Commit f409530e authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Peter Zijlstra
Browse files

task_work: Introduce task_work_cancel() again 



Re-introduce task_work_cancel(), this time to cancel an actual callback
and not *any* callback pointing to a given function. This is going to be
needed for perf events event freeing.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-3-frederic@kernel.org
parent 68cbd415

include/linux/task_work.h

+1 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ int task_work_add(struct task_struct *task, struct callback_head *twork, 
struct callback_head *task_work_cancel_match(struct task_struct *task,

	bool (*match)(struct callback_head *, void *data), void *data);

struct callback_head *task_work_cancel_func(struct task_struct *, task_work_func_t);

bool task_work_cancel(struct task_struct *task, struct callback_head *cb);

void task_work_run(void);



static inline void exit_task_work(struct task_struct *task)

kernel/task_work.c

+24 −0
Original line number Diff line number Diff line
@@ -136,6 +136,30 @@ task_work_cancel_func(struct task_struct *task, task_work_func_t func) 
	return task_work_cancel_match(task, task_work_func_match, func);

}



static bool task_work_match(struct callback_head *cb, void *data)

{

	return cb == data;

}



/**

 * task_work_cancel - cancel a pending work added by task_work_add()

 * @task: the task which should execute the work

 * @cb: the callback to remove if queued

 *

 * Remove a callback from a task's queue if queued.

 *

 * RETURNS:

 * True if the callback was queued and got cancelled, false otherwise.

 */

bool task_work_cancel(struct task_struct *task, struct callback_head *cb)

{

	struct callback_head *ret;



	ret = task_work_cancel_match(task, task_work_match, cb);



	return ret == cb;

}



/**

 * task_work_run - execute the works added by task_work_add()

 *