summaryrefslogtreecommitdiff
path: root/include/linux/string.h
diff options
context:
space:
mode:
authorMaxime Ripard <maxime@cerno.tech>2022-10-18 15:00:03 +0200
committerMaxime Ripard <maxime@cerno.tech>2022-10-18 15:00:03 +0200
commita140a6a2d5ec0329ad05cd3532a91ad0ce58dceb (patch)
treeb2d44a1da423c53bd6c3ab3facd45ff5f2087ffd /include/linux/string.h
parent28743e25fa1c867675bd8ff976eb92d4251f13a1 (diff)
parent9abf2313adc1ca1b6180c508c25f22f9395cc780 (diff)
Merge drm/drm-next into drm-misc-next
Let's kick-off this release cycle. Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Diffstat (limited to 'include/linux/string.h')
-rw-r--r--include/linux/string.h43
1 files changed, 43 insertions, 0 deletions
diff --git a/include/linux/string.h b/include/linux/string.h
index 61ec7e4f6311..cf7607b32102 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -261,6 +261,49 @@ void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count,
int pad);
/**
+ * strtomem_pad - Copy NUL-terminated string to non-NUL-terminated buffer
+ *
+ * @dest: Pointer of destination character array (marked as __nonstring)
+ * @src: Pointer to NUL-terminated string
+ * @pad: Padding character to fill any remaining bytes of @dest after copy
+ *
+ * This is a replacement for strncpy() uses where the destination is not
+ * a NUL-terminated string, but with bounds checking on the source size, and
+ * an explicit padding character. If padding is not required, use strtomem().
+ *
+ * Note that the size of @dest is not an argument, as the length of @dest
+ * must be discoverable by the compiler.
+ */
+#define strtomem_pad(dest, src, pad) do { \
+ const size_t _dest_len = __builtin_object_size(dest, 1); \
+ \
+ BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \
+ _dest_len == (size_t)-1); \
+ memcpy_and_pad(dest, _dest_len, src, strnlen(src, _dest_len), pad); \
+} while (0)
+
+/**
+ * strtomem - Copy NUL-terminated string to non-NUL-terminated buffer
+ *
+ * @dest: Pointer of destination character array (marked as __nonstring)
+ * @src: Pointer to NUL-terminated string
+ *
+ * This is a replacement for strncpy() uses where the destination is not
+ * a NUL-terminated string, but with bounds checking on the source size, and
+ * without trailing padding. If padding is required, use strtomem_pad().
+ *
+ * Note that the size of @dest is not an argument, as the length of @dest
+ * must be discoverable by the compiler.
+ */
+#define strtomem(dest, src) do { \
+ const size_t _dest_len = __builtin_object_size(dest, 1); \
+ \
+ BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \
+ _dest_len == (size_t)-1); \
+ memcpy(dest, src, min(_dest_len, strnlen(src, _dest_len))); \
+} while (0)
+
+/**
* memset_after - Set a value after a struct member to the end of a struct
*
* @obj: Address of target struct instance