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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 5B9FCC5519F for ; Wed, 18 Nov 2020 16:05:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AA08247CB for ; Wed, 18 Nov 2020 16:05:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727749AbgKRQEl (ORCPT ); Wed, 18 Nov 2020 11:04:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:53144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726163AbgKRQEk (ORCPT ); Wed, 18 Nov 2020 11:04:40 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 F40FC20756; Wed, 18 Nov 2020 16:04:38 +0000 (UTC) Date: Wed, 18 Nov 2020 11:04:37 -0500 From: Steven Rostedt To: Masami Hiramatsu Cc: Linus Torvalds , Chen Yu , Chen Yu , LKML , Ingo Molnar , Jonathan Corbet Subject: Re: [PATCH v4 2/4] tools/bootconfig: Fix to check the write failure correctly Message-ID: <20201118110437.36e84496@gandalf.local.home> In-Reply-To: <160571373504.277955.1260524414275036851.stgit@devnote2> References: <160571371674.277955.11736890010190945946.stgit@devnote2> <160571373504.277955.1260524414275036851.stgit@devnote2> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 19 Nov 2020 00:35:35 +0900 Masami Hiramatsu wrote: > Fix to check the write(2) failure including partial write > correctly and try to rollback the partial write, because > if there is no BOOTCONFIG_MAGIC string, we can not remove it. > > Fixes: 85c46b78da58 ("bootconfig: Add bootconfig magic word for indicating bootconfig explicitly") > Suggested-by: Linus Torvalds > Signed-off-by: Masami Hiramatsu > Tested-by: Chen Yu > --- > tools/bootconfig/main.c | 27 +++++++++++++++++++++++---- > 1 file changed, 23 insertions(+), 4 deletions(-) > > diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c > index 52eb2bbe8966..905bfaefae35 100644 > --- a/tools/bootconfig/main.c > +++ b/tools/bootconfig/main.c > @@ -337,6 +337,7 @@ static int delete_xbc(const char *path) > > static int apply_xbc(const char *path, const char *xbc_path) > { > + struct stat stat; > u32 size, csum; > char *buf, *data; > int ret, fd; > @@ -394,16 +395,26 @@ static int apply_xbc(const char *path, const char *xbc_path) > return ret; > } > /* TODO: Ensure the @path is initramfs/initrd image */ > + if (fstat(fd, &stat) < 0) { > + pr_err("Failed to get the size of %s\n", path); > + goto out; > + } > ret = write(fd, data, size + 8); > - if (ret < 0) { > + if (ret < size + 8) { > + if (ret < 0) > + ret = -errno; > pr_err("Failed to apply a boot config: %d\n", ret); > - goto out; > + if (ret < 0) > + goto out; > + goto out_rollback; > } > /* Write a magic word of the bootconfig */ > ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN); > - if (ret < 0) { > + if (ret < BOOTCONFIG_MAGIC_LEN) { > + if (ret < 0) > + ret = -errno; > pr_err("Failed to apply a boot config magic: %d\n", ret); > - goto out; > + goto out_rollback; > } > ret = 0; > out: > @@ -411,6 +422,14 @@ static int apply_xbc(const char *path, const char *xbc_path) > free(data); > > return ret; > + > +out_rollback: > + if (ftruncate(fd, stat.st_size) < 0) { If the first write fails (doesn't modify the initrd), and then this fails, you will show a message of: "may be corrupted. Recommend to rebuild", when that would not be the case. Should a test of the size be done again, to see if it is already the same? out_rollback: old_size = stat.st_size; if (stat(fd, &stat) < 0) /* Shouldn't happen, it worked once before */ goto print_error; if (old_size < stat.st_size) if (ftruncate(fd, old_size) < 0) goto print_error; goto out; print_error: > + ret = -errno; > + pr_err("Failed to rollback the write error: %d\n", ret); > + pr_err("The initrd %s may be corrupted. Recommend to rebuild.\n", path); > + } > + goto out; > } > > static int usage(void) -- Steve