+
+ /* Doing anything with the disposition of SIGABRT requires a lock,
+ * so that it cannot be changed while abort is terminating the
+ * process and so any change made by abort can't be observed. */
+ if (sig == SIGABRT) {
+ __block_all_sigs(&set);
+ LOCK(__abort_lock);
+ }
+ int r = __libc_sigaction(sig, sa, old);
+ if (sig == SIGABRT) {
+ UNLOCK(__abort_lock);
+ __restore_sigs(&set);
+ }
+ return r;