[PATCH net-next v3 0/6] netconsole: support automatic target recovery

[Andre Carvalho <asantostc@gmail.com>]

This patchset introduces target resume capability to netconsole allowing
it to recover targets when underlying low-level interface comes back
online.

The patchset starts by refactoring netconsole state representation in
order to allow representing deactivated targets (targets that are
disabled due to interfaces going down).

It then modifies netconsole to handle NETDEV_UP events for such targets
and setups netpoll. Targets are matched with incoming interfaces
depending on how they were initially bound in netconsole (by mac or
interface name).

The patchset includes a selftest that validates netconsole target state
transitions and that target is functional after resumed.

Signed-off-by: Andre Carvalho <asantostc@gmail.com>
---
Changes in v3:
- Resume by mac or interface name depending on how target was created.
- Attempt to resume target without holding target list lock, by moving
  the target to a temporary list. This is required as netpoll may
  attempt to allocate memory.
- Link to v2: https://lore.kernel.org/r/20250921-netcons-retrigger-v2-0-a0e84006237f@gmail.com

Changes in v2:
- Attempt to resume target in the same thread, instead of using
workqueue .
- Add wrapper around __netpoll_setup (patch 4).
- Renamed resume_target to maybe_resume_target and moved conditionals to
inside its implementation, keeping code more clear.
- Verify that device addr matches target mac address when target was
setup using mac.
- Update selftest to cover targets bound by mac and interface name.
- Fix typo in selftest comment and sort tests alphabetically in
  Makefile.
- Link to v1:
https://lore.kernel.org/r/20250909-netcons-retrigger-v1-0-3aea904926cf@gmail.com

---
Andre Carvalho (4):
      netconsole: convert 'enabled' flag to enum for clearer state management
      netpoll: add wrapper around __netpoll_setup with dev reference
      netconsole: resume previously deactivated target
      selftests: netconsole: validate target resume

Breno Leitao (2):
      netconsole: add target_state enum
      netconsole: add STATE_DEACTIVATED to track targets disabled by low level

 drivers/net/netconsole.c                           | 126 ++++++++++++++++-----
 include/linux/netpoll.h                            |   1 +
 net/core/netpoll.c                                 |  20 ++++
 tools/testing/selftests/drivers/net/Makefile       |   1 +
 .../selftests/drivers/net/lib/sh/lib_netcons.sh    |  30 ++++-
 .../selftests/drivers/net/netcons_resume.sh        |  92 +++++++++++++++
 6 files changed, 238 insertions(+), 32 deletions(-)
---
base-commit: a0c3aefb08cd81864b17c23c25b388dba90b9dad
change-id: 20250816-netcons-retrigger-a4f547bfc867

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