2023-04-12 10:08:01

by David Laight

Subject: RE: [PATCH 1/2] x86: profiling: remove lock functions hack for !FRAME_POINTER

From: Chen Zhongjin
> Sent: 12 April 2023 08:02
...
> > 4. !CONFIG_FRAME_POINTER is probably even more rare today than it was in
> > 2006
>
> No. !CONFIG_FRAME_POINTER is more common today because of UNWINDER_ORC.
> And that is why the bug is triggered more frequently.

CONFIG_FRAME_POINTER is pretty much required (on x86-64)
for the user copy checks that are enabled in distro kernels.

David

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2023-04-19 16:42:53

by Josh Poimboeuf

Subject: Re: [PATCH 1/2] x86: profiling: remove lock functions hack for !FRAME_POINTER

On Wed, Apr 12, 2023 at 10:01:18AM +0000, David Laight wrote:
> From: Chen Zhongjin
> > Sent: 12 April 2023 08:02
> ...
> > > 4. !CONFIG_FRAME_POINTER is probably even more rare today than it was in
> > > 2006
> >
> > No. !CONFIG_FRAME_POINTER is more common today because of UNWINDER_ORC.
> > And that is why the bug is triggered more frequently.
>
> CONFIG_FRAME_POINTER is pretty much required (on x86-64)
> for the user copy checks that are enabled in distro kernels.

CONFIG_FRAME_POINTER is pretty much deprecated. The only distro still
using it (that I know of) is Ubuntu.

--
Josh