Patch "pstore/ram: Use memcpy_fromio() to save old buffer" has been added to the 4.8-stable tree

Patch "pstore/ram: Use memcpy_fromio() to save old buffer" has been added to the 4.8-stable tree

[gregkh]

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

    pstore/ram: Use memcpy_fromio() to save old buffer

to the 4.8-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:
     pstore-ram-use-memcpy_fromio-to-save-old-buffer.patch
and it can be found in the queue-4.8 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 d771fdf94180de2bd811ac90cba75f0f346abf8d Mon Sep 17 00:00:00 2001
From: Andrew Bresticker <abrestic@chromium.org>
Date: Mon, 15 Feb 2016 09:19:49 +0100
Subject: pstore/ram: Use memcpy_fromio() to save old buffer

From: Andrew Bresticker <abrestic@chromium.org>

commit d771fdf94180de2bd811ac90cba75f0f346abf8d upstream.

The ramoops buffer may be mapped as either I/O memory or uncached
memory.  On ARM64, this results in a device-type (strongly-ordered)
mapping.  Since unnaligned accesses to device-type memory will
generate an alignment fault (regardless of whether or not strict
alignment checking is enabled), it is not safe to use memcpy().
memcpy_fromio() is guaranteed to only use aligned accesses, so use
that instead.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com>
Reviewed-by: Puneet Kumar <puneetster@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/pstore/ram_core.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -286,8 +286,8 @@ void persistent_ram_save_old(struct pers
 	}
 
 	prz->old_log_size = size;
-	memcpy(prz->old_log, &buffer->data[start], size - start);
-	memcpy(prz->old_log + size - start, &buffer->data[0], start);
+	memcpy_fromio(prz->old_log, &buffer->data[start], size - start);
+	memcpy_fromio(prz->old_log + size - start, &buffer->data[0], start);
 }
 
 int notrace persistent_ram_write(struct persistent_ram_zone *prz,


Patches currently in stable-queue which might be from abrestic@chromium.org are

queue-4.8/pstore-ram-use-memcpy_fromio-to-save-old-buffer.patch