Re: [PATCH] x86, traps: Fix ist_enter from userspace

[Sasha Levin]

On 01/31/2015 08:01 AM, Andy Lutomirski wrote:
> context_tracking_user_exit() has no effect if in_interrupt() returns true,
> so ist_enter() didn't work.  Fix it by calling exception_enter(), and thus
> context_tracking_user_exit(), before incrementing the preempt count.
> 
> This also adds an assertion that will catch the problem reliably if
> CONFIG_PROVE_RCU=y to help prevent the bug from being reintroduced.
> 
> Fixes: 959274753857 x86, traps: Track entry into and exit from IST context
> Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>

I was running something like that overnight, looks like it fixes the problem.

	Tested-by: Sasha Levin <sasha.levin@xxxxxxxxxx>


Thanks,
Sasha
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