3 files changed, 63 insertions, 1 deletions

diff --git a/include/stdio.h b/include/stdio.h
index 070d4e5..285fe21 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -6,17 +6,24 @@
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
 
+#define __errordecl(name, msg) extern void name(void) __attribute__((__error__(msg)))
+
+__errordecl(__fgets_error, "fgets: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 char *
 __fortify_fgets(char *s, int n, FILE *fp)
 {
         size_t bos = __builtin_object_size(s, 0);
 
+        if (__builtin_constant_p(n) && (size_t)n > bos)
+                __fgets_error();
+
         if ((size_t)n > bos)
                 __builtin_trap();
         return fgets(s, n, fp);
 }
 
+__errordecl(__vsnprintf_error, "vsnprintf: buffer overflow detected");
 static inline
 __attribute__ ((always_inline))
 __attribute__ ((__format__ (printf, 3, 0)))
@@ -27,6 +34,9 @@ __fortify_vsnprintf(char *__restrict s, size_t n, const char *__restrict fmt,
 {
         size_t bos = __builtin_object_size(s, 0);
 
+        if (__builtin_constant_p(n) && n > bos)
+                __vsnprintf_error();
+
         if (n > bos)
                 __builtin_trap();
         return vsnprintf(s, n, fmt, ap);
@@ -36,13 +46,17 @@ __fortify_vsnprintf(char *__restrict s, size_t n, const char *__restrict fmt,
 #define fgets(s, n, fp) __fortify_fgets(s, n, fp)
 #undef vsnprintf
 #define vsnprintf(s, n, fmt, ap) __fortify_vsnprintf(s, n, fmt, ap)
+
+__errordecl(__snprintf_error, "snprintf: buffer overflow detected");
 #undef snprintf
 #define snprintf(s, n, fmt, ...) ({ \
         size_t _n = (n); \
         size_t bos = __builtin_object_size(s, 0); \
+        if (__builtin_constant_p(_n) && _n > bos) \
+                __snprintf_error(); \
         if (_n > bos) \
                 __builtin_trap(); \
-        snprintf(s, _n, fmt, __VA_ARGS__); \
+        snprintf(s, _n, fmt, ## __VA_ARGS__); \
 })
 
 #endif
diff --git a/include/string.h b/include/string.h
index 107df9b..e464eab 100644
--- a/include/string.h
+++ b/include/string.h
@@ -6,6 +6,9 @@
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
 
+#define __errordecl(name, msg) extern void name(void) __attribute__((__error__(msg)))
+
+__errordecl(__memcpy_error, "memcpy: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 void *
 __fortify_memcpy(void *__restrict dest, const void *__restrict src, size_t n)
@@ -14,6 +17,9 @@ __fortify_memcpy(void *__restrict dest, const void *__restrict src, size_t n)
         char *d = dest;
         const char *s = src;
 
+        if (__builtin_constant_p(n) && n > bos)
+                __memcpy_error();
+
         /* trap if pointers are overlapping */
         if ((d <= s && d + n > s) ||
             (s <= d && s + n > d))
@@ -23,23 +29,31 @@ __fortify_memcpy(void *__restrict dest, const void *__restrict src, size_t n)
         return memcpy(dest, src, n);
 }
 
+__errordecl(__memmove_error, "memmove: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 void *
 __fortify_memmove(void *__restrict dest, const void *__restrict src, size_t n)
 {
         size_t bos = __builtin_object_size(dest, 0);
 
+        if (__builtin_constant_p(n) && n > bos)
+                __memmove_error();
+
         if (n > bos)
                 __builtin_trap();
         return memmove(dest, src, n);
 }
 
+__errordecl(__memset_error, "memset: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 void *
 __fortify_memset(void *dest, int c, size_t n)
 {
         size_t bos = __builtin_object_size(dest, 0);
 
+        if (__builtin_constant_p(n) && n > bos)
+                __memset_error();
+
         if (n > bos)
                 __builtin_trap();
         return memset(dest, c, n);
@@ -56,12 +70,16 @@ __fortify_stpcpy(char *__restrict dest, const char *__restrict src)
         return stpcpy(dest, src);
 }
 
+__errordecl(__stpncpy_error, "stpncpy: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 char *
 __fortify_stpncpy(char *__restrict dest, const char *__restrict src, size_t n)
 {
         size_t bos = __builtin_object_size(dest, 0);
 
+        if (__builtin_costant_p(n) && n > bos)
+                __stpncpy_error();
+
         if (n > bos)
                 __builtin_trap();
         return stpncpy(dest, src, n);
@@ -89,6 +107,7 @@ __fortify_strcpy(char *__restrict dest, const char *__restrict src)
         return strcpy(dest, src);
 }
 
+__errordecl(__strncat_error, "strncat: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 char *
 __fortify_strncat(char *__restrict dest, const char *__restrict src, size_t n)
@@ -96,6 +115,9 @@ __fortify_strncat(char *__restrict dest, const char *__restrict src, size_t n)
         size_t bos = __builtin_object_size(dest, 0);
         size_t slen, dlen;
 
+        if (__builtin_constant_p(n) && n > bos)
+                __strncat_error();
+
         if (n > bos) {
                 slen = strlen(src);
                 dlen = strlen(dest);
@@ -107,24 +129,32 @@ __fortify_strncat(char *__restrict dest, const char *__restrict src, size_t n)
         return strncat(dest, src, n);
 }
 
+__errordecl(__strncpy_error, "strncpy: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 char *
 __fortify_strncpy(char *__restrict dest, const char *__restrict src, size_t n)
 {
         size_t bos = __builtin_object_size(dest, 0);
 
+        if (__builtin_constant_p(n) && n > bos)
+                __strncpy_error();
+
         if (n > bos)
                 __builtin_trap();
         return strncpy(dest, src, n);
 }
 
 #ifdef _GNU_SOURCE
+__errordecl(__mempcpy_error, "mempcpy: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 void *
 __fortify_mempcpy(void *__restrict dest, const void *__restrict src, size_t n)
 {
         size_t bos = __builtin_object_size(dest, 0);
 
+        if (__builtin_constant_p(n) && n > bos)
+                __mempcpy_error();
+
         if (n > bos)
                 __builtin_trap();
         return mempcpy(dest, src, n);
@@ -132,23 +162,31 @@ __fortify_mempcpy(void *__restrict dest, const void *__restrict src, size_t n)
 #endif
 
 #if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+__errordecl(__strlcat_error, "strlcat: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 size_t
 __fortify_strlcat(char *__restrict dest, const char *__restrict src, size_t n)
 {
         size_t bos = __builtin_object_size(dest, 0);
 
+        if (__builtin_constant_p(n) && n > bos)
+                __strlcat_error();
+
         if (n > bos)
                 __builtin_trap();
         return strlcat(dest, src, n);
 }
 
+__errordecl(__strlcpy_error, "strlcpy: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 size_t
 __fortify_strlcpy(char *__restrict dest, const char *__restrict src, size_t n)
 {
         size_t bos = __builtin_object_size(dest, 0);
 
+        if (__builtin_constant_p(n) && n > bos)
+                __strlcpy_error();
+
         if (n > bos)
                 __builtin_trap();
         return strlcpy(dest, src, n);
diff --git a/include/strings.h b/include/strings.h
index c2f3bcd..4086fe4 100644
--- a/include/strings.h
+++ b/include/strings.h
@@ -6,26 +6,36 @@
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
 
+#define __errordecl(name, msg) extern void name(void) __attribute__((__error__(msg)))
+
 #if defined(_GNU_SOURCE) || defined(_BSD_SOURCE) || defined(_POSIX_SOURCE) \
  || (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE+0 < 200809L) \
  || (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE+0 < 700)
+__errordecl(__bcopy_error, "bcopy: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 void
 __fortify_bcopy(const void *__restrict src, void *__restrict dest, size_t n)
 {
         size_t bos = __builtin_object_size(dest, 0);
 
+        if (__builtin_constant_p(n) && n > bos)
+                __bcopy_error();
+
         if (n > bos)
                 __builtin_trap();
         return bcopy(src, dest, n);
 }
 
+__errordecl(__bzero_error, "bzero: buffer overflow detected");
 static inline __attribute__ ((always_inline))
 void
 __fortify_bzero(void *src, size_t n)
 {
         size_t bos = __builtin_object_size(src, 0);
 
+        if (__builtin_constant_p(n) && n > bos)
+                __bzero_error();
+
         if (n > bos)
                 __builtin_trap();
         return bzero(src, n);