Commit 53b15717 authored by Liu Shixin's avatar Liu Shixin
Browse files

dhugetlb: make free_huge_page_to_dhugetlb_pool irq safe 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAU4UZ


CVE: NA

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

Like commit db71ef79 ("hugetlb: make free_huge_page irq safe") said,
the spinlock may be interrupt by hugetlb freeing path, which will results
deadlock. This patch fix such deadlock scenarios by changing spin_lock to
spin_lock_irq in every path.

Fixes: 0bc0d0d5 ("dhugetlb: backport dynamic hugetlb feature")
Signed-off-by: default avatarLiu Shixin <liushixin2@huawei.com>
parent 7de51028

mm/hugetlb.c

+18 −15
Original line number Diff line number Diff line
@@ -1387,6 +1387,7 @@ static void free_huge_page_to_dhugetlb_pool(struct page *page, 
{

	struct hstate *h = page_hstate(page);

	struct dhugetlb_pool *hpool;

	unsigned long flags;



	hpool = get_dhugetlb_pool_from_dhugetlb_pagelist(page);

	if (unlikely(!hpool)) {
@@ -1394,7 +1395,7 @@ static void free_huge_page_to_dhugetlb_pool(struct page *page, 
		return;

	}



	spin_lock(&hpool->lock);

	spin_lock_irqsave(&hpool->lock, flags);

	if (PageHWPoison(page))

		goto out;

	ClearPagePool(page);
@@ -1424,7 +1425,7 @@ static void free_huge_page_to_dhugetlb_pool(struct page *page, 
					  DHUGETLB_FREE_1G);

	}

out:

	spin_unlock(&hpool->lock);

	spin_unlock_irqrestore(&hpool->lock, flags);

	dhugetlb_pool_put(hpool);

}

#else
@@ -3380,6 +3381,7 @@ static inline void dhugetlb_percpu_pool_unlock_all(struct dhugetlb_pool *hpool) 
 */

void dhugetlb_lock_all(struct dhugetlb_pool *hpool)

{

	local_irq_disable();

	dhugetlb_percpu_pool_lock_all(hpool);

	spin_lock(&hpool->lock);

}
@@ -3390,6 +3392,7 @@ void dhugetlb_unlock_all(struct dhugetlb_pool *hpool) 


	spin_unlock(&hpool->lock);

	dhugetlb_percpu_pool_unlock_all(hpool);

	local_irq_enable();

}



bool dhugetlb_pool_get(struct dhugetlb_pool *hpool)
@@ -3452,8 +3455,8 @@ int alloc_hugepage_from_hugetlb(struct dhugetlb_pool *hpool, 
	if (!h)

		return -ENOMEM;



	spin_lock(&hpool->lock);

	spin_lock_irq(&hugetlb_lock);

	spin_lock_irq(&hpool->lock);

	spin_lock(&hugetlb_lock);

	if (h->free_huge_pages_node[nid] < size) {

		ret = -ENOMEM;

		goto out_unlock;
@@ -3475,8 +3478,8 @@ int alloc_hugepage_from_hugetlb(struct dhugetlb_pool *hpool, 
	}

	ret = 0;

out_unlock:

	spin_unlock_irq(&hugetlb_lock);

	spin_unlock(&hpool->lock);

	spin_unlock(&hugetlb_lock);

	spin_unlock_irq(&hpool->lock);

	return ret;

}
@@ -3759,13 +3762,13 @@ static void try_migrate_pages(struct dhugetlb_pool *hpool) 
	msleep(sleep_interval);

	dhugetlb_pool_force_empty(hpool->attach_memcg);



	spin_lock(&hpool->lock);

	spin_lock_irq(&hpool->lock);

	nr_free_pages = hpool->free_pages;

	spin_unlock(&hpool->lock);

	spin_unlock_irq(&hpool->lock);

	for (i = 0; i < NR_SMPOOL; i++) {

		spin_lock(&hpool->smpool[i].lock);

		spin_lock_irq(&hpool->smpool[i].lock);

		nr_free_pages += hpool->smpool[i].free_pages;

		spin_unlock(&hpool->smpool[i].lock);

		spin_unlock_irq(&hpool->smpool[i].lock);

	}



	if (nr_free_pages >> HUGETLB_PAGE_ORDER < hpool->nr_split_2M) {
@@ -4194,7 +4197,7 @@ static void dhugetlb_collect_2M_pages(struct dhugetlb_pool *hpool, 
	 * first, and then try to lock every lock in order to avoid deadlock.

	 */

	if (count > hpool->free_unreserved_2M) {

		spin_unlock(&hpool->lock);

		spin_unlock_irq(&hpool->lock);

		dhugetlb_lock_all(hpool);

		merge_free_small_page(hpool, count - hpool->free_unreserved_2M);

		/* Keep hpool->lock */
@@ -4213,7 +4216,7 @@ void dhugetlb_reserve_hugepages(struct dhugetlb_pool *hpool, 
{

	unsigned long delta;



	spin_lock(&hpool->lock);

	spin_lock_irq(&hpool->lock);

	if (gigantic) {

		if (count > hpool->total_reserved_1G) {

			delta = min(count - hpool->total_reserved_1G,
@@ -4248,7 +4251,7 @@ void dhugetlb_reserve_hugepages(struct dhugetlb_pool *hpool, 
			hpool->free_unreserved_2M += delta;

		}

	}

	spin_unlock(&hpool->lock);

	spin_unlock_irq(&hpool->lock);

}



static int dhugetlb_acct_memory(struct hstate *h, long delta,
@@ -4259,7 +4262,7 @@ static int dhugetlb_acct_memory(struct hstate *h, long delta, 
	if (delta == 0)

		return 0;



	spin_lock(&hpool->lock);

	spin_lock_irq(&hpool->lock);

	if (hstate_is_gigantic(h)) {

		if (delta > 0 && delta <= hpool->free_reserved_1G -

					  hpool->mmap_reserved_1G) {
@@ -4293,7 +4296,7 @@ static int dhugetlb_acct_memory(struct hstate *h, long delta, 
						   DHUGETLB_UNRESV_2M);

		}

	}

	spin_unlock(&hpool->lock);

	spin_unlock_irq(&hpool->lock);



	return ret;

}