From 412c98c1bef65fe7589f1300e93735d96130307c Mon Sep 17 00:00:00 2001 From: Steve Cornelius Date: Mon, 15 Jun 2015 16:52:59 -0700 Subject: [PATCH] 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 Signed-off-by: Victoria Milhoan Signed-off-by: Herbert Xu --- drivers/crypto/caam/caamrng.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c index 26a544b..5095337 100644 --- a/drivers/crypto/caam/caamrng.c +++ b/drivers/crypto/caam/caamrng.c @@ -56,7 +56,7 @@ /* Buffer, its dma address and lock */ struct buf_data { - u8 buf[RN_BUF_SIZE]; + u8 buf[RN_BUF_SIZE] ____cacheline_aligned; dma_addr_t addr; struct completion filled; u32 hw_desc[DESC_JOB_O_LEN]; -- 2.7.4