X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fsignal%2Fsigaction.c;h=d5f47741370e1b352b300a9ec690dd0153fe60cc;hb=3f65494a4cb2544eb16af3fa64a161bd8142f487;hp=5499bd181c37c06978f4c0a55d9571078b9faffd;hpb=3c5c5e6f926feea7b823a96c2872885b100fe31f;p=musl

diff --git a/src/signal/sigaction.c b/src/signal/sigaction.c
index 5499bd18..d5f47741 100644
--- a/src/signal/sigaction.c
+++ b/src/signal/sigaction.c
@@ -1,4 +1,3 @@
-#include <stdlib.h>
 #include <signal.h>
 #include <errno.h>
 #include <string.h>
@@ -9,9 +8,7 @@
 
 void __restore(), __restore_rt();
 
-static pthread_t dummy(void) { return 0; }
-weak_alias(dummy, __pthread_self_def);
-
+static int unmask_done;
 static unsigned long handler_set[_NSIG/(8*sizeof(long))];
 
 void __get_handler_set(sigset_t *set)
@@ -30,7 +27,20 @@ int __libc_sigaction(int sig, const struct sigaction *restrict sa, struct sigact
 		if ((uintptr_t)sa->sa_handler > 1UL) {
 			a_or_l(handler_set+(sig-1)/(8*sizeof(long)),
 				1UL<<(sig-1)%(8*sizeof(long)));
-			__pthread_self_def();
+
+			/* If pthread_create has not yet been called,
+			 * implementation-internal signals might not
+			 * yet have been unblocked. They must be
+			 * unblocked before any signal handler is
+			 * installed, so that an application cannot
+			 * receive an illegal sigset_t (with them
+			 * blocked) as part of the ucontext_t passed
+			 * to the signal handler. */
+			if (!libc.threaded && !unmask_done) {
+				__syscall(SYS_rt_sigprocmask, SIG_UNBLOCK,
+					SIGPT_SET, 0, _NSIG/8);
+				unmask_done = 1;
+			}
 		}
 		ksa.handler = sa->sa_handler;
 		ksa.flags = sa->sa_flags | SA_RESTORER;