[PATCH 2/5] ipc/mqueue.c: Remove duplicated code

From: Manfred Spraul
Date: Sun Oct 20 2019 - 08:33:37 EST


Patch from Davidlohr, I just added this change log.
pipelined_send() and pipelined_receive() are identical, so merge them.

Signed-off-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Signed-off-by: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
---
ipc/mqueue.c | 31 ++++++++++++++++++-------------
1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 3d920ff15c80..270456530f6a 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -918,17 +918,12 @@ SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
* The same algorithm is used for senders.
*/

-/* pipelined_send() - send a message directly to the task waiting in
- * sys_mq_timedreceive() (without inserting message into a queue).
- */
-static inline void pipelined_send(struct wake_q_head *wake_q,
+static inline void __pipelined_op(struct wake_q_head *wake_q,
struct mqueue_inode_info *info,
- struct msg_msg *message,
- struct ext_wait_queue *receiver)
+ struct ext_wait_queue *this)
{
- receiver->msg = message;
- list_del(&receiver->list);
- wake_q_add(wake_q, receiver->task);
+ list_del(&this->list);
+ wake_q_add(wake_q, this->task);
/*
* Rely on the implicit cmpxchg barrier from wake_q_add such
* that we can ensure that updating receiver->state is the last
@@ -937,7 +932,19 @@ static inline void pipelined_send(struct wake_q_head *wake_q,
* yet, at that point we can later have a use-after-free
* condition and bogus wakeup.
*/
- receiver->state = STATE_READY;
+ this->state = STATE_READY;
+}
+
+/* pipelined_send() - send a message directly to the task waiting in
+ * sys_mq_timedreceive() (without inserting message into a queue).
+ */
+static inline void pipelined_send(struct wake_q_head *wake_q,
+ struct mqueue_inode_info *info,
+ struct msg_msg *message,
+ struct ext_wait_queue *receiver)
+{
+ receiver->msg = message;
+ __pipelined_op(wake_q, info, receiver);
}

/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
@@ -955,9 +962,7 @@ static inline void pipelined_receive(struct wake_q_head *wake_q,
if (msg_insert(sender->msg, info))
return;

- list_del(&sender->list);
- wake_q_add(wake_q, sender->task);
- sender->state = STATE_READY;
+ __pipelined_op(wake_q, info, sender);
}

static int do_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
--
2.21.0