From: compudj <compudj@04897980-b3bd-0310-b5e0-8ef037075253>
Date: Thu, 9 Mar 2006 17:49:43 +0000 (+0000)
Subject: sem wait signal safety
X-Git-Tag: v0.12.20~1861
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=be5cc22c25f72553656aea2665a070b09e05ffaa;p=lttv.git

sem wait signal safety

git-svn-id: http://ltt.polymtl.ca/svn@1628 04897980-b3bd-0310-b5e0-8ef037075253
---

diff --git a/usertrace-fast/ltt/ltt-usertrace-fast.h b/usertrace-fast/ltt/ltt-usertrace-fast.h
index 318eff6a..45b8b6c0 100644
--- a/usertrace-fast/ltt/ltt-usertrace-fast.h
+++ b/usertrace-fast/ltt/ltt-usertrace-fast.h
@@ -17,6 +17,7 @@
 #include <syscall.h>
 #include <asm/timex.h>
 #include <semaphore.h>
+#include <signal.h>
 
 #include <ltt/ltt-facility-id-user_generic.h>
 #include <ltt/ltt-generic.h>
@@ -410,7 +411,24 @@ static inline void * __attribute__((no_instrument_function)) ltt_reserve_slot(
 				//if((SUBBUF_TRUNC(offset_begin, ltt_buf) 
 				//				- SUBBUF_TRUNC(atomic_read(&ltt_buf->consumed), ltt_buf))
 				//					>= ltt_buf->alloc_size) {
-				sem_wait(&ltt_buf->writer_sem);
+				/* sem_wait is not signal safe. Disable signals around it. */
+				{
+					sigset_t oldset, set;
+
+					/* Disable signals */
+					ret = sigfillset(&set);
+					if(ret) perror("LTT Error in sigfillset\n"); 
+					
+					ret = pthread_sigmask(SIG_BLOCK, &set, &oldset);
+					if(ret) perror("LTT Error in pthread_sigmask\n");
+
+					sem_wait(&ltt_buf->writer_sem);
+
+					/* Enable signals */
+					ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+					if(ret) perror("LTT Error in pthread_sigmask\n");
+				}
+
 					/* go on with the write */
 
 				//} else {