Patch "crypto: caam - fix RNG buffer cache alignment" has been added to the 3.10-stable tree

Patch "crypto: caam - fix RNG buffer cache alignment" has been added to the 3.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    crypto: caam - fix RNG buffer cache alignment

to the 3.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     crypto-caam-fix-rng-buffer-cache-alignment.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 412c98c1bef65fe7589f1300e93735d96130307c Mon Sep 17 00:00:00 2001
From: Steve Cornelius <steve.cornelius@freescale.com>
Date: Mon, 15 Jun 2015 16:52:59 -0700
Subject: crypto: caam - fix RNG buffer cache alignment

From: Steve Cornelius <steve.cornelius@freescale.com>

commit 412c98c1bef65fe7589f1300e93735d96130307c upstream.

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.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/crypto/caam/caamrng.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 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];


Patches currently in stable-queue which might be from steve.cornelius@freescale.com are

queue-3.10/crypto-caam-fix-rng-buffer-cache-alignment.patch
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