static void host_signal_handler(int host_signum, siginfo_t *info,
void *puc);
+
+/*
+ * System includes define _NSIG as SIGRTMAX + 1,
+ * but qemu (like the kernel) defines TARGET_NSIG as TARGET_SIGRTMAX
+ * and the first signal is SIGHUP defined as 1
+ * Signal number 0 is reserved for use as kill(pid, 0), to test whether
+ * a process exists without sending it a signal.
+ */
+QEMU_BUILD_BUG_ON(__SIGRTMAX + 1 != _NSIG);
static uint8_t host_to_target_signal_table[_NSIG] = {
[SIGHUP] = TARGET_SIGHUP,
[SIGINT] = TARGET_SIGINT,
[SIGPWR] = TARGET_SIGPWR,
[SIGSYS] = TARGET_SIGSYS,
/* next signals stay the same */
- /* Nasty hack: Reverse SIGRTMIN and SIGRTMAX to avoid overlap with
- host libpthread signals. This assumes no one actually uses SIGRTMAX :-/
- To fix this properly we need to do manual signal delivery multiplexed
- over a single host signal. */
- [__SIGRTMIN] = __SIGRTMAX,
- [__SIGRTMAX] = __SIGRTMIN,
};
-static uint8_t target_to_host_signal_table[_NSIG];
+static uint8_t target_to_host_signal_table[TARGET_NSIG + 1];
+
+/* valid sig is between 1 and _NSIG - 1 */
int host_to_target_signal(int sig)
{
- if (sig < 0 || sig >= _NSIG)
+ if (sig < 1 || sig >= _NSIG) {
return sig;
+ }
return host_to_target_signal_table[sig];
}
+/* valid sig is between 1 and TARGET_NSIG */
int target_to_host_signal(int sig)
{
- if (sig < 0 || sig >= _NSIG)
+ if (sig < 1 || sig > TARGET_NSIG) {
return sig;
+ }
return target_to_host_signal_table[sig];
}
void host_to_target_sigset_internal(target_sigset_t *d,
const sigset_t *s)
{
- int i;
+ int host_sig, target_sig;
target_sigemptyset(d);
- for (i = 1; i <= TARGET_NSIG; i++) {
- if (sigismember(s, i)) {
- target_sigaddset(d, host_to_target_signal(i));
+ for (host_sig = 1; host_sig < _NSIG; host_sig++) {
+ target_sig = host_to_target_signal(host_sig);
+ if (target_sig < 1 || target_sig > TARGET_NSIG) {
+ continue;
+ }
+ if (sigismember(s, host_sig)) {
+ target_sigaddset(d, target_sig);
}
}
}
void target_to_host_sigset_internal(sigset_t *d,
const target_sigset_t *s)
{
- int i;
+ int host_sig, target_sig;
sigemptyset(d);
- for (i = 1; i <= TARGET_NSIG; i++) {
- if (target_sigismember(s, i)) {
- sigaddset(d, target_to_host_signal(i));
+ for (target_sig = 1; target_sig <= TARGET_NSIG; target_sig++) {
+ host_sig = target_to_host_signal(target_sig);
+ if (host_sig < 1 || host_sig >= _NSIG) {
+ continue;
+ }
+ if (target_sigismember(s, target_sig)) {
+ sigaddset(d, host_sig);
}
}
}
sigfillset(&set);
sigprocmask(SIG_SETMASK, &set, 0);
- return atomic_xchg(&ts->signal_pending, 1);
+ return qatomic_xchg(&ts->signal_pending, 1);
}
/* Wrapper for sigprocmask function
}
}
+static void signal_table_init(void)
+{
+ int host_sig, target_sig, count;
+
+ /*
+ * Signals are supported starting from TARGET_SIGRTMIN and going up
+ * until we run out of host realtime signals.
+ * glibc at least uses only the lower 2 rt signals and probably
+ * nobody's using the upper ones.
+ * it's why SIGRTMIN (34) is generally greater than __SIGRTMIN (32)
+ * To fix this properly we need to do manual signal delivery multiplexed
+ * over a single host signal.
+ * Attempts for configure "missing" signals via sigaction will be
+ * silently ignored.
+ */
+ for (host_sig = SIGRTMIN; host_sig <= SIGRTMAX; host_sig++) {
+ target_sig = host_sig - SIGRTMIN + TARGET_SIGRTMIN;
+ if (target_sig <= TARGET_NSIG) {
+ host_to_target_signal_table[host_sig] = target_sig;
+ }
+ }
+
+ /* generate signal conversion tables */
+ for (target_sig = 1; target_sig <= TARGET_NSIG; target_sig++) {
+ target_to_host_signal_table[target_sig] = _NSIG; /* poison */
+ }
+ for (host_sig = 1; host_sig < _NSIG; host_sig++) {
+ if (host_to_target_signal_table[host_sig] == 0) {
+ host_to_target_signal_table[host_sig] = host_sig;
+ }
+ target_sig = host_to_target_signal_table[host_sig];
+ if (target_sig <= TARGET_NSIG) {
+ target_to_host_signal_table[target_sig] = host_sig;
+ }
+ }
+
+ if (trace_event_get_state_backends(TRACE_SIGNAL_TABLE_INIT)) {
+ for (target_sig = 1, count = 0; target_sig <= TARGET_NSIG; target_sig++) {
+ if (target_to_host_signal_table[target_sig] == _NSIG) {
+ count++;
+ }
+ }
+ trace_signal_table_init(count);
+ }
+}
+
void signal_init(void)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
struct sigaction act;
struct sigaction oact;
- int i, j;
+ int i;
int host_sig;
- /* generate signal conversion tables */
- for(i = 1; i < _NSIG; i++) {
- if (host_to_target_signal_table[i] == 0)
- host_to_target_signal_table[i] = i;
- }
- for(i = 1; i < _NSIG; i++) {
- j = host_to_target_signal_table[i];
- target_to_host_signal_table[j] = i;
- }
+ /* initialize signal conversion tables */
+ signal_table_init();
/* Set the signal mask from the host mask. */
sigprocmask(0, 0, &ts->signal_mask);
- /* set all host signal handlers. ALL signals are blocked during
- the handlers to serialize them. */
- memset(sigact_table, 0, sizeof(sigact_table));
-
sigfillset(&act.sa_mask);
act.sa_flags = SA_SIGINFO;
act.sa_sigaction = host_signal_handler;
for(i = 1; i <= TARGET_NSIG; i++) {
#ifdef CONFIG_GPROF
- if (i == SIGPROF) {
+ if (i == TARGET_SIGPROF) {
continue;
}
#endif
ts->sync_signal.info = *info;
ts->sync_signal.pending = sig;
/* signal that a new signal is pending */
- atomic_set(&ts->signal_pending, 1);
+ qatomic_set(&ts->signal_pending, 1);
return 1; /* indicates that the signal was queued */
}
int host_sig;
int ret = 0;
+ trace_signal_do_sigaction_guest(sig, TARGET_NSIG);
+
if (sig < 1 || sig > TARGET_NSIG || sig == TARGET_SIGKILL || sig == TARGET_SIGSTOP) {
return -TARGET_EINVAL;
}
/* we update the host linux signal state */
host_sig = target_to_host_signal(sig);
+ trace_signal_do_sigaction_host(host_sig, TARGET_NSIG);
+ if (host_sig > SIGRTMAX) {
+ /* we don't have enough host signals to map all target signals */
+ qemu_log_mask(LOG_UNIMP, "Unsupported target signal #%d, ignored\n",
+ sig);
+ /*
+ * we don't return an error here because some programs try to
+ * register an handler for all possible rt signals even if they
+ * don't need it.
+ * An error here can abort them whereas there can be no problem
+ * to not have the signal available later.
+ * This is the case for golang,
+ * See https://github.com/golang/go/issues/33746
+ * So we silently ignore the error.
+ */
+ return 0;
+ }
if (host_sig != SIGSEGV && host_sig != SIGBUS) {
sigfillset(&act1.sa_mask);
act1.sa_flags = SA_SIGINFO;
handler = sa->_sa_handler;
}
- if (do_strace) {
+ if (unlikely(qemu_loglevel_mask(LOG_STRACE))) {
print_taken_signal(sig, &k->info);
}
sigset_t set;
sigset_t *blocked_set;
- while (atomic_read(&ts->signal_pending)) {
+ while (qatomic_read(&ts->signal_pending)) {
/* FIXME: This is not threadsafe. */
sigfillset(&set);
sigprocmask(SIG_SETMASK, &set, 0);
* of unblocking might cause us to take another host signal which
* will set signal_pending again).
*/
- atomic_set(&ts->signal_pending, 0);
+ qatomic_set(&ts->signal_pending, 0);
ts->in_sigsuspend = 0;
set = ts->signal_mask;
sigdelset(&set, SIGSEGV);
projects / mirror_qemu.git / blobdiff