Commit 6b2c28471, moved the allocation of cpus_in_cluster to the x2apic_prepare_cpu() callback. However, it forgot to move the cpumask_set_cpu() call that uses it.
This generates a NULL pointer dereference during boot in machines with x2apic_mode=true. Signed-off-by: Luiz Capitulino <[email protected]> --- arch/x86/kernel/apic/x2apic_cluster.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c index 6368fa6..18b1704 100644 --- a/arch/x86/kernel/apic/x2apic_cluster.c +++ b/arch/x86/kernel/apic/x2apic_cluster.c @@ -165,6 +165,8 @@ int x2apic_prepare_cpu(unsigned int cpu) return -ENOMEM; } + cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, cpu)); + return 0; } @@ -185,12 +187,9 @@ int x2apic_dead_cpu(unsigned int this_cpu) static int x2apic_cluster_probe(void) { - int cpu = smp_processor_id(); - 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); return 1; -- 2.5.5
