* the whole sa_mask is ignored and instead of not adding the signal
* in question to the mask. That means if it's not blockable the
* signal must be unblocked at the beginning of signal handlers.
+ *
+ * It turns out that NetBSD's SA_NODEFER doesn't DTRT in a different
+ * way: if SA_NODEFER is set and the signal is in sa_mask, the signal
+ * will be unblocked in the sigmask during the signal handler. -- RMK
+ * X-mas day, 2005
*/
static volatile int sigaction_nodefer_works = -1;
+#define SA_NODEFER_TEST_BLOCK_SIGNAL SIGABRT
+#define SA_NODEFER_TEST_KILL_SIGNAL SIGUSR1
+
static void
sigaction_nodefer_test_handler(int signal, siginfo_t *info, void *void_context)
{
int i;
sigemptyset(&empty);
sigprocmask(SIG_BLOCK, &empty, ¤t);
+ /* There should be exactly two blocked signals: the two we added
+ * to sa_mask when setting up the handler. NetBSD doesn't block
+ * the signal we're handling when SA_NODEFER is set; Linux before
+ * 2.6.13 or so also doesn't block the other signal when
+ * SA_NODEFER is set. */
for(i = 1; i < NSIG; i++)
- if (sigismember(¤t, i) != ((i == SIGABRT) ? 1 : 0)) {
+ if (sigismember(¤t, i) !=
+ (((i == SA_NODEFER_TEST_BLOCK_SIGNAL) || (i == signal)) ? 1 : 0)) {
FSHOW_SIGNAL((stderr, "SA_NODEFER doesn't work, signal %d\n", i));
sigaction_nodefer_works = 0;
}
sa.sa_flags = SA_SIGINFO | SA_NODEFER;
sa.sa_sigaction = sigaction_nodefer_test_handler;
sigemptyset(&sa.sa_mask);
- sigaddset(&sa.sa_mask, SIGABRT);
- sigaction(SIGUSR1, &sa, &old_sa);
+ sigaddset(&sa.sa_mask, SA_NODEFER_TEST_BLOCK_SIGNAL);
+ sigaddset(&sa.sa_mask, SA_NODEFER_TEST_KILL_SIGNAL);
+ sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &sa, &old_sa);
/* Make sure no signals are blocked. */
{
sigset_t empty;
sigemptyset(&empty);
sigprocmask(SIG_SETMASK, &empty, 0);
}
- kill(getpid(), SIGUSR1);
+ kill(getpid(), SA_NODEFER_TEST_KILL_SIGNAL);
while (sigaction_nodefer_works == -1);
- sigaction(SIGUSR1, &old_sa, NULL);
+ sigaction(SA_NODEFER_TEST_KILL_SIGNAL, &old_sa, NULL);
}
+#undef SA_NODEFER_TEST_BLOCK_SIGNAL
+#undef SA_NODEFER_TEST_KILL_SIGNAL
+
static void
unblock_me_trampoline(int signal, siginfo_t *info, void *void_context)
{