Re: Lockless/Get_User_Pages_Fast causes Xorg 1.4.99.* to lock

From: Hugh Dickins
Date: Mon Jul 07 2008 - 08:03:18 EST


On Mon, 7 Jul 2008, Nick Piggin wrote:
> On Monday 07 July 2008 20:39, Hugh Dickins wrote:
> > On Mon, 7 Jul 2008, Nick Piggin wrote:
> > > I think we need a similar fix for s390 too. If so, then it really should
> > > get into 2.6.26, but this late in the release, I hope an s390 maintainer
> > > might be able to test and verify the fix?
> >
> > Wow, yes, I hadn't realized s390 is ahead of the game there: glad you're
> > back to spot that. But yes, we'd prefer maintainer to confirm and push.
> >
> >
> > [PATCH]] s390: protect _PAGE_SPECIAL bit against mprotect
> >
> > Stop mprotect's pte_modify from wiping out the s390 pte_special bit, which
> > caused oops thereafter when vm_normal_page thought X's abnormal was normal.
> >
> > Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
> > Acked-by: Hugh Dickins <hugh@xxxxxxxxxxx>
>
> Thanks, I feel silly to take the authorship of this before your x86
> version gets in (and will likely not be credited if it is folded
> before merging)
>
> Martin, could you please credit Hugh for the debugging? :)

Oh, I'm more anxious for your fix to get to Linus than for credit
to be fairly apportioned - we don't need an Oscar ceremony here!

But if Martin does choose to add credits, then it's Ryan's and
Zan's x86 reports that should be credited - they did the hard work.
I didn't mention them in the x86 patch because at that stage I was
just making a wild guess that this might be the cause of their problems.

Hugh
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