From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3y1fl40y57zDsPC for ; Tue, 26 Sep 2017 22:04:32 +1000 (AEST) In-Reply-To: <20170922033221.31609-1-mikey@neuling.org> To: Michael Neuling From: Michael Ellerman Cc: mikey@neuling.org, linuxppc-dev@lists.ozlabs.org, Nicholas Piggin Subject: Re: [v3] powerpc: Handle MCE on POWER9 with only DSISR bit 33 set Message-Id: <3y1fl36stCz9tXn@ozlabs.org> Date: Tue, 26 Sep 2017 22:04:31 +1000 (AEST) List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2017-09-22 at 03:32:21 UTC, Michael Neuling wrote: > On POWER9 DD2.1 and below, it's possible for a paste instruction to > cause a Machine Check Exception (MCE) where only DSISR bit 33 is > set. This will result in the MCE handler seeing an unknown event, > which triggers linux to crash. > > We change this by detecting unknown events caused by load/stores in > the MCE handler and marking them as handled so that we no longer > crash. > > An MCE that occurs like this is spurious, so we don't need to do > anything in terms of servicing it. If there is something that needs to > be serviced, the CPU will raise the MCE again with the correct DSISR > so that it can be serviced properly. > > Signed-off-by: Michael Neuling > Reviewed-by: Nicholas Piggin Acked-by: Balbir SIngh Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/d8bd9f3f0925d22726de159531bfe3 cheers