| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.8 028/140] pstore/ram: Use memcpy_fromio() to save old buffer | Date | Wed, 26 Oct 2016 14:21:28 +0200 |
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4.8-stable review patch. If anyone has any objections, please let me know.
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From: Andrew Bresticker <abrestic@chromium.org>
commit d771fdf94180de2bd811ac90cba75f0f346abf8d upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/pstore/ram_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -286,8 +286,8 @@ void persistent_ram_save_old(struct pers } 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,
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