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Subject: Re: [PATCH v9 1/7] powerpc/mce: Schedule work from irq_work
To:     Santosh Sivaraj <santosh@fossix.org>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>
Cc:     "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
        Mahesh Salgaonkar <mahesh@linux.ibm.com>,
        Reza Arbab <arbab@linux.ibm.com>,
        Balbir Singh <bsingharora@gmail.com>,
        Chandan Rajendra <chandan@linux.vnet.ibm.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Nicholas Piggin <npiggin@gmail.com>,
        christophe leroy <christophe.leroy@c-s.fr>,
        stable@vger.kernel.org
References: <20190812092236.16648-1-santosh@fossix.org>
 <20190812092236.16648-2-santosh@fossix.org>
From:   Mahesh Jagannath Salgaonkar <mahesh@linux.vnet.ibm.com>
Date:   Tue, 13 Aug 2019 10:16:21 +0530
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On 8/12/19 2:52 PM, Santosh Sivaraj wrote:
> schedule_work() cannot be called from MCE exception context as MCE can
> interrupt even in interrupt disabled context.
> 
> fixes: 733e4a4c ("powerpc/mce: hookup memory_failure for UE errors")
> Suggested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
> Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
> Cc: stable@vger.kernel.org # v4.15+
> ---
>  arch/powerpc/kernel/mce.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)

Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>

Thanks,
-Mahesh.

> 
> diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
> index b18df633eae9..cff31d4a501f 100644
> --- a/arch/powerpc/kernel/mce.c
> +++ b/arch/powerpc/kernel/mce.c
> @@ -33,6 +33,7 @@ static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
>  					mce_ue_event_queue);
>  
>  static void machine_check_process_queued_event(struct irq_work *work);
> +static void machine_check_ue_irq_work(struct irq_work *work);
>  void machine_check_ue_event(struct machine_check_event *evt);
>  static void machine_process_ue_event(struct work_struct *work);
>  
> @@ -40,6 +41,10 @@ static struct irq_work mce_event_process_work = {
>          .func = machine_check_process_queued_event,
>  };
>  
> +static struct irq_work mce_ue_event_irq_work = {
> +	.func = machine_check_ue_irq_work,
> +};
> +
>  DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
>  
>  static void mce_set_error_info(struct machine_check_event *mce,
> @@ -199,6 +204,10 @@ void release_mce_event(void)
>  	get_mce_event(NULL, true);
>  }
>  
> +static void machine_check_ue_irq_work(struct irq_work *work)
> +{
> +	schedule_work(&mce_ue_event_work);
> +}
>  
>  /*
>   * Queue up the MCE event which then can be handled later.
> @@ -216,7 +225,7 @@ void machine_check_ue_event(struct machine_check_event *evt)
>  	memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
>  
>  	/* Queue work to process this event later. */
> -	schedule_work(&mce_ue_event_work);
> +	irq_work_queue(&mce_ue_event_irq_work);
>  }
>  
>  /*
>