[PATCH v4 1/5] test_firmware: add test case for SIGCHLD on sync fallback

From: "Luis R. Rodriguez" <mcgrof@kernel.org>
To: gregkh@linuxfoundation.org
Cc: wagi@monom.org, yi1.li@linux.intel.com,
	takahiro.akashi@linaro.org, bjorn.andersson@linaro.org,
	luto@kernel.org, ebiederm@xmission.com,
	dmitry.torokhov@gmail.com, arend.vanspriel@broadcom.com,
	dwmw2@infradead.org, rjw@rjwysocki.net, atull@kernel.org,
	moritz.fischer@ettus.com, pmladek@suse.com,
	johannes.berg@intel.com, emmanuel.grumbach@intel.com,
	luciano.coelho@intel.com, kvalo@codeaurora.org,
	torvalds@linux-foundation.org, keescook@chromium.org,
	dhowells@redhat.com, pjones@redhat.com, hdegoede@redhat.com,
	alan@linux.intel.com, tytso@mit.edu, dave@stgolabs.net,
	mawilcox@microsoft.com, tglx@linutronix.de, peterz@infradead.org,
	mfuzzey@parkeon.com, jakub.kicinski@netronome.com,
	nbroeking@me.com, jewalt@lgsinnovations.com,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Luis R. Rodriguez" <mcgrof@kernel.org>
Subject: [PATCH v4 1/5] test_firmware: add test case for SIGCHLD on sync fallback
Date: Thu, 20 Jul 2017 13:13:38 -0700	[thread overview]
Message-ID: <20170720201342.7320-2-mcgrof@kernel.org> (raw)
In-Reply-To: <20170720201342.7320-1-mcgrof@kernel.org>

It has been reported that SIGCHLD will trigger an immediate abort
on sync firmware requests which rely on the sysfs interface for a
trigger. This is unexpected behaviour, this reproduces this issue.

This test case currenty fails.

Reported-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
 tools/testing/selftests/firmware/fw_fallback.sh | 31 +++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/tools/testing/selftests/firmware/fw_fallback.sh b/tools/testing/selftests/firmware/fw_fallback.sh
index 2e4c22d5abf7..8f511035f783 100755
--- a/tools/testing/selftests/firmware/fw_fallback.sh
+++ b/tools/testing/selftests/firmware/fw_fallback.sh
@@ -134,6 +134,27 @@ load_fw_custom_cancel()
 	wait
 }
 
+load_fw_fallback_with_child()
+{
+	local name="$1"
+	local file="$2"
+
+	# This is the value already set but we want to be explicit
+	echo 4 >/sys/class/firmware/timeout
+
+	sleep 1 &
+	SECONDS_BEFORE=$(date +%s)
+	echo -n "$name" >"$DIR"/trigger_request 2>/dev/null
+	SECONDS_AFTER=$(date +%s)
+	SECONDS_DELTA=$(($SECONDS_AFTER - $SECONDS_BEFORE))
+	if [ "$SECONDS_DELTA" -lt 4 ]; then
+		RET=1
+	else
+		RET=0
+	fi
+	wait
+	return $RET
+}
 
 trap "test_finish" EXIT
 
@@ -221,4 +242,14 @@ else
 	echo "$0: cancelling custom fallback mechanism works"
 fi
 
+set +e
+load_fw_fallback_with_child "nope-signal-$NAME" "$FW"
+if [ "$?" -eq 0 ]; then
+	echo "$0: SIGCHLD on sync ignored as expected" >&2
+else
+	echo "$0: error - sync firmware request cancelled due to SIGCHLD" >&2
+	exit 1
+fi
+set -e
+
 exit 0
-- 
2.11.0
