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crypto/arm64: sm4/xts - Merge ksimd scopes to reduce stack bloat

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Merge the two ksimd scopes in the implementation of SM4-XTS to prevent
stack bloat in cases where the compiler fails to combine the stack slots
for the kernel mode FP/SIMD buffers.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20251203163803.157541-6-ardb@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
This commit is contained in:
Ard Biesheuvel 2025-12-03 17:38:06 +01:00 committed by Eric Biggers
parent a9a8b1a383
commit 6f7d948192
1 changed files with 22 additions and 24 deletions
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46
arch/arm64/crypto/sm4-ce-glue.c
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@ -346,11 +346,11 @@ static int sm4_xts_crypt(struct skcipher_request *req, bool encrypt)
tail = 0;
}
while ((nbytes = walk.nbytes) >= SM4_BLOCK_SIZE) {
if (nbytes < walk.total)
nbytes &= ~(SM4_BLOCK_SIZE - 1);
scoped_ksimd() {
while ((nbytes = walk.nbytes) >= SM4_BLOCK_SIZE) {
if (nbytes < walk.total)
nbytes &= ~(SM4_BLOCK_SIZE - 1);
scoped_ksimd() {
if (encrypt)
sm4_ce_xts_enc(ctx->key1.rkey_enc, walk.dst.virt.addr,
walk.src.virt.addr, walk.iv, nbytes,
@ -359,32 +359,30 @@ static int sm4_xts_crypt(struct skcipher_request *req, bool encrypt)
sm4_ce_xts_dec(ctx->key1.rkey_dec, walk.dst.virt.addr,
walk.src.virt.addr, walk.iv, nbytes,
rkey2_enc);
rkey2_enc = NULL;
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
if (err)
return err;
}
rkey2_enc = NULL;
if (likely(tail == 0))
return 0;
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
/* handle ciphertext stealing */
dst = src = scatterwalk_ffwd(sg_src, req->src, subreq.cryptlen);
if (req->dst != req->src)
dst = scatterwalk_ffwd(sg_dst, req->dst, subreq.cryptlen);
skcipher_request_set_crypt(&subreq, src, dst,
SM4_BLOCK_SIZE + tail, req->iv);
err = skcipher_walk_virt(&walk, &subreq, false);
if (err)
return err;
}
if (likely(tail == 0))
return 0;
/* handle ciphertext stealing */
dst = src = scatterwalk_ffwd(sg_src, req->src, subreq.cryptlen);
if (req->dst != req->src)
dst = scatterwalk_ffwd(sg_dst, req->dst, subreq.cryptlen);
skcipher_request_set_crypt(&subreq, src, dst, SM4_BLOCK_SIZE + tail,
req->iv);
err = skcipher_walk_virt(&walk, &subreq, false);
if (err)
return err;
scoped_ksimd() {
if (encrypt)
sm4_ce_xts_enc(ctx->key1.rkey_enc, walk.dst.virt.addr,
walk.src.virt.addr, walk.iv, walk.nbytes,