lkml.org 
[lkml]   [2023]   [Jul]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] mfd: qcom-pm8xxx: Fix potential deadlock on &chip->pm_irq_lock
On Thu, Jul 20, 2023 at 07:13:30AM +0000, Chengfeng Ye wrote:
> As &chip->pm_irq_lock is acquired by pm8xxx_irq_handler() under irq
> context, other process context code should disable irq before acquiring
> the lock.
>
> Since .irq_set_type and .irq_get_irqchip_state callbacks are generally
> executed from process context without irq disabled by default, the same
> lock acquision should disable irq.
>
> Possible deadlock scenario
> pm8xxx_irq_set_type()
> -> pm8xxx_config_irq()
> -> spin_lock(&chip->pm_irq_lock)
> <irq interrupt>
> -> pm8xxx_irq_handler()
> -> pm8xxx_irq_master_handler()
> -> pm8xxx_irq_block_handler()
> -> pm8xxx_read_block_irq()
> -> spin_lock(&chip->pm_irq_lock) (deadlock here)
>
> This flaw was found using an experimental static analysis tool we are
> developing for irq-related deadlock.
>
> Fix the potential deadlock by spin_lock_irqsave().
>
> Signed-off-by: Chengfeng Ye <dg573847474@gmail.com>

Reviewed-by: Bjorn Andersson <quic_bjorande@quicinc.com>

Regards,
Bjorn

\
 
 \ /
  Last update: 2023-07-20 20:49    [W:0.048 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site