From patchwork Tue Jan 7 20:53:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 234273 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 26116C33C9B for ; Tue, 7 Jan 2020 21:23:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E47C72087F for ; Tue, 7 Jan 2020 21:23:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578432233; bh=ghJPWWuvqI+2W+7yB5CB5Xw2G0Ec0DSRSw0S2VlnfGc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dlFzQvRdpBMLGYl0uJPMbWxkzVHODNGwaM8/VTiDfWiRAirTbqizFrQ3QYXR7xP28 /KaJZcsOW5IlTwhqUVKYpr5zZ5BvDmd5Ft7SX1PyIXrZBA28Z1fVwoHBT4zItOyvob Ee9Bjzcik6tMFouPbvFx/fvUtXLBNUZOyKbmxE4w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728484AbgAGVBC (ORCPT ); Tue, 7 Jan 2020 16:01:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:37424 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728477AbgAGVBA (ORCPT ); Tue, 7 Jan 2020 16:01:00 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 B06D021744; Tue, 7 Jan 2020 21:00:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578430860; bh=ghJPWWuvqI+2W+7yB5CB5Xw2G0Ec0DSRSw0S2VlnfGc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X3a71wNqP4FKYb30vhBZ5xFe05xen1sQDC2TyFBGX4RzXD8ejyn3X9OoHqjbgqk5N 6ShPbOxNouJgv7RYu3tEvKI1jkUemHQKvrFk9MxrDCalluP/56mQALZ4GgICY/+UT7 Nz5Tl3t1piIjS01evoz4/vV6dOwdzE05WEV+7eoA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Aleksandr Yashkin , Nikolay Merinov , Ariel Gilman , Kees Cook Subject: [PATCH 5.4 089/191] pstore/ram: Write new dumps to start of recycled zones Date: Tue, 7 Jan 2020 21:53:29 +0100 Message-Id: <20200107205337.761682618@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200107205332.984228665@linuxfoundation.org> References: <20200107205332.984228665@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Aleksandr Yashkin commit 9e5f1c19800b808a37fb9815a26d382132c26c3d upstream. The ram_core.c routines treat przs as circular buffers. When writing a new crash dump, the old buffer needs to be cleared so that the new dump doesn't end up in the wrong place (i.e. at the end). The solution to this problem is to reset the circular buffer state before writing a new Oops dump. Signed-off-by: Aleksandr Yashkin Signed-off-by: Nikolay Merinov Signed-off-by: Ariel Gilman Link: https://lore.kernel.org/r/20191223133816.28155-1-n.merinov@inango-systems.com Fixes: 896fc1f0c4c6 ("pstore/ram: Switch to persistent_ram routines") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman --- fs/pstore/ram.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -407,6 +407,17 @@ static int notrace ramoops_pstore_write( prz = cxt->dprzs[cxt->dump_write_cnt]; + /* + * Since this is a new crash dump, we need to reset the buffer in + * case it still has an old dump present. Without this, the new dump + * will get appended, which would seriously confuse anything trying + * to check dump file contents. Specifically, ramoops_read_kmsg_hdr() + * expects to find a dump header in the beginning of buffer data, so + * we must to reset the buffer values, in order to ensure that the + * header will be written to the beginning of the buffer. + */ + persistent_ram_zap(prz); + /* Build header and append record contents. */ hlen = ramoops_write_kmsg_hdr(prz, record); if (!hlen)