The following commit has been merged into the perf/core branch of tip:
Commit-ID: f409530e4db9dd11b88cb7703c97c8f326ff6566
Gitweb: https://git.kernel.org/tip/f409530e4db9dd11b88cb7703c97c8f326ff6566
Author: Frederic Weisbecker <frederic@xxxxxxxxxx>
AuthorDate: Fri, 21 Jun 2024 11:15:59 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 09 Jul 2024 13:26:32 +02:00
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: Frederic Weisbecker <frederic@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20240621091601.18227-3-frederic@xxxxxxxxxx
---
include/linux/task_work.h | 1 +
kernel/task_work.c | 24 ++++++++++++++++++++++++
2 files changed, 25 insertions(+)
diff --git a/include/linux/task_work.h b/include/linux/task_work.h
index 23ab01a..26b8a47 100644
--- a/include/linux/task_work.h
+++ b/include/linux/task_work.h
@@ -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)
diff --git a/kernel/task_work.c b/kernel/task_work.c
index 54ac240..2134ac8 100644
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -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()
*
|