lib-signals: Don't assert-crash with nested signal handler calls.

--HG--
branch : HEAD

diff --git a/src/lib/lib-signals.c b/src/lib/lib-signals.c
index fe13c170b3fd2489542815be14902c2f07587502..db5c6110c8d0e71f2f4961854e3258bef57247f9 100644 (file)
--- a/src/lib/lib-signals.c
+++ b/src/lib/lib-signals.c
@@ -95,7 +95,8 @@ static void sig_handler(int signo, siginfo_t *si, void *context ATTR_UNUSED)
                return;
 
        /* remember that we're inside a signal handler which might have been
-          called at any time. don't do anything that's unsafe. */
+          called at any time. don't do anything that's unsafe. we might also
+          get interrupted by another signal while inside this handler. */
        for (h = signal_handlers[signo]; h != NULL; h = h->next) {
                if (!h->delayed)
                        h->handler(si, h->context);
@@ -125,7 +126,7 @@ static void signal_read(void *context ATTR_UNUSED)
        siginfo_t signals[MAX_SIGNAL_VALUE+1];
        sigset_t fullset, oldset;
        struct signal_handler *h;
-       char buf[2];
+       char buf[64];
        int signo;
        ssize_t ret;
 
@@ -134,8 +135,9 @@ static void signal_read(void *context ATTR_UNUSED)
        if (sigprocmask(SIG_BLOCK, &fullset, &oldset) < 0)
                i_fatal("sigprocmask() failed: %m");
 
+       /* typically we should read only a single byte, but if a signal
+          is sent while signal handler is running we might get more. */
        ret = read(sig_pipe_fd[0], buf, sizeof(buf));
-       i_assert(ret <= 1);
        if (ret > 0) {
                memcpy(signals, pending_signals, sizeof(signals));
                memset(pending_signals, 0, sizeof(pending_signals));