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From: Santosh Sivaraj <santosh@fossix.org>
To: Ganesh Goudar <ganeshgr@linux.ibm.com>,
	linuxppc-dev@lists.ozlabs.org, mpe@ellerman.id.au
Cc: Ganesh Goudar <ganeshgr@linux.ibm.com>,
	mahesh@linux.ibm.com, npiggin@gmail.com
Subject: Re: [PATCH] powerpc/mce: save ignore_event flag unconditionally for UE
Date: Tue, 20 Apr 2021 12:52:55 +0530
Message-ID: <87eef5zagg.fsf@fossix.org> (raw)
In-Reply-To: <20210407045816.352276-1-ganeshgr@linux.ibm.com>


Hi Ganesh,

Ganesh Goudar <ganeshgr@linux.ibm.com> writes:

> When we hit an UE while using machine check safe copy routines,
> ignore_event flag is set and the event is ignored by mce handler,
> And the flag is also saved for defered handling and printing of
> mce event information, But as of now saving of this flag is done
> on checking if the effective address is provided or physical address
> is calculated, which is not right.
>
> Save ignore_event flag regardless of whether the effective address is
> provided or physical address is calculated.
>
> Without this change following log is seen, when the event is to be
> ignored.
>
> [  512.971365] MCE: CPU1: machine check (Severe)  UE Load/Store [Recovered]
> [  512.971509] MCE: CPU1: NIP: [c0000000000b67c0] memcpy+0x40/0x90
> [  512.971655] MCE: CPU1: Initiator CPU
> [  512.971739] MCE: CPU1: Unknown
> [  512.972209] MCE: CPU1: machine check (Severe)  UE Load/Store [Recovered]
> [  512.972334] MCE: CPU1: NIP: [c0000000000b6808] memcpy+0x88/0x90
> [  512.972456] MCE: CPU1: Initiator CPU
> [  512.972534] MCE: CPU1: Unknown
>
> Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
> ---
>  arch/powerpc/kernel/mce.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
> index 11f0cae086ed..db9363e131ce 100644
> --- a/arch/powerpc/kernel/mce.c
> +++ b/arch/powerpc/kernel/mce.c
> @@ -131,6 +131,8 @@ void save_mce_event(struct pt_regs *regs, long handled,
>  	 * Populate the mce error_type and type-specific error_type.
>  	 */
>  	mce_set_error_info(mce, mce_err);
> +	if (mce->error_type == MCE_ERROR_TYPE_UE)
> +		mce->u.ue_error.ignore_event = mce_err->ignore_event;
>  
>  	if (!addr)
>  		return;
> @@ -159,7 +161,6 @@ void save_mce_event(struct pt_regs *regs, long handled,
>  		if (phys_addr != ULONG_MAX) {
>  			mce->u.ue_error.physical_address_provided = true;
>  			mce->u.ue_error.physical_address = phys_addr;
> -			mce->u.ue_error.ignore_event = mce_err->ignore_event;
>  			machine_check_ue_event(mce);
>  		}
>  	}

Small nit:
Setting ignore event can happen before the phys_addr check, under the existing
check for MCE_ERROR_TYPE_UE, instead of repeating the same condition again.

Except for the above nit



Thanks,
Santosh
> -- 
> 2.26.2

  reply index

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-07  4:58 Ganesh Goudar
2021-04-20  7:22 ` Santosh Sivaraj [this message]
2021-04-20  7:24 ` Santosh Sivaraj
2021-04-20 10:35   ` Ganesh
2021-04-20 11:35     ` Santosh Sivaraj
2021-04-21 13:08 ` Michael Ellerman
2021-04-22  6:01 ` Ganesh
2021-04-22  6:10   ` Ganesh

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