Update.

2002-08-03  Jakub Jelinek  <jakub@redhat.com>
	    Ulrich Drepper  <drepper@redhat.com>

	* malloc/malloc.c (public_cALLOc): Only divide if at least one of
	arguments is big enough to cause an overflow.

diff --git a/ChangeLog b/ChangeLog
index c256a53..1f43736 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2002-08-03  Jakub Jelinek  <jakub@redhat.com>
+           Ulrich Drepper  <drepper@redhat.com>
+
+       * malloc/malloc.c (public_cALLOc): Only divide if at least one of
+       arguments is big enough to cause an overflow.
+
 2002-08-03  Ulrich Drepper  <drepper@redhat.com>
 
        * assert/assert.c: Use hidden_def not INTDEF.

diff --git a/malloc/malloc.c b/malloc/malloc.c
index 0440be5..08b8e86 100644 (file)
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -488,6 +488,9 @@ Void_t *(*__morecore)(ptrdiff_t) = __default_morecore;
 #endif /* _LIBC */
 #endif /* USE_DL_PREFIX */
 
+#ifndef _LIBC
+#define __builtin_expect(expr, val)    (expr)
+#endif
 
 /*
   HAVE_MEMCPY should be defined if you are not otherwise using
@@ -3466,9 +3469,13 @@ public_cALLOc(size_t n, size_t elem_size)
 
   /* size_t is unsigned so the behavior on overflow is defined.  */
   bytes = n * elem_size;
-  if (bytes / elem_size != n) {
-    MALLOC_FAILURE_ACTION;
-    return 0;
+#define HALF_INTERNAL_SIZE_T \
+  (((INTERNAL_SIZE_T) 1) << (8 * sizeof (INTERNAL_SIZE_T) / 2))
+  if (__builtin_expect ((n | elem_size) >= HALF_INTERNAL_SIZE_T, 0)) {
+    if (bytes / elem_size != n) {
+      MALLOC_FAILURE_ACTION;
+      return 0;
+    }
   }
 
   if (hook != NULL) {