Re: [PATCH 15/37] x86, pkeys: pass VMA down in to fault signal generation code

From: Thomas Gleixner
Date: Fri Nov 27 2015 - 04:30:54 EST


On Mon, 16 Nov 2015, Dave Hansen wrote:
> During a page fault, we look up the VMA to ensure that the fault
> is in a region with a valid mapping. But, in the top-level page
> fault code we don't need the VMA for much else. Once we have
> decided that an access is bad, we are going to send a signal no
> matter what and do not need the VMA any more. So we do not pass
> it down in to the signal generation code.
>
> But, for protection keys, we need the VMA. It tells us *which*
> protection key we violated if we get a PF_PK. So, we need to
> pass the VMA down and fill in siginfo->si_pkey.
>
> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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