[PATCH net] selftests: netconsole: only restore MAC when it changed on resume

[PATCH net] selftests: netconsole: only restore MAC when it changed on resume

[Andre Carvalho]

The "mac" bind mode reactivation downs the interface, restores the saved
MAC and renames it to trigger a target resume. This assumes the recreated
interface comes back with a different MAC, which is true under
MACAddressPolicy=none (as on the Netdev CI) but not when MACs are
persistent. In the persistent case netconsole resumes the target on its
own, and the down/restore/rename flow instead drops it and fails the test.

Guard the block on the MAC having actually changed so the test passes
under both policies.

Fixes: 6ecc08329bab ("selftests: netconsole: validate target resume")
Reported-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Closes: https://lore.kernel.org/netdev/f398373e-2cb4-4649-a491-9763df94d98b@kernel.org/
Signed-off-by: Andre Carvalho <asantostc@gmail.com>
---
 tools/testing/selftests/drivers/net/netconsole/netcons_resume.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/drivers/net/netconsole/netcons_resume.sh b/tools/testing/selftests/drivers/net/netconsole/netcons_resume.sh
index cb59cf436dd0..d9111f2102bc 100755
--- a/tools/testing/selftests/drivers/net/netconsole/netcons_resume.sh
+++ b/tools/testing/selftests/drivers/net/netconsole/netcons_resume.sh
@@ -44,7 +44,8 @@ function trigger_reactivation() {
 	# Restore MACs
 	ip netns exec "${NAMESPACE}" ip link set "${DSTIF}" \
 		address "${SAVED_DSTMAC}"
-	if [ "${BINDMODE}" == "mac" ]; then
+	if [ "${BINDMODE}" == "mac" ] &&
+		[ "$(mac_get "${SRCIF}")" != "${SAVED_SRCMAC}" ]; then
 		ip link set dev "${SRCIF}" down
 		ip link set dev "${SRCIF}" address "${SAVED_SRCMAC}"
 		# Rename device in order to trigger target resume, as initial

---
base-commit: 1cd23ca80784223fa2204e16203f754da4e821f8
change-id: 20260710-netcons-mac-reload-f6f5e86f9e1f

Best regards,
--  
Andre Carvalho <asantostc@gmail.com>

Re: [PATCH net] selftests: netconsole: only restore MAC when it changed on resume

[Matthieu Baerts]

Hi Andre,

On 11/07/2026 00:19, Andre Carvalho wrote:
> The "mac" bind mode reactivation downs the interface, restores the saved
> MAC and renames it to trigger a target resume. This assumes the recreated
> interface comes back with a different MAC, which is true under
> MACAddressPolicy=none (as on the Netdev CI) but not when MACs are
> persistent. In the persistent case netconsole resumes the target on its
> own, and the down/restore/rename flow instead drops it and fails the test.
> 
> Guard the block on the MAC having actually changed so the test passes
> under both policies.
Thank you for the patch, it fixed the issue on my side when not forcing
MACAddressPolicy=none.

Tested-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

Cheers,
Matt

Re: [PATCH net] selftests: netconsole: only restore MAC when it changed on resume

[Breno Leitao]

Hello Andre,

Thanks for the fix.

On Fri, Jul 10, 2026 at 11:19:17PM +0100, Andre Carvalho wrote:
> The "mac" bind mode reactivation downs the interface, restores the saved
> MAC and renames it to trigger a target resume. This assumes the recreated
> interface comes back with a different MAC, which is true under
> MACAddressPolicy=none (as on the Netdev CI) but not when MACs are
> persistent. In the persistent case netconsole resumes the target on its
> own, and the down/restore/rename flow instead drops it and fails the test.
> 
> Guard the block on the MAC having actually changed so the test passes
> under both policies.
> 
> Fixes: 6ecc08329bab ("selftests: netconsole: validate target resume")
> Reported-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
> Closes: https://lore.kernel.org/netdev/f398373e-2cb4-4649-a491-9763df94d98b@kernel.org/
> Signed-off-by: Andre Carvalho <asantostc@gmail.com>

Reviewed-by: Breno Leitao <leitao@debian.org>

FWIW: netdev CI got yellow for this patch, but, this is not realted to this
test.

https://patchwork.kernel.org/project/netdevbpf/patch/20260710-netcons-mac-reload-v1-1-3fb1bcc70b4a@gmail.com/