A racing condition is fixed in JIT reported by Mozilla.

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1647 2f5784b3-3f2a-0410-8824-cb99058d5e15

2 files changed, 6 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 41bbd5c..24e35e5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -79,6 +79,8 @@ Version 8.39 xx-xxxxxx-201x
     that certain errors, provoked by the SSE2 instruction set when JIT is used, 
     are ignored. 
 
+20. A racing condition is fixed in JIT reported by Mozilla.
+
 
 Version 8.38 23-November-2015
 -----------------------------
diff --git a/sljit/sljitUtils.c b/sljit/sljitUtils.c
index 6bd17e5..ec5c321 100644
--- a/sljit/sljitUtils.c
+++ b/sljit/sljitUtils.c
@@ -182,7 +182,10 @@ static pthread_mutex_t dev_zero_mutex = PTHREAD_MUTEX_INITIALIZER;
 static SLJIT_INLINE sljit_s32 open_dev_zero(void)
 {
 	pthread_mutex_lock(&dev_zero_mutex);
-	dev_zero = open("/dev/zero", O_RDWR);
+	/* The dev_zero might be initialized by another thread during the waiting. */
+	if (dev_zero < 0) {
+		dev_zero = open("/dev/zero", O_RDWR);
+	}
 	pthread_mutex_unlock(&dev_zero_mutex);
 	return dev_zero < 0;
 }