On Sun, Nov 09, 2025 at 11:05:56AM +0000, Andre Carvalho wrote:
> Introduce a new netconsole selftest to validate that netconsole is able
> to resume a deactivated target when the low level interface comes back.
>
> The test setups the network using netdevsim, creates a netconsole target
> and then remove/add netdevsim in order to bring the same interfaces
> back. Afterwards, the test validates that the target works as expected.
>
> Targets are created via cmdline parameters to the module to ensure that
> we are able to resume targets that were bound by mac and interface name.
>
> Signed-off-by: Andre Carvalho <[email protected]>
> ---
> tools/testing/selftests/drivers/net/Makefile | 1 +
> .../selftests/drivers/net/lib/sh/lib_netcons.sh | 30 ++++++-
> .../selftests/drivers/net/netcons_resume.sh | 92
> ++++++++++++++++++++++
> 3 files changed, 120 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/drivers/net/Makefile
> b/tools/testing/selftests/drivers/net/Makefile
> index 68e0bb603a9d..fbd81bec66cd 100644
> --- a/tools/testing/selftests/drivers/net/Makefile
> +++ b/tools/testing/selftests/drivers/net/Makefile
> @@ -17,6 +17,7 @@ TEST_PROGS := \
> netcons_cmdline.sh \
> netcons_fragmented_msg.sh \
> netcons_overflow.sh \
> + netcons_resume.sh \
> netcons_sysdata.sh \
> netpoll_basic.py \
> ping.py \
> diff --git a/tools/testing/selftests/drivers/net/lib/sh/lib_netcons.sh
> b/tools/testing/selftests/drivers/net/lib/sh/lib_netcons.sh
> index 8e1085e89647..88b4bdfa84cf 100644
> --- a/tools/testing/selftests/drivers/net/lib/sh/lib_netcons.sh
> +++ b/tools/testing/selftests/drivers/net/lib/sh/lib_netcons.sh
> @@ -186,12 +186,13 @@ function do_cleanup() {
> }
>
> function cleanup() {
> + local TARGETPATH=${1:-${NETCONS_PATH}}
> # delete netconsole dynamic reconfiguration
> - echo 0 > "${NETCONS_PATH}"/enabled
> + echo 0 > "${TARGETPATH}"/enabled
> # Remove all the keys that got created during the selftest
> - find "${NETCONS_PATH}/userdata/" -mindepth 1 -type d -delete
> + find "${TARGETPATH}/userdata/" -mindepth 1 -type d -delete
> # Remove the configfs entry
> - rmdir "${NETCONS_PATH}"
> + rmdir "${TARGETPATH}"
>
> do_cleanup
> }
> @@ -350,6 +351,29 @@ function check_netconsole_module() {
> fi
> }
>
> +function wait_target_state() {
> + local TARGET=${1}
> + local STATE=${2}
> + local FILE="${NETCONS_CONFIGFS}"/"${TARGET}"/"enabled"
local TARGET_PATH="${NETCONS_CONFIGFS}"/"${TARGET}"
> +
> + if [ "${STATE}" == "enabled" ]
> + then
> + ENABLED=1
Shouldn't they be local variables in here ?
> + else
> + ENABLED=0
> + fi
> +
> + if [ ! -f "$FILE" ]; then
if [ ! -f "${TARGET_PATH}" ]; then
> + echo "FAIL: Target does not exist." >&2
> + exit "${ksft_fail}"
> + fi
> +
> + slowwait 2 sh -c "test -n \"\$(grep \"${ENABLED}\" \"${FILE}\")\"" || {
slowwait 2 sh -c "test -n \"\$(grep \"${ENABLED}\"
\"${TARGET_PATH}/enabled\")\"" || {
> + echo "FAIL: ${TARGET} is not ${STATE}." >&2
> + }
> +}
> +
> # A wrapper to translate protocol version to udp version
> function wait_for_port() {
> local NAMESPACE=${1}
> diff --git a/tools/testing/selftests/drivers/net/netcons_resume.sh
> b/tools/testing/selftests/drivers/net/netcons_resume.sh
> new file mode 100755
> index 000000000000..404df7abef1b
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/net/netcons_resume.sh
> @@ -0,0 +1,92 @@
> +#!/usr/bin/env bash
> +# SPDX-License-Identifier: GPL-2.0
> +
> +# This test validates that netconsole is able to resume a target that was
> +# deactivated when its interface was removed when the interface is brought
> +# back up.
Comment above is a bit harder to understand.
> +#
> +# The test configures a netconsole target and then removes netdevsim module
> to
> +# cause the interface to disappear. Targets are configured via cmdline to
> ensure
> +# targets bound by interface name and mac address can be resumed.
> +# The test verifies that the target moved to disabled state before adding
> +# netdevsim and the interface back.
> +#
> +# Finally, the test verifies that the target is re-enabled automatically and
> +# the message is received on the destination interface.
> +#
> +# Author: Andre Carvalho <[email protected]>
> +
> +set -euo pipefail
> +
> +SCRIPTDIR=$(dirname "$(readlink -e "${BASH_SOURCE[0]}")")
> +
> +source "${SCRIPTDIR}"/lib/sh/lib_netcons.sh
> +
> +modprobe netdevsim 2> /dev/null || true
> +rmmod netconsole 2> /dev/null || true
> +
> +check_netconsole_module
> +
> +# Run the test twice, with different cmdline parameters
> +for BINDMODE in "ifname" "mac"
> +do
> + echo "Running with bind mode: ${BINDMODE}" >&2
> + # Set current loglevel to KERN_INFO(6), and default to KERN_NOTICE(5)
> + echo "6 5" > /proc/sys/kernel/printk
> +
> + # Create one namespace and two interfaces
> + set_network
> + trap do_cleanup EXIT
can we keep these trap lines outside of the loop?
> +
> + # Create the command line for netconsole, with the configuration from
> + # the function above
> + CMDLINE=$(create_cmdline_str "${BINDMODE}")
> +
> + # The content of kmsg will be save to the following file
> + OUTPUT_FILE="/tmp/${TARGET}-${BINDMODE}"
> +
> + # Load the module, with the cmdline set
> + modprobe netconsole "${CMDLINE}"
> + # Expose cmdline target in configfs
> + mkdir ${NETCONS_CONFIGFS}"/cmdline0"
> + trap 'cleanup "${NETCONS_CONFIGFS}"/cmdline0' EXIT
> +
> + # Target should be enabled
> + wait_target_state "cmdline0" "enabled"
> +
> + # Remove low level module
> + rmmod netdevsim
> + # Target should be disabled
> + wait_target_state "cmdline0" "disabled"
> +
> + # Add back low level module
> + modprobe netdevsim
> + # Recreate namespace and two interfaces
> + set_network
> + # Target should be enabled again
> + wait_target_state "cmdline0" "enabled"
> +
> + # Listen for netconsole port inside the namespace and destination
> + # interface
> + listen_port_and_save_to "${OUTPUT_FILE}" &
> + # Wait for socat to start and listen to the port.
> + wait_local_port_listen "${NAMESPACE}" "${PORT}" udp
> + # Send the message
> + echo "${MSG}: ${TARGET}" > /dev/kmsg
> + # Wait until socat saves the file to disk
> + busywait "${BUSYWAIT_TIMEOUT}" test -s "${OUTPUT_FILE}"
> + # Make sure the message was received in the dst part
> + # and exit
> + validate_msg "${OUTPUT_FILE}"
> +
> + # kill socat in case it is still running
> + pkill_socat
> + # Cleanup & unload the module
> + cleanup "${NETCONS_CONFIGFS}/cmdline0"
> + rmmod netconsole
Why do we need to remove netconsole module in here?
Thanks for this patch. This is solving a real issue we have right now.
--breno
