Commit 07e53c79 authored by Wang Wensheng's avatar Wang Wensheng
Browse files

mm/sharepool: Implement mg_sp_id_of_current() 

ascend inclusion
category: Feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8LNGH



---------------------------------------------

This is used to get the local group id of current process.  When
the process is exiting, the caller of sp_free/sp_unshare must
supply a real spg_id instead of zero. Because the current->mm is NULL
and we cannot access the spg via the mm_struct of current.

Signed-off-by: default avatarWang Wensheng <wangwensheng4@huawei.com>
parent 61df94ce

mm/share_pool.c

+102 −2
Original line number Diff line number Diff line
@@ -505,9 +505,81 @@ static int sp_group_setup_mapping(struct mm_struct *mm, struct sp_group *spg) 
		return sp_group_setup_mapping_normal(mm, spg);

}



static struct sp_group *sp_group_create(int spg_id);

static void sp_group_put_locked(struct sp_group *spg);

static int sp_group_link_task(struct mm_struct *mm, struct sp_group *spg,

			      unsigned long prot, struct sp_group_node **pnode);

static int init_local_group(struct mm_struct *mm)

{

	int ret;

	struct sp_group *spg;

	struct sp_group_master *master = mm->sp_group_master;



	spg = sp_group_create(SPG_ID_LOCAL);

	if (IS_ERR(spg))

		return PTR_ERR(spg);



	ret = sp_group_link_task(mm, spg, PROT_READ | PROT_WRITE, NULL);

	sp_group_put_locked(spg);

	if (!ret)

		master->local = spg;



	return ret;

}



/* The caller must hold sp_global_sem and the input @mm cannot be freed */

static int sp_init_group_master_locked(struct task_struct *tsk, struct mm_struct *mm)

{

	int ret;

	struct sp_group_master *master;



	if (mm->sp_group_master)

		return 0;



	master = kmalloc(sizeof(struct sp_group_master), GFP_KERNEL);

	if (!master)

		return -ENOMEM;



	INIT_LIST_HEAD(&master->group_head);

	master->group_num = 0;

	master->mm = mm;

	master->tgid = tsk->tgid;

	get_task_comm(master->comm, current);

	meminfo_init(&master->meminfo);

	mm->sp_group_master = master;

	sp_add_group_master(master);



	ret = init_local_group(mm);

	if (ret)

		goto free_master;



	return 0;



free_master:

	sp_del_group_master(master);

	mm->sp_group_master = NULL;

	kfree(master);



	return ret;

}



static int sp_init_group_master(struct task_struct *tsk, struct mm_struct *mm)

{

	return -EOPNOTSUPP;

	int ret;



	down_read(&sp_global_sem);

	/* The sp_group_master would never change once set */

	if (mm->sp_group_master) {

		up_read(&sp_global_sem);

		return 0;

	}

	up_read(&sp_global_sem);



	down_write(&sp_global_sem);

	ret = sp_init_group_master_locked(tsk, mm);

	up_write(&sp_global_sem);



	return ret;

}



static void update_mem_usage_alloc(unsigned long size, bool inc,
@@ -1317,7 +1389,35 @@ EXPORT_SYMBOL_GPL(mg_sp_group_add_task); 


int mg_sp_id_of_current(void)

{

	int ret, spg_id;

	struct sp_group_master *master;



	if (!sp_is_enabled())

		return -EOPNOTSUPP;



	if ((current->flags & PF_KTHREAD) || !current->mm)

		return -EINVAL;



	down_read(&sp_global_sem);

	master = current->mm->sp_group_master;

	if (master) {

		spg_id = master->local->id;

		up_read(&sp_global_sem);

		return spg_id;

	}

	up_read(&sp_global_sem);



	down_write(&sp_global_sem);

	ret = sp_init_group_master_locked(current, current->mm);

	if (ret) {

		up_write(&sp_global_sem);

		return ret;

	}

	master = current->mm->sp_group_master;

	spg_id = master->local->id;

	up_write(&sp_global_sem);



	return spg_id;

}

EXPORT_SYMBOL_GPL(mg_sp_id_of_current);