Commit 5db46ac2 authored Mar 14, 2019 by Arnd Bergmann Committed by Herbert Xu Mar 22, 2019

crypto: ccree - reduce kernel stack usage with clang



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: 63ee04c8 ("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>

parent 6570737c

drivers/crypto/ccree/cc_cipher.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -321,7 +321,6 @@ 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);
		@@ -347,6 +346,7 @@ 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)) {

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