[PATCH 3/5] exit: add kernel_waitid_prepare() helper

[Jens Axboe <axboe@xxxxxxxxx>]

Move the setup logic out of kernel_waitid(), and into a separate helper.

No functional changes intended in this patch.

Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
 kernel/exit.c | 41 +++++++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 14 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index d8fb124cc038..8934c91a9fe1 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1662,14 +1662,12 @@ static long do_wait(struct wait_opts *wo)
 	return retval;
 }
 
-static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
-			  int options, struct rusage *ru)
+static int kernel_waitid_prepare(struct wait_opts *wo, int which, pid_t upid,
+				 struct waitid_info *infop, int options,
+				 struct rusage *ru, unsigned int *f_flags)
 {
-	struct wait_opts wo;
 	struct pid *pid = NULL;
 	enum pid_type type;
-	long ret;
-	unsigned int f_flags = 0;
 
 	if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED|
 			__WNOTHREAD|__WCLONE|__WALL))
@@ -1703,7 +1701,7 @@ static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
 		if (upid < 0)
 			return -EINVAL;
 
-		pid = pidfd_get_pid(upid, &f_flags);
+		pid = pidfd_get_pid(upid, f_flags);
 		if (IS_ERR(pid))
 			return PTR_ERR(pid);
 
@@ -1712,19 +1710,34 @@ static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
 		return -EINVAL;
 	}
 
-	wo.wo_type	= type;
-	wo.wo_pid	= pid;
-	wo.wo_flags	= options;
-	wo.wo_info	= infop;
-	wo.wo_rusage	= ru;
-	if (f_flags & O_NONBLOCK)
-		wo.wo_flags |= WNOHANG;
+	wo->wo_type	= type;
+	wo->wo_pid	= pid;
+	wo->wo_flags	= options;
+	wo->wo_info	= infop;
+	wo->wo_rusage	= ru;
+	if (*f_flags & O_NONBLOCK)
+		wo->wo_flags |= WNOHANG;
+
+	return 0;
+}
+
+static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
+			  int options, struct rusage *ru)
+{
+	struct wait_opts wo;
+	long ret;
+	unsigned int f_flags = 0;
+
+	ret = kernel_waitid_prepare(&wo, which, upid, infop, options, ru,
+					&f_flags);
+	if (ret)
+		return ret;
 
 	ret = do_wait(&wo);
 	if (!ret && !(options & WNOHANG) && (f_flags & O_NONBLOCK))
 		ret = -EAGAIN;
 
-	put_pid(pid);
+	put_pid(wo.wo_pid);
 	return ret;
 }
 
-- 
2.40.1