer;
1075 	} else {
1076 		unsigned int idx = thumb;
1077 
1078 		if (ka->sa.sa_flags & TARGET_SA_SIGINFO)
1079 			idx += 2;
1080 
1081 		if (__put_user(retcodes[idx], rc))
1082 			return 1;
1083 #if 0
1084 		flush_icache_range((target_ulong)rc,
1085 				   (target_ulong)(rc + 1));
1086 #endif
1087 		retcode = ((target_ulong)rc) + thumb;
1088 	}
1089 
1090 	env->regs[0] = usig;
1091 	env->regs[13] = h2g(frame);
1092 	env->regs[14] = retcode;
1093 	env->regs[15] = handler & (thumb ? ~1 : ~3);
1094 
1095 #if 0
1096 #ifdef TARGET_CONFIG_CPU_32
1097 	env->cpsr = cpsr;
1098 #endif
1099 #endif
1100 
1101 	return 0;
1102 }
1103 
1104 static void setup_frame(int usig, struct emulated_sigaction *ka,
1105 			target_sigset_t *set, CPUState *regs)
1106 {
1107 	struct sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
1108 	int i, err = 0;
1109 
1110 	err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);
1111 
1112         for(i = 1; i < TARGET_NSIG_WORDS; i++) {
1113             if (__put_user(set->sig[i], &frame->extramask[i - 1]))
1114                 return;
1115 	}
1116 
1117 	if (err == 0)
1118             err = setup_return(regs, ka, &frame->retcode, frame, usig);
1119         //	return err;
1120 }
1121 
1122 static void setup_rt_frame(int usig, struct emulated_sigaction *ka,
1123                            target_siginfo_t *info,
1124 			   target_sigset_t *set, CPUState *env)
1125 {
1126 	struct rt_sigframe *frame = get_sigframe(ka, env, sizeof(*frame));
1127 	int i, err = 0;
1128 
1129 	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
1130             return /* 1 */;
1131 
1132 	__put_user_error(&frame->info, (target_ulong *)&frame->pinfo, err);
1133 	__put_user_error(&frame->uc, (target_ulong *)&frame->puc, err);
1134 	err |= copy_siginfo_to_user(&frame->info, info);
1135 
1136 	/* Clear all the bits of the ucontext we don't use.  */
1137 	memset(&frame->uc, 0, offsetof(struct target_ucontext, tuc_mcontext));
1138 
1139 	err |= setup_sigcontext(&frame->uc.tuc_mcontext, /*&frame->fpstate,*/
1140 				env, set->sig[0]);
1141         for(i = 0; i < TARGET_NSIG_WORDS; i++) {
1142             if (__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]))
1143                 return;
1144         }
1145 
1146 	if (err == 0)
1147 		err = setup_return(env, ka, &frame->retcode, frame, usig);
1148 
1149 	if (err == 0) {
1150 		/*
1151 		 * For realtime signals we must also set the second and third
1152 		 * arguments for the signal handler.
1153 		 *   -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
1154 		 */
1155             env->regs[1] = (target_ulong)frame->pinfo;
1156             env->regs[2] = (target_ulong)frame->puc;
1157 	}
1158 
1159         //	return err;
1160 }
1161 
1162 static int
1163 restore_sigcontext(CPUState *env, struct target_sigcontext *sc)
1164 {
1165 	int err = 0;
1166         uint32_t cpsr;
1167 
1168 	__get_user_error(env->regs[0], &sc->arm_r0, err);
1169 	__get_user_error(env->regs[1], &sc->arm_r1, err);
1170 	__get_user_error(env->regs[2], &sc->arm_r2, err);
1171 	__get_user_error(env->regs[3], &sc->arm_r3, err);
1172 	__get_user_error(env->regs[4], &sc->arm_r4, err);
1173 	__get_user_error(env->regs[5], &sc->arm_r5, err);
1174 	__get_user_error(env->regs[6], &sc->arm_r6, err);
1175 	__get_user_error(env->regs[7], &sc->arm_r7, err);
1176 	__get_user_error(env->regs[8], &sc->arm_r8, err);
1177 	__get_user_error(env->regs[9], &sc->arm_r9, err);
1178 	__get_user_error(env->regs[10], &sc->arm_r10, err);
1179 	__get_user_error(env->regs[11], &sc->arm_fp, err);
1180 	__get_user_error(env->regs[12], &sc->arm_ip, err);
1181 	__get_user_error(env->regs[13], &sc->arm_sp, err);
1182 	__get_user_error(env->regs[14], &sc->arm_lr, err);
1183 	__get_user_error(env->regs[15], &sc->arm_pc, err);
1184 #ifdef TARGET_CONFIG_CPU_32
1185 	__get_user_error(cpsr, &sc->arm_cpsr, err);
1186         cpsr_write(env, cpsr, 0xffffffff);
1187 #endif
1188 
1189 	err |= !valid_user_regs(env);
1190 
1191 	return err;
1192 }
1193 
1194 long do_sigreturn(CPUState *env)
1195 {
1196 	struct sigframe *frame;
1197 	target_sigset_t set;
1198         sigset_t host_set;
1199         int i;
1200 
1201 	/*
1202 	 * Since we stacked the signal on a 64-bit boundary,
1203 	 * then 'sp' should be word aligned here.  If it's
1204 	 * not, then the user is trying to mess with us.
1205 	 */
1206 	if (env->regs[13] & 7)
1207 		goto badframe;
1208 
1209 	frame = (struct sigframe *)g2h(env->regs[13]);
1210 
1211 #if 0
1212 	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
1213 		goto badframe;
1214 #endif
1215 	if (__get_user(set.sig[0], &frame->sc.oldmask))
1216             goto badframe;
1217         for(i = 1; i < TARGET_NSIG_WORDS; i++) {
1218             if (__get_user(set.sig[i], &frame->extramask[i - 1]))
1219                 goto badframe;
1220         }
1221 
1222         target_to_host_sigset_internal(&host_set, &set);
1223         sigprocmask(SIG_SETMASK, &host_set, NULL);
1224 
1225 	if (restore_sigcontext(env, &frame->sc))
1226 		goto badframe;
1227 
1228 #if 0
1229 	/* Send SIGTRAP if we're single-stepping */
1230 	if (ptrace_cancel_bpt(current))
1231 		send_sig(SIGTRAP, current, 1);
1232 #endif
1233 	return env->regs[0];
1234 
1235 badframe:
1236         force_sig(SIGSEGV /* , current */);
1237 	return 0;
1238 }
1239 
1240 long do_rt_sigreturn(CPUState *env)
1241 {
1242 	struct rt_sigframe *frame;
1243         sigset_t host_set;
1244 
1245 	/*
1246 	 * Since we stacked the signal on a 64-bit boundary,
1247 	 * then 'sp' should be word aligned here.  If it's
1248 	 * not, then the user is trying to mess with us.
1249 	 */
1250 	if (env->regs[13] & 7)
1251 		goto badframe;
1252 
1253 	frame = (struct rt_sigframe *)env->regs[13];
1254 
1255 #if 0
1256 	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
1257 		goto badframe;
1258 #endif
1259         target_to_host_sigset(&host_set, &frame->uc.tuc_sigmask);
1260         sigprocmask(SIG_SETMASK, &host_set, NULL);
1261 
1262 	if (restore_sigcontext(env, &frame->uc.tuc_mcontext))
1263 		goto badframe;
1264 
1265 #if 0
1266 	/* Send SIGTRAP if we're single-stepping */
1267 	if (ptrace_cancel_bpt(current))
1268 		send_sig(SIGTRAP, current, 1);
1269 #endif
1270 	return env->regs[0];
1271 
1272 badframe:
1273         force_sig(SIGSEGV /* , current */);
1274 	return 0;
1275 }
1276 
1277 #elif defined(TARGET_SPARC)
1278 
1279 #define __SUNOS_MAXWIN   31
1280 
1281 /* This is what SunOS does, so shall I. */
1282 struct target_sigcontext {
1283         target_ulong sigc_onstack;      /* state to restore */
1284 
1285         target_ulong sigc_mask;         /* sigmask to restore */
1286         target_ulong sigc_sp;           /* stack pointer */
1287         target_ulong sigc_pc;           /* program counter */
1288         target_ulong sigc_npc;          /* next program counter */
1289         target_ulong sigc_psr;          /* for condition codes etc */
1290         target_ulong sigc_g1;           /* User uses these two registers */
1291         target_ulong sigc_o0;           /* within the trampoline code. */
1292 
1293         /* Now comes information regarding the users window set
1294          * at the time of the signal.
1295          */
1296         target_ulong sigc_oswins;       /* outstanding windows */
1297 
1298         /* stack ptrs for each regwin buf */
1299         char *sigc_spbuf[__SUNOS_MAXWIN];
1300 
1301         /* Windows to restore after signal */
1302         struct {
1303                 target_ulong locals[8];
1304                 target_ulong ins[8];
1305         } sigc_wbuf[__SUNOS_MAXWIN];
1306 };
1307 /* A Sparc stack frame */
1308 struct sparc_stackf {
1309         target_ulong locals[8];
1310         target_ulong ins[6];
1311         struct sparc_stackf *fp;
1312         target_ulong callers_pc;
1313         char *structptr;
1314         target_ulong xargs[6];
1315         target_ulong xxargs[1];
1316 };
1317 
1318 typedef struct {
1319         struct {
1320                 target_ulong psr;
1321                 target_ulong pc;
1322                 target_ulong npc;
1323                 target_ulong y;
1324                 target_ulong u_regs[16]; /* globals and ins */
1325         }               si_regs;
1326         int             si_mask;
1327 } __siginfo_t;
1328 
1329 typedef struct {
1330         unsigned   long si_float_regs [32];
1331         unsigned   long si_fsr;
1332         unsigned   long si_fpqdepth;
1333         struct {
1334                 unsigned long *insn_addr;
1335                 unsigned long insn;
1336         } si_fpqueue [16];
1337 } qemu_siginfo_fpu_t;
1338 
1339 
1340 struct target_signal_frame {
1341 	struct sparc_stackf	ss;
1342 	__siginfo_t		info;
1343 	qemu_siginfo_fpu_t 	*fpu_save;
1344 	target_ulong		insns[2] __attribute__ ((aligned (8)));
1345 	target_ulong		extramask[TARGET_NSIG_WORDS - 1];
1346 	target_ulong		extra_size; /* Should be 0 */
1347 	qemu_siginfo_fpu_t	fpu_state;
1348 };
1349 struct target_rt_signal_frame {
1350 	struct sparc_stackf	ss;
1351 	siginfo_t		info;
1352 	target_ulong		regs[20];
1353 	sigset_t		mask;
1354 	qemu_siginfo_fpu_t 	*fpu_save;
1355 	unsigned int		insns[2];
1356 	stack_t			stack;
1357 	unsigned int		extra_size; /* Should be 0 */
1358 	qemu_siginfo_fpu_t	fpu_state;
1359 };
1360 
1361 #define UREG_O0        16
1362 #define UREG_O6        22
1363 #define UREG_I0        0
1364 #define UREG_I1        1
1365 #define UREG_I2        2
1366 #define UREG_I6        6
1367 #define UREG_I7        7
1368 #define UREG_L0	       8
1369 #define UREG_FP        UREG_I6
1370 #define UREG_SP        UREG_O6
1371 
1372 static inline void *get_sigframe(struct emulated_sigaction *sa, CPUState *env, unsigned long framesize)
1373 {
1374 	unsigned long sp;
1375 
1376 	sp = env->regwptr[UREG_FP];
1377 #if 0
1378 
1379 	/* This is the X/Open sanctioned signal stack switching.  */
1380 	if (sa->sa_flags & TARGET_SA_ONSTACK) {
1381 		if (!on_sig_stack(sp) && !((current->sas_ss_sp + current->sas_ss_size) & 7))
1382 			sp = current->sas_ss_sp + current->sas_ss_size;
1383 	}
1384 #endif
1385 	return g2h(sp - framesize);
1386 }
1387 
1388 static int
1389 setup___siginfo(__siginfo_t *si, CPUState *env, target_ulong mask)
1390 {
1391 	int err = 0, i;
1392 
1393 	err |= __put_user(env->psr, &si->si_regs.psr);
1394 	err |= __put_user(env->pc, &si->si_regs.pc);
1395 	err |= __put_user(env->npc, &si->si_regs.npc);
1396 	err |= __put_user(env->y, &si->si_regs.y);
1397 	for (i=0; i < 8; i++) {
1398 		err |= __put_user(env->gregs[i], &si->si_regs.u_regs[i]);
1399 	}
1400 	for (i=0; i < 8; i++) {
1401 		err |= __put_user(env->regwptr[UREG_I0 + i], &si->si_regs.u_regs[i+8]);
1402 	}
1403 	err |= __put_user(mask, &si->si_mask);
1404 	return err;
1405 }
1406 
1407 #if 0
1408 static int
1409 setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
1410 		 CPUState *env, unsigned long mask)
1411 {
1412 	int err = 0;
1413 
1414 	err |= __put_user(mask, &sc->sigc_mask);
1415 	err |= __put_user(env->regwptr[UREG_SP], &sc->sigc_sp);
1416 	err |= __put_user(env->pc, &sc->sigc_pc);
1417 	err |= __put_user(env->npc, &sc->sigc_npc);
1418 	err |= __put_user(env->psr, &sc->sigc_psr);
1419 	err |= __put_user(env->gregs[1], &sc->sigc_g1);
1420 	err |= __put_user(env->regwptr[UREG_O0], &sc->sigc_o0);
1421 
1422 	return err;
1423 }
1424 #endif
1425 #define NF_ALIGNEDSZ  (((sizeof(struct target_signal_frame) + 7) & (~7)))
1426 
1427 static void setup_frame(int sig, struct emulated_sigaction *ka,
1428 			target_sigset_t *set, CPUState *env)
1429 {
1430 	struct target_signal_frame *sf;
1431 	int sigframe_size, err, i;
1432 
1433 	/* 1. Make sure everything is clean */
1434 	//synchronize_user_stack();
1435 
1436         sigframe_size = NF_ALIGNEDSZ;
1437 
1438 	sf = (struct target_signal_frame *)
1439 		get_sigframe(ka, env, sigframe_size);
1440 
1441 	//fprintf(stderr, "sf: %x pc %x fp %x sp %x\n", sf, env->pc, env->regwptr[UREG_FP], env->regwptr[UREG_SP]);
1442 #if 0
1443 	if (invalid_frame_pointer(sf, sigframe_size))
1444 		goto sigill_and_return;
1445 #endif
1446 	/* 2. Save the current process state */
1447 	err = setup___siginfo(&sf->info, env, set->sig[0]);
1448 	err |= __put_user(0, &sf->extra_size);
1449 
1450 	//err |= save_fpu_state(regs, &sf->fpu_state);
1451 	//err |= __put_user(&sf->fpu_state, &sf->fpu_save);
1452 
1453 	err |= __put_user(set->sig[0], &sf->info.si_mask);
1454 	for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) {
1455 		err |= __put_user(set->sig[i + 1], &sf->extramask[i]);
1456 	}
1457 
1458 	for (i = 0; i < 8; i++) {
1459 	  	err |= __put_user(env->regwptr[i + UREG_L0], &sf->ss.locals[i]);
1460 	}
1461 	for (i = 0; i < 8; i++) {
1462 	  	err |= __put_user(env->regwptr[i + UREG_I0], &sf->ss.ins[i]);
1463 	}
1464 	if (err)
1465 		goto sigsegv;
1466 
1467 	/* 3. signal handler back-trampoline and parameters */
1468 	env->regwptr[UREG_FP] = h2g(sf);
1469 	env->regwptr[UREG_I0] = sig;
1470 	env->regwptr[UREG_I1] = h2g(&sf->info);
1471 	env->regwptr[UREG_I2] = h2g(&sf->info);
1472 
1473 	/* 4. signal handler */
1474 	env->pc = (unsigned long) ka->sa._sa_handler;
1475 	env->npc = (env->pc + 4);
1476 	/* 5. return to kernel instructions */
1477 	if (ka->sa.sa_restorer)
1478 		env->regwptr[UREG_I7] = (unsigned long)ka->sa.sa_restorer;
1479 	else {
1480 		env->regwptr[UREG_I7] = h2g(&(sf->insns[0]) - 2);
1481 
1482 		/* mov __NR_sigreturn, %g1 */
1483 		err |= __put_user(0x821020d8, &sf->insns[0]);
1484 
1485 		/* t 0x10 */
1486 		err |= __put_user(0x91d02010, &sf->insns[1]);
1487 		if (err)
1488 			goto sigsegv;
1489 
1490 		/* Flush instruction space. */
1491 		//flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
1492                 //		tb_flush(env);
1493 	}
1494 	return;
1495 
1496         //sigill_and_return:
1497 	force_sig(TARGET_SIGILL);
1498 sigsegv:
1499 	//fprintf(stderr, "force_sig\n");
1500 	force_sig(TARGET_SIGSEGV);
1501 }
1502 static inline int
1503 restore_fpu_state(CPUState *env, qemu_siginfo_fpu_t *fpu)
1504 {
1505         int err;
1506 #if 0
1507 #ifdef CONFIG_SMP
1508         if (current->flags & PF_USEDFPU)
1509                 regs->psr &= ~PSR_EF;
1510 #else
1511         if (current == last_task_used_math) {
1512                 last_task_used_math = 0;
1513                 regs->psr &= ~PSR_EF;
1514         }
1515 #endif
1516         current->used_math = 1;
1517         current->flags &= ~PF_USEDFPU;
1518 #endif
1519 #if 0
1520         if (verify_area (VERIFY_READ, fpu, sizeof(*fpu)))
1521                 return -EFAULT;
1522 #endif
1523 
1524         err = __copy_from_user(&env->fpr[0], &fpu->si_float_regs[0],
1525 	                             (sizeof(unsigned long) * 32));
1526         err |= __get_user(env->fsr, &fpu->si_fsr);
1527 #if 0
1528         err |= __get_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
1529         if (current->thread.fpqdepth != 0)
1530                 err |= __copy_from_user(&current->thread.fpqueue[0],
1531                                         &fpu->si_fpqueue[0],
1532                                         ((sizeof(unsigned long) +
1533                                         (sizeof(unsigned long *)))*16));
1534 #endif
1535         return err;
1536 }
1537 
1538 
1539 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
1540                            target_siginfo_t *info,
1541 			   target_sigset_t *set, CPUState *env)
1542 {
1543     fprintf(stderr, "setup_rt_frame: not implemented\n");
1544 }
1545 
1546 long do_sigreturn(CPUState *env)
1547 {
1548         struct target_signal_frame *sf;
1549         uint32_t up_psr, pc, npc;
1550         target_sigset_t set;
1551         sigset_t host_set;
1552         target_ulong fpu_save;
1553         int err, i;
1554 
1555         sf = (struct target_signal_frame *)g2h(env->regwptr[UREG_FP]);
1556 #if 0
1557 	fprintf(stderr, "sigreturn\n");
1558 	fprintf(stderr, "sf: %x pc %x fp %x sp %x\n", sf, env->pc, env->regwptr[UREG_FP], env->regwptr[UREG_SP]);
1559 #endif
1560 	//cpu_dump_state(env, stderr, fprintf, 0);
1561 
1562         /* 1. Make sure we are not getting garbage from the user */
1563 #if 0
1564         if (verify_area (VERIFY_READ, sf, sizeof (*sf)))
1565                 goto segv_and_exit;
1566 #endif
1567 
1568         if (((uint) sf) & 3)
1569                 goto segv_and_exit;
1570 
1571         err = __get_user(pc,  &sf->info.si_regs.pc);
1572         err |= __get_user(npc, &sf->info.si_regs.npc);
1573 
1574         if ((pc | npc) & 3)
1575                 goto segv_and_exit;
1576 
1577         /* 2. Restore the state */
1578         err |= __get_user(up_psr, &sf->info.si_regs.psr);
1579 
1580         /* User can only change condition codes and FPU enabling in %psr. */
1581         env->psr = (up_psr & (PSR_ICC /* | PSR_EF */))
1582                   | (env->psr & ~(PSR_ICC /* | PSR_EF */));
1583 
1584 	env->pc = pc;
1585 	env->npc = npc;
1586         err |= __get_user(env->y, &sf->info.si_regs.y);
1587 	for (i=0; i < 8; i++) {
1588 		err |= __get_user(env->gregs[i], &sf->info.si_regs.u_regs[i]);
1589 	}
1590 	for (i=0; i < 8; i++) {
1591 		err |= __get_user(env->regwptr[i + UREG_I0], &sf->info.si_regs.u_regs[i+8]);
1592 	}
1593 
1594         err |= __get_user(fpu_save, (target_ulong *)&sf->fpu_save);
1595 
1596         //if (fpu_save)
1597         //        err |= restore_fpu_state(env, fpu_save);
1598 
1599         /* This is pretty much atomic, no amount locking would prevent
1600          * the races which exist anyways.
1601          */
1602         err |= __get_user(set.sig[0], &sf->info.si_mask);
1603         for(i = 1; i < TARGET_NSIG_WORDS; i++) {
1604             err |= (__get_user(set.sig[i], &sf->extramask[i - 1]));
1605         }
1606 
1607         target_to_host_sigset_internal(&host_set, &set);
1608         sigprocmask(SIG_SETMASK, &host_set, NULL);
1609 
1610         if (err)
1611                 goto segv_and_exit;
1612 
1613         return env->regwptr[0];
1614 
1615 segv_and_exit:
1616 	force_sig(TARGET_SIGSEGV);
1617 }
1618 
1619 long do_rt_sigreturn(CPUState *env)
1620 {
1621     fprintf(stderr, "do_rt_sigreturn: not implemented\n");
1622     return -ENOSYS;
1623 }
1624 
1625 #elif defined(TARGET_MIPS)
1626 
1627 struct target_sigcontext {
1628     uint32_t   sc_regmask;     /* Unused */
1629     uint32_t   sc_status;
1630     uint64_t   sc_pc;
1631     uint64_t   sc_regs[32];
1632     uint64_t   sc_fpregs[32];
1633     uint32_t   sc_ownedfp;     /* Unused */
1634     uint32_t   sc_fpc_csr;
1635     uint32_t   sc_fpc_eir;     /* Unused */
1636     uint32_t   sc_used_math;
1637     uint32_t   sc_dsp;         /* dsp status, was sc_ssflags */
1638     uint64_t   sc_mdhi;
1639     uint64_t   sc_mdlo;
1640     target_ulong   sc_hi1;         /* Was sc_cause */
1641     target_ulong   sc_lo1;         /* Was sc_badvaddr */
1642     target_ulong   sc_hi2;         /* Was sc_sigset[4] */
1643     target_ulong   sc_lo2;
1644     target_ulong   sc_hi3;
1645     target_ulong   sc_lo3;
1646 };
1647 
1648 struct sigframe {
1649     uint32_t sf_ass[4];			/* argument save space for o32 */
1650     uint32_t sf_code[2];			/* signal trampoline */
1651     struct target_sigcontext sf_sc;
1652     target_sigset_t sf_mask;
1653 };
1654 
1655 /* Install trampoline to jump back from signal handler */
1656 static inline int install_sigtramp(unsigned int *tramp,   unsigned int syscall)
1657 {
1658     int err;
1659 
1660     /*
1661     * Set up the return code ...
1662     *
1663     *         li      v0, __NR__foo_sigreturn
1664     *         syscall
1665     */
1666 
1667     err = __put_user(0x24020000 + syscall, tramp + 0);
1668     err |= __put_user(0x0000000c          , tramp + 1);
1669     /* flush_cache_sigtramp((unsigned long) tramp); */
1670     return err;
1671 }
1672 
1673 static inline int
1674 setup_sigcontext(CPUState *regs, struct target_sigcontext *sc)
1675 {
1676     int err = 0;
1677 
1678     err |= __put_user(regs->PC, &sc->sc_pc);
1679 
1680     #define save_gp_reg(i) do {   					\
1681         err |= __put_user(regs->gpr[i], &sc->sc_regs[i]);		\
1682     } while(0)
1683     __put_user(0, &sc->sc_regs[0]); save_gp_reg(1); save_gp_reg(2);
1684     save_gp_reg(3); save_gp_reg(4); save_gp_reg(5); save_gp_reg(6);
1685     save_gp_reg(7); save_gp_reg(8); save_gp_reg(9); save_gp_reg(10);
1686     save_gp_reg(11); save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
1687     save_gp_reg(15); save_gp_reg(16); save_gp_reg(17); save_gp_reg(18);
1688     save_gp_reg(19); save_gp_reg(20); save_gp_reg(21); save_gp_reg(22);
1689     save_gp_reg(23); save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
1690     save_gp_reg(27); save_gp_reg(28); save_gp_reg(29); save_gp_reg(30);
1691     save_gp_reg(31);
1692     #undef save_gp_reg
1693 
1694     err |= __put_user(regs->HI, &sc->sc_mdhi);
1695     err |= __put_user(regs->LO, &sc->sc_mdlo);
1696 
1697     /* Not used yet, but might be useful if we ever have DSP suppport */
1698 #if 0
1699     if (cpu_has_dsp) {
1700 	err |= __put_user(mfhi1(), &sc->sc_hi1);
1701 	err |= __put_user(mflo1(), &sc->sc_lo1);
1702 	err |= __put_user(mfhi2(), &sc->sc_hi2);
1703 	err |= __put_user(mflo2(), &sc->sc_lo2);
1704 	err |= __put_user(mfhi3(), &sc->sc_hi3);
1705 	err |= __put_user(mflo3(), &sc->sc_lo3);
1706 	err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
1707     }
1708     /* same with 64 bit */
1709     #ifdef CONFIG_64BIT
1710     err |= __put_user(regs->hi, &sc->sc_hi[0]);
1711     err |= __put_user(regs->lo, &sc->sc_lo[0]);
1712     if (cpu_has_dsp) {
1713 	err |= __put_user(mfhi1(), &sc->sc_hi[1]);
1714 	err |= __put_user(mflo1(), &sc->sc_lo[1]);
1715 	err |= __put_user(mfhi2(), &sc->sc_hi[2]);
1716 	err |= __put_user(mflo2(), &sc->sc_lo[2]);
1717 	err |= __put_user(mfhi3(), &sc->sc_hi[3]);
1718 	err |= __put_user(mflo3(), &sc->sc_lo[3]);
1719 	err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
1720     }
1721     #endif
1722 
1723 
1724     #endif
1725 
1726 
1727     #if 0
1728     err |= __put_user(!!used_math(), &sc->sc_used_math);
1729 
1730     if (!used_math())
1731 	goto out;
1732 
1733     /*
1734     * Save FPU state to signal context.  Signal handler will "inherit"
1735     * current FPU state.
1736     */
1737     preempt_disable();
1738 
1739     if (!is_fpu_owner()) {
1740 	own_fpu();
1741 	restore_fp(current);
1742     }
1743     err |= save_fp_context(sc);
1744 
1745     preempt_enable();
1746     out:
1747 #endif
1748     return err;
1749 }
1750 
1751 static inline int
1752 restore_sigcontext(CPUState *regs, struct target_sigcontext *sc)
1753 {
1754     int err = 0;
1755 
1756     err |= __get_user(regs->CP0_EPC, &sc->sc_pc);
1757 
1758     err |= __get_user(regs->HI, &sc->sc_mdhi);
1759     err |= __get_user(regs->LO, &sc->sc_mdlo);
1760 
1761     #define restore_gp_reg(i) do {   					\
1762         err |= __get_user(regs->gpr[i], &sc->sc_regs[i]);		\
1763     } while(0)
1764     restore_gp_reg( 1); restore_gp_reg( 2); restore_gp_reg( 3);
1765     restore_gp_reg( 4); restore_gp_reg( 5); restore_gp_reg( 6);
1766     restore_gp_reg( 7); restore_gp_reg( 8); restore_gp_reg( 9);
1767     restore_gp_reg(10); restore_gp_reg(11); restore_gp_reg(12);
1768     restore_gp_reg(13); restore_gp_reg(14); restore_gp_reg(15);
1769     restore_gp_reg(16); restore_gp_reg(17); restore_gp_reg(18);
1770     restore_gp_reg(19); restore_gp_reg(20); restore_gp_reg(21);
1771     restore_gp_reg(22); restore_gp_reg(23); restore_gp_reg(24);
1772     restore_gp_reg(25); restore_gp_reg(26); restore_gp_reg(27);
1773     restore_gp_reg(28); restore_gp_reg(29); restore_gp_reg(30);
1774     restore_gp_reg(31);
1775     #undef restore_gp_reg
1776 
1777 #if 0
1778     if (cpu_has_dsp) {
1779 	err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
1780 	err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
1781 	err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
1782 	err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
1783 	err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
1784 	err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
1785 	err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
1786     }
1787     #ifdef CONFIG_64BIT
1788     err |= __get_user(regs->hi, &sc->sc_hi[0]);
1789     err |= __get_user(regs->lo, &sc->sc_lo[0]);
1790     if (cpu_has_dsp) {
1791 	err |= __get_user(treg, &sc->sc_hi[1]); mthi1(treg);
1792 	err |= __get_user(treg, &sc->sc_lo[1]); mthi1(treg);
1793 	err |= __get_user(treg, &sc->sc_hi[2]); mthi2(treg);
1794 	err |= __get_user(treg, &sc->sc_lo[2]); mthi2(treg);
1795 	err |= __get_user(treg, &sc->sc_hi[3]); mthi3(treg);
1796 	err |= __get_user(treg, &sc->sc_lo[3]); mthi3(treg);
1797 	err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
1798     }
1799     #endif
1800 
1801     err |= __get_user(used_math, &sc->sc_used_math);
1802     conditional_used_math(used_math);
1803 
1804     preempt_disable();
1805 
1806     if (used_math()) {
1807 	/* restore fpu context if we have used it before */
1808 	own_fpu();
1809 	err |= restore_fp_context(sc);
1810     } else {
1811 	/* signal handler may have used FPU.  Give it up. */
1812 	lose_fpu();
1813     }
1814 
1815     preempt_enable();
1816 #endif
1817     return err;
1818 }
1819 /*
1820  * Determine which stack to use..
1821  */
1822 static inline void *
1823 get_sigframe(struct emulated_sigaction *ka, CPUState *regs, size_t frame_size)
1824 {
1825     unsigned long sp;
1826 
1827     /* Default to using normal stack */
1828     sp = regs->gpr[29];
1829 
1830     /*
1831      * FPU emulator may have it's own trampoline active just
1832      * above the user stack, 16-bytes before the next lowest
1833      * 16 byte boundary.  Try to avoid trashing it.
1834      */
1835     sp -= 32;
1836 
1837 #if 0
1838     /* This is the X/Open sanctioned signal stack switching.  */
1839     if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
1840 	sp = current->sas_ss_sp + current->sas_ss_size;
1841 #endif
1842 
1843     return g2h((sp - frame_size) & ~7);
1844 }
1845 
1846 static void setup_frame(int sig, struct emulated_sigaction * ka,
1847    		target_sigset_t *set, CPUState *regs)
1848 {
1849     struct sigframe *frame;
1850     int i;
1851 
1852     frame = get_sigframe(ka, regs, sizeof(*frame));
1853     if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
1854 	goto give_sigsegv;
1855 
1856     install_sigtramp(frame->sf_code, TARGET_NR_sigreturn);
1857 
1858     if(setup_sigcontext(regs, &frame->sf_sc))
1859 	goto give_sigsegv;
1860 
1861     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
1862 	if(__put_user(set->sig[i], &frame->sf_mask.sig[i]))
1863 	    goto give_sigsegv;
1864     }
1865 
1866     /*
1867     * Arguments to signal handler:
1868     *
1869     *   a0 = signal number
1870     *   a1 = 0 (should be cause)
1871     *   a2 = pointer to struct sigcontext
1872     *
1873     * $25 and PC point to the signal handler, $29 points to the
1874     * struct sigframe.
1875     */
1876     regs->gpr[ 4] = sig;
1877     regs->gpr[ 5] = 0;
1878     regs->gpr[ 6] = h2g(&frame->sf_sc);
1879     regs->gpr[29] = h2g(frame);
1880     regs->gpr[31] = h2g(frame->sf_code);
1881     /* The original kernel code sets CP0_EPC to the handler
1882     * since it returns to userland using eret
1883     * we cannot do this here, and we must set PC directly */
1884     regs->PC = regs->gpr[25] = ka->sa._sa_handler;
1885     return;
1886 
1887 give_sigsegv:
1888     force_sig(TARGET_SIGSEGV/*, current*/);
1889     return;
1890 }
1891 
1892 long do_sigreturn(CPUState *regs)
1893 {
1894    struct sigframe *frame;
1895    sigset_t blocked;
1896    target_sigset_t target_set;
1897    int i;
1898 
1899 #if defined(DEBUG_SIGNAL)
1900    fprintf(stderr, "do_sigreturn\n");
1901 #endif
1902    frame = (struct sigframe *) regs->gpr[29];
1903    if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
1904    	goto badframe;
1905 
1906    for(i = 0; i < TARGET_NSIG_WORDS; i++) {
1907    	if(__get_user(target_set.sig[i], &frame->sf_mask.sig[i]))
1908 	    goto badframe;
1909    }
1910 
1911    target_to_host_sigset_internal(&blocked, &target_set);
1912    sigprocmask(SIG_SETMASK, &blocked, NULL);
1913 
1914    if (restore_sigcontext(regs, &frame->sf_sc))
1915    	goto badframe;
1916 
1917 #if 0
1918    /*
1919     * Don't let your children do this ...
1920     */
1921    __asm__ __volatile__(
1922    	"move\t$29, %0\n\t"
1923    	"j\tsyscall_exit"
1924    	:/* no outputs */
1925    	:"r" (&regs));
1926    /* Unreached */
1927 #endif
1928 
1929     regs->PC = regs->CP0_EPC;
1930    /* I am not sure this is right, but it seems to work
1931     * maybe a problem with nested signals ? */
1932     regs->CP0_EPC = 0;
1933     return 0;
1934 
1935 badframe:
1936    force_sig(TARGET_SIGSEGV/*, current*/);
1937    return 0;
1938 
1939 }
1940 
1941 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
1942                            target_siginfo_t *info,
1943 			   target_sigset_t *set, CPUState *env)
1944 {
1945     fprintf(stderr, "setup_rt_frame: not implemented\n");
1946 }
1947 
1948 long do_rt_sigreturn(CPUState *env)
1949 {
1950     fprintf(stderr, "do_rt_sigreturn: not implemented\n");
1951     return -ENOSYS;
1952 }
1953 
1954 #else
1955 
1956 static void setup_frame(int sig, struct emulated_sigaction *ka,
1957 			target_sigset_t *set, CPUState *env)
1958 {
1959     fprintf(stderr, "setup_frame: not implemented\n");
1960 }
1961 
1962 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
1963                            target_siginfo_t *info,
1964 			   target_sigset_t *set, CPUState *env)
1965 {
1966     fprintf(stderr, "setup_rt_frame: not implemented\n");
1967 }
1968 
1969 long do_sigreturn(CPUState *env)
1970 {
1971     fprintf(stderr, "do_sigreturn: not implemented\n");
1972     return -ENOSYS;
1973 }
1974 
1975 long do_rt_sigreturn(CPUState *env)
1976 {
1977     fprintf(stderr, "do_rt_sigreturn: not implemented\n");
1978     return -ENOSYS;
1979 }
1980 
1981 #endif
1982 
1983 void process_pending_signals(void *cpu_env)
1984 {
1985     int sig;
1986     target_ulong handler;
1987     sigset_t set, old_set;
1988     target_sigset_t target_old_set;
1989     struct emulated_sigaction *k;
1990     struct sigqueue *q;
1991 
1992     if (!signal_pending)
1993         return;
1994 
1995     k = sigact_table;
1996     for(sig = 1; sig <= TARGET_NSIG; sig++) {
1997         if (k->pending)
1998             goto handle_signal;
1999         k++;
2000     }
2001     /* if no signal is pending, just return */
2002     signal_pending = 0;
2003     return;
2004 
2005  handle_signal:
2006 #ifdef DEBUG_SIGNAL
2007     fprintf(stderr, "qemu: process signal %d\n", sig);
2008 #endif
2009     /* dequeue signal */
2010     q = k->first;
2011     k->first = q->next;
2012     if (!k->first)
2013         k->pending = 0;
2014 
2015     sig = gdb_handlesig (cpu_env, sig);
2016     if (!sig) {
2017         fprintf (stderr, "Lost signal\n");
2018         abort();
2019     }
2020 
2021     handler = k->sa._sa_handler;
2022     if (handler == TARGET_SIG_DFL) {
2023         /* default handler : ignore some signal. The other are fatal */
2024         if (sig != TARGET_SIGCHLD &&
2025             sig != TARGET_SIGURG &&
2026             sig != TARGET_SIGWINCH) {
2027             force_sig(sig);
2028         }
2029     } else if (handler == TARGET_SIG_IGN) {
2030         /* ignore sig */
2031     } else if (handler == TARGET_SIG_ERR) {
2032         force_sig(sig);
2033     } else {
2034         /* compute the blocked signals during the handler execution */
2035         target_to_host_sigset(&set, &k->sa.sa_mask);
2036         /* SA_NODEFER indicates that the current signal should not be
2037            blocked during the handler */
2038         if (!(k->sa.sa_flags & TARGET_SA_NODEFER))
2039             sigaddset(&set, target_to_host_signal(sig));
2040 
2041         /* block signals in the handler using Linux */
2042         sigprocmask(SIG_BLOCK, &set, &old_set);
2043         /* save the previous blocked signal state to restore it at the
2044            end of the signal execution (see do_sigreturn) */
2045         host_to_target_sigset_internal(&target_old_set, &old_set);
2046 
2047         /* if the CPU is in VM86 mode, we restore the 32 bit values */
2048 #ifdef TARGET_I386
2049         {
2050             CPUX86State *env = cpu_env;
2051             if (env->eflags & VM_MASK)
2052                 save_v86_state(env);
2053         }
2054 #endif
2055         /* prepare the stack frame of the virtual CPU */
2056         if (k->sa.sa_flags & TARGET_SA_SIGINFO)
2057             setup_rt_frame(sig, k, &q->info, &target_old_set, cpu_env);
2058         else
2059             setup_frame(sig, k, &target_old_set, cpu_env);
2060 	if (k->sa.sa_flags & TARGET_SA_RESETHAND)
2061             k->sa._sa_handler = TARGET_SIG_DFL;
2062     }
2063     if (q != &k->info)
2064         free_sigqueue(q);
2065 }
2066 
2067 
2068