Merge branch 'openvswitch-syzbot-splat-fix-and-introduce-selftest'

Aaron Conole says:

====================
openvswitch: syzbot splat fix and introduce selftest

Syzbot recently caught a splat when dropping features from
openvswitch datapaths that are in-use.  The WARN() call is
definitely too large a hammer for the situation, so change
to pr_warn.

Second patch in the series introduces a new selftest suite which
can help show that an issue is fixed.  This change might be
more suited to net-next tree, so it has been separated out
as an additional patch and can be either applied to either tree
based on preference.
====================

Link: https://lore.kernel.org/r/20221025105018.466157-1-aconole@redhat.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

MAINTAINERS

@@ -15436,6 +15436,7 @@ S:	Maintained
 W:	http://openvswitch.org
 F:	include/uapi/linux/openvswitch.h
 F:	net/openvswitch/
+F:	tools/testing/selftests/net/openvswitch/
 
 OPERATING PERFORMANCE POINTS (OPP)
 M:	Viresh Kumar <vireshk@kernel.org>

net/openvswitch/datapath.c

@@ -1616,7 +1616,8 @@ static void ovs_dp_reset_user_features(struct sk_buff *skb,
 	if (IS_ERR(dp))
 		return;
 
-	WARN(dp->user_features, "Dropping previously announced user features\n");
+	pr_warn("%s: Dropping previously announced user features\n",
+		ovs_dp_name(dp));
 	dp->user_features = 0;
 }
 

tools/testing/selftests/Makefile

@@ -49,6 +49,7 @@ TARGETS += net
 TARGETS += net/af_unix
 TARGETS += net/forwarding
 TARGETS += net/mptcp
+TARGETS += net/openvswitch
 TARGETS += netfilter
 TARGETS += nsfs
 TARGETS += pidfd

tools/testing/selftests/net/openvswitch/Makefile

+# SPDX-License-Identifier: GPL-2.0
+
+top_srcdir = ../../../../..
+
+CFLAGS =  -Wall -Wl,--no-as-needed -O2 -g -I$(top_srcdir)/usr/include $(KHDR_INCLUDES)
+
+TEST_PROGS := openvswitch.sh
+
+TEST_FILES := ovs-dpctl.py
+
+EXTRA_CLEAN := test_netlink_checks
+
+include ../../lib.mk

tools/testing/selftests/net/openvswitch/openvswitch.sh

+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# OVS kernel module self tests
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+PAUSE_ON_FAIL=no
+VERBOSE=0
+TRACING=0
+
+tests="
+	netlink_checks				ovsnl: validate netlink attrs and settings"
+
+info() {
+    [ $VERBOSE = 0 ] || echo $*
+}
+
+ovs_base=`pwd`
+sbxs=
+sbx_add () {
+	info "adding sandbox '$1'"
+
+	sbxs="$sbxs $1"
+
+	NO_BIN=0
+
+	# Create sandbox.
+	local d="$ovs_base"/$1
+	if [ -e $d ]; then
+		info "removing $d"
+		rm -rf "$d"
+	fi
+	mkdir "$d" || return 1
+	ovs_setenv $1
+}
+
+ovs_exit_sig() {
+	[ -e ${ovs_dir}/cleanup ] && . "$ovs_dir/cleanup"
+}
+
+on_exit() {
+	echo "$1" > ${ovs_dir}/cleanup.tmp
+	cat ${ovs_dir}/cleanup >> ${ovs_dir}/cleanup.tmp
+	mv ${ovs_dir}/cleanup.tmp ${ovs_dir}/cleanup
+}
+
+ovs_setenv() {
+	sandbox=$1
+
+	ovs_dir=$ovs_base${1:+/$1}; export ovs_dir
+
+	test -e ${ovs_dir}/cleanup || : > ${ovs_dir}/cleanup
+}
+
+ovs_sbx() {
+	if test "X$2" != X; then
+		(ovs_setenv $1; shift; "$@" >> ${ovs_dir}/debug.log)
+	else
+		ovs_setenv $1
+	fi
+}
+
+ovs_add_dp () {
+	info "Adding DP/Bridge IF: sbx:$1 dp:$2 {$3, $4, $5}"
+	sbxname="$1"
+	shift
+	ovs_sbx "$sbxname" python3 $ovs_base/ovs-dpctl.py add-dp $*
+	on_exit "ovs_sbx $sbxname python3 $ovs_base/ovs-dpctl.py del-dp $1;"
+}
+
+usage() {
+	echo
+	echo "$0 [OPTIONS] [TEST]..."
+	echo "If no TEST argument is given, all tests will be run."
+	echo
+	echo "Options"
+	echo "  -t: capture traffic via tcpdump"
+	echo "  -v: verbose"
+	echo "  -p: pause on failure"
+	echo
+	echo "Available tests${tests}"
+	exit 1
+}
+
+# netlink_validation
+# - Create a dp
+# - check no warning with "old version" simulation
+test_netlink_checks () {
+	sbx_add "test_netlink_checks" || return 1
+
+	info "setting up new DP"
+	ovs_add_dp "test_netlink_checks" nv0 || return 1
+	# now try again
+	PRE_TEST=$(dmesg | grep -E "RIP: [0-9a-fA-Fx]+:ovs_dp_cmd_new\+")
+	ovs_add_dp "test_netlink_checks" nv0 -V 0 || return 1
+	POST_TEST=$(dmesg | grep -E "RIP: [0-9a-fA-Fx]+:ovs_dp_cmd_new\+")
+	if [ "$PRE_TEST" != "$POST_TEST" ]; then
+		info "failed - gen warning"
+		return 1
+	fi
+
+	return 0
+}
+
+run_test() {
+	(
+	tname="$1"
+	tdesc="$2"
+
+	if ! lsmod | grep openvswitch >/dev/null 2>&1; then
+		stdbuf -o0 printf "TEST: %-60s  [NOMOD]\n" "${tdesc}"
+		return $ksft_skip
+	fi
+
+	if python3 ovs-dpctl.py -h 2>&1 | \
+	     grep "Need to install the python" >/dev/null 2>&1; then
+		stdbuf -o0 printf "TEST: %-60s  [PYLIB]\n" "${tdesc}"
+		return $ksft_skip
+	fi
+	printf "TEST: %-60s  [START]\n" "${tname}"
+
+	unset IFS
+
+	eval test_${tname}
+	ret=$?
+
+	if [ $ret -eq 0 ]; then
+		printf "TEST: %-60s  [ OK ]\n" "${tdesc}"
+		ovs_exit_sig
+		rm -rf "$ovs_dir"
+	elif [ $ret -eq 1 ]; then
+		printf "TEST: %-60s  [FAIL]\n" "${tdesc}"
+		if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
+			echo
+			echo "Pausing. Logs in $ovs_dir/. Hit enter to continue"
+			read a
+		fi
+		ovs_exit_sig
+		[ "${PAUSE_ON_FAIL}" = "yes" ] || rm -rf "$ovs_dir"
+		exit 1
+	elif [ $ret -eq $ksft_skip ]; then
+		printf "TEST: %-60s  [SKIP]\n" "${tdesc}"
+	elif [ $ret -eq 2 ]; then
+		rm -rf test_${tname}
+		run_test "$1" "$2"
+	fi
+
+	return $ret
+	)
+	ret=$?
+	case $ret in
+		0)
+			[ $all_skipped = true ] && [ $exitcode=$ksft_skip ] && exitcode=0
+			all_skipped=false
+		;;
+		$ksft_skip)
+			[ $all_skipped = true ] && exitcode=$ksft_skip
+		;;
+		*)
+			all_skipped=false
+			exitcode=1
+		;;
+	esac
+
+	return $ret
+}
+
+
+exitcode=0
+desc=0
+all_skipped=true
+
+while getopts :pvt o
+do
+	case $o in
+	p) PAUSE_ON_FAIL=yes;;
+	v) VERBOSE=1;;
+	t) if which tcpdump > /dev/null 2>&1; then
+		TRACING=1
+	   else
+		echo "=== tcpdump not available, tracing disabled"
+	   fi
+	   ;;
+	*) usage;;
+	esac
+done
+shift $(($OPTIND-1))
+
+IFS="	
+"
+
+for arg do
+	# Check first that all requested tests are available before running any
+	command -v > /dev/null "test_${arg}" || { echo "=== Test ${arg} not found"; usage; }
+done
+
+name=""
+desc=""
+for t in ${tests}; do
+	[ "${name}" = "" ]	&& name="${t}"	&& continue
+	[ "${desc}" = "" ]	&& desc="${t}"
+
+	run_this=1
+	for arg do
+		[ "${arg}" != "${arg#--*}" ] && continue
+		[ "${arg}" = "${name}" ] && run_this=1 && break
+		run_this=0
+	done
+	if [ $run_this -eq 1 ]; then
+		run_test "${name}" "${desc}"
+	fi
+	name=""
+	desc=""
+done
+
+exit ${exitcode}