From: Mansour Moufid <mansourmoufid@gmail.com>
Date: Tue, 20 Sep 2011 01:25:23 +0000 (-0400)
Subject: Fix a potentially useless integer overflow check.
X-Git-Tag: tor-0.2.3.5-alpha~14^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1ba90ab655fab036f00ba0185ca7b456612a12bd;p=thirdparty%2Ftor.git

Fix a potentially useless integer overflow check.

GCC 4.2 and maybe other compilers optimize away unsigned integer
overflow checks of the form (foo + bar < foo), for all bar.

Fix one such check in `src/common/OpenBSD_malloc_Linux.c'.
---

diff --git a/src/common/OpenBSD_malloc_Linux.c b/src/common/OpenBSD_malloc_Linux.c
index 19dac77657..445135c6bb 100644
--- a/src/common/OpenBSD_malloc_Linux.c
+++ b/src/common/OpenBSD_malloc_Linux.c
@@ -1236,7 +1236,7 @@ imalloc(size_t size)
 		ptralloc = 1;
 		size = malloc_pagesize;
 	}
-	if ((size + malloc_pagesize) < size) {	/* Check for overflow */
+	if (size > SIZE_MAX - malloc_pagesize) { /* Check for overflow */
 		result = NULL;
 		errno = ENOMEM;
 	} else if (size <= malloc_maxsize)