| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.7 150/184] irqchip/atmel-aic: Fix potential deadlock in ->xlate() | Date | Thu, 22 Sep 2016 19:41:24 +0200 |
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4.7-stable review patch. If anyone has any objections, please let me know.
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From: Boris Brezillon <boris.brezillon@free-electrons.com>
commit 5eb0d6eb3fac3daa60d9190eed9fa41cf809c756 upstream.
aic5_irq_domain_xlate() and aic_irq_domain_xlate() take the generic chip lock without disabling interrupts, which can lead to a deadlock if an interrupt occurs while the lock is held in one of these functions.
Replace irq_gc_{lock,unlock}() calls by irq_gc_{lock_irqsave,unlock_irqrestore}() ones to prevent this bug from happening.
Fixes: b1479ebb7720 ("irqchip: atmel-aic: Add atmel AIC/AIC5 drivers") Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Link: http://lkml.kernel.org/r/1473775109-4192-2-git-send-email-boris.brezillon@free-electrons.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/irqchip/irq-atmel-aic.c | 5 +++-- drivers/irqchip/irq-atmel-aic5.c | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-)
--- a/drivers/irqchip/irq-atmel-aic.c +++ b/drivers/irqchip/irq-atmel-aic.c @@ -176,6 +176,7 @@ static int aic_irq_domain_xlate(struct i { struct irq_domain_chip_generic *dgc = d->gc; struct irq_chip_generic *gc; + unsigned long flags; unsigned smr; int idx; int ret; @@ -194,11 +195,11 @@ static int aic_irq_domain_xlate(struct i gc = dgc->gc[idx]; - irq_gc_lock(gc); + irq_gc_lock_irqsave(gc, flags); smr = irq_reg_readl(gc, AT91_AIC_SMR(*out_hwirq)); aic_common_set_priority(intspec[2], &smr); irq_reg_writel(gc, smr, AT91_AIC_SMR(*out_hwirq)); - irq_gc_unlock(gc); + irq_gc_unlock_irqrestore(gc, flags); return ret; } --- a/drivers/irqchip/irq-atmel-aic5.c +++ b/drivers/irqchip/irq-atmel-aic5.c @@ -258,6 +258,7 @@ static int aic5_irq_domain_xlate(struct unsigned int *out_type) { struct irq_chip_generic *bgc = irq_get_domain_generic_chip(d, 0); + unsigned long flags; unsigned smr; int ret; @@ -269,12 +270,12 @@ static int aic5_irq_domain_xlate(struct if (ret) return ret; - irq_gc_lock(bgc); + irq_gc_lock_irqsave(bgc, flags); irq_reg_writel(bgc, *out_hwirq, AT91_AIC5_SSR); smr = irq_reg_readl(bgc, AT91_AIC5_SMR); aic_common_set_priority(intspec[2], &smr); irq_reg_writel(bgc, smr, AT91_AIC5_SMR); - irq_gc_unlock(bgc); + irq_gc_unlock_irqrestore(bgc, flags); return ret; }
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