On Tue, Oct 15, 2024 at 11:05 PM Lorenzo Stoakes
<lorenzo.stoakes@xxxxxxxxxx> wrote:
>
> On Tue, Oct 15, 2024 at 12:40:41PM -0700, Suren Baghdasaryan wrote:
> [snip]
> > > -struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags)
> > > +struct pid *__pidfd_get_pid(unsigned int pidfd, bool pin_pid,
> > > + bool allow_proc, unsigned int *flags,
> > > + struct fd *fd)
> > > {
> > > - struct fd f;
> > > + struct file *file;
> > > struct pid *pid;
> > > + struct fd f = fdget(pidfd);
> > >
> > > - f = fdget(fd);
> > > - if (!fd_file(f))
> > > + file = fd_file(f);
> > > + if (!file)
> > > return ERR_PTR(-EBADF);
> > >
> > > - pid = pidfd_pid(fd_file(f));
> > > - if (!IS_ERR(pid)) {
> > > - get_pid(pid);
> > > - *flags = fd_file(f)->f_flags;
> > > + pid = pidfd_pid(file);
> > > + /* If we allow opening a pidfd via /proc/<pid>, do so. */
> > > + if (IS_ERR(pid) && allow_proc)
> > > + pid = tgid_pidfd_to_pid(file);
> > > +
> > > + if (IS_ERR(pid)) {
> > > + fdput(f);
> > > + return pid;
> > > }
> > >
> > > - fdput(f);
> > > + if (pin_pid)
> > > + get_pid(pid);
> > > + else
> > > + WARN_ON_ONCE(!fd); /* Nothing to keep pid/pidfd around? */
> > > +
> > > + if (flags)
> > > + *flags = file->f_flags;
> > > +
> > > + /*
> > > + * If the user provides an fd output then it will handle decrementing
> > > + * its reference counter.
> > > + */
> > > + if (fd)
> > > + *fd = f;
> > > + else
> > > + /* Otherwise we release it. */
> > > + fdput(f);
> > > +
> > > return pid;
> > > }
> >
> > There is an EXPORT_SYMBOL_GPL(pidfd_get_pid) right after this line. It
> > should also be changed to EXPORT_SYMBOL_GPL(__pidfd_get_pid),
> > otherwise __pidfd_get_pid() will not be exported. A module calling
> > pidfd_get_pid() now inlined in the header file will try to call
> > __pidfd_get_pid() and will have trouble resolving this symbol.
>
> Hmm hang on not there isn't? I don't see that anywhere?
Doh! Sorry, I didn't realize the export was an out-of-tree Android
change. Never mind...
>
> [snip]
