Commit 025839c1 authored by Peng Liu's avatar Peng Liu Committed by Liu Shixin
Browse files

hugetlb: fix wrong use of nr_online_nodes 

mainline inclusion
from mainline-v5.19-rc1
commit 0a7a0f6f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6OWV4
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0a7a0f6f7f3679c906fc55e3805c1d5e2c566f55

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

Patch series "hugetlb: Fix some incorrect behavior", v3.

This series fix three bugs of hugetlb:
1) Invalid use of nr_online_nodes;
2) Inconsistency between 1G hugepage and 2M hugepage;
3) Useless information in dmesg.

This patch (of 4):

Certain systems are designed to have sparse/discontiguous nodes.  In this
case, nr_online_nodes can not be used to walk through numa node.  Also, a
valid node may be greater than nr_online_nodes.

However, in hugetlb, it is assumed that nodes are contiguous.

For sparse/discontiguous nodes, the current code may treat a valid node
as invalid, and will fail to allocate all hugepages on a valid node that
"nid >= nr_online_nodes".

As David suggested:

	if (tmp >= nr_online_nodes)
		goto invalid;

Just imagine node 0 and node 2 are online, and node 1 is offline.
Assuming that "node < 2" is valid is wrong.

Recheck all the places that use nr_online_nodes, and repair them one by
one.

[liupeng256@huawei.com: v4]
  Link: https://lkml.kernel.org/r/20220416103526.3287348-1-liupeng256@huawei.com
Link: https://lkml.kernel.org/r/20220413032915.251254-1-liupeng256@huawei.com
Link: https://lkml.kernel.org/r/20220413032915.251254-2-liupeng256@huawei.com


Fixes: 4178158e ("hugetlbfs: fix issue of preallocation of gigantic pages can't work")
Fixes: b5389086 ("hugetlbfs: extend the definition of hugepages parameter to support node allocation")
Fixes: e79ce983 ("hugetlbfs: fix a truncation issue in hugepages parameter")
Fixes: f9317f77 ("hugetlb: clean up potential spectre issue warnings")
Signed-off-by: default avatarPeng Liu <liupeng256@huawei.com>
Suggested-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarBaolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: default avatarDavidlohr Bueso <dave@stgolabs.net>
Reviewed-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Zhenguo Yao <yaozhenguo1@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Liu Yuntao <liuyuntao10@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Conflicts:
	mm/hugetlb.c
Signed-off-by: default avatarLiu Shixin <liushixin2@huawei.com>
parent 7e747d5c

mm/hugetlb.c

+4 −6
Original line number Diff line number Diff line
@@ -2642,8 +2642,6 @@ int __alloc_bootmem_huge_page(struct hstate *h, int nid) 
	struct huge_bootmem_page *m = NULL; /* initialize for clang */

	int nr_nodes, node;



	if (nid != NUMA_NO_NODE && nid >= nr_online_nodes)

		return 0;

	/* do node specific alloc */

	if (nid != NUMA_NO_NODE) {

		m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h),
@@ -2751,7 +2749,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 
	}



	/* do node specific alloc */

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

	for_each_online_node(i) {

		if (h->max_huge_pages_node[i] > 0) {

			hugetlb_hstate_alloc_pages_onenode(h, i);

			node_specific_alloc = true;
@@ -3488,7 +3486,7 @@ static int __init hugetlb_init(void) 
			default_hstate.max_huge_pages =

				default_hstate_max_huge_pages;



			for (i = 0; i < nr_online_nodes; i++)

			for_each_online_node(i)

				default_hstate.max_huge_pages_node[i] =

					default_hugepages_in_node[i];

		}
@@ -3607,7 +3605,7 @@ static int __init hugepages_setup(char *s) 
				pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n");

				return 0;

			}

			if (tmp >= nr_online_nodes)

			if (tmp >= MAX_NUMNODES || !node_online(tmp))

				goto invalid;

			node = tmp;

			p += count + 1;
@@ -3737,7 +3735,7 @@ static int __init default_hugepagesz_setup(char *s) 
	 */

	if (default_hstate_max_huge_pages) {

		default_hstate.max_huge_pages = default_hstate_max_huge_pages;

		for (i = 0; i < nr_online_nodes; i++)

		for_each_online_node(i)

			default_hstate.max_huge_pages_node[i] =

				default_hugepages_in_node[i];

		if (hstate_is_gigantic(&default_hstate))