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