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[libmpx, committed] Add zero length check for memmove wrapper
- From: Ilya Enkovich <enkovich dot gnu at gmail dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 9 Apr 2015 13:12:43 +0300
- Subject: [libmpx, committed] Add zero length check for memmove wrapper
- Authentication-results: sourceware.org; auth=none
Hi,
This patch adds a zero length check into memmove wrapper (also affecting memcpy and mempcpy) to avoid unnecessary bounds checks. Tested on on x86_64-unknown-linux-gnu. Applied to trunk.
Thanks,
Ilya
--
libmpx/
2015-04-09 Ilya Enkovich <ilya.enkovich@intel.com>
* mpxwrap/mpx_wrappers.c (__mpx_wrapper_memmove): Add
zero length check.
gcc/testsuite/
2015-04-09 Ilya Enkovich <ilya.enkovich@intel.com>
* gcc.target/i386/mpx/memmove-zero-length.c: New.
diff --git a/gcc/testsuite/gcc.target/i386/mpx/memmove-zero-length.c b/gcc/testsuite/gcc.target/i386/mpx/memmove-zero-length.c
new file mode 100644
index 0000000..78bfdeb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/mpx/memmove-zero-length.c
@@ -0,0 +1,18 @@
+/* { dg-do run } */
+/* { dg-options "-fcheck-pointer-bounds -mmpx" } */
+
+
+#include "mpx-check.h"
+#include "string.h"
+
+int mpx_test (int argc, const char **argv)
+{
+ int *buf = (int *)malloc (100 * sizeof(int));
+
+ memmove (buf, NULL, 0);
+ memmove (NULL, buf, 0);
+
+ free (buf);
+
+ return 0;
+}
diff --git a/libmpx/mpxwrap/mpx_wrappers.c b/libmpx/mpxwrap/mpx_wrappers.c
index ef4be8d..58670aa 100644
--- a/libmpx/mpxwrap/mpx_wrappers.c
+++ b/libmpx/mpxwrap/mpx_wrappers.c
@@ -97,6 +97,9 @@ __mpx_wrapper_memmove (void *dst, const void *src, size_t n)
size_t offset_src = ((size_t) s) & (sizeof (void *) - 1);
size_t offset_dst = ((size_t) d) & (sizeof (void *) - 1);
+ if (n == 0)
+ return ret;
+
__bnd_chk_ptr_bounds (dst, n);
__bnd_chk_ptr_bounds (src, n);