Commit d771fdf9 authored Feb 15, 2016 by Andrew Bresticker Committed by Kees Cook Sep 08, 2016

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 <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>
Cc: stable@vger.kernel.org

parent 7e75678d

fs/pstore/ram_core.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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,

Admin message