powerpc/watchdog: Do not trigger SMP crash from touch_nmi_watchdog
authorNicholas Piggin <npiggin@gmail.com>
Fri, 29 Sep 2017 03:29:39 +0000 (13:29 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Wed, 4 Oct 2017 00:26:02 +0000 (11:26 +1100)
commit80e4d70b06863e0104e5a0dc78aa3710297fbd4b
treed707065ffc110e279cf12328d121a1ad780164de
parentd58fdd9d7f220f34830838af4e7b21854469ae8a
powerpc/watchdog: Do not trigger SMP crash from touch_nmi_watchdog

In xmon, touch_nmi_watchdog() is not expected to be checking that
other CPUs have not touched the watchdog, so the code will just call
touch_nmi_watchdog() once before re-enabling hard interrupts.

Just update our CPU's state, and ignore apparently stuck SMP threads.

Arguably touch_nmi_watchdog should check for SMP lockups, and callers
should be fixed, but that's not trivial for the input code of xmon.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/kernel/watchdog.c