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From: james.morse@arm•com (James Morse)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH] arm64: fault: Don't populate ESR context for user fault on kernel VA
Date: Tue, 06 Mar 2018 17:59:06 +0000	[thread overview]
Message-ID: <5A9ED6EA.3040700@arm.com> (raw)
In-Reply-To: <20180306160553.GN32331@e103592.cambridge.arm.com>

Hi Dave, Peter,

On 06/03/18 16:05, Dave Martin wrote:
> On Tue, Mar 06, 2018 at 03:59:59PM +0000, Peter Maydell wrote:
>> AFAIK the major thing that consumers actually are after here
>> is the WnR information, so preserving that and sanitizing
>> the rest of the ESR if necessary would be a less risky fix IMHO.
> 
> If there is a way of squashing the syndrome information so that it
> reports a fixed syndrome except for information about what userspace
> attempted to do (i.e., WnR -- I dunno if there's anything else), that
> seems reasonable.

Anything else? For the RAS stuff I planned to use this to indicate whether a
SIBGUS due to hwpoison was due to an instruction or data abort, so a
sanitised-EC field would be good.

(this lets KVMs user-space inject the correct flavour of external-abort)


Thanks,

James

  parent reply	other threads:[~2018-03-06 17:59 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-05 10:31 [RFC PATCH] arm64: fault: Don't populate ESR context for user fault on kernel VA Will Deacon
2018-03-05 13:27 ` Robin Murphy
2018-03-05 15:56   ` Will Deacon
2018-03-05 14:05 ` Dave Martin
2018-03-05 17:24   ` Will Deacon
2018-03-06 15:59     ` Peter Maydell
2018-03-06 16:05       ` Dave Martin
2018-03-06 17:54         ` Will Deacon
2018-03-07 10:50           ` Dave P Martin
2018-03-06 17:59         ` James Morse [this message]
2018-03-06 18:16           ` James Morse
2018-03-06 14:49   ` Catalin Marinas

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