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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-24 19:21:00 +0300 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2020-03-06 04:28:21 +0300 |
| commit | 5a8a076506af03f83f83d80412a7c0b06b687ee1 (patch) | |
| tree | 3748195e05adfc39d2516d7d077d782067a290a1 /drivers/crypto/mediatek | |
| parent | d282eeeb112a00b05595a034ac4cae8532a4c2fc (diff) | |
| download | linux-5a8a076506af03f83f83d80412a7c0b06b687ee1.tar.xz | |
crypto: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto/mediatek')
| -rw-r--r-- | drivers/crypto/mediatek/mtk-sha.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/crypto/mediatek/mtk-sha.c b/drivers/crypto/mediatek/mtk-sha.c index 9e9f48bb7f85..bd6309e57ab8 100644 --- a/drivers/crypto/mediatek/mtk-sha.c +++ b/drivers/crypto/mediatek/mtk-sha.c @@ -107,7 +107,7 @@ struct mtk_sha_ctx { u8 id; u8 buf[SHA_BUF_SIZE] __aligned(sizeof(u32)); - struct mtk_sha_hmac_ctx base[0]; + struct mtk_sha_hmac_ctx base[]; }; struct mtk_sha_drv { |