The patch titled
Subject: watchdog: if panicking and we dumped everything, don't re-enable dumping
has been added to the -mm mm-nonmm-unstable branch. Its filename is
watchdog-if-panicking-and-we-dumped-everything-dont-re-enable-dumping.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/watchdog-if-panicking-and-we-dumped-everything-dont-re-enable-dumping.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Douglas Anderson <dianders@xxxxxxxxxxxx>
Subject: watchdog: if panicking and we dumped everything, don't re-enable dumping
Date: Wed, 20 Dec 2023 13:15:37 -0800
If, as part of handling a hardlockup or softlockup, we've already dumped
all CPUs and we're just about to panic, don't reenable dumping and give
some other CPU a chance to hop in there and add some confusing logs right
as the panic is happening.
Link: https://lkml.kernel.org/r/20231220131534.4.Id3a9c7ec2d7d83e4080da6f8662ba2226b40543f@changeid
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Cc: John Ogness <john.ogness@xxxxxxxxxxxxx>
Cc: Lecopzer Chen <lecopzer.chen@xxxxxxxxxxxx>
Cc: Li Zhe <lizhe.67@xxxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Pingfan Liu <kernelfans@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/watchdog.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/kernel/watchdog.c~watchdog-if-panicking-and-we-dumped-everything-dont-re-enable-dumping
+++ a/kernel/watchdog.c
@@ -192,7 +192,8 @@ void watchdog_hardlockup_check(unsigned
if (sysctl_hardlockup_all_cpu_backtrace) {
trigger_allbutcpu_cpu_backtrace(cpu);
- clear_bit_unlock(0, &hard_lockup_nmi_warn);
+ if (!hardlockup_panic)
+ clear_bit_unlock(0, &hard_lockup_nmi_warn);
}
if (hardlockup_panic)
@@ -548,7 +549,8 @@ static enum hrtimer_restart watchdog_tim
if (softlockup_all_cpu_backtrace) {
trigger_allbutcpu_cpu_backtrace(smp_processor_id());
- clear_bit_unlock(0, &soft_lockup_nmi_warn);
+ if (!softlockup_panic)
+ clear_bit_unlock(0, &soft_lockup_nmi_warn);
}
add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK);
_
Patches currently in -mm which might be from dianders@xxxxxxxxxxxx are
watchdog-hardlockup-adopt-softlockup-logic-avoiding-double-dumps.patch
watchdog-softlockup-use-printk_cpu_sync_get_irqsave-to-serialize-reporting.patch
watchdog-hardlockup-use-printk_cpu_sync_get_irqsave-to-serialize-reporting.patch
watchdog-if-panicking-and-we-dumped-everything-dont-re-enable-dumping.patch
