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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 40C52C63697 for ; Thu, 19 Nov 2020 01:41:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C8B71246D1 for ; Thu, 19 Nov 2020 01:41:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ODt+YiVU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727441AbgKSBlP (ORCPT ); Wed, 18 Nov 2020 20:41:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:50538 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726457AbgKSBlO (ORCPT ); Wed, 18 Nov 2020 20:41:14 -0500 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 CF87C246CA; Thu, 19 Nov 2020 01:41:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605750073; bh=XJFUJT3s4NHQ8xeFGYjhvyZXbH7UIOQDzS5N4CPVVHM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ODt+YiVU4k4MM0Z/shnTryIJjWhA1kHL+uPRbTv94JSMVnXeLx8wiJBmyYYGKs7Xr ziJgNkrE4DauXfq/p/hLXsj92t6s1zZUTqH1vJ/do5sI+MgavOKVV32ARCzoXAMre3 +OoFIvxljqABMI7E/NRzbLuhZ5vE8crnQo/YumPo= Date: Thu, 19 Nov 2020 10:41:09 +0900 From: Masami Hiramatsu To: Steven Rostedt 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: <20201119104109.8ab69359ce81d74c7d2d9c3f@kernel.org> In-Reply-To: <20201118110437.36e84496@gandalf.local.home> References: <160571371674.277955.11736890010190945946.stgit@devnote2> <160571373504.277955.1260524414275036851.stgit@devnote2> <20201118110437.36e84496@gandalf.local.home> X-Mailer: Sylpheed 3.7.0 (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 Wed, 18 Nov 2020 11:04:37 -0500 Steven Rostedt wrote: > 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? Please see the above 2 write error check. You can find if (ret < 0) goto out; only in the first check. (I know, it might a bit misleadable) So, the first write is failed with error message, it doesn't call rollback. > > 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; If the old_size is current size, ftruncate must do nothing, doesn't it? Thank you, > > 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 -- Masami Hiramatsu