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x86/apic/x2apic, smp/hotplug: Don't use before alloc in x2apic_cluster_probe() 

I made a mistake while converting the driver to the hotplug state
machine and as a result x2apic_cluster_probe() was accessing
cpus_in_cluster before allocating it.

This patch fixes it by setting the cpumask after the allocation the
memory succeeded.

While at it, I marked two functions static which are only used within
this file.

Reported-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 6b2c28471d ("x86/x2apic: Convert to CPU hotplug state machine")
Link: http://lkml.kernel.org/r/1470924515-9444-1-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Sebastian Andrzej Siewior 2016-08-11 16:08:35 +02:00 committed by Ingo Molnar
parent 5bc653b731
commit d52c0569ba
1 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
arch/x86/kernel/apic/x2apic_cluster.c
View File

@ -155,7 +155,7 @@ static void init_x2apic_ldr(void)
/*
* At CPU state changes, update the x2apic cluster sibling info.
*/
int x2apic_prepare_cpu(unsigned int cpu)
static int x2apic_prepare_cpu(unsigned int cpu)
{
if (!zalloc_cpumask_var(&per_cpu(cpus_in_cluster, cpu), GFP_KERNEL))
return -ENOMEM;
@ -168,7 +168,7 @@ int x2apic_prepare_cpu(unsigned int cpu)
return 0;
}
int x2apic_dead_cpu(unsigned int this_cpu)
static int x2apic_dead_cpu(unsigned int this_cpu)
{
int cpu;
@ -186,13 +186,18 @@ int x2apic_dead_cpu(unsigned int this_cpu)
static int x2apic_cluster_probe(void)
{
int cpu = smp_processor_id();
int ret;
if (!x2apic_mode)
return 0;
ret = cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "X2APIC_PREPARE",
x2apic_prepare_cpu, x2apic_dead_cpu);
if (ret < 0) {
pr_err("Failed to register X2APIC_PREPARE\n");
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;
}