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authorMarc Zyngier <maz@kernel.org>2022-02-24 13:12:25 +0300
committerMarc Zyngier <maz@kernel.org>2022-03-01 13:06:25 +0300
commita6aca2f460e203781dc41391913cc5b54f4bc0ce (patch)
treeb7e3d153e1e7feafbbf01506f0439cb1e8556354 /drivers/irqchip/qcom-pdc.c
parentd494d088ac44b9cf561362a7856fa20b656be64f (diff)
downloadlinux-a6aca2f460e203781dc41391913cc5b54f4bc0ce.tar.xz
irqchip/qcom-pdc: Fix broken locking
pdc_enable_intr() serves as a primitive to qcom_pdc_gic_{en,dis}able, and has a raw spinlock for mutual exclusion, which is uses with interruptible primitives. This means that this critical section can itself be interrupted. Should the interrupt also be a PDC interrupt, and the endpoint driver perform an irq_disable() on that interrupt, we end-up in a deadlock. Fix this by using the irqsave/irqrestore variants of the locking primitives. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Maulik Shah <quic_mkshah@quicinc.com> Link: https://lore.kernel.org/r/20220224101226.88373-5-maz@kernel.org
Diffstat (limited to 'drivers/irqchip/qcom-pdc.c')
-rw-r--r--drivers/irqchip/qcom-pdc.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c
index 837ca6998f6a..0cd20ddfae2a 100644
--- a/drivers/irqchip/qcom-pdc.c
+++ b/drivers/irqchip/qcom-pdc.c
@@ -55,17 +55,18 @@ static u32 pdc_reg_read(int reg, u32 i)
static void pdc_enable_intr(struct irq_data *d, bool on)
{
int pin_out = d->hwirq;
+ unsigned long flags;
u32 index, mask;
u32 enable;
index = pin_out / 32;
mask = pin_out % 32;
- raw_spin_lock(&pdc_lock);
+ raw_spin_lock_irqsave(&pdc_lock, flags);
enable = pdc_reg_read(IRQ_ENABLE_BANK, index);
enable = on ? ENABLE_INTR(enable, mask) : CLEAR_INTR(enable, mask);
pdc_reg_write(IRQ_ENABLE_BANK, index, enable);
- raw_spin_unlock(&pdc_lock);
+ raw_spin_unlock_irqrestore(&pdc_lock, flags);
}
static void qcom_pdc_gic_disable(struct irq_data *d)