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: Willy Tarreau <w@1wt.eu>

diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index ee3c6ec5348f2d0543eed00e7b598bb0db7cddca..eb42483dbb05e361fcb3e6e53e702fed7dd09078 100644 (file)
--- 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);
 }