Re: [REGRESSION] x86/entry: TIF_SINGLESTEP handling is still broken

From: Kyle Huey
Date: Sat Jan 30 2021 - 22:00:45 EST


On Sat, Jan 30, 2021 at 5:56 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Sat, Jan 30, 2021 at 5:32 PM Kyle Huey <me@xxxxxxxxxxxx> wrote:
> >
> > I tested that with 2991552447707d791d9d81a5dc161f9e9e90b163 reverted
> > and Yuxuan's patch applied to Linus's tip rr works and passes all
> > tests.
>
> There's a patch in the -tip tree that hasn't been merged yet:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/urgent
>
> (there's only that one patch in that branch right now, commit ID
> 41c1a06d1d1544bed9692ba72a5692454eee1945).
>
> It should be making its way my direction any day now, but in the
> meantime if you can verify that it makes things work for you, that
> would be great..

Right, I'm saying that that is not sufficient.

41c1a06d1d1544bed9692ba72a5692454eee1945 does indeed fix the bug
introduced in 64eb35f701f04b30706e21d1b02636b5d31a37d2, but
2991552447707d791d9d81a5dc161f9e9e90b163 introduced another bug that
remains unfixed.

- Kyle