lkml.org 
[lkml]   [2016]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.4 087/118] irqchip/atmel-aic: Fix potential deadlock in ->xlate()
Date
4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

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;
@@ -194,12 +195,12 @@ 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));
ret = aic_common_set_priority(intspec[2], &smr);
if (!ret)
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;

@@ -269,13 +270,13 @@ 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);
ret = aic_common_set_priority(intspec[2], &smr);
if (!ret)
irq_reg_writel(bgc, intspec[2] | smr, AT91_AIC5_SMR);
- irq_gc_unlock(bgc);
+ irq_gc_unlock_irqrestore(bgc, flags);

return ret;
}

\
 
 \ /
  Last update: 2016-09-23 00:04    [W:0.333 / U:0.460 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site