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From: Scott Wood <scottwood@freescale.com>
To: Micha Nelissen <micha.nelissen@Prodrive.nl>
Cc: Martijn de Gouw <martijn.de.gouw@Prodrive.nl>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	Anton Blanchard <anton@samba.org>
Subject: Re: powerpc: Don't silently handle machine checks from userspace
Date: Tue, 6 Nov 2012 10:34:15 -0600	[thread overview]
Message-ID: <1352219655.21833.0@snotra> (raw)
In-Reply-To: <39F93B8F6D09AC4DA45E2F19603FA69C324EEDCD@exc02.bk.prodrive.nl> (from micha.nelissen@Prodrive.nl on Tue Nov  6 03:21:37 2012)

On 11/06/2012 03:21:37 AM, Micha Nelissen wrote:
> From: Scott Wood [mailto:scottwood@freescale.com]
> > > Therefore I request to put this check back, and even to put the
> > > removed code at the top of the machine check handler because =20
> there is
> > > no point in trying to recover from a user space bus error anyway.
> >
> > Why is there no point trying to recover?  For example, see =20
> MCSR_ICPERR
> > and MCSR_DCPERR_MC in machine_check_e500mc.  The machine check is =20
> just
> > letting us know that there was an error and the read-only cache got
> > dumped (i.e. it was a correctable error).
>=20
> Oh I overlooked those cases; those correctable errors shouldn't be =20
> bus errors for the user space process?
>=20
> Hmm I guess there is no simple solution then, since the "recover" =20
> function also prints the kernel messages about the machine check =20
> being in kernel mode without having checked whether it really was in =20
> kernel mode. In the past the user mode check was in between.

It shouldn't be that difficult to make it say "in user mode" or "in =20
kernel mode" depending on which it was... or just remove that phrase =20
altogether and let the following output indicate whether it was in =20
kernel mode.

-Scott=

  reply	other threads:[~2012-11-06 16:34 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-02 11:48 powerpc: Don't silently handle machine checks from userspace Martijn de Gouw
2012-11-02 16:36 ` Scott Wood
2012-11-06  9:21   ` Micha Nelissen
2012-11-06 16:34     ` Scott Wood [this message]
2012-11-06 16:43       ` Micha Nelissen
2012-11-06 20:13         ` Scott Wood

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