xref: /qemu/linux-user/signal.c (revision 8dd77cca03ac6325bda61dbdb8b8a2021fe524c3)
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 == SIGIO) {
211 	tinfo->_sifields._sigpoll._fd = info->si_fd;
212     } else if (sig >= TARGET_SIGRTMIN) {
213         tinfo->_sifields._rt._pid = info->si_pid;
214         tinfo->_sifields._rt._uid = info->si_uid;
215         /* XXX: potential problem if 64 bit */
216         tinfo->_sifields._rt._sigval.sival_ptr =
217             (target_ulong)info->si_value.sival_ptr;
218     }
219 }
220 
221 static void tswap_siginfo(target_siginfo_t *tinfo,
222                           const target_siginfo_t *info)
223 {
224     int sig;
225     sig = info->si_signo;
226     tinfo->si_signo = tswap32(sig);
227     tinfo->si_errno = tswap32(info->si_errno);
228     tinfo->si_code = tswap32(info->si_code);
229     if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV ||
230         sig == SIGBUS || sig == SIGTRAP) {
231         tinfo->_sifields._sigfault._addr =
232             tswapl(info->_sifields._sigfault._addr);
233     } else if (sig == SIGIO) {
234 	tinfo->_sifields._sigpoll._fd = tswap32(info->_sifields._sigpoll._fd);
235     } else if (sig >= TARGET_SIGRTMIN) {
236         tinfo->_sifields._rt._pid = tswap32(info->_sifields._rt._pid);
237         tinfo->_sifields._rt._uid = tswap32(info->_sifields._rt._uid);
238         tinfo->_sifields._rt._sigval.sival_ptr =
239             tswapl(info->_sifields._rt._sigval.sival_ptr);
240     }
241 }
242 
243 
244 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
245 {
246     host_to_target_siginfo_noswap(tinfo, info);
247     tswap_siginfo(tinfo, tinfo);
248 }
249 
250 /* XXX: we support only POSIX RT signals are used. */
251 /* XXX: find a solution for 64 bit (additional malloced data is needed) */
252 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
253 {
254     info->si_signo = tswap32(tinfo->si_signo);
255     info->si_errno = tswap32(tinfo->si_errno);
256     info->si_code = tswap32(tinfo->si_code);
257     info->si_pid = tswap32(tinfo->_sifields._rt._pid);
258     info->si_uid = tswap32(tinfo->_sifields._rt._uid);
259     info->si_value.sival_ptr =
260         (void *)tswapl(tinfo->_sifields._rt._sigval.sival_ptr);
261 }
262 
263 void signal_init(void)
264 {
265     struct sigaction act;
266     int i, j;
267 
268     /* generate signal conversion tables */
269     for(i = 1; i <= 64; i++) {
270         if (host_to_target_signal_table[i] == 0)
271             host_to_target_signal_table[i] = i;
272     }
273     for(i = 1; i <= 64; i++) {
274         j = host_to_target_signal_table[i];
275         target_to_host_signal_table[j] = i;
276     }
277 
278     /* set all host signal handlers. ALL signals are blocked during
279        the handlers to serialize them. */
280     sigfillset(&act.sa_mask);
281     act.sa_flags = SA_SIGINFO;
282     act.sa_sigaction = host_signal_handler;
283     for(i = 1; i < NSIG; i++) {
284         sigaction(i, &act, NULL);
285     }
286 
287     memset(sigact_table, 0, sizeof(sigact_table));
288 
289     first_free = &sigqueue_table[0];
290     for(i = 0; i < MAX_SIGQUEUE_SIZE - 1; i++)
291         sigqueue_table[i].next = &sigqueue_table[i + 1];
292     sigqueue_table[MAX_SIGQUEUE_SIZE - 1].next = NULL;
293 }
294 
295 /* signal queue handling */
296 
297 static inline struct sigqueue *alloc_sigqueue(void)
298 {
299     struct sigqueue *q = first_free;
300     if (!q)
301         return NULL;
302     first_free = q->next;
303     return q;
304 }
305 
306 static inline void free_sigqueue(struct sigqueue *q)
307 {
308     q->next = first_free;
309     first_free = q;
310 }
311 
312 /* abort execution with signal */
313 void __attribute((noreturn)) force_sig(int sig)
314 {
315     int host_sig;
316     host_sig = target_to_host_signal(sig);
317     fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n",
318             sig, strsignal(host_sig));
319 #if 1
320     _exit(-host_sig);
321 #else
322     {
323         struct sigaction act;
324         sigemptyset(&act.sa_mask);
325         act.sa_flags = SA_SIGINFO;
326         act.sa_sigaction = SIG_DFL;
327         sigaction(SIGABRT, &act, NULL);
328         abort();
329     }
330 #endif
331 }
332 
333 /* queue a signal so that it will be send to the virtual CPU as soon
334    as possible */
335 int queue_signal(int sig, target_siginfo_t *info)
336 {
337     struct emulated_sigaction *k;
338     struct sigqueue *q, **pq;
339     target_ulong handler;
340 
341 #if defined(DEBUG_SIGNAL)
342     fprintf(stderr, "queue_signal: sig=%d\n",
343             sig);
344 #endif
345     k = &sigact_table[sig - 1];
346     handler = k->sa._sa_handler;
347     if (handler == TARGET_SIG_DFL) {
348         /* default handler : ignore some signal. The other are fatal */
349         if (sig != TARGET_SIGCHLD &&
350             sig != TARGET_SIGURG &&
351             sig != TARGET_SIGWINCH) {
352             force_sig(sig);
353         } else {
354             return 0; /* indicate ignored */
355         }
356     } else if (handler == TARGET_SIG_IGN) {
357         /* ignore signal */
358         return 0;
359     } else if (handler == TARGET_SIG_ERR) {
360         force_sig(sig);
361     } else {
362         pq = &k->first;
363         if (sig < TARGET_SIGRTMIN) {
364             /* if non real time signal, we queue exactly one signal */
365             if (!k->pending)
366                 q = &k->info;
367             else
368                 return 0;
369         } else {
370             if (!k->pending) {
371                 /* first signal */
372                 q = &k->info;
373             } else {
374                 q = alloc_sigqueue();
375                 if (!q)
376                     return -EAGAIN;
377                 while (*pq != NULL)
378                     pq = &(*pq)->next;
379             }
380         }
381         *pq = q;
382         q->info = *info;
383         q->next = NULL;
384         k->pending = 1;
385         /* signal that a new signal is pending */
386         signal_pending = 1;
387         return 1; /* indicates that the signal was queued */
388     }
389 }
390 
391 static void host_signal_handler(int host_signum, siginfo_t *info,
392                                 void *puc)
393 {
394     int sig;
395     target_siginfo_t tinfo;
396 
397     /* the CPU emulator uses some host signals to detect exceptions,
398        we we forward to it some signals */
399     if (host_signum == SIGSEGV || host_signum == SIGBUS
400 #if defined(TARGET_I386) && defined(USE_CODE_COPY)
401         || host_signum == SIGFPE
402 #endif
403         ) {
404         if (cpu_signal_handler(host_signum, info, puc))
405             return;
406     }
407 
408     /* get target signal number */
409     sig = host_to_target_signal(host_signum);
410     if (sig < 1 || sig > TARGET_NSIG)
411         return;
412 #if defined(DEBUG_SIGNAL)
413     fprintf(stderr, "qemu: got signal %d\n", sig);
414 #endif
415     host_to_target_siginfo_noswap(&tinfo, info);
416     if (queue_signal(sig, &tinfo) == 1) {
417         /* interrupt the virtual CPU as soon as possible */
418         cpu_interrupt(global_env, CPU_INTERRUPT_EXIT);
419     }
420 }
421 
422 int do_sigaction(int sig, const struct target_sigaction *act,
423                  struct target_sigaction *oact)
424 {
425     struct emulated_sigaction *k;
426     struct sigaction act1;
427     int host_sig;
428 
429     if (sig < 1 || sig > TARGET_NSIG || sig == SIGKILL || sig == SIGSTOP)
430         return -EINVAL;
431     k = &sigact_table[sig - 1];
432 #if defined(DEBUG_SIGNAL)
433     fprintf(stderr, "sigaction sig=%d act=0x%08x, oact=0x%08x\n",
434             sig, (int)act, (int)oact);
435 #endif
436     if (oact) {
437         oact->_sa_handler = tswapl(k->sa._sa_handler);
438         oact->sa_flags = tswapl(k->sa.sa_flags);
439 #if !defined(TARGET_MIPS)
440         oact->sa_restorer = tswapl(k->sa.sa_restorer);
441 #endif
442         oact->sa_mask = k->sa.sa_mask;
443     }
444     if (act) {
445         k->sa._sa_handler = tswapl(act->_sa_handler);
446         k->sa.sa_flags = tswapl(act->sa_flags);
447 #if !defined(TARGET_MIPS)
448         k->sa.sa_restorer = tswapl(act->sa_restorer);
449 #endif
450         k->sa.sa_mask = act->sa_mask;
451 
452         /* we update the host linux signal state */
453         host_sig = target_to_host_signal(sig);
454         if (host_sig != SIGSEGV && host_sig != SIGBUS) {
455             sigfillset(&act1.sa_mask);
456             act1.sa_flags = SA_SIGINFO;
457             if (k->sa.sa_flags & TARGET_SA_RESTART)
458                 act1.sa_flags |= SA_RESTART;
459             /* NOTE: it is important to update the host kernel signal
460                ignore state to avoid getting unexpected interrupted
461                syscalls */
462             if (k->sa._sa_handler == TARGET_SIG_IGN) {
463                 act1.sa_sigaction = (void *)SIG_IGN;
464             } else if (k->sa._sa_handler == TARGET_SIG_DFL) {
465                 act1.sa_sigaction = (void *)SIG_DFL;
466             } else {
467                 act1.sa_sigaction = host_signal_handler;
468             }
469             sigaction(host_sig, &act1, NULL);
470         }
471     }
472     return 0;
473 }
474 
475 #ifndef offsetof
476 #define offsetof(type, field) ((size_t) &((type *)0)->field)
477 #endif
478 
479 static inline int copy_siginfo_to_user(target_siginfo_t *tinfo,
480                                        const target_siginfo_t *info)
481 {
482     tswap_siginfo(tinfo, info);
483     return 0;
484 }
485 
486 #ifdef TARGET_I386
487 
488 /* from the Linux kernel */
489 
490 struct target_fpreg {
491 	uint16_t significand[4];
492 	uint16_t exponent;
493 };
494 
495 struct target_fpxreg {
496 	uint16_t significand[4];
497 	uint16_t exponent;
498 	uint16_t padding[3];
499 };
500 
501 struct target_xmmreg {
502 	target_ulong element[4];
503 };
504 
505 struct target_fpstate {
506 	/* Regular FPU environment */
507 	target_ulong 	cw;
508 	target_ulong	sw;
509 	target_ulong	tag;
510 	target_ulong	ipoff;
511 	target_ulong	cssel;
512 	target_ulong	dataoff;
513 	target_ulong	datasel;
514 	struct target_fpreg	_st[8];
515 	uint16_t	status;
516 	uint16_t	magic;		/* 0xffff = regular FPU data only */
517 
518 	/* FXSR FPU environment */
519 	target_ulong	_fxsr_env[6];	/* FXSR FPU env is ignored */
520 	target_ulong	mxcsr;
521 	target_ulong	reserved;
522 	struct target_fpxreg	_fxsr_st[8];	/* FXSR FPU reg data is ignored */
523 	struct target_xmmreg	_xmm[8];
524 	target_ulong	padding[56];
525 };
526 
527 #define X86_FXSR_MAGIC		0x0000
528 
529 struct target_sigcontext {
530 	uint16_t gs, __gsh;
531 	uint16_t fs, __fsh;
532 	uint16_t es, __esh;
533 	uint16_t ds, __dsh;
534 	target_ulong edi;
535 	target_ulong esi;
536 	target_ulong ebp;
537 	target_ulong esp;
538 	target_ulong ebx;
539 	target_ulong edx;
540 	target_ulong ecx;
541 	target_ulong eax;
542 	target_ulong trapno;
543 	target_ulong err;
544 	target_ulong eip;
545 	uint16_t cs, __csh;
546 	target_ulong eflags;
547 	target_ulong esp_at_signal;
548 	uint16_t ss, __ssh;
549         target_ulong fpstate; /* pointer */
550 	target_ulong oldmask;
551 	target_ulong cr2;
552 };
553 
554 typedef struct target_sigaltstack {
555 	target_ulong ss_sp;
556 	int ss_flags;
557 	target_ulong ss_size;
558 } target_stack_t;
559 
560 struct target_ucontext {
561         target_ulong	  tuc_flags;
562 	target_ulong      tuc_link;
563 	target_stack_t	  tuc_stack;
564 	struct target_sigcontext tuc_mcontext;
565 	target_sigset_t	  tuc_sigmask;	/* mask last for extensibility */
566 };
567 
568 struct sigframe
569 {
570     target_ulong pretcode;
571     int sig;
572     struct target_sigcontext sc;
573     struct target_fpstate fpstate;
574     target_ulong extramask[TARGET_NSIG_WORDS-1];
575     char retcode[8];
576 };
577 
578 struct rt_sigframe
579 {
580     target_ulong pretcode;
581     int sig;
582     target_ulong pinfo;
583     target_ulong puc;
584     struct target_siginfo info;
585     struct target_ucontext uc;
586     struct target_fpstate fpstate;
587     char retcode[8];
588 };
589 
590 /*
591  * Set up a signal frame.
592  */
593 
594 /* XXX: save x87 state */
595 static int
596 setup_sigcontext(struct target_sigcontext *sc, struct target_fpstate *fpstate,
597 		 CPUX86State *env, unsigned long mask)
598 {
599 	int err = 0;
600 
601 	err |= __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
602 	err |= __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
603 	err |= __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
604 	err |= __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
605 	err |= __put_user(env->regs[R_EDI], &sc->edi);
606 	err |= __put_user(env->regs[R_ESI], &sc->esi);
607 	err |= __put_user(env->regs[R_EBP], &sc->ebp);
608 	err |= __put_user(env->regs[R_ESP], &sc->esp);
609 	err |= __put_user(env->regs[R_EBX], &sc->ebx);
610 	err |= __put_user(env->regs[R_EDX], &sc->edx);
611 	err |= __put_user(env->regs[R_ECX], &sc->ecx);
612 	err |= __put_user(env->regs[R_EAX], &sc->eax);
613 	err |= __put_user(env->exception_index, &sc->trapno);
614 	err |= __put_user(env->error_code, &sc->err);
615 	err |= __put_user(env->eip, &sc->eip);
616 	err |= __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
617 	err |= __put_user(env->eflags, &sc->eflags);
618 	err |= __put_user(env->regs[R_ESP], &sc->esp_at_signal);
619 	err |= __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
620 
621         cpu_x86_fsave(env, (void *)fpstate, 1);
622         fpstate->status = fpstate->sw;
623         err |= __put_user(0xffff, &fpstate->magic);
624         err |= __put_user(fpstate, &sc->fpstate);
625 
626 	/* non-iBCS2 extensions.. */
627 	err |= __put_user(mask, &sc->oldmask);
628 	err |= __put_user(env->cr[2], &sc->cr2);
629 	return err;
630 }
631 
632 /*
633  * Determine which stack to use..
634  */
635 
636 static inline void *
637 get_sigframe(struct emulated_sigaction *ka, CPUX86State *env, size_t frame_size)
638 {
639 	unsigned long esp;
640 
641 	/* Default to using normal stack */
642 	esp = env->regs[R_ESP];
643 #if 0
644 	/* This is the X/Open sanctioned signal stack switching.  */
645 	if (ka->sa.sa_flags & SA_ONSTACK) {
646 		if (sas_ss_flags(esp) == 0)
647 			esp = current->sas_ss_sp + current->sas_ss_size;
648 	}
649 
650 	/* This is the legacy signal stack switching. */
651 	else
652 #endif
653         if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&
654             !(ka->sa.sa_flags & TARGET_SA_RESTORER) &&
655             ka->sa.sa_restorer) {
656             esp = (unsigned long) ka->sa.sa_restorer;
657 	}
658         return g2h((esp - frame_size) & -8ul);
659 }
660 
661 static void setup_frame(int sig, struct emulated_sigaction *ka,
662 			target_sigset_t *set, CPUX86State *env)
663 {
664 	struct sigframe *frame;
665 	int i, err = 0;
666 
667 	frame = get_sigframe(ka, env, sizeof(*frame));
668 
669 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
670 		goto give_sigsegv;
671 	err |= __put_user((/*current->exec_domain
672 		           && current->exec_domain->signal_invmap
673 		           && sig < 32
674 		           ? current->exec_domain->signal_invmap[sig]
675 		           : */ sig),
676 		          &frame->sig);
677 	if (err)
678 		goto give_sigsegv;
679 
680 	setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0]);
681 	if (err)
682 		goto give_sigsegv;
683 
684         for(i = 1; i < TARGET_NSIG_WORDS; i++) {
685             if (__put_user(set->sig[i], &frame->extramask[i - 1]))
686                 goto give_sigsegv;
687         }
688 
689 	/* Set up to return from userspace.  If provided, use a stub
690 	   already in userspace.  */
691 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
692 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
693 	} else {
694 		err |= __put_user(frame->retcode, &frame->pretcode);
695 		/* This is popl %eax ; movl $,%eax ; int $0x80 */
696 		err |= __put_user(0xb858, (short *)(frame->retcode+0));
697 #if defined(TARGET_X86_64)
698 #warning "Fix this !"
699 #else
700 		err |= __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2));
701 #endif
702 		err |= __put_user(0x80cd, (short *)(frame->retcode+6));
703 	}
704 
705 	if (err)
706 		goto give_sigsegv;
707 
708 	/* Set up registers for signal handler */
709 	env->regs[R_ESP] = h2g(frame);
710 	env->eip = (unsigned long) ka->sa._sa_handler;
711 
712         cpu_x86_load_seg(env, R_DS, __USER_DS);
713         cpu_x86_load_seg(env, R_ES, __USER_DS);
714         cpu_x86_load_seg(env, R_SS, __USER_DS);
715         cpu_x86_load_seg(env, R_CS, __USER_CS);
716 	env->eflags &= ~TF_MASK;
717 
718 	return;
719 
720 give_sigsegv:
721 	if (sig == TARGET_SIGSEGV)
722 		ka->sa._sa_handler = TARGET_SIG_DFL;
723 	force_sig(TARGET_SIGSEGV /* , current */);
724 }
725 
726 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
727                            target_siginfo_t *info,
728 			   target_sigset_t *set, CPUX86State *env)
729 {
730 	struct rt_sigframe *frame;
731 	int i, err = 0;
732 
733 	frame = get_sigframe(ka, env, sizeof(*frame));
734 
735 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
736 		goto give_sigsegv;
737 
738 	err |= __put_user((/*current->exec_domain
739 		    	   && current->exec_domain->signal_invmap
740 		    	   && sig < 32
741 		    	   ? current->exec_domain->signal_invmap[sig]
742 			   : */sig),
743 			  &frame->sig);
744 	err |= __put_user((target_ulong)&frame->info, &frame->pinfo);
745 	err |= __put_user((target_ulong)&frame->uc, &frame->puc);
746 	err |= copy_siginfo_to_user(&frame->info, info);
747 	if (err)
748 		goto give_sigsegv;
749 
750 	/* Create the ucontext.  */
751 	err |= __put_user(0, &frame->uc.tuc_flags);
752 	err |= __put_user(0, &frame->uc.tuc_link);
753 	err |= __put_user(/*current->sas_ss_sp*/ 0,
754 			  &frame->uc.tuc_stack.ss_sp);
755 	err |= __put_user(/* sas_ss_flags(regs->esp) */ 0,
756 			  &frame->uc.tuc_stack.ss_flags);
757 	err |= __put_user(/* current->sas_ss_size */ 0,
758 			  &frame->uc.tuc_stack.ss_size);
759 	err |= setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate,
760 			        env, set->sig[0]);
761         for(i = 0; i < TARGET_NSIG_WORDS; i++) {
762             if (__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]))
763                 goto give_sigsegv;
764         }
765 
766 	/* Set up to return from userspace.  If provided, use a stub
767 	   already in userspace.  */
768 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
769 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
770 	} else {
771 		err |= __put_user(frame->retcode, &frame->pretcode);
772 		/* This is movl $,%eax ; int $0x80 */
773 		err |= __put_user(0xb8, (char *)(frame->retcode+0));
774 		err |= __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1));
775 		err |= __put_user(0x80cd, (short *)(frame->retcode+5));
776 	}
777 
778 	if (err)
779 		goto give_sigsegv;
780 
781 	/* Set up registers for signal handler */
782 	env->regs[R_ESP] = (unsigned long) frame;
783 	env->eip = (unsigned long) ka->sa._sa_handler;
784 
785         cpu_x86_load_seg(env, R_DS, __USER_DS);
786         cpu_x86_load_seg(env, R_ES, __USER_DS);
787         cpu_x86_load_seg(env, R_SS, __USER_DS);
788         cpu_x86_load_seg(env, R_CS, __USER_CS);
789 	env->eflags &= ~TF_MASK;
790 
791 	return;
792 
793 give_sigsegv:
794 	if (sig == TARGET_SIGSEGV)
795 		ka->sa._sa_handler = TARGET_SIG_DFL;
796 	force_sig(TARGET_SIGSEGV /* , current */);
797 }
798 
799 static int
800 restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax)
801 {
802 	unsigned int err = 0;
803 
804         cpu_x86_load_seg(env, R_GS, lduw(&sc->gs));
805         cpu_x86_load_seg(env, R_FS, lduw(&sc->fs));
806         cpu_x86_load_seg(env, R_ES, lduw(&sc->es));
807         cpu_x86_load_seg(env, R_DS, lduw(&sc->ds));
808 
809         env->regs[R_EDI] = ldl(&sc->edi);
810         env->regs[R_ESI] = ldl(&sc->esi);
811         env->regs[R_EBP] = ldl(&sc->ebp);
812         env->regs[R_ESP] = ldl(&sc->esp);
813         env->regs[R_EBX] = ldl(&sc->ebx);
814         env->regs[R_EDX] = ldl(&sc->edx);
815         env->regs[R_ECX] = ldl(&sc->ecx);
816         env->eip = ldl(&sc->eip);
817 
818         cpu_x86_load_seg(env, R_CS, lduw(&sc->cs) | 3);
819         cpu_x86_load_seg(env, R_SS, lduw(&sc->ss) | 3);
820 
821 	{
822 		unsigned int tmpflags;
823                 tmpflags = ldl(&sc->eflags);
824 		env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
825                 //		regs->orig_eax = -1;		/* disable syscall checks */
826 	}
827 
828 	{
829 		struct _fpstate * buf;
830                 buf = (void *)ldl(&sc->fpstate);
831 		if (buf) {
832 #if 0
833 			if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
834 				goto badframe;
835 #endif
836                         cpu_x86_frstor(env, (void *)buf, 1);
837 		}
838 	}
839 
840         *peax = ldl(&sc->eax);
841 	return err;
842 #if 0
843 badframe:
844 	return 1;
845 #endif
846 }
847 
848 long do_sigreturn(CPUX86State *env)
849 {
850     struct sigframe *frame = (struct sigframe *)g2h(env->regs[R_ESP] - 8);
851     target_sigset_t target_set;
852     sigset_t set;
853     int eax, i;
854 
855 #if defined(DEBUG_SIGNAL)
856     fprintf(stderr, "do_sigreturn\n");
857 #endif
858     /* set blocked signals */
859     if (__get_user(target_set.sig[0], &frame->sc.oldmask))
860         goto badframe;
861     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
862         if (__get_user(target_set.sig[i], &frame->extramask[i - 1]))
863             goto badframe;
864     }
865 
866     target_to_host_sigset_internal(&set, &target_set);
867     sigprocmask(SIG_SETMASK, &set, NULL);
868 
869     /* restore registers */
870     if (restore_sigcontext(env, &frame->sc, &eax))
871         goto badframe;
872     return eax;
873 
874 badframe:
875     force_sig(TARGET_SIGSEGV);
876     return 0;
877 }
878 
879 long do_rt_sigreturn(CPUX86State *env)
880 {
881 	struct rt_sigframe *frame = (struct rt_sigframe *)g2h(env->regs[R_ESP] - 4);
882         sigset_t set;
883         //	stack_t st;
884 	int eax;
885 
886 #if 0
887 	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
888 		goto badframe;
889 #endif
890         target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
891         sigprocmask(SIG_SETMASK, &set, NULL);
892 
893 	if (restore_sigcontext(env, &frame->uc.tuc_mcontext, &eax))
894 		goto badframe;
895 
896 #if 0
897 	if (__copy_from_user(&st, &frame->uc.tuc_stack, sizeof(st)))
898 		goto badframe;
899 	/* It is more difficult to avoid calling this function than to
900 	   call it and ignore errors.  */
901 	do_sigaltstack(&st, NULL, regs->esp);
902 #endif
903 	return eax;
904 
905 badframe:
906 	force_sig(TARGET_SIGSEGV);
907 	return 0;
908 }
909 
910 #elif defined(TARGET_ARM)
911 
912 struct target_sigcontext {
913 	target_ulong trap_no;
914 	target_ulong error_code;
915 	target_ulong oldmask;
916 	target_ulong arm_r0;
917 	target_ulong arm_r1;
918 	target_ulong arm_r2;
919 	target_ulong arm_r3;
920 	target_ulong arm_r4;
921 	target_ulong arm_r5;
922 	target_ulong arm_r6;
923 	target_ulong arm_r7;
924 	target_ulong arm_r8;
925 	target_ulong arm_r9;
926 	target_ulong arm_r10;
927 	target_ulong arm_fp;
928 	target_ulong arm_ip;
929 	target_ulong arm_sp;
930 	target_ulong arm_lr;
931 	target_ulong arm_pc;
932 	target_ulong arm_cpsr;
933 	target_ulong fault_address;
934 };
935 
936 typedef struct target_sigaltstack {
937 	target_ulong ss_sp;
938 	int ss_flags;
939 	target_ulong ss_size;
940 } target_stack_t;
941 
942 struct target_ucontext {
943     target_ulong tuc_flags;
944     target_ulong tuc_link;
945     target_stack_t tuc_stack;
946     struct target_sigcontext tuc_mcontext;
947     target_sigset_t  tuc_sigmask;	/* mask last for extensibility */
948 };
949 
950 struct sigframe
951 {
952     struct target_sigcontext sc;
953     target_ulong extramask[TARGET_NSIG_WORDS-1];
954     target_ulong retcode;
955 };
956 
957 struct rt_sigframe
958 {
959     struct target_siginfo *pinfo;
960     void *puc;
961     struct target_siginfo info;
962     struct target_ucontext uc;
963     target_ulong retcode;
964 };
965 
966 #define TARGET_CONFIG_CPU_32 1
967 
968 /*
969  * For ARM syscalls, we encode the syscall number into the instruction.
970  */
971 #define SWI_SYS_SIGRETURN	(0xef000000|(TARGET_NR_sigreturn + ARM_SYSCALL_BASE))
972 #define SWI_SYS_RT_SIGRETURN	(0xef000000|(TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE))
973 
974 /*
975  * For Thumb syscalls, we pass the syscall number via r7.  We therefore
976  * need two 16-bit instructions.
977  */
978 #define SWI_THUMB_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_sigreturn))
979 #define SWI_THUMB_RT_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_rt_sigreturn))
980 
981 static const target_ulong retcodes[4] = {
982 	SWI_SYS_SIGRETURN,	SWI_THUMB_SIGRETURN,
983 	SWI_SYS_RT_SIGRETURN,	SWI_THUMB_RT_SIGRETURN
984 };
985 
986 
987 #define __put_user_error(x,p,e) __put_user(x, p)
988 #define __get_user_error(x,p,e) __get_user(x, p)
989 
990 static inline int valid_user_regs(CPUState *regs)
991 {
992     return 1;
993 }
994 
995 static int
996 setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
997 		 CPUState *env, unsigned long mask)
998 {
999 	int err = 0;
1000 
1001 	__put_user_error(env->regs[0], &sc->arm_r0, err);
1002 	__put_user_error(env->regs[1], &sc->arm_r1, err);
1003 	__put_user_error(env->regs[2], &sc->arm_r2, err);
1004 	__put_user_error(env->regs[3], &sc->arm_r3, err);
1005 	__put_user_error(env->regs[4], &sc->arm_r4, err);
1006 	__put_user_error(env->regs[5], &sc->arm_r5, err);
1007 	__put_user_error(env->regs[6], &sc->arm_r6, err);
1008 	__put_user_error(env->regs[7], &sc->arm_r7, err);
1009 	__put_user_error(env->regs[8], &sc->arm_r8, err);
1010 	__put_user_error(env->regs[9], &sc->arm_r9, err);
1011 	__put_user_error(env->regs[10], &sc->arm_r10, err);
1012 	__put_user_error(env->regs[11], &sc->arm_fp, err);
1013 	__put_user_error(env->regs[12], &sc->arm_ip, err);
1014 	__put_user_error(env->regs[13], &sc->arm_sp, err);
1015 	__put_user_error(env->regs[14], &sc->arm_lr, err);
1016 	__put_user_error(env->regs[15], &sc->arm_pc, err);
1017 #ifdef TARGET_CONFIG_CPU_32
1018 	__put_user_error(cpsr_read(env), &sc->arm_cpsr, err);
1019 #endif
1020 
1021 	__put_user_error(/* current->thread.trap_no */ 0, &sc->trap_no, err);
1022 	__put_user_error(/* current->thread.error_code */ 0, &sc->error_code, err);
1023 	__put_user_error(/* current->thread.address */ 0, &sc->fault_address, err);
1024 	__put_user_error(mask, &sc->oldmask, err);
1025 
1026 	return err;
1027 }
1028 
1029 static inline void *
1030 get_sigframe(struct emulated_sigaction *ka, CPUState *regs, int framesize)
1031 {
1032 	unsigned long sp = regs->regs[13];
1033 
1034 #if 0
1035 	/*
1036 	 * This is the X/Open sanctioned signal stack switching.
1037 	 */
1038 	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
1039 		sp = current->sas_ss_sp + current->sas_ss_size;
1040 #endif
1041 	/*
1042 	 * ATPCS B01 mandates 8-byte alignment
1043 	 */
1044 	return g2h((sp - framesize) & ~7);
1045 }
1046 
1047 static int
1048 setup_return(CPUState *env, struct emulated_sigaction *ka,
1049 	     target_ulong *rc, void *frame, int usig)
1050 {
1051 	target_ulong handler = (target_ulong)ka->sa._sa_handler;
1052 	target_ulong retcode;
1053 	int thumb = 0;
1054 #if defined(TARGET_CONFIG_CPU_32)
1055 #if 0
1056 	target_ulong cpsr = env->cpsr;
1057 
1058 	/*
1059 	 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
1060 	 */
1061 	if (ka->sa.sa_flags & SA_THIRTYTWO)
1062 		cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
1063 
1064 #ifdef CONFIG_ARM_THUMB
1065 	if (elf_hwcap & HWCAP_THUMB) {
1066 		/*
1067 		 * The LSB of the handler determines if we're going to
1068 		 * be using THUMB or ARM mode for this signal handler.
1069 		 */
1070 		thumb = handler & 1;
1071 
1072 		if (thumb)
1073 			cpsr |= T_BIT;
1074 		else
1075 			cpsr &= ~T_BIT;
1076 	}
1077 #endif
1078 #endif
1079 #endif /* TARGET_CONFIG_CPU_32 */
1080 
1081 	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
1082 		retcode = (target_ulong)ka->sa.sa_restorer;
1083 	} else {
1084 		unsigned int idx = thumb;
1085 
1086 		if (ka->sa.sa_flags & TARGET_SA_SIGINFO)
1087 			idx += 2;
1088 
1089 		if (__put_user(retcodes[idx], rc))
1090 			return 1;
1091 #if 0
1092 		flush_icache_range((target_ulong)rc,
1093 				   (target_ulong)(rc + 1));
1094 #endif
1095 		retcode = ((target_ulong)rc) + thumb;
1096 	}
1097 
1098 	env->regs[0] = usig;
1099 	env->regs[13] = h2g(frame);
1100 	env->regs[14] = retcode;
1101 	env->regs[15] = handler & (thumb ? ~1 : ~3);
1102 
1103 #if 0
1104 #ifdef TARGET_CONFIG_CPU_32
1105 	env->cpsr = cpsr;
1106 #endif
1107 #endif
1108 
1109 	return 0;
1110 }
1111 
1112 static void setup_frame(int usig, struct emulated_sigaction *ka,
1113 			target_sigset_t *set, CPUState *regs)
1114 {
1115 	struct sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
1116 	int i, err = 0;
1117 
1118 	err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);
1119 
1120         for(i = 1; i < TARGET_NSIG_WORDS; i++) {
1121             if (__put_user(set->sig[i], &frame->extramask[i - 1]))
1122                 return;
1123 	}
1124 
1125 	if (err == 0)
1126             err = setup_return(regs, ka, &frame->retcode, frame, usig);
1127         //	return err;
1128 }
1129 
1130 static void setup_rt_frame(int usig, struct emulated_sigaction *ka,
1131                            target_siginfo_t *info,
1132 			   target_sigset_t *set, CPUState *env)
1133 {
1134 	struct rt_sigframe *frame = get_sigframe(ka, env, sizeof(*frame));
1135 	int i, err = 0;
1136 
1137 	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
1138             return /* 1 */;
1139 
1140 	__put_user_error(&frame->info, (target_ulong *)&frame->pinfo, err);
1141 	__put_user_error(&frame->uc, (target_ulong *)&frame->puc, err);
1142 	err |= copy_siginfo_to_user(&frame->info, info);
1143 
1144 	/* Clear all the bits of the ucontext we don't use.  */
1145 	memset(&frame->uc, 0, offsetof(struct target_ucontext, tuc_mcontext));
1146 
1147 	err |= setup_sigcontext(&frame->uc.tuc_mcontext, /*&frame->fpstate,*/
1148 				env, set->sig[0]);
1149         for(i = 0; i < TARGET_NSIG_WORDS; i++) {
1150             if (__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]))
1151                 return;
1152         }
1153 
1154 	if (err == 0)
1155 		err = setup_return(env, ka, &frame->retcode, frame, usig);
1156 
1157 	if (err == 0) {
1158 		/*
1159 		 * For realtime signals we must also set the second and third
1160 		 * arguments for the signal handler.
1161 		 *   -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
1162 		 */
1163             env->regs[1] = (target_ulong)frame->pinfo;
1164             env->regs[2] = (target_ulong)frame->puc;
1165 	}
1166 
1167         //	return err;
1168 }
1169 
1170 static int
1171 restore_sigcontext(CPUState *env, struct target_sigcontext *sc)
1172 {
1173 	int err = 0;
1174         uint32_t cpsr;
1175 
1176 	__get_user_error(env->regs[0], &sc->arm_r0, err);
1177 	__get_user_error(env->regs[1], &sc->arm_r1, err);
1178 	__get_user_error(env->regs[2], &sc->arm_r2, err);
1179 	__get_user_error(env->regs[3], &sc->arm_r3, err);
1180 	__get_user_error(env->regs[4], &sc->arm_r4, err);
1181 	__get_user_error(env->regs[5], &sc->arm_r5, err);
1182 	__get_user_error(env->regs[6], &sc->arm_r6, err);
1183 	__get_user_error(env->regs[7], &sc->arm_r7, err);
1184 	__get_user_error(env->regs[8], &sc->arm_r8, err);
1185 	__get_user_error(env->regs[9], &sc->arm_r9, err);
1186 	__get_user_error(env->regs[10], &sc->arm_r10, err);
1187 	__get_user_error(env->regs[11], &sc->arm_fp, err);
1188 	__get_user_error(env->regs[12], &sc->arm_ip, err);
1189 	__get_user_error(env->regs[13], &sc->arm_sp, err);
1190 	__get_user_error(env->regs[14], &sc->arm_lr, err);
1191 	__get_user_error(env->regs[15], &sc->arm_pc, err);
1192 #ifdef TARGET_CONFIG_CPU_32
1193 	__get_user_error(cpsr, &sc->arm_cpsr, err);
1194         cpsr_write(env, cpsr, 0xffffffff);
1195 #endif
1196 
1197 	err |= !valid_user_regs(env);
1198 
1199 	return err;
1200 }
1201 
1202 long do_sigreturn(CPUState *env)
1203 {
1204 	struct sigframe *frame;
1205 	target_sigset_t set;
1206         sigset_t host_set;
1207         int i;
1208 
1209 	/*
1210 	 * Since we stacked the signal on a 64-bit boundary,
1211 	 * then 'sp' should be word aligned here.  If it's
1212 	 * not, then the user is trying to mess with us.
1213 	 */
1214 	if (env->regs[13] & 7)
1215 		goto badframe;
1216 
1217 	frame = (struct sigframe *)g2h(env->regs[13]);
1218 
1219 #if 0
1220 	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
1221 		goto badframe;
1222 #endif
1223 	if (__get_user(set.sig[0], &frame->sc.oldmask))
1224             goto badframe;
1225         for(i = 1; i < TARGET_NSIG_WORDS; i++) {
1226             if (__get_user(set.sig[i], &frame->extramask[i - 1]))
1227                 goto badframe;
1228         }
1229 
1230         target_to_host_sigset_internal(&host_set, &set);
1231         sigprocmask(SIG_SETMASK, &host_set, NULL);
1232 
1233 	if (restore_sigcontext(env, &frame->sc))
1234 		goto badframe;
1235 
1236 #if 0
1237 	/* Send SIGTRAP if we're single-stepping */
1238 	if (ptrace_cancel_bpt(current))
1239 		send_sig(SIGTRAP, current, 1);
1240 #endif
1241 	return env->regs[0];
1242 
1243 badframe:
1244         force_sig(SIGSEGV /* , current */);
1245 	return 0;
1246 }
1247 
1248 long do_rt_sigreturn(CPUState *env)
1249 {
1250 	struct rt_sigframe *frame;
1251         sigset_t host_set;
1252 
1253 	/*
1254 	 * Since we stacked the signal on a 64-bit boundary,
1255 	 * then 'sp' should be word aligned here.  If it's
1256 	 * not, then the user is trying to mess with us.
1257 	 */
1258 	if (env->regs[13] & 7)
1259 		goto badframe;
1260 
1261 	frame = (struct rt_sigframe *)env->regs[13];
1262 
1263 #if 0
1264 	if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
1265 		goto badframe;
1266 #endif
1267         target_to_host_sigset(&host_set, &frame->uc.tuc_sigmask);
1268         sigprocmask(SIG_SETMASK, &host_set, NULL);
1269 
1270 	if (restore_sigcontext(env, &frame->uc.tuc_mcontext))
1271 		goto badframe;
1272 
1273 #if 0
1274 	/* Send SIGTRAP if we're single-stepping */
1275 	if (ptrace_cancel_bpt(current))
1276 		send_sig(SIGTRAP, current, 1);
1277 #endif
1278 	return env->regs[0];
1279 
1280 badframe:
1281         force_sig(SIGSEGV /* , current */);
1282 	return 0;
1283 }
1284 
1285 #elif defined(TARGET_SPARC)
1286 
1287 #define __SUNOS_MAXWIN   31
1288 
1289 /* This is what SunOS does, so shall I. */
1290 struct target_sigcontext {
1291         target_ulong sigc_onstack;      /* state to restore */
1292 
1293         target_ulong sigc_mask;         /* sigmask to restore */
1294         target_ulong sigc_sp;           /* stack pointer */
1295         target_ulong sigc_pc;           /* program counter */
1296         target_ulong sigc_npc;          /* next program counter */
1297         target_ulong sigc_psr;          /* for condition codes etc */
1298         target_ulong sigc_g1;           /* User uses these two registers */
1299         target_ulong sigc_o0;           /* within the trampoline code. */
1300 
1301         /* Now comes information regarding the users window set
1302          * at the time of the signal.
1303          */
1304         target_ulong sigc_oswins;       /* outstanding windows */
1305 
1306         /* stack ptrs for each regwin buf */
1307         char *sigc_spbuf[__SUNOS_MAXWIN];
1308 
1309         /* Windows to restore after signal */
1310         struct {
1311                 target_ulong locals[8];
1312                 target_ulong ins[8];
1313         } sigc_wbuf[__SUNOS_MAXWIN];
1314 };
1315 /* A Sparc stack frame */
1316 struct sparc_stackf {
1317         target_ulong locals[8];
1318         target_ulong ins[6];
1319         struct sparc_stackf *fp;
1320         target_ulong callers_pc;
1321         char *structptr;
1322         target_ulong xargs[6];
1323         target_ulong xxargs[1];
1324 };
1325 
1326 typedef struct {
1327         struct {
1328                 target_ulong psr;
1329                 target_ulong pc;
1330                 target_ulong npc;
1331                 target_ulong y;
1332                 target_ulong u_regs[16]; /* globals and ins */
1333         }               si_regs;
1334         int             si_mask;
1335 } __siginfo_t;
1336 
1337 typedef struct {
1338         unsigned   long si_float_regs [32];
1339         unsigned   long si_fsr;
1340         unsigned   long si_fpqdepth;
1341         struct {
1342                 unsigned long *insn_addr;
1343                 unsigned long insn;
1344         } si_fpqueue [16];
1345 } qemu_siginfo_fpu_t;
1346 
1347 
1348 struct target_signal_frame {
1349 	struct sparc_stackf	ss;
1350 	__siginfo_t		info;
1351 	qemu_siginfo_fpu_t 	*fpu_save;
1352 	target_ulong		insns[2] __attribute__ ((aligned (8)));
1353 	target_ulong		extramask[TARGET_NSIG_WORDS - 1];
1354 	target_ulong		extra_size; /* Should be 0 */
1355 	qemu_siginfo_fpu_t	fpu_state;
1356 };
1357 struct target_rt_signal_frame {
1358 	struct sparc_stackf	ss;
1359 	siginfo_t		info;
1360 	target_ulong		regs[20];
1361 	sigset_t		mask;
1362 	qemu_siginfo_fpu_t 	*fpu_save;
1363 	unsigned int		insns[2];
1364 	stack_t			stack;
1365 	unsigned int		extra_size; /* Should be 0 */
1366 	qemu_siginfo_fpu_t	fpu_state;
1367 };
1368 
1369 #define UREG_O0        16
1370 #define UREG_O6        22
1371 #define UREG_I0        0
1372 #define UREG_I1        1
1373 #define UREG_I2        2
1374 #define UREG_I6        6
1375 #define UREG_I7        7
1376 #define UREG_L0	       8
1377 #define UREG_FP        UREG_I6
1378 #define UREG_SP        UREG_O6
1379 
1380 static inline void *get_sigframe(struct emulated_sigaction *sa, CPUState *env, unsigned long framesize)
1381 {
1382 	unsigned long sp;
1383 
1384 	sp = env->regwptr[UREG_FP];
1385 #if 0
1386 
1387 	/* This is the X/Open sanctioned signal stack switching.  */
1388 	if (sa->sa_flags & TARGET_SA_ONSTACK) {
1389 		if (!on_sig_stack(sp) && !((current->sas_ss_sp + current->sas_ss_size) & 7))
1390 			sp = current->sas_ss_sp + current->sas_ss_size;
1391 	}
1392 #endif
1393 	return g2h(sp - framesize);
1394 }
1395 
1396 static int
1397 setup___siginfo(__siginfo_t *si, CPUState *env, target_ulong mask)
1398 {
1399 	int err = 0, i;
1400 
1401 	err |= __put_user(env->psr, &si->si_regs.psr);
1402 	err |= __put_user(env->pc, &si->si_regs.pc);
1403 	err |= __put_user(env->npc, &si->si_regs.npc);
1404 	err |= __put_user(env->y, &si->si_regs.y);
1405 	for (i=0; i < 8; i++) {
1406 		err |= __put_user(env->gregs[i], &si->si_regs.u_regs[i]);
1407 	}
1408 	for (i=0; i < 8; i++) {
1409 		err |= __put_user(env->regwptr[UREG_I0 + i], &si->si_regs.u_regs[i+8]);
1410 	}
1411 	err |= __put_user(mask, &si->si_mask);
1412 	return err;
1413 }
1414 
1415 #if 0
1416 static int
1417 setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
1418 		 CPUState *env, unsigned long mask)
1419 {
1420 	int err = 0;
1421 
1422 	err |= __put_user(mask, &sc->sigc_mask);
1423 	err |= __put_user(env->regwptr[UREG_SP], &sc->sigc_sp);
1424 	err |= __put_user(env->pc, &sc->sigc_pc);
1425 	err |= __put_user(env->npc, &sc->sigc_npc);
1426 	err |= __put_user(env->psr, &sc->sigc_psr);
1427 	err |= __put_user(env->gregs[1], &sc->sigc_g1);
1428 	err |= __put_user(env->regwptr[UREG_O0], &sc->sigc_o0);
1429 
1430 	return err;
1431 }
1432 #endif
1433 #define NF_ALIGNEDSZ  (((sizeof(struct target_signal_frame) + 7) & (~7)))
1434 
1435 static void setup_frame(int sig, struct emulated_sigaction *ka,
1436 			target_sigset_t *set, CPUState *env)
1437 {
1438 	struct target_signal_frame *sf;
1439 	int sigframe_size, err, i;
1440 
1441 	/* 1. Make sure everything is clean */
1442 	//synchronize_user_stack();
1443 
1444         sigframe_size = NF_ALIGNEDSZ;
1445 
1446 	sf = (struct target_signal_frame *)
1447 		get_sigframe(ka, env, sigframe_size);
1448 
1449 	//fprintf(stderr, "sf: %x pc %x fp %x sp %x\n", sf, env->pc, env->regwptr[UREG_FP], env->regwptr[UREG_SP]);
1450 #if 0
1451 	if (invalid_frame_pointer(sf, sigframe_size))
1452 		goto sigill_and_return;
1453 #endif
1454 	/* 2. Save the current process state */
1455 	err = setup___siginfo(&sf->info, env, set->sig[0]);
1456 	err |= __put_user(0, &sf->extra_size);
1457 
1458 	//err |= save_fpu_state(regs, &sf->fpu_state);
1459 	//err |= __put_user(&sf->fpu_state, &sf->fpu_save);
1460 
1461 	err |= __put_user(set->sig[0], &sf->info.si_mask);
1462 	for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) {
1463 		err |= __put_user(set->sig[i + 1], &sf->extramask[i]);
1464 	}
1465 
1466 	for (i = 0; i < 8; i++) {
1467 	  	err |= __put_user(env->regwptr[i + UREG_L0], &sf->ss.locals[i]);
1468 	}
1469 	for (i = 0; i < 8; i++) {
1470 	  	err |= __put_user(env->regwptr[i + UREG_I0], &sf->ss.ins[i]);
1471 	}
1472 	if (err)
1473 		goto sigsegv;
1474 
1475 	/* 3. signal handler back-trampoline and parameters */
1476 	env->regwptr[UREG_FP] = h2g(sf);
1477 	env->regwptr[UREG_I0] = sig;
1478 	env->regwptr[UREG_I1] = h2g(&sf->info);
1479 	env->regwptr[UREG_I2] = h2g(&sf->info);
1480 
1481 	/* 4. signal handler */
1482 	env->pc = (unsigned long) ka->sa._sa_handler;
1483 	env->npc = (env->pc + 4);
1484 	/* 5. return to kernel instructions */
1485 	if (ka->sa.sa_restorer)
1486 		env->regwptr[UREG_I7] = (unsigned long)ka->sa.sa_restorer;
1487 	else {
1488 		env->regwptr[UREG_I7] = h2g(&(sf->insns[0]) - 2);
1489 
1490 		/* mov __NR_sigreturn, %g1 */
1491 		err |= __put_user(0x821020d8, &sf->insns[0]);
1492 
1493 		/* t 0x10 */
1494 		err |= __put_user(0x91d02010, &sf->insns[1]);
1495 		if (err)
1496 			goto sigsegv;
1497 
1498 		/* Flush instruction space. */
1499 		//flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
1500                 //		tb_flush(env);
1501 	}
1502 	return;
1503 
1504         //sigill_and_return:
1505 	force_sig(TARGET_SIGILL);
1506 sigsegv:
1507 	//fprintf(stderr, "force_sig\n");
1508 	force_sig(TARGET_SIGSEGV);
1509 }
1510 static inline int
1511 restore_fpu_state(CPUState *env, qemu_siginfo_fpu_t *fpu)
1512 {
1513         int err;
1514 #if 0
1515 #ifdef CONFIG_SMP
1516         if (current->flags & PF_USEDFPU)
1517                 regs->psr &= ~PSR_EF;
1518 #else
1519         if (current == last_task_used_math) {
1520                 last_task_used_math = 0;
1521                 regs->psr &= ~PSR_EF;
1522         }
1523 #endif
1524         current->used_math = 1;
1525         current->flags &= ~PF_USEDFPU;
1526 #endif
1527 #if 0
1528         if (verify_area (VERIFY_READ, fpu, sizeof(*fpu)))
1529                 return -EFAULT;
1530 #endif
1531 
1532 #if 0
1533         /* XXX: incorrect */
1534         err = __copy_from_user(&env->fpr[0], &fpu->si_float_regs[0],
1535 	                             (sizeof(unsigned long) * 32));
1536 #endif
1537         err |= __get_user(env->fsr, &fpu->si_fsr);
1538 #if 0
1539         err |= __get_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
1540         if (current->thread.fpqdepth != 0)
1541                 err |= __copy_from_user(&current->thread.fpqueue[0],
1542                                         &fpu->si_fpqueue[0],
1543                                         ((sizeof(unsigned long) +
1544                                         (sizeof(unsigned long *)))*16));
1545 #endif
1546         return err;
1547 }
1548 
1549 
1550 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
1551                            target_siginfo_t *info,
1552 			   target_sigset_t *set, CPUState *env)
1553 {
1554     fprintf(stderr, "setup_rt_frame: not implemented\n");
1555 }
1556 
1557 long do_sigreturn(CPUState *env)
1558 {
1559         struct target_signal_frame *sf;
1560         uint32_t up_psr, pc, npc;
1561         target_sigset_t set;
1562         sigset_t host_set;
1563         target_ulong fpu_save;
1564         int err, i;
1565 
1566         sf = (struct target_signal_frame *)g2h(env->regwptr[UREG_FP]);
1567 #if 0
1568 	fprintf(stderr, "sigreturn\n");
1569 	fprintf(stderr, "sf: %x pc %x fp %x sp %x\n", sf, env->pc, env->regwptr[UREG_FP], env->regwptr[UREG_SP]);
1570 #endif
1571 	//cpu_dump_state(env, stderr, fprintf, 0);
1572 
1573         /* 1. Make sure we are not getting garbage from the user */
1574 #if 0
1575         if (verify_area (VERIFY_READ, sf, sizeof (*sf)))
1576                 goto segv_and_exit;
1577 #endif
1578 
1579         if (((uint) sf) & 3)
1580                 goto segv_and_exit;
1581 
1582         err = __get_user(pc,  &sf->info.si_regs.pc);
1583         err |= __get_user(npc, &sf->info.si_regs.npc);
1584 
1585         if ((pc | npc) & 3)
1586                 goto segv_and_exit;
1587 
1588         /* 2. Restore the state */
1589         err |= __get_user(up_psr, &sf->info.si_regs.psr);
1590 
1591         /* User can only change condition codes and FPU enabling in %psr. */
1592         env->psr = (up_psr & (PSR_ICC /* | PSR_EF */))
1593                   | (env->psr & ~(PSR_ICC /* | PSR_EF */));
1594 
1595 	env->pc = pc;
1596 	env->npc = npc;
1597         err |= __get_user(env->y, &sf->info.si_regs.y);
1598 	for (i=0; i < 8; i++) {
1599 		err |= __get_user(env->gregs[i], &sf->info.si_regs.u_regs[i]);
1600 	}
1601 	for (i=0; i < 8; i++) {
1602 		err |= __get_user(env->regwptr[i + UREG_I0], &sf->info.si_regs.u_regs[i+8]);
1603 	}
1604 
1605         err |= __get_user(fpu_save, (target_ulong *)&sf->fpu_save);
1606 
1607         //if (fpu_save)
1608         //        err |= restore_fpu_state(env, fpu_save);
1609 
1610         /* This is pretty much atomic, no amount locking would prevent
1611          * the races which exist anyways.
1612          */
1613         err |= __get_user(set.sig[0], &sf->info.si_mask);
1614         for(i = 1; i < TARGET_NSIG_WORDS; i++) {
1615             err |= (__get_user(set.sig[i], &sf->extramask[i - 1]));
1616         }
1617 
1618         target_to_host_sigset_internal(&host_set, &set);
1619         sigprocmask(SIG_SETMASK, &host_set, NULL);
1620 
1621         if (err)
1622                 goto segv_and_exit;
1623 
1624         return env->regwptr[0];
1625 
1626 segv_and_exit:
1627 	force_sig(TARGET_SIGSEGV);
1628 }
1629 
1630 long do_rt_sigreturn(CPUState *env)
1631 {
1632     fprintf(stderr, "do_rt_sigreturn: not implemented\n");
1633     return -ENOSYS;
1634 }
1635 
1636 #elif defined(TARGET_MIPS)
1637 
1638 struct target_sigcontext {
1639     uint32_t   sc_regmask;     /* Unused */
1640     uint32_t   sc_status;
1641     uint64_t   sc_pc;
1642     uint64_t   sc_regs[32];
1643     uint64_t   sc_fpregs[32];
1644     uint32_t   sc_ownedfp;     /* Unused */
1645     uint32_t   sc_fpc_csr;
1646     uint32_t   sc_fpc_eir;     /* Unused */
1647     uint32_t   sc_used_math;
1648     uint32_t   sc_dsp;         /* dsp status, was sc_ssflags */
1649     uint64_t   sc_mdhi;
1650     uint64_t   sc_mdlo;
1651     target_ulong   sc_hi1;         /* Was sc_cause */
1652     target_ulong   sc_lo1;         /* Was sc_badvaddr */
1653     target_ulong   sc_hi2;         /* Was sc_sigset[4] */
1654     target_ulong   sc_lo2;
1655     target_ulong   sc_hi3;
1656     target_ulong   sc_lo3;
1657 };
1658 
1659 struct sigframe {
1660     uint32_t sf_ass[4];			/* argument save space for o32 */
1661     uint32_t sf_code[2];			/* signal trampoline */
1662     struct target_sigcontext sf_sc;
1663     target_sigset_t sf_mask;
1664 };
1665 
1666 /* Install trampoline to jump back from signal handler */
1667 static inline int install_sigtramp(unsigned int *tramp,   unsigned int syscall)
1668 {
1669     int err;
1670 
1671     /*
1672     * Set up the return code ...
1673     *
1674     *         li      v0, __NR__foo_sigreturn
1675     *         syscall
1676     */
1677 
1678     err = __put_user(0x24020000 + syscall, tramp + 0);
1679     err |= __put_user(0x0000000c          , tramp + 1);
1680     /* flush_cache_sigtramp((unsigned long) tramp); */
1681     return err;
1682 }
1683 
1684 static inline int
1685 setup_sigcontext(CPUState *regs, struct target_sigcontext *sc)
1686 {
1687     int err = 0;
1688 
1689     err |= __put_user(regs->PC[regs->current_tc], &sc->sc_pc);
1690 
1691 #define save_gp_reg(i) do {   							\
1692         err |= __put_user(regs->gpr[i][regs->current_tc], &sc->sc_regs[i]);	\
1693     } while(0)
1694     __put_user(0, &sc->sc_regs[0]); save_gp_reg(1); save_gp_reg(2);
1695     save_gp_reg(3); save_gp_reg(4); save_gp_reg(5); save_gp_reg(6);
1696     save_gp_reg(7); save_gp_reg(8); save_gp_reg(9); save_gp_reg(10);
1697     save_gp_reg(11); save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
1698     save_gp_reg(15); save_gp_reg(16); save_gp_reg(17); save_gp_reg(18);
1699     save_gp_reg(19); save_gp_reg(20); save_gp_reg(21); save_gp_reg(22);
1700     save_gp_reg(23); save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
1701     save_gp_reg(27); save_gp_reg(28); save_gp_reg(29); save_gp_reg(30);
1702     save_gp_reg(31);
1703 #undef save_gp_reg
1704 
1705     err |= __put_user(regs->HI[0][regs->current_tc], &sc->sc_mdhi);
1706     err |= __put_user(regs->LO[0][regs->current_tc], &sc->sc_mdlo);
1707 
1708     /* Not used yet, but might be useful if we ever have DSP suppport */
1709 #if 0
1710     if (cpu_has_dsp) {
1711 	err |= __put_user(mfhi1(), &sc->sc_hi1);
1712 	err |= __put_user(mflo1(), &sc->sc_lo1);
1713 	err |= __put_user(mfhi2(), &sc->sc_hi2);
1714 	err |= __put_user(mflo2(), &sc->sc_lo2);
1715 	err |= __put_user(mfhi3(), &sc->sc_hi3);
1716 	err |= __put_user(mflo3(), &sc->sc_lo3);
1717 	err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
1718     }
1719     /* same with 64 bit */
1720 #ifdef CONFIG_64BIT
1721     err |= __put_user(regs->hi, &sc->sc_hi[0]);
1722     err |= __put_user(regs->lo, &sc->sc_lo[0]);
1723     if (cpu_has_dsp) {
1724 	err |= __put_user(mfhi1(), &sc->sc_hi[1]);
1725 	err |= __put_user(mflo1(), &sc->sc_lo[1]);
1726 	err |= __put_user(mfhi2(), &sc->sc_hi[2]);
1727 	err |= __put_user(mflo2(), &sc->sc_lo[2]);
1728 	err |= __put_user(mfhi3(), &sc->sc_hi[3]);
1729 	err |= __put_user(mflo3(), &sc->sc_lo[3]);
1730 	err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
1731     }
1732 #endif
1733 #endif
1734 
1735 #if 0
1736     err |= __put_user(!!used_math(), &sc->sc_used_math);
1737 
1738     if (!used_math())
1739 	goto out;
1740 
1741     /*
1742     * Save FPU state to signal context.  Signal handler will "inherit"
1743     * current FPU state.
1744     */
1745     preempt_disable();
1746 
1747     if (!is_fpu_owner()) {
1748 	own_fpu();
1749 	restore_fp(current);
1750     }
1751     err |= save_fp_context(sc);
1752 
1753     preempt_enable();
1754     out:
1755 #endif
1756     return err;
1757 }
1758 
1759 static inline int
1760 restore_sigcontext(CPUState *regs, struct target_sigcontext *sc)
1761 {
1762     int err = 0;
1763 
1764     err |= __get_user(regs->CP0_EPC, &sc->sc_pc);
1765 
1766     err |= __get_user(regs->HI[0][regs->current_tc], &sc->sc_mdhi);
1767     err |= __get_user(regs->LO[0][regs->current_tc], &sc->sc_mdlo);
1768 
1769 #define restore_gp_reg(i) do {   							\
1770         err |= __get_user(regs->gpr[i][regs->current_tc], &sc->sc_regs[i]);		\
1771     } while(0)
1772     restore_gp_reg( 1); restore_gp_reg( 2); restore_gp_reg( 3);
1773     restore_gp_reg( 4); restore_gp_reg( 5); restore_gp_reg( 6);
1774     restore_gp_reg( 7); restore_gp_reg( 8); restore_gp_reg( 9);
1775     restore_gp_reg(10); restore_gp_reg(11); restore_gp_reg(12);
1776     restore_gp_reg(13); restore_gp_reg(14); restore_gp_reg(15);
1777     restore_gp_reg(16); restore_gp_reg(17); restore_gp_reg(18);
1778     restore_gp_reg(19); restore_gp_reg(20); restore_gp_reg(21);
1779     restore_gp_reg(22); restore_gp_reg(23); restore_gp_reg(24);
1780     restore_gp_reg(25); restore_gp_reg(26); restore_gp_reg(27);
1781     restore_gp_reg(28); restore_gp_reg(29); restore_gp_reg(30);
1782     restore_gp_reg(31);
1783 #undef restore_gp_reg
1784 
1785 #if 0
1786     if (cpu_has_dsp) {
1787 	err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
1788 	err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
1789 	err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
1790 	err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
1791 	err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
1792 	err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
1793 	err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
1794     }
1795 #ifdef CONFIG_64BIT
1796     err |= __get_user(regs->hi, &sc->sc_hi[0]);
1797     err |= __get_user(regs->lo, &sc->sc_lo[0]);
1798     if (cpu_has_dsp) {
1799 	err |= __get_user(treg, &sc->sc_hi[1]); mthi1(treg);
1800 	err |= __get_user(treg, &sc->sc_lo[1]); mthi1(treg);
1801 	err |= __get_user(treg, &sc->sc_hi[2]); mthi2(treg);
1802 	err |= __get_user(treg, &sc->sc_lo[2]); mthi2(treg);
1803 	err |= __get_user(treg, &sc->sc_hi[3]); mthi3(treg);
1804 	err |= __get_user(treg, &sc->sc_lo[3]); mthi3(treg);
1805 	err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
1806     }
1807 #endif
1808 
1809     err |= __get_user(used_math, &sc->sc_used_math);
1810     conditional_used_math(used_math);
1811 
1812     preempt_disable();
1813 
1814     if (used_math()) {
1815 	/* restore fpu context if we have used it before */
1816 	own_fpu();
1817 	err |= restore_fp_context(sc);
1818     } else {
1819 	/* signal handler may have used FPU.  Give it up. */
1820 	lose_fpu();
1821     }
1822 
1823     preempt_enable();
1824 #endif
1825     return err;
1826 }
1827 /*
1828  * Determine which stack to use..
1829  */
1830 static inline void *
1831 get_sigframe(struct emulated_sigaction *ka, CPUState *regs, size_t frame_size)
1832 {
1833     unsigned long sp;
1834 
1835     /* Default to using normal stack */
1836     sp = regs->gpr[29][regs->current_tc];
1837 
1838     /*
1839      * FPU emulator may have it's own trampoline active just
1840      * above the user stack, 16-bytes before the next lowest
1841      * 16 byte boundary.  Try to avoid trashing it.
1842      */
1843     sp -= 32;
1844 
1845 #if 0
1846     /* This is the X/Open sanctioned signal stack switching.  */
1847     if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
1848 	sp = current->sas_ss_sp + current->sas_ss_size;
1849 #endif
1850 
1851     return g2h((sp - frame_size) & ~7);
1852 }
1853 
1854 static void setup_frame(int sig, struct emulated_sigaction * ka,
1855    		target_sigset_t *set, CPUState *regs)
1856 {
1857     struct sigframe *frame;
1858     int i;
1859 
1860     frame = get_sigframe(ka, regs, sizeof(*frame));
1861     if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
1862 	goto give_sigsegv;
1863 
1864     install_sigtramp(frame->sf_code, TARGET_NR_sigreturn);
1865 
1866     if(setup_sigcontext(regs, &frame->sf_sc))
1867 	goto give_sigsegv;
1868 
1869     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
1870 	if(__put_user(set->sig[i], &frame->sf_mask.sig[i]))
1871 	    goto give_sigsegv;
1872     }
1873 
1874     /*
1875     * Arguments to signal handler:
1876     *
1877     *   a0 = signal number
1878     *   a1 = 0 (should be cause)
1879     *   a2 = pointer to struct sigcontext
1880     *
1881     * $25 and PC point to the signal handler, $29 points to the
1882     * struct sigframe.
1883     */
1884     regs->gpr[ 4][regs->current_tc] = sig;
1885     regs->gpr[ 5][regs->current_tc] = 0;
1886     regs->gpr[ 6][regs->current_tc] = h2g(&frame->sf_sc);
1887     regs->gpr[29][regs->current_tc] = h2g(frame);
1888     regs->gpr[31][regs->current_tc] = h2g(frame->sf_code);
1889     /* The original kernel code sets CP0_EPC to the handler
1890     * since it returns to userland using eret
1891     * we cannot do this here, and we must set PC directly */
1892     regs->PC[regs->current_tc] = regs->gpr[25][regs->current_tc] = ka->sa._sa_handler;
1893     return;
1894 
1895 give_sigsegv:
1896     force_sig(TARGET_SIGSEGV/*, current*/);
1897     return;
1898 }
1899 
1900 long do_sigreturn(CPUState *regs)
1901 {
1902     struct sigframe *frame;
1903     sigset_t blocked;
1904     target_sigset_t target_set;
1905     int i;
1906 
1907 #if defined(DEBUG_SIGNAL)
1908     fprintf(stderr, "do_sigreturn\n");
1909 #endif
1910     frame = (struct sigframe *) regs->gpr[29][regs->current_tc];
1911     if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
1912    	goto badframe;
1913 
1914     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
1915    	if(__get_user(target_set.sig[i], &frame->sf_mask.sig[i]))
1916 	    goto badframe;
1917     }
1918 
1919     target_to_host_sigset_internal(&blocked, &target_set);
1920     sigprocmask(SIG_SETMASK, &blocked, NULL);
1921 
1922     if (restore_sigcontext(regs, &frame->sf_sc))
1923    	goto badframe;
1924 
1925 #if 0
1926     /*
1927      * Don't let your children do this ...
1928      */
1929     __asm__ __volatile__(
1930    	"move\t$29, %0\n\t"
1931    	"j\tsyscall_exit"
1932    	:/* no outputs */
1933    	:"r" (&regs));
1934     /* Unreached */
1935 #endif
1936 
1937     regs->PC[regs->current_tc] = regs->CP0_EPC;
1938     /* I am not sure this is right, but it seems to work
1939     * maybe a problem with nested signals ? */
1940     regs->CP0_EPC = 0;
1941     return 0;
1942 
1943 badframe:
1944     force_sig(TARGET_SIGSEGV/*, current*/);
1945     return 0;
1946 }
1947 
1948 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
1949                            target_siginfo_t *info,
1950 			   target_sigset_t *set, CPUState *env)
1951 {
1952     fprintf(stderr, "setup_rt_frame: not implemented\n");
1953 }
1954 
1955 long do_rt_sigreturn(CPUState *env)
1956 {
1957     fprintf(stderr, "do_rt_sigreturn: not implemented\n");
1958     return -ENOSYS;
1959 }
1960 
1961 #else
1962 
1963 static void setup_frame(int sig, struct emulated_sigaction *ka,
1964 			target_sigset_t *set, CPUState *env)
1965 {
1966     fprintf(stderr, "setup_frame: not implemented\n");
1967 }
1968 
1969 static void setup_rt_frame(int sig, struct emulated_sigaction *ka,
1970                            target_siginfo_t *info,
1971 			   target_sigset_t *set, CPUState *env)
1972 {
1973     fprintf(stderr, "setup_rt_frame: not implemented\n");
1974 }
1975 
1976 long do_sigreturn(CPUState *env)
1977 {
1978     fprintf(stderr, "do_sigreturn: not implemented\n");
1979     return -ENOSYS;
1980 }
1981 
1982 long do_rt_sigreturn(CPUState *env)
1983 {
1984     fprintf(stderr, "do_rt_sigreturn: not implemented\n");
1985     return -ENOSYS;
1986 }
1987 
1988 #endif
1989 
1990 void process_pending_signals(void *cpu_env)
1991 {
1992     int sig;
1993     target_ulong handler;
1994     sigset_t set, old_set;
1995     target_sigset_t target_old_set;
1996     struct emulated_sigaction *k;
1997     struct sigqueue *q;
1998 
1999     if (!signal_pending)
2000         return;
2001 
2002     k = sigact_table;
2003     for(sig = 1; sig <= TARGET_NSIG; sig++) {
2004         if (k->pending)
2005             goto handle_signal;
2006         k++;
2007     }
2008     /* if no signal is pending, just return */
2009     signal_pending = 0;
2010     return;
2011 
2012  handle_signal:
2013 #ifdef DEBUG_SIGNAL
2014     fprintf(stderr, "qemu: process signal %d\n", sig);
2015 #endif
2016     /* dequeue signal */
2017     q = k->first;
2018     k->first = q->next;
2019     if (!k->first)
2020         k->pending = 0;
2021 
2022     sig = gdb_handlesig (cpu_env, sig);
2023     if (!sig) {
2024         fprintf (stderr, "Lost signal\n");
2025         abort();
2026     }
2027 
2028     handler = k->sa._sa_handler;
2029     if (handler == TARGET_SIG_DFL) {
2030         /* default handler : ignore some signal. The other are fatal */
2031         if (sig != TARGET_SIGCHLD &&
2032             sig != TARGET_SIGURG &&
2033             sig != TARGET_SIGWINCH) {
2034             force_sig(sig);
2035         }
2036     } else if (handler == TARGET_SIG_IGN) {
2037         /* ignore sig */
2038     } else if (handler == TARGET_SIG_ERR) {
2039         force_sig(sig);
2040     } else {
2041         /* compute the blocked signals during the handler execution */
2042         target_to_host_sigset(&set, &k->sa.sa_mask);
2043         /* SA_NODEFER indicates that the current signal should not be
2044            blocked during the handler */
2045         if (!(k->sa.sa_flags & TARGET_SA_NODEFER))
2046             sigaddset(&set, target_to_host_signal(sig));
2047 
2048         /* block signals in the handler using Linux */
2049         sigprocmask(SIG_BLOCK, &set, &old_set);
2050         /* save the previous blocked signal state to restore it at the
2051            end of the signal execution (see do_sigreturn) */
2052         host_to_target_sigset_internal(&target_old_set, &old_set);
2053 
2054         /* if the CPU is in VM86 mode, we restore the 32 bit values */
2055 #if defined(TARGET_I386) && !defined(TARGET_X86_64)
2056         {
2057             CPUX86State *env = cpu_env;
2058             if (env->eflags & VM_MASK)
2059                 save_v86_state(env);
2060         }
2061 #endif
2062         /* prepare the stack frame of the virtual CPU */
2063         if (k->sa.sa_flags & TARGET_SA_SIGINFO)
2064             setup_rt_frame(sig, k, &q->info, &target_old_set, cpu_env);
2065         else
2066             setup_frame(sig, k, &target_old_set, cpu_env);
2067 	if (k->sa.sa_flags & TARGET_SA_RESETHAND)
2068             k->sa._sa_handler = TARGET_SIG_DFL;
2069     }
2070     if (q != &k->info)
2071         free_sigqueue(q);
2072 }
2073