diff options
| author | Yufen Wang <wangyufen@huawei.com> | 2018-11-02 11:51:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-12 19:46:58 +0100 |
| commit | 4660207706ca8b7f30dee8550ec48e02b048a558 (patch) | |
| tree | 3be9109d7a43cbc81098cf6cc5d1302b12aab513 /arch | |
| parent | 433f2f810291c39dfd29364dae236fac8b1e72b5 (diff) | |
ARM: 8808/1: kexec:offline panic_smp_self_stop CPU
[ Upstream commit 82c08c3e7f171aa7f579b231d0abbc1d62e91974 ]
In case panic() and panic() called at the same time on different CPUS.
For example:
CPU 0:
panic()
__crash_kexec
machine_crash_shutdown
crash_smp_send_stop
machine_kexec
BUG_ON(num_online_cpus() > 1);
CPU 1:
panic()
local_irq_disable
panic_smp_self_stop
If CPU 1 calls panic_smp_self_stop() before crash_smp_send_stop(), kdump
fails. CPU1 can't receive the ipi irq, CPU1 will be always online.
To fix this problem, this patch split out the panic_smp_self_stop()
and add set_cpu_online(smp_processor_id(), false).
Signed-off-by: Yufen Wang <wangyufen@huawei.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/kernel/smp.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 0978282d5fc2..f574a5e0d589 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -693,6 +693,21 @@ void smp_send_stop(void) pr_warn("SMP: failed to stop secondary CPUs\n"); } +/* In case panic() and panic() called at the same time on CPU1 and CPU2, + * and CPU 1 calls panic_smp_self_stop() before crash_smp_send_stop() + * CPU1 can't receive the ipi irqs from CPU2, CPU1 will be always online, + * kdump fails. So split out the panic_smp_self_stop() and add + * set_cpu_online(smp_processor_id(), false). + */ +void panic_smp_self_stop(void) +{ + pr_debug("CPU %u will stop doing anything useful since another CPU has paniced\n", + smp_processor_id()); + set_cpu_online(smp_processor_id(), false); + while (1) + cpu_relax(); +} + /* * not supported here */ |