From: Furquan Shaikh <furquan@google.com>
Date: Mon, 15 Feb 2016 08:19:48 +0000 (+0100)
Subject: pstore/ram: Use memcpy_toio instead of memcpy
X-Git-Tag: firefly_0821_release~176^2~4^2~22^2~95
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=93a6ca7f6d02c7ffd49af699c874977872000e18;p=firefly-linux-kernel-4.4.55.git

pstore/ram: Use memcpy_toio instead of memcpy

commit 7e75678d23167c2527e655658a8ef36a36c8b4d9 upstream.

persistent_ram_update uses vmap / iomap based on whether the buffer is in
memory region or reserved region. However, both map it as non-cacheable
memory. For armv8 specifically, non-cacheable mapping requests use a
memory type that has to be accessed aligned to the request size. memcpy()
doesn't guarantee that.

Signed-off-by: Furquan Shaikh <furquan@google.com>
Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Olof Johansson <olofj@chromium.org>
Tested-by: Furquan Shaikh <furquan@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 9cc6efe0b785..cc83231d9168 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -263,7 +263,7 @@ static void notrace persistent_ram_update(struct persistent_ram_zone *prz,
 	const void *s, unsigned int start, unsigned int count)
 {
 	struct persistent_ram_buffer *buffer = prz->buffer;
-	memcpy(buffer->data + start, s, count);
+	memcpy_toio(buffer->data + start, s, count);
 	persistent_ram_update_ecc(prz, start, count);
 }