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| author | Paul Burton <paul.burton@imgtec.com> | 2016-04-21 10:31:54 (GMT) |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-04-21 19:04:29 (GMT) |
| commit | 91951f980e521d8f7e92283735b99fb9f4b05d93 (patch) | |
| tree | dd870503ba69eec8a7eef85189e4f235d52222d4 /drivers/irqchip | |
| parent | 4589f450fb285ab85f7513b6649e51ec2a820653 (diff) | |
| download | linux-91951f980e521d8f7e92283735b99fb9f4b05d93.tar.xz | |
irqchip/mips-gic: Don't overrun pcpu_masks array
Commit 2a0787051182 ("irqchip/mips-gic: Use gic_vpes instead of
NR_CPUS") & commit 78930f09b940 ("irqchip/mips-gic: Clear percpu_masks
correctly when mapping") both introduce code which accesses gic_vpes
entries in the pcpu_masks array. However, this array has length NR_CPUS.
If NR_CPUS is less than gic_vpes (ie. the kernel supports use of less
CPUs than are present in the system) then we overrun the array, clobber
some other data & generally die pretty promptly.
Most notably this affects uniprocessor kernels running on any multicore
or multithreaded Malta with a GIC (ie. the vast majority of real Malta
boards).
Fix this by only accessing up to min(gic_vpes, NR_CPUS) entries in the
pcpu_masks array, preventing the array overrun.
Fixes: 2a0787051182 ("irqchip/mips-gic: Use gic_vpes instead of NR_CPUS")
Fixes: 78930f09b940 ("irqchip/mips-gic: Clear percpu_masks correctly when mapping")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Link: http://lkml.kernel.org/r/1461234714-9975-1-git-send-email-paul.burton@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers/irqchip')
| -rw-r--r-- | drivers/irqchip/irq-mips-gic.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c index 94a30da..4dffccf 100644 --- a/drivers/irqchip/irq-mips-gic.c +++ b/drivers/irqchip/irq-mips-gic.c @@ -467,7 +467,7 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask, gic_map_to_vpe(irq, mips_cm_vp_id(cpumask_first(&tmp))); /* Update the pcpu_masks */ - for (i = 0; i < gic_vpes; i++) + for (i = 0; i < min(gic_vpes, NR_CPUS); i++) clear_bit(irq, pcpu_masks[i].pcpu_mask); set_bit(irq, pcpu_masks[cpumask_first(&tmp)].pcpu_mask); @@ -707,7 +707,7 @@ static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq, spin_lock_irqsave(&gic_lock, flags); gic_map_to_pin(intr, gic_cpu_pin); gic_map_to_vpe(intr, vpe); - for (i = 0; i < gic_vpes; i++) + for (i = 0; i < min(gic_vpes, NR_CPUS); i++) clear_bit(intr, pcpu_masks[i].pcpu_mask); set_bit(intr, pcpu_masks[vpe].pcpu_mask); spin_unlock_irqrestore(&gic_lock, flags); |