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authorThomas Zimmermann <tzimmermann@suse.de>2022-10-20 10:09:00 +0300
committerThomas Zimmermann <tzimmermann@suse.de>2022-10-20 10:09:00 +0300
commit1aca5ce036e3499336d1a2ace3070f908381c055 (patch)
tree32b53fca3cff8c6c084d9c1d94d1761c3618e739 /include/linux/string.h
parent01f2cf53844b01e691516b465df1b6ab01b03230 (diff)
parent9abf2313adc1ca1b6180c508c25f22f9395cc780 (diff)
downloadlinux-1aca5ce036e3499336d1a2ace3070f908381c055.tar.xz
Merge drm/drm-fixes into drm-misc-fixes
Backmerging to get v6.1-rc1. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
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