From b70f9d27eab5c23e668350927a358621071bc415 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <ben.hutchings@codethink.co.uk>
Date: Wed, 4 Apr 2018 22:38:49 +0200
Subject: [PATCH] test_firmware: fix setting old custom fw path back on exit,
second try
commit e538409257d0217a9bc715686100a5328db75a15 upstream.
Commit 65c79230576 tried to clear the custom firmware path on exit by
writing a single space to the firmware_class.path parameter. This
doesn't work because nothing strips this space from the value stored
and fw_get_filesystem_firmware() only ignores zero-length paths.
Instead, write a null byte.
Fixes: 0a8adf58475 ("test: add firmware_class loader test")
Fixes: 65c79230576 ("test_firmware: fix setting old custom fw path back on exit")
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/testing/selftests/firmware/fw_filesystem.sh | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/firmware/fw_filesystem.sh b/tools/testing/selftests/firmware/fw_filesystem.sh
index 17e16fcaa0cc..99d7f13a5637 100755
--- a/tools/testing/selftests/firmware/fw_filesystem.sh
+++ b/tools/testing/selftests/firmware/fw_filesystem.sh
@@ -29,9 +29,11 @@ test_finish()
echo "$OLD_TIMEOUT" >/sys/class/firmware/timeout
fi
if [ "$OLD_FWPATH" = "" ]; then
- OLD_FWPATH=" "
+ # A zero-length write won't work; write a null byte
+ printf '\000' >/sys/module/firmware_class/parameters/path
+ else
+ echo -n "$OLD_FWPATH" >/sys/module/firmware_class/parameters/path
fi
- echo -n "$OLD_FWPATH" >/sys/module/firmware_class/parameters/path
rm -f "$FW"
rmdir "$FWPATH"
}