Re: [PATCH -v5 6/5] context_tracking: fix exception_enter when already in IN_KERNEL
From: Rik van Riel
Date: Thu Feb 12 2015 - 11:44:31 EST
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On 02/12/2015 10:42 AM, Frederic Weisbecker wrote:
> On Wed, Feb 11, 2015 at 02:43:19PM -0500, Rik van Riel wrote:
>> If exception_enter happens when already in IN_KERNEL state, the
>> code still calls context_tracking_exit, which ends up in
>> rcu_eqs_exit_common, which explodes with a WARN_ON when it is
>> called in a situation where dynticks are not enabled.
> Fortunately context_tracking_exit() already has a current_state ==
> IN_KERNEL check so this shouldn't be a problem.
No, it had a hard-coded "current_state == IN_USER" check,
which is very close, but ...
... I replaced that with a state argument, and forgot to
ensure that it never gets called with state == IN_KERNEL.
This patch fixes that.
> Meanwhile I'll still take the patch, it's better to handle that
> from the caller.
All rights reversed
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