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From: Minchan Kim <minchan@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	linux-mm <linux-mm@kvack.org>,
	linux-api@vger.kernel.org, oleksandr@redhat.com,
	Suren Baghdasaryan <surenb@google.com>,
	Tim Murray <timmurray@google.com>,
	Daniel Colascione <dancol@google.com>,
	Sandeep Patil <sspatil@google.com>,
	Sonny Rao <sonnyrao@google.com>,
	Brian Geffon <bgeffon@google.com>, Michal Hocko <mhocko@suse.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Shakeel Butt <shakeelb@google.com>,
	John Dias <joaodias@google.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	sj38.park@gmail.com, alexander.h.duyck@linux.intel.com,
	Jann Horn <jannh@google.com>, Minchan Kim <minchan@kernel.org>,
	Christian Brauner <christian@brauner.io>
Subject: [PATCH v5 4/7] pid: export pidfd_get_pid
Date: Fri, 14 Feb 2020 09:05:17 -0800	[thread overview]
Message-ID: <20200214170520.160271-5-minchan@kernel.org> (raw)
In-Reply-To: <20200214170520.160271-1-minchan@kernel.org>

process_madvise syscall needs pidfd_get_pid function to translate
pidfd to pid so this patch exports the function.

Cc: Christian Brauner <christian@brauner.io>
Suggested-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
 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.
  *
-- 
2.25.0.265.gbab2e86ba0-goog


  parent reply	other threads:[~2020-02-14 17:06 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-14 17:05 [PATCH v5 0/7] introduce memory hinting API for external process Minchan Kim
2020-02-14 17:05 ` [PATCH v5 1/7] mm: pass task and mm to do_madvise Minchan Kim
2020-02-14 17:25   ` Jann Horn
2020-02-14 18:22     ` Jens Axboe
2020-02-14 18:45       ` Minchan Kim
2020-02-14 19:09         ` Jens Axboe
2020-02-14 19:31           ` Minchan Kim
2020-02-14 17:05 ` [PATCH v5 2/7] mm: introduce external memory hinting API Minchan Kim
2020-02-14 17:05 ` [PATCH v5 3/7] mm: check fatal signal pending of target process Minchan Kim
2020-02-14 17:05 ` Minchan Kim [this message]
2020-02-17  7:59   ` [PATCH v5 4/7] pid: export pidfd_get_pid Christoph Hellwig
2020-02-19  1:02     ` Minchan Kim
2020-02-14 17:05 ` [PATCH v5 5/7] mm: support both pid and pidfd for process_madvise Minchan Kim
2020-02-14 17:05 ` [PATCH v5 6/7] mm/madvise: employ mmget_still_valid for write lock Minchan Kim
2020-02-14 17:05 ` [PATCH v5 7/7] mm/madvise: allow KSM hints for remote API Minchan Kim

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