Compared to offsetof(), struct_size() provides additional compile-time checks for structs with flexible arrays (e.g., __must_be_array()). No functional changes intended. Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxx> --- Changes in v2: - Add missing include - Link to v1: https://lore.kernel.org/lkml/20250503103415.281123-2-thorsten.blum@xxxxxxxxx/ --- fs/overlayfs/util.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 0819c739cc2f..e33d2257c642 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -15,6 +15,7 @@ #include <linux/uuid.h> #include <linux/namei.h> #include <linux/ratelimit.h> +#include <linux/overflow.h> #include "overlayfs.h" /* Get write access to upper mnt - may fail if upper sb was remounted ro */ @@ -145,9 +146,9 @@ void ovl_stack_free(struct ovl_path *stack, unsigned int n) struct ovl_entry *ovl_alloc_entry(unsigned int numlower) { - size_t size = offsetof(struct ovl_entry, __lowerstack[numlower]); - struct ovl_entry *oe = kzalloc(size, GFP_KERNEL); + struct ovl_entry *oe; + oe = kzalloc(struct_size(oe, __lowerstack, numlower), GFP_KERNEL); if (oe) oe->__numlower = numlower; -- 2.49.0
