Re: [PATCH 2/6] ipc/mqueue.c: Remove duplicated code

[Peter Zijlstra]

On Sat, Oct 12, 2019 at 07:49:54AM +0200, Manfred Spraul wrote:
> +static inline void __pipelined_op(struct wake_q_head *wake_q,
> struct mqueue_inode_info *info,
> +   struct ext_wait_queue *this)
>  {
> + 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.
>*/
> +this->state = STATE_READY;

  ^^ whitespace damage

> +}

Re: [PATCH 2/6] ipc/mqueue.c: Remove duplicated code

[Davidlohr Bueso]

On Sat, 12 Oct 2019, Manfred Spraul wrote:


Patch entirely from Davidlohr:
pipelined_send() and pipelined_receive() are identical, so merge them.



Sorry, yeah feel free to add my:

Signed-off-by: Davidlohr Bueso 


Signed-off-by: Manfred Spraul 
Cc: Davidlohr Bueso 
---
ipc/mqueue.c | 31 ++-
1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 3d920ff15c80..be48c0ba92f7 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

[PATCH 2/6] ipc/mqueue.c: Remove duplicated code

[Manfred Spraul]

Patch entirely from Davidlohr:
pipelined_send() and pipelined_receive() are identical, so merge them.

Signed-off-by: Manfred Spraul 
Cc: Davidlohr Bueso 
---
 ipc/mqueue.c | 31 ++-
 1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 3d920ff15c80..be48c0ba92f7 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