diff options
Diffstat (limited to 'include/linux/string.h')
| -rw-r--r-- | include/linux/string.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/string.h b/include/linux/string.h index a467e617eeb0..0bec4151b0eb 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -200,6 +200,7 @@ static inline const char *kbasename(const char *path) void fortify_panic(const char *name) __noreturn __cold; void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter"); void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter"); +void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter"); void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter"); #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) @@ -395,4 +396,33 @@ __FORTIFY_INLINE char *strcpy(char *p, const char *q) #endif +/** + * memcpy_and_pad - Copy one buffer to another with padding + * @dest: Where to copy to + * @dest_len: The destination buffer size + * @src: Where to copy from + * @count: The number of bytes to copy + * @pad: Character to use for padding if space is left in destination. + */ +__FORTIFY_INLINE void memcpy_and_pad(void *dest, size_t dest_len, + const void *src, size_t count, int pad) +{ + size_t dest_size = __builtin_object_size(dest, 0); + size_t src_size = __builtin_object_size(src, 0); + + if (__builtin_constant_p(dest_len) && __builtin_constant_p(count)) { + if (dest_size < dest_len && dest_size < count) + __write_overflow(); + else if (src_size < dest_len && src_size < count) + __read_overflow3(); + } + if (dest_size < dest_len) + fortify_panic(__func__); + if (dest_len > count) { + memcpy(dest, src, count); + memset(dest + count, pad, dest_len - count); + } else + memcpy(dest, src, dest_len); +} + #endif /* _LINUX_STRING_H_ */ |