On Mon, Nov 26, 2018 at 7:12 PM, Dan Rue <dan.rue@xxxxxxxxxx> wrote:
> diff -Z is used to trim the trailing whitespace when comparing the
> loaded firmware file with the source firmware file. However, per the
> comment in the source code, -Z should not be necessary. In testing, the
> input and output files are identical.
>
> Additionally, -Z is not a standard option and is not available in
> environments such as busybox. When -Z is not supported, diff fails with
> a usage error, which is suppressed, but then causes read_firmwares() to
> exit with a false failure message.
>
> Signed-off-by: Dan Rue <dan.rue@xxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
-Kees
> ---
> tools/testing/selftests/firmware/fw_filesystem.sh | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/firmware/fw_filesystem.sh b/tools/testing/selftests/firmware/fw_filesystem.sh
> index a4320c4b44dc..466cf2f91ba0 100755
> --- a/tools/testing/selftests/firmware/fw_filesystem.sh
> +++ b/tools/testing/selftests/firmware/fw_filesystem.sh
> @@ -155,11 +155,8 @@ read_firmwares()
> {
> for i in $(seq 0 3); do
> config_set_read_fw_idx $i
> - # Verify the contents are what we expect.
> - # -Z required for now -- check for yourself, md5sum
> - # on $FW and DIR/read_firmware will yield the same. Even
> - # cmp agrees, so something is off.
> - if ! diff -q -Z "$FW" $DIR/read_firmware 2>/dev/null ; then
> + # Verify the contents match
> + if ! diff -q "$FW" $DIR/read_firmware 2>/dev/null ; then
> echo "request #$i: firmware was not loaded" >&2
> exit 1
> fi
> @@ -171,7 +168,7 @@ read_firmwares_expect_nofile()
> for i in $(seq 0 3); do
> config_set_read_fw_idx $i
> # Ensures contents differ
> - if diff -q -Z "$FW" $DIR/read_firmware 2>/dev/null ; then
> + if diff -q "$FW" $DIR/read_firmware 2>/dev/null ; then
> echo "request $i: file was not expected to match" >&2
> exit 1
> fi
> --
> 2.19.1
>
--
Kees Cook
