watchdog/hpwdt: Only claim UNKNOWN NMI if from iLO
authorJerry Hoemann <jerry.hoemann@hpe.com>
Wed, 13 Dec 2023 21:53:38 +0000 (14:53 -0700)
committerWim Van Sebroeck <wim@linux-watchdog.org>
Sun, 17 Dec 2023 15:14:21 +0000 (16:14 +0100)
commitdced0b3e51dd2af3730efe14dd86b5e3173f0a65
treefaf2931fb4619302eef02d71727a6fdd0757457b
parentda24118732925d5fd5b9ce8aff58b213a2e051ed
watchdog/hpwdt: Only claim UNKNOWN NMI if from iLO

Avoid unnecessary crashes by claiming only NMIs that are due to
ERROR signalling or generated by the hpwdt hardware device.

The code does this, but only for iLO5.

The intent was to preserve legacy, Gen9 and earlier, semantics of
using hpwdt for error containtment as hardware/firmware would signal
fatal IO errors as an NMI with the expectation of hpwdt crashing
the system.  Howerver, these IO errors should be received by hpwdt
as an NMI_IO_CHECK.  So the test is overly permissive and should
not be limited to only ilo5.

We need to enable this protection for future iLOs not matching the
current PCI IDs.

Fixes: 62290a5c194b ("watchdog: hpwdt: Claim NMIs generated by iLO5")
Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20231213215340.495734-2-jerry.hoemann@hpe.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
drivers/watchdog/hpwdt.c