[CRYPTO] Add alignmask for low-level cipher implementations
The VIA Padlock device requires the input and output buffers to
be aligned on 16-byte boundaries. This patch adds the alignmask
attribute for low-level cipher implementations to indicate their
alignment requirements.
The mid-level crypt() function will copy the input/output buffers
if they are not aligned correctly before they are passed to the
low-level implementation.
Strictly speaking, some of the software implementations require
the buffers to be aligned on 4-byte boundaries as they do 32-bit
loads. However, it is not clear whether it is better to copy
the buffers or pay the penalty for unaligned loads/stores.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/crypto/api.c b/crypto/api.c
index 394169a..f55856b 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -168,6 +168,12 @@
{
int ret = 0;
struct crypto_alg *q;
+
+ if (alg->cra_alignmask & (alg->cra_alignmask + 1))
+ return -EINVAL;
+
+ if (alg->cra_alignmask > PAGE_SIZE)
+ return -EINVAL;
down_write(&crypto_alg_sem);