summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorFrederic Weisbecker <frederic@kernel.org>2024-06-21 11:15:59 +0200
committerPeter Zijlstra <peterz@infradead.org>2024-07-09 13:26:32 +0200
commitf409530e4db9dd11b88cb7703c97c8f326ff6566 (patch)
tree212a4af10e9204f1d4c0abf7cc5a01584347a993
parent68cbd415dd4b9c5b9df69f0f091879e56bf5907a (diff)
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@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240621091601.18227-3-frederic@kernel.org
-rw-r--r--include/linux/task_work.h1
-rw-r--r--kernel/task_work.c24
2 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/task_work.h b/include/linux/task_work.h
index 23ab01ae185e..26b8a47f41fc 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 54ac24059daa..2134ac8057a9 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()
*