Re: [PATCH stable 6.6] lib/buildid: Handle memfd_secret() files in build_id_parse()

[Chen Linxuan]

Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> 于2025年3月11日周二 19:14写道：
>
> On Tue, Mar 11, 2025 at 06:05:55PM +0800, Chen Linxuan wrote:
> > Backport of a similar change from commit 5ac9b4e935df ("lib/buildid:
> > Handle memfd_secret() files in build_id_parse()") to address an issue
> > where accessing secret memfd contents through build_id_parse() would
> > trigger faults.
> >
> > Original report and repro can be found in [0].
> >
> >   [0] https://lore.kernel.org/bpf/ZwyG8Uro%2FSyTXAni@ly-workstation/
> >
> > This repro will cause BUG: unable to handle kernel paging request in
> > build_id_parse in 5.15/6.1/6.6.
> >
> > Some other discussions can be found in [1].
> >
> >   [1] https://lore.kernel.org/bpf/20241104175256.2327164-1-jolsa@xxxxxxxxxx/T/#u
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Fixes: 88a16a130933 ("perf: Add build id data in mmap2 event")
> > Signed-off-by: Chen Linxuan <chenlinxuan@xxxxxxxxxx>
>
> You dropped all the original signed-off-by and changelog text.  Just

The original commit is based on commit de3ec364c3c3 ("lib/buildid: add
single folio-based file reader abstraction"). `git cherry-pick` result lots of
conflicts. So I rewrite same logic on old code.

> provide a backport with all of the original information, and then if you
> had to do something "different", put that in the signed-off-by area.
> THere are loads of examples on the list for how that was done.

Do you means that I should:

1. Run git cherry-pick 5ac9b4e935df on stable branches;
2. Resolve conflicts by drop all changes then apply changes
   as I send in this email;
3. Note why content of this patch is different from the original
   one after original signed-off-by area, but before the --- separator.

I am not familiar with contributing to stable kernel tree.
Sorry for bothering.

>
> thanks,
>
> greg k-h
>
>