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Thu, 14 Jan 2021 10:38:45 +0000 (UTC) Received: by mail-pf1-f171.google.com with SMTP id c12so3088719pfo.10 for ; Thu, 14 Jan 2021 02:38:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=0cYwNXoL62ufowFhR51LMghCmA8txi2r5XxTjm0v6q4=; b=WAckzXA3NYKMKzPO7d3fxmhmFa8XPvuFtpLdTcYJt0gP2l6AyanNdZetxWYn6M6gh8 EKuAhkJ6BYRwelX6ez+H0e0UwT09Rsu1xybpU2VtIhSNwzQ4q564A5sHSawFcgoY9os5 aRZU6FJl2PWqX/JDf7WGYUMv6bB57KPfWNlRn5mAAwJ4TbBZjzwFRwyh+fKQFrlN9HMc AvQvmaLzm4gORcjnaSbXJ8kNWYLsxPdqFhs/H/MNrGp7PBz5QrXC8MhkbZ1saUcpzFhT 28eZaFI5C/HuYjZZMBu5/YFIV5rta7rOuHR6JMNWnCGh2KIUhh/mpFuG8LKNOD1QzfZ+ KVZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=0cYwNXoL62ufowFhR51LMghCmA8txi2r5XxTjm0v6q4=; 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CPU0: CPU1: if (PageHuge(page)) put_page(page) __free_huge_page(page) spin_lock(&hugetlb_lock= ) update_and_free_page(pa= ge) set_compound_page_dto= r(page, NULL_COMPOUND_DTOR) spin_unlock(&hugetlb_lo= ck) isolate_huge_page(page) // trigger BUG_ON VM_BUG_ON_PAGE(!PageHead(page), page) spin_lock(&hugetlb_lock) page_huge_active(page) // trigger BUG_ON VM_BUG_ON_PAGE(!PageHuge(page), page) spin_unlock(&hugetlb_lock) When we isolate a HugeTLB page on CPU0. Meanwhile, we free it to the buddy allocator on CPU1. Then, we can trigger a BUG_ON on CPU0. Because it is already freed to the buddy allocator. Fixes: c8721bbbdd36 ("mm: memory-hotplug: enable memory hotplug to handle= hugepage") Signed-off-by: Muchun Song Reviewed-by: Mike Kravetz Acked-by: Michal Hocko Cc: stable@vger.kernel.org --- mm/hugetlb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 1b789d1fd06b..43b7a044f248 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5574,9 +5574,9 @@ bool isolate_huge_page(struct page *page, struct li= st_head *list) { bool ret =3D true; =20 - VM_BUG_ON_PAGE(!PageHead(page), page); spin_lock(&hugetlb_lock); - if (!page_huge_active(page) || !get_page_unless_zero(page)) { + if (!PageHeadHuge(page) || !page_huge_active(page) || + !get_page_unless_zero(page)) { ret =3D false; goto unlock; } --=20 2.11.0