crypto: caam - fix RNG buffer cache alignment
authorSteve Cornelius <steve.cornelius@freescale.com>
Mon, 15 Jun 2015 23:52:59 +0000 (16:52 -0700)
committerHerbert Xu <herbert@gondor.apana.org.au>
Tue, 16 Jun 2015 06:20:38 +0000 (14:20 +0800)
commit412c98c1bef65fe7589f1300e93735d96130307c
tree9c3fdce06977b37ace84d7f154ead430a00a43da
parent6fd4b15603124c1b56e03db29b41ec39d8a077b9
crypto: caam - fix RNG buffer cache alignment

The hwrng output buffers (2) are cast inside of a a struct (caam_rng_ctx)
allocated in one DMA-tagged region. While the kernel's heap allocator
should place the overall struct on a cacheline aligned boundary, the 2
buffers contained within may not necessarily align. Consenquently, the ends
of unaligned buffers may not fully flush, and if so, stale data will be left
behind, resulting in small repeating patterns.

This fix aligns the buffers inside the struct.

Note that not all of the data inside caam_rng_ctx necessarily needs to be
DMA-tagged, only the buffers themselves require this. However, a fix would
incur the expense of error-handling bloat in the case of allocation failure.

Cc: stable@vger.kernel.org
Signed-off-by: Steve Cornelius <steve.cornelius@freescale.com>
Signed-off-by: Victoria Milhoan <vicki.milhoan@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
drivers/crypto/caam/caamrng.c