提交 999737ef 编写于 作者: M Mike Kravetz 提交者: Zheng Zengkai

hugetlb: add per-hstate mutex to synchronize user adjustments

mainline inclusion
from mainline-v5.13-rc1
commit 29383967
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I3ZCW9
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2938396771c8fd0870b5284319f9e78b4b552a79

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

The helper routine hstate_next_node_to_alloc accesses and modifies the
hstate variable next_nid_to_alloc.  The helper is used by the routines
alloc_pool_huge_page and adjust_pool_surplus.  adjust_pool_surplus is
called with hugetlb_lock held.  However, alloc_pool_huge_page can not be
called with the hugetlb lock held as it will call the page allocator.
Two instances of alloc_pool_huge_page could be run in parallel or
alloc_pool_huge_page could run in parallel with adjust_pool_surplus
which may result in the variable next_nid_to_alloc becoming invalid for
the caller and pages being allocated on the wrong node.

Both alloc_pool_huge_page and adjust_pool_surplus are only called from
the routine set_max_huge_pages after boot.  set_max_huge_pages is only
called as the reusult of a user writing to the proc/sysfs nr_hugepages,
or nr_hugepages_mempolicy file to adjust the number of hugetlb pages.

It makes little sense to allow multiple adjustment to the number of
hugetlb pages in parallel.  Add a mutex to the hstate and use it to only
allow one hugetlb page adjustment at a time.  This will synchronize
modifications to the next_nid_to_alloc variable.

Link: https://lkml.kernel.org/r/20210409205254.242291-4-mike.kravetz@oracle.comSigned-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NMuchun Song <songmuchun@bytedance.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NChen Huang <chenhuang5@huawei.com>
Signed-off-by: NNanyong Sun <sunnanyong@huawei.com>
Reviewed-by: NTong Tiangen <tongtiangen@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
上级 6592d62f
......@@ -545,6 +545,7 @@ HPAGEFLAG(Freed, freed)
#define HSTATE_NAME_LEN 32
/* Defines one hugetlb page size */
struct hstate {
struct mutex resize_lock;
int next_nid_to_alloc;
int next_nid_to_free;
unsigned int order;
......
......@@ -2609,6 +2609,11 @@ static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid,
else
return -ENOMEM;
/*
* resize_lock mutex prevents concurrent adjustments to number of
* pages in hstate via the proc/sysfs interfaces.
*/
mutex_lock(&h->resize_lock);
spin_lock(&hugetlb_lock);
/*
......@@ -2641,6 +2646,7 @@ static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid,
if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) {
if (count > persistent_huge_pages(h)) {
spin_unlock(&hugetlb_lock);
mutex_unlock(&h->resize_lock);
NODEMASK_FREE(node_alloc_noretry);
return -EINVAL;
}
......@@ -2715,6 +2721,7 @@ static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid,
out:
h->max_huge_pages = persistent_huge_pages(h);
spin_unlock(&hugetlb_lock);
mutex_unlock(&h->resize_lock);
NODEMASK_FREE(node_alloc_noretry);
......@@ -3201,6 +3208,7 @@ void __init hugetlb_add_hstate(unsigned int order)
BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE);
BUG_ON(order == 0);
h = &hstates[hugetlb_max_hstate++];
mutex_init(&h->resize_lock);
h->order = order;
h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
h->nr_huge_pages = 0;
......
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