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From:   Kyle Huey <me@kylehuey.com>
Date:   Sat, 30 Jan 2021 18:50:43 -0800
Message-ID: <CAP045ApxLJ7vXOVp5Cwx7WEyDr6v01D9YD3xGFDv3WAp6czaMQ@mail.gmail.com>
Subject: Re: [REGRESSION] x86/entry: TIF_SINGLESTEP handling is still broken
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Andy Lutomirski <luto@kernel.org>,
        Gabriel Krisman Bertazi <krisman@collabora.com>,
        open list <linux-kernel@vger.kernel.org>,
        "Robert O'Callahan" <rocallahan@gmail.com>
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On Sat, Jan 30, 2021 at 5:56 PM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> On Sat, Jan 30, 2021 at 5:32 PM Kyle Huey <me@kylehuey.com> 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