2 * Emulation of Linux signals
4 * Copyright (c) 2003 Fabrice Bellard
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.
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.
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., 51 Franklin Street - Fifth Floor, Boston,
28 #include <sys/ucontext.h>
43 #define MAX_SIGQUEUE_SIZE 1024
46 struct sigqueue *next;
47 target_siginfo_t info;
50 struct emulated_sigaction {
51 struct target_sigaction sa;
52 int pending; /* true if signal is pending */
53 struct sigqueue *first;
54 struct sigqueue info; /* in order to always have memory for the
55 first signal, we put it here */
58 static struct sigaltstack target_sigaltstack_used = {
62 static struct emulated_sigaction sigact_table[NSIG];
63 static struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
64 static struct sigqueue *first_free; /* first free siginfo queue entry */
65 static int signal_pending; /* non zero if a signal may be pending */
67 static void host_signal_handler(int host_signum, siginfo_t *info,
71 static inline int host_to_target_signal(int sig)
76 static inline int target_to_host_signal(int sig)
81 /* siginfo conversion */
85 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info)
90 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo)
95 void signal_init(void)
100 /* set all host signal handlers. ALL signals are blocked during
101 the handlers to serialize them. */
102 sigfillset(&act.sa_mask);
103 act.sa_flags = SA_SIGINFO;
104 act.sa_sigaction = host_signal_handler;
105 for(i = 1; i < NSIG; i++) {
106 sigaction(i, &act, NULL);
109 memset(sigact_table, 0, sizeof(sigact_table));
111 first_free = &sigqueue_table[0];
112 for(i = 0; i < MAX_SIGQUEUE_SIZE - 1; i++)
113 sigqueue_table[i].next = &sigqueue_table[i + 1];
114 sigqueue_table[MAX_SIGQUEUE_SIZE - 1].next = NULL;
117 /* signal queue handling */
119 static inline struct sigqueue *alloc_sigqueue(void)
121 struct sigqueue *q = first_free;
124 first_free = q->next;
128 static inline void free_sigqueue(struct sigqueue *q)
130 q->next = first_free;
134 /* abort execution with signal */
135 void __attribute((noreturn)) force_sig(int sig)
138 host_sig = target_to_host_signal(sig);
139 fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n",
140 sig, strsignal(host_sig));
144 /* queue a signal so that it will be send to the virtual CPU as soon
146 int queue_signal(int sig, target_siginfo_t *info)
148 struct emulated_sigaction *k;
149 struct sigqueue *q, **pq;
150 target_ulong handler;
152 #if defined(DEBUG_SIGNAL)
153 fprintf(stderr, "queue_signal: sig=%d\n",
156 k = &sigact_table[sig - 1];
157 handler = (target_ulong)k->sa.sa_handler;
158 if (handler == SIG_DFL) {
159 /* default handler : ignore some signal. The other are fatal */
160 if (sig != SIGCHLD &&
165 return 0; /* indicate ignored */
167 } else if (handler == host_to_target_signal(SIG_IGN)) {
170 } else if (handler == host_to_target_signal(SIG_ERR)) {
178 q = alloc_sigqueue();
188 /* signal that a new signal is pending */
190 return 1; /* indicates that the signal was queued */
194 static void host_signal_handler(int host_signum, siginfo_t *info,
198 target_siginfo_t tinfo;
200 /* the CPU emulator uses some host signals to detect exceptions,
201 we we forward to it some signals */
202 if (host_signum == SIGSEGV || host_signum == SIGBUS) {
203 if (cpu_signal_handler(host_signum, (void*)info, puc))
207 /* get target signal number */
208 sig = host_to_target_signal(host_signum);
209 if (sig < 1 || sig > NSIG)
212 #if defined(DEBUG_SIGNAL)
213 fprintf(stderr, "qemu: got signal %d\n", sig);
215 if (queue_signal(sig, &tinfo) == 1) {
216 /* interrupt the virtual CPU as soon as possible */
217 cpu_interrupt(global_env, CPU_INTERRUPT_EXIT);
221 int do_sigaltstack(const struct sigaltstack *ss, struct sigaltstack *oss)
223 /* XXX: test errors */
226 oss->ss_sp = tswap32(target_sigaltstack_used.ss_sp);
227 oss->ss_size = tswap32(target_sigaltstack_used.ss_size);
228 oss->ss_flags = tswap32(target_sigaltstack_used.ss_flags);
232 target_sigaltstack_used.ss_sp = tswap32(ss->ss_sp);
233 target_sigaltstack_used.ss_size = tswap32(ss->ss_size);
234 target_sigaltstack_used.ss_flags = tswap32(ss->ss_flags);
239 int do_sigaction(int sig, const struct sigaction *act,
240 struct sigaction *oact)
242 struct emulated_sigaction *k;
243 struct sigaction act1;
246 if (sig < 1 || sig > NSIG)
249 k = &sigact_table[sig - 1];
250 #if defined(DEBUG_SIGNAL)
251 fprintf(stderr, "sigaction 1 sig=%d act=0x%08x, oact=0x%08x\n",
252 sig, (int)act, (int)oact);
255 #if defined(DEBUG_SIGNAL)
256 fprintf(stderr, "sigaction 1 sig=%d act=0x%08x, oact=0x%08x\n",
257 sig, (int)act, (int)oact);
260 oact->sa_handler = tswapl(k->sa.sa_handler);
261 oact->sa_flags = tswapl(k->sa.sa_flags);
262 oact->sa_mask = tswapl(k->sa.sa_mask);
265 #if defined(DEBUG_SIGNAL)
266 fprintf(stderr, "sigaction handler 0x%x flag 0x%x mask 0x%x\n",
267 act->sa_handler, act->sa_flags, act->sa_mask);
270 k->sa.sa_handler = tswapl(act->sa_handler);
271 k->sa.sa_flags = tswapl(act->sa_flags);
272 k->sa.sa_mask = tswapl(act->sa_mask);
273 /* we update the host signal state */
274 host_sig = target_to_host_signal(sig);
275 if (host_sig != SIGSEGV && host_sig != SIGBUS) {
276 #if defined(DEBUG_SIGNAL)
277 fprintf(stderr, "sigaction handler going to call sigaction\n",
278 act->sa_handler, act->sa_flags, act->sa_mask);
281 sigfillset(&act1.sa_mask);
282 act1.sa_flags = SA_SIGINFO;
283 if (k->sa.sa_flags & SA_RESTART)
284 act1.sa_flags |= SA_RESTART;
285 /* NOTE: it is important to update the host kernel signal
286 ignore state to avoid getting unexpected interrupted
288 if (k->sa.sa_handler == SIG_IGN) {
289 act1.sa_sigaction = (void *)SIG_IGN;
290 } else if (k->sa.sa_handler == SIG_DFL) {
291 act1.sa_sigaction = (void *)SIG_DFL;
293 act1.sa_sigaction = host_signal_handler;
295 sigaction(host_sig, &act1, NULL);
305 get_sigframe(struct emulated_sigaction *ka, CPUX86State *env, size_t frame_size)
308 if(target_sigaltstack_used.ss_flags & SA_DISABLE)
311 /* Default to using normal stack */
312 esp = env->regs[R_ESP];
314 return (void *)((esp - frame_size) & -8ul);
318 return target_sigaltstack_used.ss_sp;
322 static void setup_frame(int sig, struct emulated_sigaction *ka,
323 void *set, CPUState *env)
328 fprintf(stderr, "setup_frame %d\n", sig);
329 frame = get_sigframe(ka, env, sizeof(*frame));
331 /* Set up registers for signal handler */
332 env->regs[R_ESP] = (unsigned long) frame;
333 env->eip = (unsigned long) ka->sa.sa_handler;
335 env->eflags &= ~TF_MASK;
341 ka->sa.sa_handler = SIG_DFL;
342 force_sig(SIGSEGV /* , current */);
345 long do_sigreturn(CPUState *env, int num)
348 struct target_sigcontext *scp = get_int_arg(&i, env);
349 /* XXX Get current signal number */
350 /* XXX Adjust accordin to sc_onstack, sc_mask */
351 if(tswapl(scp->sc_onstack) & 0x1)
352 target_sigaltstack_used.ss_flags |= ~SA_DISABLE;
354 target_sigaltstack_used.ss_flags &= SA_DISABLE;
355 int set = tswapl(scp->sc_eax);
356 sigprocmask(SIG_SETMASK, &set, NULL);
358 fprintf(stderr, "do_sigreturn: partially implemented %x EAX:%x EBX:%x\n", scp->sc_mask, tswapl(scp->sc_eax), tswapl(scp->sc_ebx));
359 fprintf(stderr, "ECX:%x EDX:%x EDI:%x\n", scp->sc_ecx, tswapl(scp->sc_edx), tswapl(scp->sc_edi));
360 fprintf(stderr, "EIP:%x\n", tswapl(scp->sc_eip));
362 env->regs[R_EAX] = tswapl(scp->sc_eax);
363 env->regs[R_EBX] = tswapl(scp->sc_ebx);
364 env->regs[R_ECX] = tswapl(scp->sc_ecx);
365 env->regs[R_EDX] = tswapl(scp->sc_edx);
366 env->regs[R_EDI] = tswapl(scp->sc_edi);
367 env->regs[R_ESI] = tswapl(scp->sc_esi);
368 env->regs[R_EBP] = tswapl(scp->sc_ebp);
369 env->regs[R_ESP] = tswapl(scp->sc_esp);
370 env->segs[R_SS].selector = (void*)tswapl(scp->sc_ss);
371 env->eflags = tswapl(scp->sc_eflags);
372 env->eip = tswapl(scp->sc_eip);
373 env->segs[R_CS].selector = (void*)tswapl(scp->sc_cs);
374 env->segs[R_DS].selector = (void*)tswapl(scp->sc_ds);
375 env->segs[R_ES].selector = (void*)tswapl(scp->sc_es);
376 env->segs[R_FS].selector = (void*)tswapl(scp->sc_fs);
377 env->segs[R_GS].selector = (void*)tswapl(scp->sc_gs);
379 /* Again, because our caller's caller will reset EAX */
380 return env->regs[R_EAX];
385 static void setup_frame(int sig, struct emulated_sigaction *ka,
386 void *set, CPUState *env)
388 fprintf(stderr, "setup_frame: not implemented\n");
391 long do_sigreturn(CPUState *env, int num)
394 struct target_sigcontext *scp = get_int_arg(&i, env);
395 fprintf(stderr, "do_sigreturn: not implemented\n");
401 void process_pending_signals(void *cpu_env)
403 struct emulated_sigaction *k;
405 target_ulong handler;
413 for(sig = 1; sig <= NSIG; sig++) {
419 /* if no signal is pending, just return */
424 fprintf(stderr, "qemu: process signal %d\n", sig);
432 sig = gdb_handlesig (cpu_env, sig);
434 fprintf (stderr, "Lost signal\n");
438 handler = k->sa.sa_handler;
439 if (handler == SIG_DFL) {
440 /* default handler : ignore some signal. The other are fatal */
441 if (sig != SIGCHLD &&
446 } else if (handler == SIG_IGN) {
448 } else if (handler == SIG_ERR) {
452 setup_frame(sig, k, 0, cpu_env);
453 if (k->sa.sa_flags & SA_RESETHAND)
454 k->sa.sa_handler = SIG_DFL;