[PATCH AUTOSEL 4.19 253/671] crypto: ccree - reduce kernel stack usage with clang

Sasha Levin
2020-01-16T17:03:56Z

From: Arnd Bergmann <arnd@arndb.de>

[ Upstream commit 5db46ac29a6797541943d3c4081821747e342732 ]

Building with clang for a 32-bit architecture runs over the stack
frame limit in the setkey function:

drivers/crypto/ccree/cc_cipher.c:318:12: error: stack frame size of 1152 bytes in function 'cc_cipher_setkey' [-Werror,-Wframe-larger-than=]

The problem is that there are two large variables: the temporary
'tmp' array and the SHASH_DESC_ON_STACK() declaration. Moving
the first into the block in which it is used reduces the
total frame size to 768 bytes, which seems more reasonable
and is under the warning limit.

Fixes: 63ee04c8b491 ("crypto: ccree - add skcipher support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-By: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/crypto/ccree/cc_cipher.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/ccree/cc_cipher.c b/drivers/crypto/ccree/cc_cipher.c
index 54a39164aab8..28a5b8b38fa2 100644
--- a/drivers/crypto/ccree/cc_cipher.c
+++ b/drivers/crypto/ccree/cc_cipher.c
@@ -306,7 +306,6 @@ static int cc_cipher_setkey(struct crypto_skcipher *sktfm, const u8 *key,
struct crypto_tfm *tfm = crypto_skcipher_tfm(sktfm);
struct cc_cipher_ctx *ctx_p = crypto_tfm_ctx(tfm);
struct device *dev = drvdata_to_dev(ctx_p->drvdata);
- u32 tmp[DES3_EDE_EXPKEY_WORDS];
struct cc_crypto_alg *cc_alg =
container_of(tfm->__crt_alg, struct cc_crypto_alg,
skcipher_alg.base);
@@ -332,6 +331,7 @@ static int cc_cipher_setkey(struct crypto_skcipher *sktfm, const u8 *key,
* HW does the expansion on its own.
*/
if (ctx_p->flow_mode == S_DIN_to_DES) {
+ u32 tmp[DES3_EDE_EXPKEY_WORDS];
if (keylen == DES3_EDE_KEY_SIZE &&
__des3_ede_setkey(tmp, &tfm->crt_flags, key,
DES3_EDE_KEY_SIZE)) {
--
2.20.1