From: Andrew Bresticker Date: Mon, 15 Feb 2016 08:19:49 +0000 (+0100) Subject: pstore/ram: Use memcpy_fromio() to save old buffer X-Git-Tag: v4.9-rc1~106^2~1 X-Git-Url: http://git.cascardo.eti.br/?a=commitdiff_plain;h=d771fdf94180de2bd811ac90cba75f0f346abf8d;p=cascardo%2Flinux.git pstore/ram: Use memcpy_fromio() to save old buffer 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 Signed-off-by: Enric Balletbo Serra Reviewed-by: Puneet Kumar Signed-off-by: Kees Cook Cc: stable@vger.kernel.org --- diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index b40282768c3f..3975deec02f8 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -297,8 +297,8 @@ void persistent_ram_save_old(struct persistent_ram_zone *prz) } 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,