From: Eric Biggers Date: Sat, 20 Apr 2024 05:54:55 +0000 (-0700) Subject: crypto: x86/aes-xts - simplify loop in xts_crypt_slowpath() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6a805864740cf46ac449ba6cd04fa8a683b27593;p=linux.git crypto: x86/aes-xts - simplify loop in xts_crypt_slowpath() Since the total length processed by the loop in xts_crypt_slowpath() is a multiple of AES_BLOCK_SIZE, just round the length down to AES_BLOCK_SIZE even on the last step. This doesn't change behavior, as the last step will process a multiple of AES_BLOCK_SIZE regardless. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index 110b3282a1f27..02a4c0c276dfd 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -935,16 +935,13 @@ xts_crypt_slowpath(struct skcipher_request *req, xts_crypt_func crypt_func) err = skcipher_walk_virt(&walk, req, false); while (walk.nbytes) { - unsigned int nbytes = walk.nbytes; - - if (nbytes < walk.total) - nbytes = round_down(nbytes, AES_BLOCK_SIZE); - kernel_fpu_begin(); - (*crypt_func)(&ctx->crypt_ctx, walk.src.virt.addr, - walk.dst.virt.addr, nbytes, req->iv); + (*crypt_func)(&ctx->crypt_ctx, + walk.src.virt.addr, walk.dst.virt.addr, + walk.nbytes & ~(AES_BLOCK_SIZE - 1), req->iv); kernel_fpu_end(); - err = skcipher_walk_done(&walk, walk.nbytes - nbytes); + err = skcipher_walk_done(&walk, + walk.nbytes & (AES_BLOCK_SIZE - 1)); } if (err || !tail)