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). The LLVMLinux Project is working towards the ability of
providing the Linux kernel developer the choice of using the Clang compiler
toolchain. This is a part of a series of patches which remove the use of VLAIS
from crypto code, dm-crypt, jbd2, libcrc32c, netfilter, and usb gadget. Other
patches to allow Clang to be used will follow.
Jan-Simon Möller (2):
Remove VLAIS usage from crypto/hmac.c
Remove VLAIS usage from crypto/testmgr.c
crypto/hmac.c | 27 +++++++++++++--------------
crypto/testmgr.c | 23 +++++++++++++----------
2 files changed, 26 insertions(+), 24 deletions(-)
--
1.7.9.5
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/testmgr.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 941d75c..5b7b3a6 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -1578,16 +1578,19 @@ static int alg_test_crc32c(const struct alg_test_desc *desc,
}
do {
- struct {
- struct shash_desc shash;
- char ctx[crypto_shash_descsize(tfm)];
- } sdesc;
-
- sdesc.shash.tfm = tfm;
- sdesc.shash.flags = 0;
-
- *(u32 *)sdesc.ctx = le32_to_cpu(420553207);
- err = crypto_shash_final(&sdesc.shash, (u8 *)&val);
+ 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 *)((unsigned long)(sdesc
+ + sizeof(struct shash_desc) + CRYPTO_MINALIGN - 1)
+ & ~(CRYPTO_MINALIGN - 1));
+
+ shash->tfm = tfm;
+ shash->flags = 0;
+
+ *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
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
Quoting Behan Webster <[email protected]>:
> From: Jan-Simon M?ller <[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 M?ller <[email protected]>
> Cc: [email protected]
> Signed-off-by: Behan Webster <[email protected]>
> ---
> crypto/testmgr.c | 23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/crypto/testmgr.c b/crypto/testmgr.c
> index 941d75c..5b7b3a6 100644
> --- a/crypto/testmgr.c
> +++ b/crypto/testmgr.c
> @@ -1578,16 +1578,19 @@ static int alg_test_crc32c(const struct
> alg_test_desc *desc,
> }
>
> do {
> - struct {
> - struct shash_desc shash;
> - char ctx[crypto_shash_descsize(tfm)];
> - } sdesc;
> -
> - sdesc.shash.tfm = tfm;
> - sdesc.shash.flags = 0;
> -
> - *(u32 *)sdesc.ctx = le32_to_cpu(420553207);
> - err = crypto_shash_final(&sdesc.shash, (u8 *)&val);
> + 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 *)((unsigned long)(sdesc
> + + sizeof(struct shash_desc) + CRYPTO_MINALIGN - 1)
> + & ~(CRYPTO_MINALIGN - 1));
I think you should use '(u32 *)shash_desc_ctx(shash)' instead of
getting ctx pointer manually.
> +
> + shash->tfm = tfm;
> + shash->flags = 0;
> +
> + *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);
I don't think imposing the limitations of a non-gcc compiler
is rasonable.
On Wed, Oct 31, 2012 at 12:41:32PM -0400, David Miller wrote:
>
> I don't think imposing the limitations of a non-gcc compiler
> is rasonable.
I agree.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt