[PATCH] x86/apic: Do not use smp_processor_id() in preemptible code

From: Borislav Petkov
Date: Tue Sep 26 2017 - 13:09:06 EST


From: Borislav Petkov <bp@xxxxxxx>

Call stack is:

check_preemption_disabled
? x2apic_prepare_cpu
x2apic_dead_cpu
cpuhp_invoke_callback
? cpuhp_kick_ap_work
? cpumask_next
_cpu_down
freeze_secondary_cpus
hibernation_snapshot
...

i.e., box is doing suspend-to-disk.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/kernel/apic/x2apic_cluster.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c
index 3da94277140f..6050c5364bdc 100644
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -156,7 +156,7 @@ static int x2apic_dead_cpu(unsigned int dead_cpu)
{
struct cluster_mask *cmsk = per_cpu(cluster_masks, dead_cpu);

- cpumask_clear_cpu(smp_processor_id(), &cmsk->mask);
+ cpumask_clear_cpu(dead_cpu, &cmsk->mask);
free_cpumask_var(per_cpu(ipi_mask, dead_cpu));
return 0;
}
--
2.13.0