-Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally.
Use the new TRAILING_OVERLAP() helper to fix the following warning: crypto/drbg.c:1445:27: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] This helper creates a union between a flexible-array member (FAM) and a set of MEMBERS that would otherwise follow it. This overlays the trailing MEMBER char ctx[]; onto the FAM struct shash_desc::__ctx,[] while keeping the FAM and the start of MEMBER aligned. The static_assert() ensures this alignment remains, and it's intentionally placed inmediately after the corresponding structures --no blank line in between. Signed-off-by: Gustavo A. R. Silva <[email protected]> --- crypto/drbg.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/crypto/drbg.c b/crypto/drbg.c index 511a27c91813..e9f9775c237f 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -1442,9 +1442,12 @@ static void drbg_kcapi_set_entropy(struct crypto_rng *tfm, #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) struct sdesc { - struct shash_desc shash; - char ctx[]; + /* Must be last as it ends in a flexible-array member. */ + TRAILING_OVERLAP(struct shash_desc, shash, __ctx, + char ctx[]; + ); }; +static_assert(offsetof(struct sdesc, shash.__ctx) == offsetof(struct sdesc, ctx)); static int drbg_init_hash_kernel(struct drbg_state *drbg) { -- 2.43.0
