cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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resume_user_mode.h (1896B)

      1/* SPDX-License-Identifier: GPL-2.0-only */
      2
      3#ifndef LINUX_RESUME_USER_MODE_H
      4#define LINUX_RESUME_USER_MODE_H
      5
      6#include <linux/sched.h>
      7#include <linux/task_work.h>
      8#include <linux/memcontrol.h>
      9#include <linux/blk-cgroup.h>
     10
     11/**
     12 * set_notify_resume - cause resume_user_mode_work() to be called
     13 * @task:		task that will call resume_user_mode_work()
     14 *
     15 * Calling this arranges that @task will call resume_user_mode_work()
     16 * before returning to user mode.  If it's already running in user mode,
     17 * it will enter the kernel and call resume_user_mode_work() soon.
     18 * If it's blocked, it will not be woken.
     19 */
     20static inline void set_notify_resume(struct task_struct *task)
     21{
     22	if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME))
     23		kick_process(task);
     24}
     25
     26
     27/**
     28 * resume_user_mode_work - Perform work before returning to user mode
     29 * @regs:		user-mode registers of @current task
     30 *
     31 * This is called when %TIF_NOTIFY_RESUME has been set.  Now we are
     32 * about to return to user mode, and the user state in @regs can be
     33 * inspected or adjusted.  The caller in arch code has cleared
     34 * %TIF_NOTIFY_RESUME before the call.  If the flag gets set again
     35 * asynchronously, this will be called again before we return to
     36 * user mode.
     37 *
     38 * Called without locks.
     39 */
     40static inline void resume_user_mode_work(struct pt_regs *regs)
     41{
     42	clear_thread_flag(TIF_NOTIFY_RESUME);
     43	/*
     44	 * This barrier pairs with task_work_add()->set_notify_resume() after
     45	 * hlist_add_head(task->task_works);
     46	 */
     47	smp_mb__after_atomic();
     48	if (unlikely(task_work_pending(current)))
     49		task_work_run();
     50
     51#ifdef CONFIG_KEYS_REQUEST_CACHE
     52	if (unlikely(current->cached_requested_key)) {
     53		key_put(current->cached_requested_key);
     54		current->cached_requested_key = NULL;
     55	}
     56#endif
     57
     58	mem_cgroup_handle_over_high();
     59	blkcg_maybe_throttle_current();
     60
     61	rseq_handle_notify_resume(NULL, regs);
     62}
     63
     64#endif /* LINUX_RESUME_USER_MODE_H */