Add stpcpy/stpncpy.

Add tests for the above.

Add the fortify implementations of __stpcpy_chk and __stpncpy_chk.

Modify the strncpy test to cover more cases and use this template for
stpncpy.

Add all of the fortify test cases.

Bug: 13746695
Change-Id: I8c0f0d4991a878b8e8734fff12c8b73b07fdd344

1 files changed, 39 insertions, 5 deletions

diff --git a/libc/include/string.h b/libc/include/string.h
index ec998ed..c9ae03b 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -53,6 +53,7 @@ extern char* __strrchr_chk(const char *, int, size_t);
 extern size_t strlen(const char *) __purefunc;
 extern size_t __strlen_chk(const char *, size_t);
 extern int    strcmp(const char *, const char *) __purefunc;
+extern char*  stpcpy(char* __restrict, const char* __restrict);
 extern char*  strcpy(char* __restrict, const char* __restrict);
 extern char*  strcat(char* __restrict, const char* __restrict);
 
@@ -72,6 +73,7 @@ extern size_t strnlen(const char *, size_t) __purefunc;
 extern char*  strncat(char* __restrict, const char* __restrict, size_t);
 extern char*  strndup(const char *, size_t);
 extern int    strncmp(const char *, const char *, size_t) __purefunc;
+extern char*  stpncpy(char* __restrict, const char* __restrict, size_t);
 extern char*  strncpy(char* __restrict, const char* __restrict, size_t);
 
 extern size_t strlcat(char* __restrict, const char* __restrict, size_t);
@@ -89,8 +91,8 @@ extern size_t strxfrm(char* __restrict, const char* __restrict, size_t);
 
 #if defined(__BIONIC_FORTIFY)
 
-__errordecl(__memcpy_dest_size_error, "memcpy called with size bigger than destination");
-__errordecl(__memcpy_src_size_error, "memcpy called with size bigger than source");
+__errordecl(__memcpy_dest_size_error, "memcpy: prevented write past end of buffer");
+__errordecl(__memcpy_src_size_error, "memcpy: prevented read past end of buffer");
 
 __BIONIC_FORTIFY_INLINE
 void* memcpy(void* __restrict dest, const void* __restrict src, size_t copy_amount) {
@@ -116,11 +118,43 @@ void* memmove(void *dest, const void *src, size_t len) {
 }
 
 __BIONIC_FORTIFY_INLINE
+char* stpcpy(char* __restrict dest, const char* __restrict src) {
+    return __builtin___stpcpy_chk(dest, src, __bos(dest));
+}
+
+__BIONIC_FORTIFY_INLINE
 char* strcpy(char* __restrict dest, const char* __restrict src) {
     return __builtin___strcpy_chk(dest, src, __bos(dest));
 }
 
-__errordecl(__strncpy_error, "strncpy called with size bigger than buffer");
+__errordecl(__stpncpy_error, "stpncpy: prevented write past end of buffer");
+extern char* __stpncpy_chk2(char* __restrict, const char* __restrict, size_t, size_t, size_t);
+
+__BIONIC_FORTIFY_INLINE
+char* stpncpy(char* __restrict dest, const char* __restrict src, size_t n) {
+    size_t bos_dest = __bos(dest);
+    size_t bos_src = __bos(src);
+    if (__builtin_constant_p(n) && (n > bos_dest)) {
+        __stpncpy_error();
+    }
+
+    if (bos_src == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
+        return __builtin___stpncpy_chk(dest, src, n, bos_dest);
+    }
+
+    if (__builtin_constant_p(n) && (n <= bos_src)) {
+        return __builtin___stpncpy_chk(dest, src, n, bos_dest);
+    }
+
+    size_t slen = __builtin_strlen(src);
+    if (__builtin_constant_p(slen)) {
+        return __builtin___stpncpy_chk(dest, src, n, bos_dest);
+    }
+
+    return __stpncpy_chk2(dest, src, n, bos_dest, bos_src);
+}
+
+__errordecl(__strncpy_error, "strncpy: prevented write past end of buffer");
 extern char* __strncpy_chk2(char* __restrict, const char* __restrict, size_t, size_t, size_t);
 
 __BIONIC_FORTIFY_INLINE
@@ -164,7 +198,7 @@ void* memset(void *s, int c, size_t n) {
 
 extern size_t __strlcpy_real(char* __restrict, const char* __restrict, size_t)
     __asm__(__USER_LABEL_PREFIX__ "strlcpy");
-__errordecl(__strlcpy_error, "strlcpy called with size bigger than buffer");
+__errordecl(__strlcpy_error, "strlcpy: prevented write past end of buffer");
 extern size_t __strlcpy_chk(char *, const char *, size_t, size_t);
 
 __BIONIC_FORTIFY_INLINE
@@ -195,7 +229,7 @@ size_t strlcpy(char* __restrict dest, const char* __restrict src, size_t size) {
 
 extern size_t __strlcat_real(char* __restrict, const char* __restrict, size_t)
     __asm__(__USER_LABEL_PREFIX__ "strlcat");
-__errordecl(__strlcat_error, "strlcat called with size bigger than buffer");
+__errordecl(__strlcat_error, "strlcat: prevented write past end of buffer");
 extern size_t __strlcat_chk(char* __restrict, const char* __restrict, size_t, size_t);