* [PATCH] x86/x2apic: fix x2apic_cluster_probe null pointer
@ 2016-08-12 5:30 Huaitong Han
2016-08-12 5:50 ` Wanpeng Li
0 siblings, 1 reply; 3+ messages in thread
From: Huaitong Han @ 2016-08-12 5:30 UTC (permalink / raw)
To: tglx, mingo, hpa; +Cc: x86, linux-kernel, Huaitong Han
percpu cpus_in_cluster is a pointer with CONFIG_CPUMASK_OFFSTACK, cpu_in_cluster
is not alloced memory before x2apic_prepare_cpu is invoked, so cpumask_set_cpu
would get a NULL pointer bug:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8105ac25>] x2apic_cluster_probe+0x35/0x70
Signed-off-by: Huaitong Han <huaitong.han@intel.com>
---
arch/x86/kernel/apic/x2apic_cluster.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c
index 6368fa6..6acb055 100644
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -190,9 +190,10 @@ static int x2apic_cluster_probe(void)
if (!x2apic_mode)
return 0;
- cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, cpu));
cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "X2APIC_PREPARE",
x2apic_prepare_cpu, x2apic_dead_cpu);
+ cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, cpu));
+
return 1;
}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/x2apic: fix x2apic_cluster_probe null pointer
2016-08-12 5:30 [PATCH] x86/x2apic: fix x2apic_cluster_probe null pointer Huaitong Han
@ 2016-08-12 5:50 ` Wanpeng Li
2016-08-12 5:59 ` Han, Huaitong
0 siblings, 1 reply; 3+ messages in thread
From: Wanpeng Li @ 2016-08-12 5:50 UTC (permalink / raw)
To: Huaitong Han
Cc: Thomas Gleixner, Ingo Molnar, H. Peter Anvin,
the arch/x86 maintainers, linux-kernel
2016-08-12 13:30 GMT+08:00 Huaitong Han <huaitong.han@intel.com>:
> percpu cpus_in_cluster is a pointer with CONFIG_CPUMASK_OFFSTACK, cpu_in_cluster
> is not alloced memory before x2apic_prepare_cpu is invoked, so cpumask_set_cpu
> would get a NULL pointer bug:
> BUG: unable to handle kernel NULL pointer dereference at (null)
> IP: [<ffffffff8105ac25>] x2apic_cluster_probe+0x35/0x70
Could you try this? https://lkml.org/lkml/2016/8/4/345
Regards,
Wanpeng Li
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/x2apic: fix x2apic_cluster_probe null pointer
2016-08-12 5:50 ` Wanpeng Li
@ 2016-08-12 5:59 ` Han, Huaitong
0 siblings, 0 replies; 3+ messages in thread
From: Han, Huaitong @ 2016-08-12 5:59 UTC (permalink / raw)
To: kernellwp; +Cc: tglx, hpa, linux-kernel, mingo, x86
On Fri, 2016-08-12 at 13:50 +0800, Wanpeng Li wrote:
> 2016-08-12 13:30 GMT+08:00 Huaitong Han <huaitong.han@intel.com>:
> > percpu cpus_in_cluster is a pointer with CONFIG_CPUMASK_OFFSTACK, cpu_in_cluster
> > is not alloced memory before x2apic_prepare_cpu is invoked, so cpumask_set_cpu
> > would get a NULL pointer bug:
> > BUG: unable to handle kernel NULL pointer dereference at (null)
> > IP: [<ffffffff8105ac25>] x2apic_cluster_probe+0x35/0x70
>
> Could you try this? https://lkml.org/lkml/2016/8/4/345
Get, it has been fixed,
http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=d52c0569bab4edc888832df44dc7ac28517134f6
>
> Regards,
> Wanpeng Li
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2016-08-12 6:00 UTC | newest]
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2016-08-12 5:30 [PATCH] x86/x2apic: fix x2apic_cluster_probe null pointer Huaitong Han
2016-08-12 5:50 ` Wanpeng Li
2016-08-12 5:59 ` Han, Huaitong
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