FAILED: patch "[PATCH] mm,hugetlb: take hugetlb_lock before decrementing" failed to apply to 5.4-stable tree

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Possible dependencies:

12df140f0bdf ("mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages") db71ef79b59b ("hugetlb: make free_huge_page irq safe")
10c6ec49802b ("hugetlb: change free_pool_huge_page to remove_pool_huge_page") 1121828a0c21 ("hugetlb: call update_and_free_page without hugetlb_lock") 6eb4e88a6d27 ("hugetlb: create remove_hugetlb_page() to separate functionality") 2938396771c8 ("hugetlb: add per-hstate mutex to synchronize user adjustments") 5c8ecb131a65 ("mm/hugetlb_cgroup: remove unnecessary VM_BUG_ON_PAGE in hugetlb_cgroup_migrate()") 5af1ab1d24e0 ("mm/hugetlb: optimize the surplus state transfer code in move_hugetlb_state()") 6c0371490140 ("hugetlb: convert PageHugeFreed to HPageFreed flag")
9157c31186c3 ("hugetlb: convert PageHugeTemporary() to HPageTemporary flag") 8f251a3d5ce3 ("hugetlb: convert page_huge_active() HPageMigratable flag") d6995da31122 ("hugetlb: use page.private for hugetlb specific page flags") dbfee5aee7e5 ("hugetlb: fix update_and_free_page contig page struct assumption") 3f1b0162f6f6 ("mm/hugetlb: remove unnecessary VM_BUG_ON_PAGE on putback_active_hugepage()") 1d88433bb008 ("mm/hugetlb: fix use after free when subpool max_hpages accounting is not enabled") 0aa7f3544aaa ("mm/hugetlb: avoid unnecessary hugetlb_acct_memory() call") ecbf4724e606 ("mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge_active") 0eb2df2b5629 ("mm: hugetlb: fix a race between isolating and freeing page") 7ffddd499ba6 ("mm: hugetlb: fix a race between freeing and dissolving the page") 585fc0d2871c ("mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 12df140f0bdfae5dcfc81800970dd7f6f632e00c Mon Sep 17 00:00:00 2001
From: Rik van Riel <[email protected]>
Date: Mon, 17 Oct 2022 20:25:05 -0400
Subject: [PATCH] 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.

index b586cdd75930..dede0337c07c 100644
@@ -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 */

From cd6ddb4b5dd029d41b380df32f81043631a26dc0 Mon Sep 17 00:00:00 2001
From: Rik van Riel <[email protected]>
Date: Wed, 26 Oct 2022 13:28:04 -0700
Subject: [PATCH] mm,hugetlb: take hugetlb_lock before decrementing
h->resv_huge_pages

commit 12df140f0bdfae5dcfc81800970dd7f6f632e00c upstream.

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.

---
 mm/hugetlb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index b6f029a1059f..2126d78f053d 100644
@@ -2218,11 +2218,11 @@ 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(&hugetlb_lock);
 		if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) {
 			SetPagePrivate(page);
 			h->resv_huge_pages--;
 		}
-		spin_lock(&hugetlb_lock);
 		list_move(&page->lru, &h->hugepage_activelist);
 		/* Fall through */
 	}

2.37.3