Re: [PATCH] man/man2/fanotify_mark.2: AT_FDCWD plus NULL path doesn't work
From: Alejandro Colomar
Date: Fri May 29 2026 - 17:46:32 EST
Hi Jann, Amir,
On 2026-05-29T23:38:11+0200, Amir Goldstein wrote:
> On Fri, May 29, 2026 at 7:27 PM Jann Horn <jannh@xxxxxxxxxx> wrote:
> >
> > The fanotify_mark.2 manpage claims that AT_FDCWD works with a NULL path,
> > but there is no kernel code for that - in fanotify_find_path(), in the
> > `if (filename == NULL)` block, the fd is only used for a normal FD
> > lookup.
> >
> > This was also already the case when this manpage was written back in
> > 2014, so remove the bogus documentation.
> >
> > Fixes: c200b422d ("fanotify_mark.2: New page documenting fanotify_mark(2)")
> > Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
>
> Hah, never noticed this.
> Apparently, hallucinations already existed in 2014 :D
>
> Acked-by: Amir Goldstein <amir73il@xxxxxxxxx>
Thanks! I've added the author of the fixed commit in the recipients.
I'll apply on Monday or so.
Have a lovely night!
Alex
>
> > ---
> > man/man2/fanotify_mark.2 | 8 --------
> > 1 file changed, 8 deletions(-)
> >
> > diff --git a/man/man2/fanotify_mark.2 b/man/man2/fanotify_mark.2
> > index e561ffd21..a3b77537c 100644
> > --- a/man/man2/fanotify_mark.2
> > +++ b/man/man2/fanotify_mark.2
> > @@ -560,14 +560,6 @@ defines the filesystem object to be marked.
> > .IP \[bu]
> > If
> > .I path
> > -is NULL, and
> > -.I dirfd
> > -takes the special value
> > -.BR AT_FDCWD ,
> > -the current working directory is to be marked.
> > -.IP \[bu]
> > -If
> > -.I path
> > is absolute, it defines the filesystem object to be marked, and
> > .I dirfd
> > is ignored.
> >
> > ---
> > base-commit: 9db8ca91f920b9aba40ed68de6b8da0ca9dbefaa
> > change-id: 20260529-fan-mark-cwd-1c760106eff9
> >
> > Best regards,
> > --
> > Jann Horn <jannh@xxxxxxxxxx>
> >
>
--
<https://www.alejandro-colomar.es>
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