Re: [PATCH] pstore: Use memcpy_toio instead of memcpy

[Kees Cook]

On Thu, Nov 13, 2014 at 10:09 AM, Furquan Shaikh <furquan@xxxxxxxxxx> wrote:
> 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@xxxxxxxxxx>
> ---
>  fs/pstore/ram_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
> index 9d7b9a8..cfbc5e4 100644
> --- a/fs/pstore/ram_core.c
> +++ b/fs/pstore/ram_core.c
> @@ -299,7 +299,7 @@ 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);
>  }
>
> --
> 2.1.0.rc2.206.gedb03e5
>

Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>

Thanks!

-Kees

-- 
Kees Cook
Chrome OS Security
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