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authorTomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>2012-05-28 18:09:18 +0900
committerIngo Molnar <mingo@kernel.org>2012-06-06 12:03:25 +0200
commitf6175f5bfb4c9f2ed32758c95f765b529b1a7f15 (patch)
tree7c33b47cea87463f4d51f80064b699bafeb2a178 /arch/x86
parent55c844a4dd16a4d1fdc0cf2a283ec631a02ec448 (diff)
x86/ioapic: Fix NULL pointer dereference on CPU hotplug after disabling irqs
In current Linux, percpu variable `vector_irq' is not cleared on offlined cpus while disabling devices' irqs. If the cpu that has the disabled irqs in vector_irq is hotplugged, __setup_vector_irq() hits invalid irq vector and may crash. This bug can be reproduced as following; # echo 0 > /sys/devices/system/cpu/cpu7/online # modprobe -r some_driver_using_interrupts # vector_irq@cpu7 uncleared # echo 1 > /sys/devices/system/cpu/cpu7/online # kernel may crash This patch fixes this bug by clearing vector_irq in __clear_irq_vector() even if the cpu is offlined. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: yrl.pp-manager.tt@hitachi.com Cc: ltc-kernel@ml.yrl.intra.hitachi.co.jp Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Alexander Gordeev <agordeev@redhat.com> Link: http://lkml.kernel.org/r/4FC340BE.7080101@hitachi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/apic/io_apic.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index ac96561d1a9..5f0ff597437 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1195,7 +1195,7 @@ static void __clear_irq_vector(int irq, struct irq_cfg *cfg)
BUG_ON(!cfg->vector);
vector = cfg->vector;
- for_each_cpu_and(cpu, cfg->domain, cpu_online_mask)
+ for_each_cpu(cpu, cfg->domain)
per_cpu(vector_irq, cpu)[vector] = -1;
cfg->vector = 0;
@@ -1203,7 +1203,7 @@ static void __clear_irq_vector(int irq, struct irq_cfg *cfg)
if (likely(!cfg->move_in_progress))
return;
- for_each_cpu_and(cpu, cfg->old_domain, cpu_online_mask) {
+ for_each_cpu(cpu, cfg->old_domain) {
for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
vector++) {
if (per_cpu(vector_irq, cpu)[vector] != irq)