From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8D7BC004C9 for ; Tue, 7 May 2019 05:56:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B15172087F for ; Tue, 7 May 2019 05:56:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557208585; bh=y9ZLVXMrz9krp9KqLxl4O+qrXhLwZoiMvHNYlQn2wu8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0mUIhoQeESE2LBedQrpX0uKHb8xy6U133BTSSkT+xkspoVvSSOV7kCgWJlIvVyL8X ApsOflBR17Eg0YfITYmPl1Y4U/h6WLRqgsJf9HKmmJL/Ah7rL960ernmVMGcVFWg50 sg1EHLyBc4YTynVyTNROSVZfCBFG3Pg55VXmAaqc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728609AbfEGF4Y (ORCPT ); Tue, 7 May 2019 01:56:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:57834 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727983AbfEGFiD (ORCPT ); Tue, 7 May 2019 01:38:03 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C11A421655; Tue, 7 May 2019 05:38:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557207482; bh=y9ZLVXMrz9krp9KqLxl4O+qrXhLwZoiMvHNYlQn2wu8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cJzielO5QAPxr5NXCU89nVN8nPJnzsYPuPtBAZGRWiZoTtL30Hh1rt72TISAzZif2 MU+Uk5v5s1Jvx9jHSvOxFb+mtUmeubSBJJsNRRMIs2YV2QuRR/yCi9G6S7qxRzmgs9 6ObaPFkKUtUDJW1vG3fdmSoaNGt1BFX59h/D15rM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jan Kara , "Aneesh Kumar K.V" , Dan Williams , Chandan Rajendra , Andrew Morton , Linus Torvalds , Sasha Levin , linux-mm@kvack.org Subject: [PATCH AUTOSEL 4.19 67/81] mm/memory.c: fix modifying of page protection by insert_pfn() Date: Tue, 7 May 2019 01:35:38 -0400 Message-Id: <20190507053554.30848-67-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190507053554.30848-1-sashal@kernel.org> References: <20190507053554.30848-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Kara [ Upstream commit cae85cb8add35f678cf487139d05e083ce2f570a ] Aneesh has reported that PPC triggers the following warning when excercising DAX code: IP set_pte_at+0x3c/0x190 LR insert_pfn+0x208/0x280 Call Trace: insert_pfn+0x68/0x280 dax_iomap_pte_fault.isra.7+0x734/0xa40 __xfs_filemap_fault+0x280/0x2d0 do_wp_page+0x48c/0xa40 __handle_mm_fault+0x8d0/0x1fd0 handle_mm_fault+0x140/0x250 __do_page_fault+0x300/0xd60 handle_page_fault+0x18 Now that is WARN_ON in set_pte_at which is VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep)); The problem is that on some architectures set_pte_at() cannot cope with a situation where there is already some (different) valid entry present. Use ptep_set_access_flags() instead to modify the pfn which is built to deal with modifying existing PTE. Link: http://lkml.kernel.org/r/20190311084537.16029-1-jack@suse.cz Fixes: b2770da64254 "mm: add vm_insert_mixed_mkwrite()" Signed-off-by: Jan Kara Reported-by: "Aneesh Kumar K.V" Reviewed-by: Aneesh Kumar K.V Acked-by: Dan Williams Cc: Chandan Rajendra Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/memory.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 9c69278173b7..e0010cb870e0 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1796,10 +1796,12 @@ static int insert_pfn(struct vm_area_struct *vma, unsigned long addr, WARN_ON_ONCE(!is_zero_pfn(pte_pfn(*pte))); goto out_unlock; } - entry = *pte; - goto out_mkwrite; - } else - goto out_unlock; + entry = pte_mkyoung(*pte); + entry = maybe_mkwrite(pte_mkdirty(entry), vma); + if (ptep_set_access_flags(vma, addr, pte, entry, 1)) + update_mmu_cache(vma, addr, pte); + } + goto out_unlock; } /* Ok, finally just insert the thing.. */ @@ -1808,7 +1810,6 @@ static int insert_pfn(struct vm_area_struct *vma, unsigned long addr, else entry = pte_mkspecial(pfn_t_pte(pfn, prot)); -out_mkwrite: if (mkwrite) { entry = pte_mkyoung(entry); entry = maybe_mkwrite(pte_mkdirty(entry), vma); -- 2.20.1