LinuxLists.cc - [PATCH v3 00/12] LLVMLinux: Patches to enable the kernel to be compiled with clang/LLVM

2014-09-15 07:30:22

Subject: [PATCH v3 00/12] LLVMLinux: Patches to enable the kernel to be compiled with clang/LLVM

From: Behan Webster <[email protected]>

These patches replace the use of Variable Length Arrays In Structs (VLAIS) in
crypto related code with C99 compliant equivalent code. A SHASH_DESC_ON_STACK()
macro is added to hash.h which is then used to replace the use of VLAIS in all
the other patches. The minimum size and alignment are maintained by the new code.

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

The LLVMLinux project aims to fully build the Linux kernel using both gcc and
clang (the C front end for the LLVM compiler infrastructure project).

Behan Webster (6):
crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code
crypto: LLVMLinux: Remove VLAIS from crypto/mv_cesa.c
crypto: LLVMLinux: Remove VLAIS from crypto/n2_core.c
crypto: LLVMLinux: Remove VLAIS from crypto/omap_sham.c
crypto: LLVMLinux: Remove VLAIS from crypto/.../qat_algs.c
security, crypto: LLVMLinux: Remove VLAIS from ima_crypto.c

Jan-Simon Möller (5):
crypto: LLVMLinux: Remove VLAIS from crypto/ccp/ccp-crypto-sha.c
crypto, dm: LLVMLinux: Remove VLAIS usage from dm-crypt
crypto: LLVMLinux: Remove VLAIS usage from crypto/hmac.c
crypto: LLVMLinux: Remove VLAIS usage from libcrc32c.c
crypto: LLVMLinux: Remove VLAIS usage from crypto/testmgr.c

Vinícius Tinti (1):
btrfs: LLVMLinux: Remove VLAIS

crypto/hmac.c | 25 +++++++---------
crypto/testmgr.c | 14 ++++-----
drivers/crypto/ccp/ccp-crypto-sha.c | 13 ++++----
drivers/crypto/mv_cesa.c | 41 +++++++++++--------------
drivers/crypto/n2_core.c | 11 +++----
drivers/crypto/omap-sham.c | 28 +++++++-----------
drivers/crypto/qat/qat_common/qat_algs.c | 31 +++++++++----------
drivers/md/dm-crypt.c | 34 +++++++++------------
fs/btrfs/hash.c | 16 +++++-----
include/crypto/hash.h | 5 ++++
lib/libcrc32c.c | 16 +++++-----
security/integrity/ima/ima_crypto.c | 51 ++++++++++++++------------------
12 files changed, 126 insertions(+), 159 deletions(-)

--
1.9.1

2014-09-15 07:30:26

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 04/12] crypto: LLVMLinux: Remove VLAIS from crypto/mv_cesa.c

From: Behan Webster <[email protected]>

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: Behan Webster <[email protected]>
Reviewed-by: Mark Charlebois <[email protected]>
Reviewed-by: Jan-Simon Möller <[email protected]>
---
drivers/crypto/mv_cesa.c | 41 ++++++++++++++++++-----------------------
1 file changed, 18 insertions(+), 23 deletions(-)

diff --git a/drivers/crypto/mv_cesa.c b/drivers/crypto/mv_cesa.c
index 29d0ee5..032c72c 100644
--- a/drivers/crypto/mv_cesa.c
+++ b/drivers/crypto/mv_cesa.c
@@ -402,26 +402,23 @@ static int mv_hash_final_fallback(struct ahash_request *req)
{
const struct mv_tfm_hash_ctx *tfm_ctx = crypto_tfm_ctx(req->base.tfm);
struct mv_req_hash_ctx *req_ctx = ahash_request_ctx(req);
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm_ctx->fallback)];
- } desc;
+ SHASH_DESC_ON_STACK(shash, tfm_ctx->fallback);
int rc;

- desc.shash.tfm = tfm_ctx->fallback;
- desc.shash.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+ shash->tfm = tfm_ctx->fallback;
+ shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
if (unlikely(req_ctx->first_hash)) {
- crypto_shash_init(&desc.shash);
- crypto_shash_update(&desc.shash, req_ctx->buffer,
+ crypto_shash_init(shash);
+ crypto_shash_update(shash, req_ctx->buffer,
req_ctx->extra_bytes);
} else {
/* only SHA1 for now....
*/
- rc = mv_hash_import_sha1_ctx(req_ctx, &desc.shash);
+ rc = mv_hash_import_sha1_ctx(req_ctx, shash);
if (rc)
goto out;
}
- rc = crypto_shash_final(&desc.shash, req->result);
+ rc = crypto_shash_final(shash, req->result);
out:
return rc;
}
@@ -794,23 +791,21 @@ static int mv_hash_setkey(struct crypto_ahash *tfm, const u8 * key,
ss = crypto_shash_statesize(ctx->base_hash);

{
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(ctx->base_hash)];
- } desc;
+ SHASH_DESC_ON_STACK(shash, ctx->base_hash);
+
unsigned int i;
char ipad[ss];
char opad[ss];

- desc.shash.tfm = ctx->base_hash;
- desc.shash.flags = crypto_shash_get_flags(ctx->base_hash) &
+ shash->tfm = ctx->base_hash;
+ shash->flags = crypto_shash_get_flags(ctx->base_hash) &
CRYPTO_TFM_REQ_MAY_SLEEP;

if (keylen > bs) {
int err;

err =
- crypto_shash_digest(&desc.shash, key, keylen, ipad);
+ crypto_shash_digest(shash, key, keylen, ipad);
if (err)
return err;

@@ -826,12 +821,12 @@ static int mv_hash_setkey(struct crypto_ahash *tfm, const u8 * key,
opad[i] ^= 0x5c;
}

- rc = crypto_shash_init(&desc.shash) ? :
- crypto_shash_update(&desc.shash, ipad, bs) ? :
- crypto_shash_export(&desc.shash, ipad) ? :
- crypto_shash_init(&desc.shash) ? :
- crypto_shash_update(&desc.shash, opad, bs) ? :
- crypto_shash_export(&desc.shash, opad);
+ rc = crypto_shash_init(shash) ? :
+ crypto_shash_update(shash, ipad, bs) ? :
+ crypto_shash_export(shash, ipad) ? :
+ crypto_shash_init(shash) ? :
+ crypto_shash_update(shash, opad, bs) ? :
+ crypto_shash_export(shash, opad);

if (rc == 0)
mv_hash_init_ivs(ctx, ipad, opad);
--
1.9.1

2014-09-15 07:31:36

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 05/12] crypto: LLVMLinux: Remove VLAIS from crypto/n2_core.c

2014-09-15 07:30:28

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 06/12] crypto: LLVMLinux: Remove VLAIS from crypto/omap_sham.c

2014-09-15 07:30:29

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 07/12] crypto: LLVMLinux: Remove VLAIS from crypto/.../qat_algs.c

From: Behan Webster <[email protected]>

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: Behan Webster <[email protected]>
Reviewed-by: Mark Charlebois <[email protected]>
Reviewed-by: Jan-Simon Möller <[email protected]>
---
drivers/crypto/qat/qat_common/qat_algs.c | 31 ++++++++++++++-----------------
1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/crypto/qat/qat_common/qat_algs.c b/drivers/crypto/qat/qat_common/qat_algs.c
index 59df488..9cabadd 100644
--- a/drivers/crypto/qat/qat_common/qat_algs.c
+++ b/drivers/crypto/qat/qat_common/qat_algs.c
@@ -152,10 +152,7 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
const uint8_t *auth_key,
unsigned int auth_keylen, uint8_t *auth_state)
{
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(ctx->hash_tfm)];
- } desc;
+ SHASH_DESC_ON_STACK(shash, ctx->hash_tfm);
struct sha1_state sha1;
struct sha256_state sha256;
struct sha512_state sha512;
@@ -167,12 +164,12 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
__be64 *hash512_state_out;
int i, offset;

- desc.shash.tfm = ctx->hash_tfm;
- desc.shash.flags = 0x0;
+ shash->tfm = ctx->hash_tfm;
+ shash->flags = 0x0;

if (auth_keylen > block_size) {
char buff[SHA512_BLOCK_SIZE];
- int ret = crypto_shash_digest(&desc.shash, auth_key,
+ int ret = crypto_shash_digest(shash, auth_key,
auth_keylen, buff);
if (ret)
return ret;
@@ -195,10 +192,10 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
*opad_ptr ^= 0x5C;
}

- if (crypto_shash_init(&desc.shash))
+ if (crypto_shash_init(shash))
return -EFAULT;

- if (crypto_shash_update(&desc.shash, ipad, block_size))
+ if (crypto_shash_update(shash, ipad, block_size))
return -EFAULT;

hash_state_out = (__be32 *)hash->sha.state1;
@@ -206,19 +203,19 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,

switch (ctx->qat_hash_alg) {
case ICP_QAT_HW_AUTH_ALGO_SHA1:
- if (crypto_shash_export(&desc.shash, &sha1))
+ if (crypto_shash_export(shash, &sha1))
return -EFAULT;
for (i = 0; i < digest_size >> 2; i++, hash_state_out++)
*hash_state_out = cpu_to_be32(*(sha1.state + i));
break;
case ICP_QAT_HW_AUTH_ALGO_SHA256:
- if (crypto_shash_export(&desc.shash, &sha256))
+ if (crypto_shash_export(shash, &sha256))
return -EFAULT;
for (i = 0; i < digest_size >> 2; i++, hash_state_out++)
*hash_state_out = cpu_to_be32(*(sha256.state + i));
break;
case ICP_QAT_HW_AUTH_ALGO_SHA512:
- if (crypto_shash_export(&desc.shash, &sha512))
+ if (crypto_shash_export(shash, &sha512))
return -EFAULT;
for (i = 0; i < digest_size >> 3; i++, hash512_state_out++)
*hash512_state_out = cpu_to_be64(*(sha512.state + i));
@@ -227,10 +224,10 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
return -EFAULT;
}

- if (crypto_shash_init(&desc.shash))
+ if (crypto_shash_init(shash))
return -EFAULT;

- if (crypto_shash_update(&desc.shash, opad, block_size))
+ if (crypto_shash_update(shash, opad, block_size))
return -EFAULT;

offset = round_up(qat_get_inter_state_size(ctx->qat_hash_alg), 8);
@@ -239,19 +236,19 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,

switch (ctx->qat_hash_alg) {
case ICP_QAT_HW_AUTH_ALGO_SHA1:
- if (crypto_shash_export(&desc.shash, &sha1))
+ if (crypto_shash_export(shash, &sha1))
return -EFAULT;
for (i = 0; i < digest_size >> 2; i++, hash_state_out++)
*hash_state_out = cpu_to_be32(*(sha1.state + i));
break;
case ICP_QAT_HW_AUTH_ALGO_SHA256:
- if (crypto_shash_export(&desc.shash, &sha256))
+ if (crypto_shash_export(shash, &sha256))
return -EFAULT;
for (i = 0; i < digest_size >> 2; i++, hash_state_out++)
*hash_state_out = cpu_to_be32(*(sha256.state + i));
break;
case ICP_QAT_HW_AUTH_ALGO_SHA512:
- if (crypto_shash_export(&desc.shash, &sha512))
+ if (crypto_shash_export(shash, &sha512))
return -EFAULT;
for (i = 0; i < digest_size >> 3; i++, hash512_state_out++)
*hash512_state_out = cpu_to_be64(*(sha512.state + i));
--
1.9.1

2014-09-15 07:31:47

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 08/12] crypto, dm: LLVMLinux: Remove VLAIS usage from dm-crypt

From: Jan-Simon Möller <[email protected]>

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 Möller <[email protected]>
Signed-off-by: Behan Webster <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: "David S. Miller" <[email protected]>
Cc: Herbert Xu <[email protected]>
---
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

2014-09-15 07:30:32

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 10/12] crypto: LLVMLinux: Remove VLAIS usage from libcrc32c.c

2014-09-15 07:30:34

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 12/12] crypto: LLVMLinux: Remove VLAIS usage from crypto/testmgr.c

2014-09-15 07:30:33

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 11/12] security, crypto: LLVMLinux: Remove VLAIS from ima_crypto.c

From: Behan Webster <[email protected]>

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: Behan Webster <[email protected]>
Reviewed-by: Mark Charlebois <[email protected]>
Reviewed-by: Jan-Simon Möller <[email protected]>
Cc: [email protected]
---
security/integrity/ima/ima_crypto.c | 51 +++++++++++++++++--------------------
1 file changed, 23 insertions(+), 28 deletions(-)

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 0bd7328..bb55737 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -380,17 +380,14 @@ static int ima_calc_file_hash_tfm(struct file *file,
loff_t i_size, offset = 0;
char *rbuf;
int rc, read = 0;
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
- } desc;
+ SHASH_DESC_ON_STACK(shash, tfm);

- desc.shash.tfm = tfm;
- desc.shash.flags = 0;
+ shash->tfm = tfm;
+ shash->flags = 0;

hash->length = crypto_shash_digestsize(tfm);

- rc = crypto_shash_init(&desc.shash);
+ rc = crypto_shash_init(shash);
if (rc != 0)
return rc;

@@ -420,7 +417,7 @@ static int ima_calc_file_hash_tfm(struct file *file,
break;
offset += rbuf_len;

- rc = crypto_shash_update(&desc.shash, rbuf, rbuf_len);
+ rc = crypto_shash_update(shash, rbuf, rbuf_len);
if (rc)
break;
}
@@ -429,7 +426,7 @@ static int ima_calc_file_hash_tfm(struct file *file,
kfree(rbuf);
out:
if (!rc)
- rc = crypto_shash_final(&desc.shash, hash->digest);
+ rc = crypto_shash_final(shash, hash->digest);
return rc;
}

@@ -487,18 +484,17 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
struct ima_digest_data *hash,
struct crypto_shash *tfm)
{
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
- } desc;
+ char desc[sizeof(struct shash_desc) +
+ crypto_shash_descsize(tfm)] CRYPTO_MINALIGN_ATTR;
+ struct shash_desc *shash = (struct shash_desc *)desc;
int rc, i;

- desc.shash.tfm = tfm;
- desc.shash.flags = 0;
+ shash->tfm = tfm;
+ shash->flags = 0;

hash->length = crypto_shash_digestsize(tfm);

- rc = crypto_shash_init(&desc.shash);
+ rc = crypto_shash_init(shash);
if (rc != 0)
return rc;

@@ -508,7 +504,7 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
u32 datalen = field_data[i].len;

if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
- rc = crypto_shash_update(&desc.shash,
+ rc = crypto_shash_update(shash,
(const u8 *) &field_data[i].len,
sizeof(field_data[i].len));
if (rc)
@@ -518,13 +514,13 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
data_to_hash = buffer;
datalen = IMA_EVENT_NAME_LEN_MAX + 1;
}
- rc = crypto_shash_update(&desc.shash, data_to_hash, datalen);
+ rc = crypto_shash_update(shash, data_to_hash, datalen);
if (rc)
break;
}

if (!rc)
- rc = crypto_shash_final(&desc.shash, hash->digest);
+ rc = crypto_shash_final(shash, hash->digest);

return rc;
}
@@ -565,15 +561,14 @@ static int __init ima_calc_boot_aggregate_tfm(char *digest,
{
u8 pcr_i[TPM_DIGEST_SIZE];
int rc, i;
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
- } desc;
+ char desc[sizeof(struct shash_desc) +
+ crypto_shash_descsize(tfm)] CRYPTO_MINALIGN_ATTR;
+ struct shash_desc *shash = (struct shash_desc *)desc;

- desc.shash.tfm = tfm;
- desc.shash.flags = 0;
+ shash->tfm = tfm;
+ shash->flags = 0;

- rc = crypto_shash_init(&desc.shash);
+ rc = crypto_shash_init(shash);
if (rc != 0)
return rc;

@@ -581,10 +576,10 @@ static int __init ima_calc_boot_aggregate_tfm(char *digest,
for (i = TPM_PCR0; i < TPM_PCR8; i++) {
ima_pcrread(i, pcr_i);
/* now accumulate with current aggregate */
- rc = crypto_shash_update(&desc.shash, pcr_i, TPM_DIGEST_SIZE);
+ rc = crypto_shash_update(shash, pcr_i, TPM_DIGEST_SIZE);
}
if (!rc)
- crypto_shash_final(&desc.shash, digest);
+ crypto_shash_final(shash, digest);
return rc;
}

--
1.9.1

2014-09-15 07:31:50

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 09/12] crypto: LLVMLinux: Remove VLAIS usage from crypto/hmac.c

2014-09-15 07:30:25

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 03/12] crypto: LLVMLinux: Remove VLAIS from crypto/ccp/ccp-crypto-sha.c

2014-09-15 07:30:23

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 01/12] crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code

From: Behan Webster <[email protected]>

Add a macro which replaces the use of a Variable Length Array In Struct (VLAIS)
with a C99 compliant equivalent. This macro instead allocates the appropriate
amount of memory using an char array.

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

struct shash_desc contains a flexible array member member ctx declared with
CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning
of the array declared after struct shash_desc with long long.

No trailing padding is required because it is not a struct type that can
be used in an array.

The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long
as would be the case for a struct containing a member with
CRYPTO_MINALIGN_ATTR.

Signed-off-by: Behan Webster <[email protected]>
---
include/crypto/hash.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index a391955..541125b 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -58,6 +58,11 @@ struct shash_desc {
void *__ctx[] CRYPTO_MINALIGN_ATTR;
};

+#define SHASH_DESC_ON_STACK(shash, tfm) \
+ char __desc[sizeof(struct shash_desc) + \
+ crypto_shash_descsize(tfm)] CRYPTO_MINALIGN_ATTR; \
+ struct shash_desc *shash = (struct shash_desc *)__desc
+
struct shash_alg {
int (*init)(struct shash_desc *desc);
int (*update)(struct shash_desc *desc, const u8 *data,
--
1.9.1

2014-09-15 07:30:24

by Behan Webster

[permalink] [raw]

Subject: [PATCH v3 02/12] btrfs: LLVMLinux: Remove VLAIS

From: Vinícius Tinti <[email protected]>

Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This is the original VLAIS struct.

struct {
struct shash_desc shash;
char ctx[crypto_shash_descsize(tfm)];
} desc;

This patch instead 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: Vinícius Tinti <[email protected]>
Reviewed-by: Jan-Simon Möller <[email protected]>
Reviewed-by: Mark Charlebois <[email protected]>
Signed-off-by: Behan Webster <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Herbert Xu <[email protected]>
---
fs/btrfs/hash.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/hash.c b/fs/btrfs/hash.c
index 85889aa..4bf4d3a 100644
--- a/fs/btrfs/hash.c
+++ b/fs/btrfs/hash.c
@@ -33,18 +33,16 @@ void btrfs_hash_exit(void)

u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
{
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
- } desc;
+ SHASH_DESC_ON_STACK(shash, tfm);
+ u32 *ctx = (u32 *)shash_desc_ctx(shash);
int err;

- desc.shash.tfm = tfm;
- desc.shash.flags = 0;
- *(u32 *)desc.ctx = crc;
+ shash->tfm = tfm;
+ shash->flags = 0;
+ *ctx = crc;

- err = crypto_shash_update(&desc.shash, address, length);
+ err = crypto_shash_update(shash, address, length);
BUG_ON(err);

- return *(u32 *)desc.ctx;
+ return *ctx;
}
--
1.9.1

--
dm-devel mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/dm-devel

2014-09-15 08:06:54

by Michał Mirosław

[permalink] [raw]

Subject: Re: [dm-devel] [PATCH v3 01/12] crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code

2014-09-15 9:30 GMT+02:00 <[email protected]>:
[...]
> +#define SHASH_DESC_ON_STACK(shash, tfm) \
> + char __desc[sizeof(struct shash_desc) + \
> + crypto_shash_descsize(tfm)] CRYPTO_MINALIGN_ATTR; \
> + struct shash_desc *shash = (struct shash_desc *)__desc
> +

char shash##__desc[] or similar? Otherwise it won't work if you use
this macro twice in the same block.

Best Regards,
Michał Mirosław

2014-09-15 08:37:44

by Behan Webster

[permalink] [raw]

Subject: Re: [dm-devel] [PATCH v3 01/12] crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code

On 09/15/14 01:06, Michał Mirosław wrote:
> 2014-09-15 9:30 GMT+02:00 <[email protected]>:
> [...]
>> +#define SHASH_DESC_ON_STACK(shash, tfm) \
>> + char __desc[sizeof(struct shash_desc) + \
>> + crypto_shash_descsize(tfm)] CRYPTO_MINALIGN_ATTR; \
>> + struct shash_desc *shash = (struct shash_desc *)__desc
>> +
> char shash##__desc[] or similar? Otherwise it won't work if you use
> this macro twice in the same block.
>
> Best Regards,
> Michał Mirosław
Good thinking. Will fix.

Behan

--
Behan Webster
[email protected]

2014-09-15 14:21:46

by Linus Torvalds

[permalink] [raw]

Subject: Re: [PATCH v3 11/12] security, crypto: LLVMLinux: Remove VLAIS from ima_crypto.c

On Mon, Sep 15, 2014 at 12:30 AM, <[email protected]> wrote:
> From: Behan Webster <[email protected]>
>
> 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.

You only made the first case use SHASH_DESC_ON_STACK, the two other
cases you left in the ugly format. Was that just an oversight, or was
there some reason for it?

Linus

2014-09-15 14:25:16

by Behan Webster

[permalink] [raw]

Subject: Re: [PATCH v3 11/12] security, crypto: LLVMLinux: Remove VLAIS from ima_crypto.c

On 09/15/14 07:21, Linus Torvalds wrote:
> On Mon, Sep 15, 2014 at 12:30 AM, <[email protected]> wrote:
>> From: Behan Webster <[email protected]>
>>
>> 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.
> You only made the first case use SHASH_DESC_ON_STACK, the two other
> cases you left in the ugly format. Was that just an oversight, or was
> there some reason for it?
>
Oversight. Will Fix.

Behan

--
Behan Webster
[email protected]

2014-09-17 09:22:12

by Herbert Xu

[permalink] [raw]

Subject: Re: [PATCH v3 01/12] crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code

On Mon, Sep 15, 2014 at 12:30:23AM -0700, [email protected] wrote:
> From: Behan Webster <[email protected]>
>
> Add a macro which replaces the use of a Variable Length Array In Struct (VLAIS)
> with a C99 compliant equivalent. This macro instead allocates the appropriate
> amount of memory using an char array.
>
> The new code can be compiled with both gcc and clang.
>
> struct shash_desc contains a flexible array member member ctx declared with
> CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning
> of the array declared after struct shash_desc with long long.
>
> No trailing padding is required because it is not a struct type that can
> be used in an array.
>
> The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long
> as would be the case for a struct containing a member with
> CRYPTO_MINALIGN_ATTR.
>
> Signed-off-by: Behan Webster <[email protected]>

Acked-by: Herbert Xu <[email protected]>

Thanks,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

2014-09-17 11:15:40

by Dmitry Kasatkin

[permalink] [raw]

Subject: Re: [PATCH v3 01/12] crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code

On 17/09/14 12:22, Herbert Xu wrote:
> On Mon, Sep 15, 2014 at 12:30:23AM -0700, [email protected] wrote:
>> From: Behan Webster <[email protected]>
>>
>> Add a macro which replaces the use of a Variable Length Array In Struct (VLAIS)
>> with a C99 compliant equivalent. This macro instead allocates the appropriate
>> amount of memory using an char array.
>>
>> The new code can be compiled with both gcc and clang.
>>
>> struct shash_desc contains a flexible array member member ctx declared with
>> CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning
>> of the array declared after struct shash_desc with long long.
>>
>> No trailing padding is required because it is not a struct type that can
>> be used in an array.
>>
>> The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long
>> as would be the case for a struct containing a member with
>> CRYPTO_MINALIGN_ATTR.
>>
>> Signed-off-by: Behan Webster <[email protected]>
> Acked-by: Herbert Xu <[email protected]>
>
> Thanks,

Just in case.
I would still follow advice from "Michał Mirosław" to use shash##__desc[]

- Dmitry

2014-09-17 11:30:35

by Herbert Xu

[permalink] [raw]

Subject: Re: [PATCH v3 01/12] crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code

On Wed, Sep 17, 2014 at 02:15:40PM +0300, Dmitry Kasatkin wrote:
> On 17/09/14 12:22, Herbert Xu wrote:
> > On Mon, Sep 15, 2014 at 12:30:23AM -0700, [email protected] wrote:
> >> From: Behan Webster <[email protected]>
> >>
> >> Add a macro which replaces the use of a Variable Length Array In Struct (VLAIS)
> >> with a C99 compliant equivalent. This macro instead allocates the appropriate
> >> amount of memory using an char array.
> >>
> >> The new code can be compiled with both gcc and clang.
> >>
> >> struct shash_desc contains a flexible array member member ctx declared with
> >> CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning
> >> of the array declared after struct shash_desc with long long.
> >>
> >> No trailing padding is required because it is not a struct type that can
> >> be used in an array.
> >>
> >> The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long
> >> as would be the case for a struct containing a member with
> >> CRYPTO_MINALIGN_ATTR.
> >>
> >> Signed-off-by: Behan Webster <[email protected]>
> > Acked-by: Herbert Xu <[email protected]>
> >
> > Thanks,
>
> Just in case.
> I would still follow advice from "Michał Mirosław" to use shash##__desc[]

Oh yes of course. My ack is more about the approach.

Cheers,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

2014-09-17 13:49:20

by Chris Mason

[permalink] [raw]

Subject: Re: [PATCH v3 02/12] btrfs: LLVMLinux: Remove VLAIS

On 09/15/2014 03:30 AM, [email protected] wrote:
> From: Vinícius Tinti <[email protected]>
>
> Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
> compliant equivalent. This is the original VLAIS struct.
>
> struct {
> struct shash_desc shash;
> char ctx[crypto_shash_descsize(tfm)];
> } desc;
>
> This patch instead 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: Vinícius Tinti <[email protected]>
> Reviewed-by: Jan-Simon Möller <[email protected]>
> Reviewed-by: Mark Charlebois <[email protected]>
> Signed-off-by: Behan Webster <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Herbert Xu <[email protected]>

Acked-by: Chris Mason <[email protected]>

On the btrfs bits. Thanks for the v3.

-chris

2014-09-17 15:26:19

by Behan Webster

[permalink] [raw]

Subject: Re: [PATCH v3 01/12] crypto: LLVMLinux: Add macro to remove use of VLAIS in crypto code

On 09/17/14 04:30, Herbert Xu wrote:
> On Wed, Sep 17, 2014 at 02:15:40PM +0300, Dmitry Kasatkin wrote:
>> On 17/09/14 12:22, Herbert Xu wrote:
>>> On Mon, Sep 15, 2014 at 12:30:23AM -0700, [email protected] wrote:
>>>> From: Behan Webster <[email protected]>
>>>>
>>>> Add a macro which replaces the use of a Variable Length Array In Struct (VLAIS)
>>>> with a C99 compliant equivalent. This macro instead allocates the appropriate
>>>> amount of memory using an char array.
>>>>
>>>> The new code can be compiled with both gcc and clang.
>>>>
>>>> struct shash_desc contains a flexible array member member ctx declared with
>>>> CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning
>>>> of the array declared after struct shash_desc with long long.
>>>>
>>>> No trailing padding is required because it is not a struct type that can
>>>> be used in an array.
>>>>
>>>> The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long
>>>> as would be the case for a struct containing a member with
>>>> CRYPTO_MINALIGN_ATTR.
>>>>
>>>> Signed-off-by: Behan Webster <[email protected]>
>>> Acked-by: Herbert Xu <[email protected]>
>>>
>>> Thanks,
>> Just in case.
>> I would still follow advice from "Michał Mirosław" to use shash##__desc[]
Absolutely. I will be posting a v4 patchset . Just waiting a bit more
for more comments on v3.

The macro from v4 will look like this which I believe will satisfy the
concern and indeed be safer than my previous version.

+#define SHASH_DESC_ON_STACK(shash, tfm) \
+ char __##shash##_desc[sizeof(struct shash_desc) + \
+ crypto_shash_descsize(tfm)] CRYPTO_MINALIGN_ATTR; \
+ struct shash_desc *shash = (struct shash_desc *)__##shash##_desc

Hmm. Is it worth adding a comment with this macro explaining the reason this works? Essentially much of what is in the commit message?

> Oh yes of course. My ack is more about the approach.

Wonderful!

Indeed. I would have asked for you to wait for v4 anyways. :)

Thank you,

Behan

--
Behan Webster
[email protected]