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Patch "pstore/ram: Use memcpy_toio instead of memcpy" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Oct 26, 2016

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

pstore/ram: Use memcpy_toio instead of memcpy

to the 4.4-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_toio-instead-of-memcpy.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 7e75678d23167c2527e655658a8ef36a36c8b4d9 Mon Sep 17 00:00:00 2001

From: Furquan Shaikh <[email protected]>
Date: Mon, 15 Feb 2016 09:19:48 +0100
Subject: pstore/ram: Use memcpy_toio instead of memcpy

From: Furquan Shaikh <[email protected]>

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.

---
 fs/pstore/ram_core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
fs/pstore/ram_core.c +1 -1
@@ -263,7 +263,7 @@ static void notrace persistent_ram_updat
 	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);
 }
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/pstore-ram-use-memcpy_toio-instead-of-memcpy.patch