From patchwork Fri May 13 14:24:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 572911 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E5BBC433F5 for ; Fri, 13 May 2022 14:33:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345728AbiEMOdl (ORCPT ); Fri, 13 May 2022 10:33:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381197AbiEMOdP (ORCPT ); Fri, 13 May 2022 10:33:15 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1766A1BDDA6; Fri, 13 May 2022 07:29:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 77E7ECE2DCA; Fri, 13 May 2022 14:29:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C9F7C34100; Fri, 13 May 2022 14:29:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652452169; bh=FZPKT8Vaud+Ka1B8TAAY9womsdW5sCwshQJQL7hUJDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hyWbC9l+hTWzWumOF4ZYUV+E7UP60sfJmlf3kqL3o9r+PURSqDLwHCMm1VQejiNcc ajOrAqHreEZsDKvX1+kL2FdvSsD3RheVumDVSmuzhfXB0TvNa//4jsQ0gzhdY06UUj oFlSNz8jKXoIrZDsFMmQY5dZdS26QM+wsMFQMxEA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Muchun Song , Mike Kravetz , Axel Rasmussen , David Rientjes , Fam Zheng , "Kirill A. Shutemov" , Lars Persson , Peter Xu , Xiongchun Duan , Zi Yan , Andrew Morton , Linus Torvalds Subject: [PATCH 5.17 06/12] mm: hugetlb: fix missing cache flush in hugetlb_mcopy_atomic_pte() Date: Fri, 13 May 2022 16:24:06 +0200 Message-Id: <20220513142228.841619815@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220513142228.651822943@linuxfoundation.org> References: <20220513142228.651822943@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Muchun Song commit 348923665a0e50ad9fc0b3bb8127d3cb976691cc upstream. folio_copy() will copy the data from one page to the target page, then the target page will be mapped to the user space address, which might have an alias issue with the kernel address used to copy the data from the page to. There are 2 ways to fix this issue. 1) insert flush_dcache_page() after folio_copy(). 2) replace folio_copy() with copy_user_huge_page() which already considers the cache maintenance. We chose 2) way to fix the issue since architectures can optimize this situation. It is also make backports easier. Link: https://lkml.kernel.org/r/20220210123058.79206-5-songmuchun@bytedance.com Fixes: 8cc5fcbb5be8 ("mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY") Signed-off-by: Muchun Song Reviewed-by: Mike Kravetz Cc: Axel Rasmussen Cc: David Rientjes Cc: Fam Zheng Cc: Kirill A. Shutemov Cc: Lars Persson Cc: Peter Xu Cc: Xiongchun Duan Cc: Zi Yan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5820,7 +5820,8 @@ int hugetlb_mcopy_atomic_pte(struct mm_s *pagep = NULL; goto out; } - folio_copy(page_folio(page), page_folio(*pagep)); + copy_user_huge_page(page, *pagep, dst_addr, dst_vma, + pages_per_huge_page(h)); put_page(*pagep); *pagep = NULL; }