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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 3606FC54E4B for ; Tue, 12 May 2020 05:15:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B87320733 for ; Tue, 12 May 2020 05:15:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="NxeO0LEO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728835AbgELFPN (ORCPT ); Tue, 12 May 2020 01:15:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725776AbgELFPM (ORCPT ); Tue, 12 May 2020 01:15:12 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D90CC061A0C for ; Mon, 11 May 2020 22:15:12 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id f7so5797334pfa.9 for ; Mon, 11 May 2020 22:15:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=hkw/Z63xQHG8uMp0IH/cCnzDA8TYdvaGr2m+4SY43mQ=; b=NxeO0LEOxjSFPTHG2C8P6nGRpFSnOQS4nM0rEMQT5Qmce3eP8ATPEFQ5t6N0YnCvl8 uXPC4uUm7iPJ23kuR7NeQ4LaqrZf6uLqsdv01pHYCOWKmjyZkdJs4+ayMsSqDgwMW4Al okZIIW6hD7YscBdv3SDXPH1XadUmgOOLWh5As= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=hkw/Z63xQHG8uMp0IH/cCnzDA8TYdvaGr2m+4SY43mQ=; b=NliYwgwMRVWiJrUkyRn90BJFLH2BGnjB62f0D7VfC77u0C98jY06uj3lCMU5i+ZEjn QDftqKOkclKeXNOHuZbdtLUR3iCYs3+0xuH4fg613rGlgkPw0zpgqn6wbGT1V4Zm4edU ByGzaIwjFNp1CT2+3A6GrAUyJCLs1IOpYkVszpz5GMWnVKidsRc9ON/FDLfBRhKsSpvX J79H/4ZZItVdBY9MnW9lEi3EnoFI80dEJbqCDAsD2eGwzZXQnK1FSMIwStu3Zpt7w/AM jdJ8AztsYVrkgdzvhwMNaPlgiB9lw+nP1nAWztKOubkfv5rESiXK5sneCeJqU3RncQLT 9FUA== X-Gm-Message-State: AGi0PubhzepeYj2SWiUpRIVcMt2stiVGknyYqn6FW0UDlezYtwfalWCQ 7VH1G7f1B+uWHUDQ6auZzU2gGHy97R8= X-Google-Smtp-Source: APiQypLHR8TY4hZJxKV8zGV9lZbtbRZMhdgZf2g/71c4CVlnO4S4AhYYCUHD5RLGcmuTYmodJ37Qhw== X-Received: by 2002:a63:4665:: with SMTP id v37mr17003825pgk.297.1589260512040; Mon, 11 May 2020 22:15:12 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id t188sm10768564pfb.185.2020.05.11.22.15.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 May 2020 22:15:11 -0700 (PDT) Date: Mon, 11 May 2020 22:15:10 -0700 From: Kees Cook To: WeiXiong Liao Cc: Anton Vorontsov , Colin Cross , Tony Luck , Jonathan Corbet , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Rob Herring , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org Subject: Re: [PATCH v8 01/11] pstore/zone: Introduce common layer to manage storage zones Message-ID: <202005112212.2E75B83@keescook> References: <20200511233229.27745-1-keescook@chromium.org> <20200511233229.27745-2-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 12, 2020 at 11:55:20AM +0800, WeiXiong Liao wrote: > On 2020/5/12 AM 7:32, Kees Cook wrote: > > [...] > > +struct psz_context { > > + struct pstore_zone **kpszs; > > + unsigned int kmsg_max_cnt; > > + unsigned int kmsg_read_cnt; > > + unsigned int kmsg_write_cnt; > > + /* > > + * These counters should be calculated during recovery. > > + * It records the oops/panic times after crashes rather than boots. > > + */ > > + unsigned int oops_counter; > > + unsigned int panic_counter; > > oops/panic_counter is designed to count the crash times since the > linux kernel was installed. pstore/zone lookup the max counter from all > valid kmsg zones when recovery and saves them to oops/panic_counter. > However, they are unable to get real number if we remove files. It's > not serious, we can fix it after this series. Since the kernel was installed? I don't see a kernel version check in here? Or do you mean "since ever", in that it's a rolling count? > And since pstore supports "max_reason", should pstore/zone count for > other reason? For now, no. I opted to try to keep this as simple as possible a port from dump_oops to max_reason for now. > > +static inline int psz_kmsg_erase(struct psz_context *cxt, > > + struct pstore_zone *zone, struct pstore_record *record) > > +{ > > + struct psz_buffer *buffer = zone->buffer; > > + struct psz_kmsg_header *hdr = > > + (struct psz_kmsg_header *)buffer->data; > > + > > + if (unlikely(!psz_ok(zone))) > > + return 0; > > + /* this zone is already updated, no need to erase */ > > + if (record->count != hdr->counter) > > + return 0; > > These codes is to fix bug that user remove files on pstore filesystem > but kmsg zone is already updated and pstore/zone should not erase > zone. It work for oops and panic because the count number is increasing. > However, it's useless for other reason of kmsg. We can fix it after this > series. Okay, sounds good. -- Kees Cook