Herbert Xu <herb...@gondor.apana.org.au> wrote:
>
> crypto: padlock-sha - Fix stack alignment
>
> The PadLock hardware requires the output buffer for SHA to be
> 128-bit aligned. We currentply place the buffer on the stack,
> and ask gcc to align it to 128 bits. That doesn't work on i386
> because the kernel stack is only aligned to 32 bits. This patch
> changes the code to align the buffer by hand so that the hardware
> doesn't fault on unaligned buffers.
>
> Reported-by: Séguier Régis <rgu...@e-teleport.net>
> Tested-by: Séguier Régis <rgu...@e-teleport.net>
> Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>
For the record I modified the patch slightly to ensure that
we get the minimum alignment from gcc.
diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c
index fe007b6..0af8057 100644
--- a/drivers/crypto/padlock-sha.c
+++ b/drivers/crypto/padlock-sha.c
@@ -70,7 +70,8 @@ static int padlock_sha1_finup(struct shash_desc *desc, const
u8 *in,
/* We can't store directly to *out as it may be unaligned. */
/* BTW Don't reduce the buffer size below 128 Bytes!
* PadLock microcode needs it that big. */
- char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN];
+ char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
+ ((aligned(STACK_ALIGN)));
char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
struct sha1_state state;
@@ -135,7 +136,8 @@ static int padlock_sha256_finup(struct shash_desc *desc,
const u8 *in,
/* We can't store directly to *out as it may be unaligned. */
/* BTW Don't reduce the buffer size below 128 Bytes!
* PadLock microcode needs it that big. */
- char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN];
+ char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
+ ((aligned(STACK_ALIGN)));
char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
struct sha256_state state;
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herb...@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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