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=-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 E84ECC282DD for ; Tue, 7 Jan 2020 21:12:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B26D32077B for ; Tue, 7 Jan 2020 21:12:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578431549; bh=LdXKwXpcbTa3rC8S+Y33KNh47g7MBqbYl8yPsEXg4kU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Q5vY2ufFpRBezUZcqgXhM5r5YkxV7AQnCAevJPgUI2w8uOOfQGHt6HUeH+5VGt0JV ln6UFQaTh9PwNqBfDFOdXSOlpiNXl3IDqhZ16AxJETb9Vv+dFrXGDro79rk52khnwC ybmAADdb+Jom67WBzJRSpDOti8mHwwngBVrN7zQw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729963AbgAGVM2 (ORCPT ); Tue, 7 Jan 2020 16:12:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:38814 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730064AbgAGVLH (ORCPT ); Tue, 7 Jan 2020 16:11:07 -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 E655620880; Tue, 7 Jan 2020 21:11:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578431466; bh=LdXKwXpcbTa3rC8S+Y33KNh47g7MBqbYl8yPsEXg4kU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BRAkhfD6/ZMgoxLTq9S6omZwISl5iY6pbhXzJ03uAfAdULppnGJfJ9IkNs93weSsq uJ4V5xGvopp1Ad1D9XUWvui+MEebsbQfuLaUvJnwjGlpj48iUdhvpWRk8Hb2D+k3Rm PFFeE7L4WwY1Hu6GFF/s9Zd2s296WfKIUeHhZsMo= 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 4.14 31/74] pstore/ram: Write new dumps to start of recycled zones Date: Tue, 7 Jan 2020 21:54:56 +0100 Message-Id: <20200107205201.534099388@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200107205135.369001641@linuxfoundation.org> References: <20200107205135.369001641@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -433,6 +433,17 @@ 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); size = record->size;