* Re: [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate()
2016-09-13 10:10 [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate() Boris Brezillon
@ 2016-09-13 10:12 ` Boris Brezillon
2016-09-13 10:28 ` Marc Zyngier
` (2 subsequent siblings)
3 siblings, 0 replies; 8+ messages in thread
From: Boris Brezillon @ 2016-09-13 10:12 UTC (permalink / raw)
To: Thomas Gleixner, Jason Cooper, Marc Zyngier
Cc: Nicolas Ferre, Jean-Christophe Plagniol-Villard,
Alexandre Belloni, linux-kernel, stable
On Tue, 13 Sep 2016 12:10:09 +0200
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:
> 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
> raw_spin_{lock_irqsave,unlock_irqrestore}() ones to prevent this bug from
> happening.
>
Forgot to mention that this problem was discovered by kernelci [1].
[1]https://storage.kernelci.org/arm-soc/v4.4-2499-gbb46b50a5130/arm-multi_v7_defconfig+CONFIG_PROVE_LOCKING=y/lab-free-electrons/boot-at91-sama5d3_xplained.html
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Fixes: b1479ebb7720 ("irqchip: atmel-aic: Add atmel AIC/AIC5 drivers")
> Cc: <stable@kernel.vger.org>
> ---
> drivers/irqchip/irq-atmel-aic.c | 5 +++--
> drivers/irqchip/irq-atmel-aic5.c | 5 +++--
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/irqchip/irq-atmel-aic.c b/drivers/irqchip/irq-atmel-aic.c
> index 112e17c2768b..447a8b0f1395 100644
> --- 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 irq_domain *d,
> {
> 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 irq_domain *d,
>
> gc = dgc->gc[idx];
>
> - irq_gc_lock(gc);
> + raw_spin_lock_irqsave(&gc->lock, 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);
> + raw_spin_unlock_irqrestore(&gc->lock, flags);
>
> return ret;
> }
> diff --git a/drivers/irqchip/irq-atmel-aic5.c b/drivers/irqchip/irq-atmel-aic5.c
> index 4f0d068e1abe..8c024107fd03 100644
> --- 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 irq_domain *d,
> 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 irq_domain *d,
> if (ret)
> return ret;
>
> - irq_gc_lock(bgc);
> + raw_spin_lock_irqsave(&bgc->lock, 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);
> + raw_spin_unlock_irqrestore(&bgc->lock, flags);
>
> return ret;
> }
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate()
2016-09-13 10:10 [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate() Boris Brezillon
2016-09-13 10:12 ` Boris Brezillon
@ 2016-09-13 10:28 ` Marc Zyngier
2016-09-13 11:23 ` Boris Brezillon
2016-09-13 12:55 ` Thomas Gleixner
3 siblings, 0 replies; 8+ messages in thread
From: Marc Zyngier @ 2016-09-13 10:28 UTC (permalink / raw)
To: Boris Brezillon, Thomas Gleixner, Jason Cooper
Cc: Nicolas Ferre, Jean-Christophe Plagniol-Villard,
Alexandre Belloni, linux-kernel, stable
On 13/09/16 11:10, Boris Brezillon wrote:
> 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
> raw_spin_{lock_irqsave,unlock_irqrestore}() ones to prevent this bug from
> happening.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Fixes: b1479ebb7720 ("irqchip: atmel-aic: Add atmel AIC/AIC5 drivers")
> Cc: <stable@kernel.vger.org>
> ---
> drivers/irqchip/irq-atmel-aic.c | 5 +++--
> drivers/irqchip/irq-atmel-aic5.c | 5 +++--
> 2 files changed, 6 insertions(+), 4 deletions(-)
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Thomas, any chance you could queue this one as a fix for 4.8-rc7?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate()
2016-09-13 10:10 [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate() Boris Brezillon
2016-09-13 10:12 ` Boris Brezillon
2016-09-13 10:28 ` Marc Zyngier
@ 2016-09-13 11:23 ` Boris Brezillon
2016-09-13 12:21 ` Marc Zyngier
2016-09-13 12:55 ` Thomas Gleixner
3 siblings, 1 reply; 8+ messages in thread
From: Boris Brezillon @ 2016-09-13 11:23 UTC (permalink / raw)
To: Thomas Gleixner, Jason Cooper, Marc Zyngier
Cc: Nicolas Ferre, Jean-Christophe Plagniol-Villard,
Alexandre Belloni, linux-kernel, stable
On Tue, 13 Sep 2016 12:10:09 +0200
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:
> 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
> raw_spin_{lock_irqsave,unlock_irqrestore}() ones to prevent this bug from
> happening.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Fixes: b1479ebb7720 ("irqchip: atmel-aic: Add atmel AIC/AIC5 drivers")
> Cc: <stable@kernel.vger.org>
Oops, should be
Cc: <stable@vger.kernel.org>
Do you want me to send a v2?
> ---
> drivers/irqchip/irq-atmel-aic.c | 5 +++--
> drivers/irqchip/irq-atmel-aic5.c | 5 +++--
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/irqchip/irq-atmel-aic.c b/drivers/irqchip/irq-atmel-aic.c
> index 112e17c2768b..447a8b0f1395 100644
> --- 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 irq_domain *d,
> {
> 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 irq_domain *d,
>
> gc = dgc->gc[idx];
>
> - irq_gc_lock(gc);
> + raw_spin_lock_irqsave(&gc->lock, 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);
> + raw_spin_unlock_irqrestore(&gc->lock, flags);
>
> return ret;
> }
> diff --git a/drivers/irqchip/irq-atmel-aic5.c b/drivers/irqchip/irq-atmel-aic5.c
> index 4f0d068e1abe..8c024107fd03 100644
> --- 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 irq_domain *d,
> 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 irq_domain *d,
> if (ret)
> return ret;
>
> - irq_gc_lock(bgc);
> + raw_spin_lock_irqsave(&bgc->lock, 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);
> + raw_spin_unlock_irqrestore(&bgc->lock, flags);
>
> return ret;
> }
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate()
2016-09-13 11:23 ` Boris Brezillon
@ 2016-09-13 12:21 ` Marc Zyngier
0 siblings, 0 replies; 8+ messages in thread
From: Marc Zyngier @ 2016-09-13 12:21 UTC (permalink / raw)
To: Boris Brezillon, Thomas Gleixner, Jason Cooper
Cc: Nicolas Ferre, Jean-Christophe Plagniol-Villard,
Alexandre Belloni, linux-kernel, stable
On 13/09/16 12:23, Boris Brezillon wrote:
> On Tue, 13 Sep 2016 12:10:09 +0200
> Boris Brezillon <boris.brezillon@free-electrons.com> wrote:
>
>> 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
>> raw_spin_{lock_irqsave,unlock_irqrestore}() ones to prevent this bug from
>> happening.
>>
>> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
>> Fixes: b1479ebb7720 ("irqchip: atmel-aic: Add atmel AIC/AIC5 drivers")
>> Cc: <stable@kernel.vger.org>
>
> Oops, should be
>
> Cc: <stable@vger.kernel.org>
>
> Do you want me to send a v2?
You might as well, so that tglx can pick the patch with my ack on it.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate()
2016-09-13 10:10 [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate() Boris Brezillon
` (2 preceding siblings ...)
2016-09-13 11:23 ` Boris Brezillon
@ 2016-09-13 12:55 ` Thomas Gleixner
2016-09-13 13:00 ` Boris Brezillon
3 siblings, 1 reply; 8+ messages in thread
From: Thomas Gleixner @ 2016-09-13 12:55 UTC (permalink / raw)
To: Boris Brezillon
Cc: Jason Cooper, Marc Zyngier, Nicolas Ferre,
Jean-Christophe Plagniol-Villard, Alexandre Belloni, linux-kernel,
stable
On Tue, 13 Sep 2016, Boris Brezillon wrote:
> 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
> raw_spin_{lock_irqsave,unlock_irqrestore}() ones to prevent this bug from
> happening.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Fixes: b1479ebb7720 ("irqchip: atmel-aic: Add atmel AIC/AIC5 drivers")
> Cc: <stable@kernel.vger.org>
> ---
> drivers/irqchip/irq-atmel-aic.c | 5 +++--
> drivers/irqchip/irq-atmel-aic5.c | 5 +++--
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/irqchip/irq-atmel-aic.c b/drivers/irqchip/irq-atmel-aic.c
> index 112e17c2768b..447a8b0f1395 100644
> --- 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 irq_domain *d,
> {
> 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 irq_domain *d,
>
> gc = dgc->gc[idx];
>
> - irq_gc_lock(gc);
> + raw_spin_lock_irqsave(&gc->lock, flags);
Please provide a primitive, i.e. irq_gc_lock_irqsave(), for it.
Thanks,
tglx
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate()
2016-09-13 12:55 ` Thomas Gleixner
@ 2016-09-13 13:00 ` Boris Brezillon
2016-09-13 13:13 ` Thomas Gleixner
0 siblings, 1 reply; 8+ messages in thread
From: Boris Brezillon @ 2016-09-13 13:00 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Jason Cooper, Marc Zyngier, Nicolas Ferre,
Jean-Christophe Plagniol-Villard, Alexandre Belloni, linux-kernel,
stable
On Tue, 13 Sep 2016 14:55:20 +0200 (CEST)
Thomas Gleixner <tglx@linutronix.de> wrote:
> On Tue, 13 Sep 2016, Boris Brezillon wrote:
>
> > 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
> > raw_spin_{lock_irqsave,unlock_irqrestore}() ones to prevent this bug from
> > happening.
> >
> > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > Fixes: b1479ebb7720 ("irqchip: atmel-aic: Add atmel AIC/AIC5 drivers")
> > Cc: <stable@kernel.vger.org>
> > ---
> > drivers/irqchip/irq-atmel-aic.c | 5 +++--
> > drivers/irqchip/irq-atmel-aic5.c | 5 +++--
> > 2 files changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/irqchip/irq-atmel-aic.c b/drivers/irqchip/irq-atmel-aic.c
> > index 112e17c2768b..447a8b0f1395 100644
> > --- 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 irq_domain *d,
> > {
> > 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 irq_domain *d,
> >
> > gc = dgc->gc[idx];
> >
> > - irq_gc_lock(gc);
> > + raw_spin_lock_irqsave(&gc->lock, flags);
>
> Please provide a primitive, i.e. irq_gc_lock_irqsave(), for it.
Sure, but that means flagging this patch for stable as well. Are you
okay with that?
>
> Thanks,
>
> tglx
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate()
2016-09-13 13:00 ` Boris Brezillon
@ 2016-09-13 13:13 ` Thomas Gleixner
0 siblings, 0 replies; 8+ messages in thread
From: Thomas Gleixner @ 2016-09-13 13:13 UTC (permalink / raw)
To: Boris Brezillon
Cc: Jason Cooper, Marc Zyngier, Nicolas Ferre,
Jean-Christophe Plagniol-Villard, Alexandre Belloni, linux-kernel,
stable
On Tue, 13 Sep 2016, Boris Brezillon wrote:
> > Please provide a primitive, i.e. irq_gc_lock_irqsave(), for it.
>
> Sure, but that means flagging this patch for stable as well. Are you
> okay with that?
Yes, it's still not huge ...
^ permalink raw reply [flat|nested] 8+ messages in thread