diff options
| author | Rik van Riel <[email protected]> | 2022-10-17 20:25:05 -0400 |
|---|---|---|
| committer | Andrew Morton <[email protected]> | 2022-10-20 21:27:23 -0700 |
| commit | 12df140f0bdfae5dcfc81800970dd7f6f632e00c (patch) | |
| tree | 4f01975b2e74e627bd9bdba5863b2f97622504c5 | |
| parent | a57b70519d1f7c53be98478623652738e5ac70d5 (diff) | |
mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages
The h->*_huge_pages counters are protected by the hugetlb_lock, but
alloc_huge_page has a corner case where it can decrement the counter
outside of the lock.
This could lead to a corrupted value of h->resv_huge_pages, which we have
observed on our systems.
Take the hugetlb_lock before decrementing h->resv_huge_pages to avoid a
potential race.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: a88c76954804 ("mm: hugetlb: fix hugepage memory leak caused by wrong reserve count")
Signed-off-by: Rik van Riel <[email protected]>
Reviewed-by: Mike Kravetz <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Glen McCready <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
| -rw-r--r-- | mm/hugetlb.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index b586cdd75930..dede0337c07c 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2924,11 +2924,11 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, page = alloc_buddy_huge_page_with_mpol(h, vma, addr); if (!page) goto out_uncharge_cgroup; + spin_lock_irq(&hugetlb_lock); if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { SetHPageRestoreReserve(page); h->resv_huge_pages--; } - spin_lock_irq(&hugetlb_lock); list_add(&page->lru, &h->hugepage_activelist); set_page_refcounted(page); /* Fall through */ |