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/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef LINUX_RESUME_USER_MODE_H
#define LINUX_RESUME_USER_MODE_H
#include <linux/sched.h>
#include <linux/task_work.h>
#include <linux/memcontrol.h>
#include <linux/rseq.h>
#include <linux/blk-cgroup.h>
/**
* set_notify_resume - cause resume_user_mode_work() to be called
* @task: task that will call resume_user_mode_work()
*
* Calling this arranges that @task will call resume_user_mode_work()
* before returning to user mode. If it's already running in user mode,
* it will enter the kernel and call resume_user_mode_work() soon.
* If it's blocked, it will not be woken.
*/
static inline void set_notify_resume(struct task_struct *task)
{
if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME))
kick_process(task);
}
/**
* resume_user_mode_work - Perform work before returning to user mode
* @regs: user-mode registers of @current task
*
* This is called when %TIF_NOTIFY_RESUME has been set. Now we are
* about to return to user mode, and the user state in @regs can be
* inspected or adjusted. The caller in arch code has cleared
* %TIF_NOTIFY_RESUME before the call. If the flag gets set again
* asynchronously, this will be called again before we return to
* user mode.
*
* Called without locks.
*/
static inline void resume_user_mode_work(struct pt_regs *regs)
{
clear_thread_flag(TIF_NOTIFY_RESUME);
/*
* This barrier pairs with task_work_add()->set_notify_resume() after
* hlist_add_head(task->task_works);
*/
smp_mb__after_atomic();
if (unlikely(task_work_pending(current)))
task_work_run();
#ifdef CONFIG_KEYS_REQUEST_CACHE
if (unlikely(current->cached_requested_key)) {
key_put(current->cached_requested_key);
current->cached_requested_key = NULL;
}
#endif
mem_cgroup_handle_over_high(GFP_KERNEL);
blkcg_maybe_throttle_current();
rseq_handle_notify_resume(NULL, regs);
}
#endif /* LINUX_RESUME_USER_MODE_H */
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