Re: powerpc: Don't silently handle machine checks from userspace

On 11/06/2012 03:21:37 AM, Micha Nelissen wrote:

From: Scott Wood [mailto:scottwood@freescale.com]

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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

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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

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and MCSR_DCPERR_MC in machine_check_e500mc.  The machine check is =20

just

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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=