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ipc/mqueue.c: remove duplicated code

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pipelined_send() and pipelined_receive() are identical, so merge them.

[manfred@colorfullife.com: add changelog]
Link: http://lkml.kernel.org/r/20191020123305.14715-3-manfred@colorfullife.com
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: <1vier1@web.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Davidlohr Bueso 2020-02-03 17:34:32 -08:00 committed by Linus Torvalds
parent 39323c64b8
commit ed29f17151
1 changed files with 19 additions and 14 deletions
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33
ipc/mqueue.c
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@ -918,6 +918,23 @@ out_name:
* The same algorithm is used for senders.
*/
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
* write operation: As once set, the receiver can continue,
* and if we don't have the reference count from the wake_q,
* yet, at that point we can later have a use-after-free
* condition and bogus wakeup.
*/
this->state = STATE_READY;
}
/* pipelined_send() - send a message directly to the task waiting in
* sys_mq_timedreceive() (without inserting message into a queue).
*/
@ -927,17 +944,7 @@ static inline void pipelined_send(struct wake_q_head *wake_q,
struct ext_wait_queue *receiver)
{
receiver->msg = message;
list_del(&receiver->list);
wake_q_add(wake_q, receiver->task);
/*
* Rely on the implicit cmpxchg barrier from wake_q_add such
* that we can ensure that updating receiver->state is the last
* write operation: As once set, the receiver can continue,
* and if we don't have the reference count from the wake_q,
* yet, at that point we can later have a use-after-free
* condition and bogus wakeup.
*/
receiver->state = STATE_READY;
__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,