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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 538CAC43381 for ; Mon, 11 Mar 2019 17:16:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1614420643 for ; Mon, 11 Mar 2019 17:16:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552324582; bh=XyRiSbakFGkwfOutv9gt2AJ+tOM59q+juMy/UfRF3kU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Qz4xuiiMxI1oiV+Jomp567jHCoWVu67pOjquRVMoB7vS65bO57ECr/T07pQ8BLItW lh+uZPu8ychom/PKSpcdZs5QCgzDbj/gnLM1vVd1eDh/FFbmG+7hXbW+6LVrBrvdmo ggR8qjZI2vd5o31+PA3X1b5Q0YYMXMvuNy49yrxU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727008AbfCKRQV (ORCPT ); Mon, 11 Mar 2019 13:16:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:41274 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726977AbfCKRQV (ORCPT ); Mon, 11 Mar 2019 13:16:21 -0400 Received: from localhost (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3F4BC205F4; Mon, 11 Mar 2019 17:16:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552324580; bh=XyRiSbakFGkwfOutv9gt2AJ+tOM59q+juMy/UfRF3kU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tqRDducpQ4e6nym3NkdKSMRpNLwWa5wcqtuiPKmLHxE4xJfvXL2f9WWnPtQ2/Qrmv WUio5cZk4a1zWCuTBBQaOhMBZMemPZ8IkdNL88sPR4JmbCpvlX8CwZ9iho2tkwEEvA vP7MwW0jiQ/ecb6+OmOJXKYeWljw8aZHLtaZbxEo= Date: Mon, 11 Mar 2019 13:16:19 -0400 From: Sasha Levin To: Will Deacon Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, marc.zyngier@arm.com Subject: Re: [PATCH AUTOSEL 4.19 47/64] arm64: ptdump: Don't iterate kernel page tables using PTRS_PER_PXX Message-ID: <20190311171619.GE158926@sasha-vm> References: <20190228151105.11277-1-sashal@kernel.org> <20190228151105.11277-47-sashal@kernel.org> <20190228151822.GB8571@fuggles.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20190228151822.GB8571@fuggles.cambridge.arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, Feb 28, 2019 at 03:18:22PM +0000, Will Deacon wrote: >On Thu, Feb 28, 2019 at 10:10:48AM -0500, Sasha Levin wrote: >> From: Will Deacon >> >> [ Upstream commit d23c808c6fc6132e812690648e14c0d6b0cbe273 ] >> >> When 52-bit virtual addressing is enabled for userspace >> (CONFIG_ARM64_USER_VA_BITS_52=y), the kernel continues to utilise 48-bit >> virtual addressing in TTBR1. Consequently, PTRS_PER_PGD reflects the >> larger page table size for userspace and the pgd pointer for kernel page >> tables is offset before being written to TTBR1. >> >> This means that we can't use PTRS_PER_PGD to iterate over kernel page >> tables unless we apply the same offset, which is fiddly to get right and >> leads to some non-idiomatic walking code. Instead, just follow the usual >> pattern when walking page tables by using a while loop driven by >> pXd_offset() and pXd_addr_end(). >> >> Reported-by: Qian Cai >> Tested-by: Qian Cai >> Acked-by: Steve Capper >> Tested-by: Steve Capper >> Signed-off-by: Will Deacon >> Signed-off-by: Sasha Levin >> --- >> arch/arm64/mm/dump.c | 59 ++++++++++++++++++++++---------------------- >> 1 file changed, 29 insertions(+), 30 deletions(-) > >This isn't needed for any released kernels. In future, is there a tag I can >use to prevent a patch from being picked up by the AUTOSEL bot? That way you >can distinguish "I forgot to cc stable" from "I deliberately didn't cc >stable". I've dropped it, thanks! Generally the bot will look into a Fixes: tag, and if the commit pointed to it is not in the tree then the patch won't be picked up. -- Thanks, Sasha