From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: Re: [PATCH v4 7/8] pid: export pidfd_get_pid Date: Wed, 12 Feb 2020 16:25:31 -0800 Message-ID: <6bb20b3d4e3362337e1a4c8a4be13f6acda5b0ec.camel@linux.intel.com> References: <20200212233946.246210-1-minchan@kernel.org> <20200212233946.246210-8-minchan@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200212233946.246210-8-minchan-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Minchan Kim , Andrew Morton Cc: LKML , linux-mm , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, oleksandr-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Suren Baghdasaryan , Tim Murray , Daniel Colascione , Sandeep Patil , Sonny Rao , Brian Geffon , Michal Hocko , Johannes Weiner , Shakeel Butt , John Dias , Joel Fernandes , Christian Brauner List-Id: linux-api@vger.kernel.org On Wed, 2020-02-12 at 15:39 -0800, Minchan Kim wrote: > process_madvise syscall needs pidfd_get_pid function to translate > pidfd to pid so this patch exports the function. > > Cc: Christian Brauner > Signed-off-by: Minchan Kim I think you might have misunderstood my earlier comments. This should be patch 2 in your set. What is patch 8 should be folded into you existing patch 2 and become patch 3 with the rest of your patches shifted by 1 since you are reordering them. Otherwise the code itself appears to not have changed anything so it looks fine to me. Reviewed-by: Alexander Duyck > --- > include/linux/pid.h | 1 + > kernel/exit.c | 17 ----------------- > kernel/pid.c | 17 +++++++++++++++++ > 3 files changed, 18 insertions(+), 17 deletions(-) > > diff --git a/include/linux/pid.h b/include/linux/pid.h > index 998ae7d24450..023d9c3a8edc 100644 > --- a/include/linux/pid.h > +++ b/include/linux/pid.h > @@ -75,6 +75,7 @@ extern const struct file_operations pidfd_fops; > struct file; > > extern struct pid *pidfd_pid(const struct file *file); > +extern struct pid *pidfd_get_pid(unsigned int fd); > > static inline struct pid *get_pid(struct pid *pid) > { > diff --git a/kernel/exit.c b/kernel/exit.c > index 0b81b26a872a..43375f9d8bbc 100644 > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -1470,23 +1470,6 @@ static long do_wait(struct wait_opts *wo) > return retval; > } > > -static struct pid *pidfd_get_pid(unsigned int fd) > -{ > - struct fd f; > - struct pid *pid; > - > - f = fdget(fd); > - if (!f.file) > - return ERR_PTR(-EBADF); > - > - pid = pidfd_pid(f.file); > - if (!IS_ERR(pid)) > - get_pid(pid); > - > - fdput(f); > - return pid; > -} > - > static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop, > int options, struct rusage *ru) > { > diff --git a/kernel/pid.c b/kernel/pid.c > index 0f4ecb57214c..360ba480a2a9 100644 > --- a/kernel/pid.c > +++ b/kernel/pid.c > @@ -496,6 +496,23 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns) > return idr_get_next(&ns->idr, &nr); > } > > +struct pid *pidfd_get_pid(unsigned int fd) > +{ > + struct fd f; > + struct pid *pid; > + > + f = fdget(fd); > + if (!f.file) > + return ERR_PTR(-EBADF); > + > + pid = pidfd_pid(f.file); > + if (!IS_ERR(pid)) > + get_pid(pid); > + > + fdput(f); > + return pid; > +} > + > /** > * pidfd_create() - Create a new pid file descriptor. > *