_FORTIFY_SOURCE: add memset / bzero support

Add _FORTIFY_SOURCE support for the following functions:

* memset
* bzero

Move the __BIONIC_FORTIFY_INLINE definition to cdefs.h so it
can be used from multiple header files.

Change-Id: Iead4d5e35de6ec97786d58ee12573f9b11135bb7

libc/Android.mk

@@ -207,6 +207,7 @@ libc_common_src_files := \
 	string/strxfrm.c \
 	string/__memcpy_chk.c \
 	string/__memmove_chk.c \
+	string/__memset_chk.c \
 	string/__strcat_chk.c \
 	string/__strcpy_chk.c \
 	string/__strncat_chk.c \

libc/include/string.h

@@ -85,27 +85,21 @@ extern char*  strsignal(int  sig);
 extern int    strcoll(const char *, const char *) __purefunc;
 extern size_t strxfrm(char *, const char *, size_t);
 
-#if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
-
-#define __BIONIC_FORTIFY_INLINE \
-    extern inline \
-    __attribute__ ((always_inline)) \
-    __attribute__ ((gnu_inline)) \
-    __attribute__ ((artificial))
+#if defined(__BIONIC_FORTIFY_INLINE)
 
 __BIONIC_FORTIFY_INLINE
 void *memcpy (void *dest, const void *src, size_t len) {
-    return __builtin___memcpy_chk (dest, src, len, __builtin_object_size (dest, 0));
+    return __builtin___memcpy_chk(dest, src, len, __builtin_object_size (dest, 0));
 }
 
 __BIONIC_FORTIFY_INLINE
 void *memmove (void *dest, const void *src, size_t len) {
-    return __builtin___memmove_chk (dest, src, len, __builtin_object_size (dest, 0));
+    return __builtin___memmove_chk(dest, src, len, __builtin_object_size (dest, 0));
 }
 
 __BIONIC_FORTIFY_INLINE
 char *strcpy(char *dest, const char *src) {
-    return __builtin___strcpy_chk (dest, src, __builtin_object_size (dest, 0));
+    return __builtin___strcpy_chk(dest, src, __builtin_object_size (dest, 0));
 }
 
 __BIONIC_FORTIFY_INLINE
@@ -115,7 +109,7 @@ char *strncpy(char *dest, const char *src, size_t n) {
 
 __BIONIC_FORTIFY_INLINE
 char *strcat(char *dest, const char *src) {
-    return __builtin___strcat_chk (dest, src, __builtin_object_size (dest, 0));
+    return __builtin___strcat_chk(dest, src, __builtin_object_size (dest, 0));
 }
 
 __BIONIC_FORTIFY_INLINE
@@ -123,8 +117,12 @@ char *strncat(char *dest, const char *src, size_t n) {
     return __builtin___strncat_chk(dest, src, n, __builtin_object_size (dest, 0));
 }
 
-#undef __BIONIC_FORTIFY_INLINE
-#endif
+__BIONIC_FORTIFY_INLINE
+void *memset (void *s, int c, size_t n) {
+    return __builtin___memset_chk(s, c, n, __builtin_object_size (s, 0));
+}
+
+#endif /* defined(__BIONIC_FORTIFY_INLINE) */
 
 __END_DECLS
 

libc/include/strings.h

@@ -51,6 +51,14 @@ char	*index(const char *, int);
 char	*rindex(const char *, int);
 int	 strcasecmp(const char *, const char *);
 int	 strncasecmp(const char *, const char *, size_t);
+
+#if defined(__BIONIC_FORTIFY_INLINE)
+__BIONIC_FORTIFY_INLINE
+void bzero (void *s, size_t n) {
+    __builtin___memset_chk(s, '\0', n, __builtin_object_size (s, 0));
+}
+#endif /* defined(__BIONIC_FORTIFY_INLINE) */
+
 __END_DECLS
 
 #endif /* !defined(_STRINGS_H_) */

libc/include/sys/cdefs.h

@@ -501,4 +501,12 @@
 #define  __BIONIC__   1
 #include <android/api-level.h>
 
+#if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
+#define __BIONIC_FORTIFY_INLINE \
+    extern inline \
+    __attribute__ ((always_inline)) \
+    __attribute__ ((gnu_inline)) \
+    __attribute__ ((artificial))
+#endif
+
 #endif /* !_SYS_CDEFS_H_ */

libc/string/__memset_chk.c

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <private/logd.h>
+
+/*
+ * Runtime implementation of __builtin____memset_chk.
+ *
+ * See
+ *   http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
+ *   http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
+ * for details.
+ *
+ * This memset check is called if _FORTIFY_SOURCE is defined and
+ * greater than 0.
+ */
+void *__memset_chk (void *dest, int c, size_t n, size_t dest_len)
+{
+    if (n > dest_len) {
+        __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
+            "*** memset buffer overflow detected ***\n");
+        abort();
+    }
+
+    return memset(dest, c, n);
+}