2012-10-31 11:20:33

by Behan Webster

Subject: [PATCH V2 1/2] Remove VLAIS usage from crypto/hmac.c

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

The use of variable length arrays in structs (VLAIS) in the Linux Kernel code
precludes the use of compilers which don't implement VLAIS (for instance the
Clang compiler). This patch instead allocates the appropriate amount of memory
using an char array.

Patch from series at
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120507/142707.html
by PaX Team.

Signed-off-by: Jan-Simon Möller <[email protected]>
Cc: [email protected]
Signed-off-by: Behan Webster <[email protected]>
---
crypto/hmac.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/crypto/hmac.c b/crypto/hmac.c
index 8d9544c..1061255 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -52,20 +52,19 @@ static int hmac_setkey(struct crypto_shash *parent,
struct hmac_ctx *ctx = align_ptr(opad + ss,
crypto_tfm_ctx_alignment());
struct crypto_shash *hash = ctx->hash;
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(hash)];
- } desc;
+ char desc[sizeof(struct shash_desc) + crypto_shash_descsize(hash)
+ + CRYPTO_MINALIGN] CRYPTO_MINALIGN_ATTR;
+ struct shash_desc *shash = (struct shash_desc *)desc;
unsigned int i;

- desc.shash.tfm = hash;
- desc.shash.flags = crypto_shash_get_flags(parent) &
- CRYPTO_TFM_REQ_MAY_SLEEP;
+ shash->tfm = hash;
+ shash->flags = crypto_shash_get_flags(parent)
+ & CRYPTO_TFM_REQ_MAY_SLEEP;

if (keylen > bs) {
int err;

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

@@ -81,12 +80,12 @@ static int hmac_setkey(struct crypto_shash *parent,
opad[i] ^= 0x5c;
}

- return 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);
+ return 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);
}

static int hmac_export(struct shash_desc *pdesc, void *out)
--
1.7.9.5

2012-10-31 11:20:34

by Behan Webster

Subject: [PATCH V2 2/2] Remove VLAIS usage from crypto/testmgr.c

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

The use of variable length arrays in structs (VLAIS) in the Linux Kernel code
precludes the use of compilers which don't implement VLAIS (for instance the
Clang compiler). This patch instead allocates the appropriate amount of memory
using an char array.

Patch from series at
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120507/142707.html
by PaX Team.

Signed-off-by: Jan-Simon Möller <[email protected]>
Cc: [email protected]
[Use shash_desc_ctx() to calculate address of ctx]
Signed-off-by: Behan Webster <[email protected]>
---
crypto/testmgr.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 941d75c..8738ff4 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -1578,16 +1578,17 @@ static int alg_test_crc32c(const struct alg_test_desc *desc,
}

do {
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
- } sdesc;
+ char sdesc[sizeof(struct shash_desc)
+ + crypto_shash_descsize(tfm)
+ + CRYPTO_MINALIGN] CRYPTO_MINALIGN_ATTR;
+ struct shash_desc *shash = (struct shash_desc *)sdesc;
+ u32 *ctx = (u32 *)shash_desc_ctx(shash);

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

- *(u32 *)sdesc.ctx = le32_to_cpu(420553207);
- err = crypto_shash_final(&sdesc.shash, (u8 *)&val);
+ *ctx = le32_to_cpu(420553207);
+ err = crypto_shash_final(shash, (u8 *)&val);
if (err) {
printk(KERN_ERR "alg: crc32c: Operation failed for "
"%s: %d\n", driver, err);
--
1.7.9.5