On Sun, Mar 02, 2025 at 02:09:36PM +0100, Oleg Nesterov wrote:
> On 02/28, Christian Brauner wrote:
> >
> > @@ -696,6 +696,10 @@ struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags)
> > return ERR_PTR(ret);
> >
> > pidfd_file = dentry_open(&path, flags, current_cred());
> > + /* Raise PIDFD_THREAD explicitly as dentry_open() strips it. */
> ^^^^^^^^^^^^^^^^^^^^^^^
> Hmm, does it?
>
> dentry_open(flags) just passes "flags" to alloc_empty_file()->init_file(),
> and init_file(flags) does
>
> f->f_flags = flags;
>
> so it seems that
dentry_open()
-> do_dentry_open()
{
f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
f->f_iocb_flags = iocb_flags(f);
}
>
> > @@ -2042,11 +2042,6 @@ static int __pidfd_prepare(struct pid *pid, unsigned int flags, struct file **re
> > if (IS_ERR(pidfd_file))
> > return PTR_ERR(pidfd_file);
> >
> > - /*
> > - * anon_inode_getfile() ignores everything outside of the
> > - * O_ACCMODE | O_NONBLOCK mask, set PIDFD_THREAD manually.
> > - */
> > - pidfd_file->f_flags |= (flags & PIDFD_THREAD);
>
> we can just kill this outdated code?
Unfortunately not.
