6 files changed, 44 insertions, 49 deletions

diff --git a/include/stdio.h b/include/stdio.h
index 2d1ee33..468bf82 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -37,7 +37,7 @@ extern "C" {
 #undef snprintf
 #undef sprintf
 
-__fortify_access(read_write, 1, 2)
+__fortify_access(write_only, 1, 2)
 __fortify_access(read_only, 3)
 _FORTIFY_FN(fgets) char *fgets(char * _FORTIFY_POS0 __s, int __n, FILE *__f)
 {
@@ -95,10 +95,10 @@ __fortify_access(read_only, 2)
 _FORTIFY_FN(vsprintf) int vsprintf(char * _FORTIFY_POS0 __s, const char *__f,
                                    __builtin_va_list __v)
 {
-        size_t __b = __bos(__s, 0);
+        size_t __b = __bos(__s, 2);
         int __r;
 
-        if (__b != (size_t)-1) {
+        if (__b) {
                 __r = __orig_vsnprintf(__s, __b, __f, __v);
                 if (__r != -1 && (size_t)__r >= __b)
                         __builtin_trap();
@@ -136,10 +136,10 @@ _FORTIFY_FN(snprintf) int snprintf(char *__s, size_t __n,
 __fortify__format(printf, 2, 3)
 _FORTIFY_FN(sprintf) int sprintf(char *__s, const char *__f, ...)
 {
-        size_t __b = __bos(__s, 0);
+        size_t __b = __bos(__s, 2);
         int __r;
 
-        if (__b != (size_t)-1) {
+        if (__b) {
                 __r = __orig_snprintf(__s, __b, __f, __builtin_va_arg_pack());
                 if (__r != -1 && (size_t)__r >= __b)
                         __builtin_trap();
diff --git a/include/stdlib.h b/include/stdlib.h
index c95bb55..bb10a7f 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -45,6 +45,7 @@ _FORTIFY_FN(realpath) char *realpath(const char *__p, char *__r)
 #ifndef PATH_MAX
 /* see man realpath(3) */
 #define PATH_MAX 4096
+#define _FORTIFY_UNDEF_PATH_MAX
 #endif
         if (__r && PATH_MAX > __bos(__r, 2)) {
                 char __buf[PATH_MAX], *__ret;
@@ -61,6 +62,10 @@ _FORTIFY_FN(realpath) char *realpath(const char *__p, char *__r)
         }
         return __orig_realpath(__p, __r);
 }
+#ifdef _FORTIFY_UNDEF_PATH_MAX
+#undef PATH_MAX
+#undef _FORTIFY_UNDEF_PATH_MAX
+#endif
 #endif
 
 #ifdef __cplusplus
diff --git a/include/string.h b/include/string.h
index 7987d17..44206f0 100644
--- a/include/string.h
+++ b/include/string.h
@@ -104,7 +104,7 @@ _FORTIFY_FN(stpncpy) char *stpncpy(char * _FORTIFY_POS0 __d, const char *__s,
 {
         size_t __b = __bos(__d, 0);
 
-        if (__n > __b && strlen(__s) + 1 > __b)
+        if (__n > __b)
                 __builtin_trap();
         return __orig_stpncpy(__d, __s, __n);
 }
@@ -140,14 +140,12 @@ _FORTIFY_FN(strncat) char *strncat(char * _FORTIFY_POS0 __d, const char *__s,
         size_t __b = __bos(__d, 0);
         size_t __sl, __dl;
 
-        if (__n > __b) {
-                __sl = strlen(__s);
-                __dl = strlen(__d);
-                if (__sl > __n)
-                        __sl = __n;
-                if (__sl + __dl + 1 > __b)
-                        __builtin_trap();
-        }
+        __sl = strlen(__s);
+        __dl = strlen(__d);
+        if (__sl > __n)
+                __sl = __n;
+        if (__sl + __dl + 1 > __b)
+                __builtin_trap();
         return __orig_strncat(__d, __s, __n);
 }
 
diff --git a/include/strings.h b/include/strings.h
index 6a17ca3..5147936 100644
--- a/include/strings.h
+++ b/include/strings.h
@@ -17,6 +17,9 @@
 #ifndef _FORTIFY_STRINGS_H
 #define _FORTIFY_STRINGS_H
 
+#if !defined(__cplusplus) && !defined(__clang__)
+__extension__
+#endif
 #include_next <strings.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
diff --git a/include/unistd.h b/include/unistd.h
index a2b3105..a73279b 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -177,7 +177,7 @@ _FORTIFY_FN(swab) void swab(const void * _FORTIFY_POS0 __os,
         size_t __bs = __bos(__os, 0);
         size_t __bd = __bos(__od, 0);
 
-        if ((size_t)__n > __bs || (size_t)__n > __bd)
+        if (__n > 0 && ((size_t)__n > __bs || (size_t)__n > __bd))
                 __builtin_trap();
         return __orig_swab(__os, __od, __n);
 }
diff --git a/include/wchar.h b/include/wchar.h
index a840f1a..4346023 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -75,16 +75,10 @@ _FORTIFY_FN(mbsnrtowcs) size_t mbsnrtowcs(wchar_t * _FORTIFY_POS0 __d,
         size_t __b = __bos(__d, 0);
         size_t __r;
 
-        if (__wn > __n / sizeof(wchar_t)) {
-                __b /= sizeof(wchar_t);
-                __r = __orig_mbsnrtowcs(__d, __s, __n, __wn > __b ? __b : __wn, __st);
-                if (__b < __wn && __d && *__s && __r != (size_t)-1)
-                        __builtin_trap();
-        } else {
-                __r = __orig_mbsnrtowcs(__d, __s, __n > __b ? __b : __n, __wn, __st);
-                if (__b < __n && __d && *__s && __r != (size_t)-1)
-                        __builtin_trap();
-        }
+        __b /= sizeof(wchar_t);
+        __r = __orig_mbsnrtowcs(__d, __s, __n, __wn > __b ? __b : __wn, __st);
+        if (__b < __wn && __d && *__s && __r != (size_t)-1)
+                __builtin_trap();
         return __r;
 }
 #endif
@@ -159,14 +153,12 @@ _FORTIFY_FN(wcsncat) wchar_t *wcsncat(wchar_t * _FORTIFY_POS0 __d,
         size_t __b = __bos(__d, 0);
         size_t __sl, __dl;
 
-        if (__n > __b / sizeof(wchar_t)) {
-                __sl = wcslen(__s);
-                __dl = wcslen(__d);
-                if (__sl > __n)
-                        __sl = __n;
-                if (__sl + __dl + 1 > __b / sizeof(wchar_t))
-                        __builtin_trap();
-        }
+        __sl = wcslen(__s);
+        __dl = wcslen(__d);
+        if (__sl > __n)
+                __sl = __n;
+        if (__sl + __dl + 1 > __b / sizeof(wchar_t))
+                __builtin_trap();
         return __orig_wcsncat(__d, __s, __n);
 }
 
@@ -190,16 +182,9 @@ _FORTIFY_FN(wcsnrtombs) size_t wcsnrtombs(char * _FORTIFY_POS0 __d,
         size_t __b = __bos(__d, 0);
         size_t __r;
 
-        if (__wn > __n / sizeof(wchar_t)) {
-                __b /= sizeof(wchar_t);
-                __r = __orig_wcsnrtombs(__d, __s, __wn > __b ? __b : __wn, __n, __st);
-                if (__b < __wn && __d && *__s && __r != (size_t)-1)
-                        __builtin_trap();
-        } else {
-                __r = __orig_wcsnrtombs(__d, __s, __wn, __n > __b ? __b : __n, __st);
-                if (__b < __n && __d && *__s && __r != (size_t)-1)
-                        __builtin_trap();
-        }
+        __r = __orig_wcsnrtombs(__d, __s, __wn, __n > __b ? __b : __n, __st);
+        if (__b < __n && __d && *__s && __r != (size_t)-1)
+                __builtin_trap();
         return __r;
 }
 #endif
@@ -228,21 +213,25 @@ _FORTIFY_FN(wcstombs) size_t wcstombs(char * _FORTIFY_POS0 __s,
 }
 
 _FORTIFY_FN(wmemcpy) wchar_t *wmemcpy(wchar_t * _FORTIFY_POS0 __d,
-                                      const wchar_t *__s, size_t __n)
+                                      const wchar_t * _FORTIFY_POS0 __s,
+                                      size_t __n)
 {
-        size_t __b = __bos(__d, 0);
+        size_t __bd = __bos(__d, 0);
+        size_t __bs = __bos(__s, 0);
 
-        if (__n > __b / sizeof(wchar_t))
+        if (__n > __bd / sizeof(wchar_t) || __n > __bs / sizeof(wchar_t))
                 __builtin_trap();
         return __orig_wmemcpy(__d, __s, __n);
 }
 
 _FORTIFY_FN(wmemmove) wchar_t *wmemmove(wchar_t * _FORTIFY_POS0 __d,
-                                        const wchar_t *__s, size_t __n)
+                                        const wchar_t * _FORTIFY_POS0 __s,
+                                        size_t __n)
 {
-        size_t __b = __bos(__d, 0);
+        size_t __bd = __bos(__d, 0);
+        size_t __bs = __bos(__s, 0);
 
-        if (__n > __b / sizeof(wchar_t))
+        if (__n > __bd / sizeof(wchar_t) || __n > __bs / sizeof(wchar_t))
                 __builtin_trap();
         return __orig_wmemmove(__d, __s, __n);
 }