diff --git a/libc/Android.mk b/libc/Android.mk
index c507457..f90520e 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -141,7 +141,9 @@
 	stdio/wbuf.c \
 	stdio/wsetup.c \
 	stdio/__snprintf_chk.c \
+	stdio/__sprintf_chk.c \
 	stdio/__vsnprintf_chk.c \
+	stdio/__vsprintf_chk.c \
 	stdlib/_rand48.c \
 	stdlib/assert.c \
 	stdlib/atexit.c \
diff --git a/libc/include/stdio.h b/libc/include/stdio.h
index cc3270d..18b19bf 100644
--- a/libc/include/stdio.h
+++ b/libc/include/stdio.h
@@ -231,12 +231,16 @@
 int	 fgetpos(FILE *, fpos_t *);
 char	*fgets(char *, int, FILE *);
 FILE	*fopen(const char *, const char *);
-int	 fprintf(FILE *, const char *, ...);
+int	 fprintf(FILE *, const char *, ...)
+		__attribute__((__format__ (printf, 2, 3)))
+		__attribute__((__nonnull__ (2)));
 int	 fputc(int, FILE *);
 int	 fputs(const char *, FILE *);
 size_t	 fread(void *, size_t, size_t, FILE *);
 FILE	*freopen(const char *, const char *, FILE *);
-int	 fscanf(FILE *, const char *, ...);
+int	 fscanf(FILE *, const char *, ...)
+		__attribute__ ((__format__ (scanf, 2, 3)))
+		__attribute__ ((__nonnull__ (2)));
 int	 fseek(FILE *, long, int);
 int	 fseeko(FILE *, off_t, int);
 int	 fsetpos(FILE *, const fpos_t *);
@@ -253,24 +257,38 @@
 extern char *sys_errlist[];
 #endif
 void	 perror(const char *);
-int	 printf(const char *, ...);
+int	 printf(const char *, ...)
+		__attribute__((__format__ (printf, 1, 2)))
+		__attribute__((__nonnull__ (1)));
 int	 putc(int, FILE *);
 int	 putchar(int);
 int	 puts(const char *);
 int	 remove(const char *);
 int	 rename(const char *, const char *);
 void	 rewind(FILE *);
-int	 scanf(const char *, ...);
+int	 scanf(const char *, ...)
+		__attribute__ ((__format__ (scanf, 1, 2)))
+		__attribute__ ((__nonnull__ (1)));
 void	 setbuf(FILE *, char *);
 int	 setvbuf(FILE *, char *, int, size_t);
-int	 sprintf(char *, const char *, ...);
-int	 sscanf(const char *, const char *, ...);
+int	 sprintf(char *, const char *, ...)
+		__attribute__((__format__ (printf, 2, 3)))
+		__attribute__((__nonnull__ (2)));
+int	 sscanf(const char *, const char *, ...)
+		__attribute__ ((__format__ (scanf, 2, 3)))
+		__attribute__ ((__nonnull__ (2)));
 FILE	*tmpfile(void);
 char	*tmpnam(char *);
 int	 ungetc(int, FILE *);
-int	 vfprintf(FILE *, const char *, __va_list);
-int	 vprintf(const char *, __va_list);
-int	 vsprintf(char *, const char *, __va_list);
+int	 vfprintf(FILE *, const char *, __va_list)
+		__attribute__((__format__ (printf, 2, 0)))
+		__attribute__((__nonnull__ (2)));
+int	 vprintf(const char *, __va_list)
+		__attribute__((__format__ (printf, 1, 0)))
+		__attribute__((__nonnull__ (1)));
+int	 vsprintf(char *, const char *, __va_list)
+		__attribute__((__format__ (printf, 2, 0)))
+		__attribute__((__nonnull__ (2)));
 
 #if __ISO_C_VISIBLE >= 1999 || __BSD_VISIBLE
 int	 snprintf(char *, size_t, const char *, ...)
@@ -453,8 +471,12 @@
  * #define fdprintf dprintf for compatibility
  */
 __BEGIN_DECLS
-int fdprintf(int, const char*, ...);
-int vfdprintf(int, const char*, __va_list);
+int fdprintf(int, const char*, ...)
+		__attribute__((__format__ (printf, 2, 3)))
+		__attribute__((__nonnull__ (2)));
+int vfdprintf(int, const char*, __va_list)
+		__attribute__((__format__ (printf, 2, 0)))
+		__attribute__((__nonnull__ (2)));
 __END_DECLS
 #endif /* _GNU_SOURCE */
 
@@ -463,11 +485,22 @@
 __BIONIC_FORTIFY_INLINE
 __attribute__((__format__ (printf, 3, 0)))
 __attribute__((__nonnull__ (3)))
-int vsnprintf(char *str, size_t size, const char *format, __va_list ap)
+int vsnprintf(char *dest, size_t size, const char *format, __va_list ap)
 {
-    return __builtin___vsnprintf_chk(str, size, 0, __builtin_object_size(str, 0), format, ap);
+    return __builtin___vsnprintf_chk(dest, size, 0,
+        __builtin_object_size(dest, 0), format, ap);
 }
 
+__BIONIC_FORTIFY_INLINE
+__attribute__((__format__ (printf, 2, 0)))
+__attribute__((__nonnull__ (2)))
+int vsprintf(char *dest, const char *format, __va_list ap)
+{
+    return __builtin___vsprintf_chk(dest, 0,
+        __builtin_object_size(dest, 0), format, ap);
+}
+
+
 # if !defined(__clang__)
 /*
  * Clang doesn't have support for __builtin_va_arg_pack()
@@ -479,7 +512,17 @@
 __attribute__((__nonnull__ (3)))
 int snprintf(char *str, size_t size, const char *format, ...)
 {
-    return __builtin___snprintf_chk(str, size, 0, __builtin_object_size(str, 0), format, __builtin_va_arg_pack());
+    return __builtin___snprintf_chk(str, size, 0,
+        __builtin_object_size(str, 0), format, __builtin_va_arg_pack());
+}
+
+__BIONIC_FORTIFY_INLINE
+__attribute__((__format__ (printf, 2, 3)))
+__attribute__((__nonnull__ (2)))
+int sprintf(char *dest, const char *format, ...)
+{
+    return __builtin___sprintf_chk(dest, 0,
+        __builtin_object_size(dest, 0), format, __builtin_va_arg_pack());
 }
 
 # endif /* !defined(__clang__) */
diff --git a/libc/stdio/__sprintf_chk.c b/libc/stdio/__sprintf_chk.c
new file mode 100644
index 0000000..67acbe1
--- /dev/null
+++ b/libc/stdio/__sprintf_chk.c
@@ -0,0 +1,58 @@
+/*
+ * 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 <stdio.h>
+#include <stdarg.h>
+
+/*
+ * Runtime implementation of __builtin____sprintf_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 sprintf check is called if _FORTIFY_SOURCE is defined and
+ * greater than 0.
+ */
+int __sprintf_chk(
+        char *dest,
+        int flags,
+        size_t dest_len_from_compiler,
+        const char *format, ...)
+{
+    va_list va;
+    int retval;
+
+    va_start(va, format);
+    retval = __vsprintf_chk(dest, flags,
+                             dest_len_from_compiler, format, va);
+    va_end(va);
+
+    return retval;
+}
diff --git a/libc/stdio/__vsprintf_chk.c b/libc/stdio/__vsprintf_chk.c
new file mode 100644
index 0000000..8a809fc
--- /dev/null
+++ b/libc/stdio/__vsprintf_chk.c
@@ -0,0 +1,61 @@
+/*
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <private/logd.h>
+
+/*
+ * Runtime implementation of __builtin____vsprintf_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 vsprintf check is called if _FORTIFY_SOURCE is defined and
+ * greater than 0.
+ */
+int __vsprintf_chk(
+        char *dest,
+        int flags,
+        size_t dest_len_from_compiler,
+        const char *format,
+        va_list va)
+{
+    int ret = vsnprintf(dest, dest_len_from_compiler, format, va);
+
+    if ((size_t) ret >= dest_len_from_compiler) {
+        __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
+            "*** vsprintf buffer overflow detected ***\n");
+        abort();
+    }
+
+    return ret;
+}