[PATCH v4 08/12] crypto, dm: LLVMLinux: Remove VLAIS usage from dm-crypt

From: behanw
Date: Tue Sep 23 2014 - 00:46:36 EST


From: Jan-Simon MÃller <dl9pf@xxxxxx>

Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using a char array using the SHASH_DESC_ON_STACK macro.

The new code can be compiled with both gcc and clang.

Signed-off-by: Jan-Simon MÃller <dl9pf@xxxxxx>
Signed-off-by: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Mark Charlebois <charlebm@xxxxxxxxx>
Acked-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: pageexec@xxxxxxxxxxx
Cc: gmazyland@xxxxxxxxx
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
---
drivers/md/dm-crypt.c | 34 ++++++++++++++--------------------
1 file changed, 14 insertions(+), 20 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index cd15e08..fc93b93 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -526,29 +526,26 @@ static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
u8 *data)
{
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
- struct {
- struct shash_desc desc;
- char ctx[crypto_shash_descsize(lmk->hash_tfm)];
- } sdesc;
+ SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
struct md5_state md5state;
__le32 buf[4];
int i, r;

- sdesc.desc.tfm = lmk->hash_tfm;
- sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+ desc->tfm = lmk->hash_tfm;
+ desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;

- r = crypto_shash_init(&sdesc.desc);
+ r = crypto_shash_init(desc);
if (r)
return r;

if (lmk->seed) {
- r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
+ r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
if (r)
return r;
}

/* Sector is always 512B, block size 16, add data of blocks 1-31 */
- r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
+ r = crypto_shash_update(desc, data + 16, 16 * 31);
if (r)
return r;

@@ -557,12 +554,12 @@ static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
buf[2] = cpu_to_le32(4024);
buf[3] = 0;
- r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
+ r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
if (r)
return r;

/* No MD5 padding here */
- r = crypto_shash_export(&sdesc.desc, &md5state);
+ r = crypto_shash_export(desc, &md5state);
if (r)
return r;

@@ -679,10 +676,7 @@ static int crypt_iv_tcw_whitening(struct crypt_config *cc,
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
u8 buf[TCW_WHITENING_SIZE];
- struct {
- struct shash_desc desc;
- char ctx[crypto_shash_descsize(tcw->crc32_tfm)];
- } sdesc;
+ SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
int i, r;

/* xor whitening with sector number */
@@ -691,16 +685,16 @@ static int crypt_iv_tcw_whitening(struct crypt_config *cc,
crypto_xor(&buf[8], (u8 *)&sector, 8);

/* calculate crc32 for every 32bit part and xor it */
- sdesc.desc.tfm = tcw->crc32_tfm;
- sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+ desc->tfm = tcw->crc32_tfm;
+ desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
for (i = 0; i < 4; i++) {
- r = crypto_shash_init(&sdesc.desc);
+ r = crypto_shash_init(desc);
if (r)
goto out;
- r = crypto_shash_update(&sdesc.desc, &buf[i * 4], 4);
+ r = crypto_shash_update(desc, &buf[i * 4], 4);
if (r)
goto out;
- r = crypto_shash_final(&sdesc.desc, &buf[i * 4]);
+ r = crypto_shash_final(desc, &buf[i * 4]);
if (r)
goto out;
}
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/