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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 15075C36010 for ; Tue, 8 Apr 2025 02:24:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=K7shp0i8xV6W4sEMIfoyEtGIoaU0RHBOh45LNxxy8wY=; b=EspGteMJL8x1xN/Doad2b1Oole CVvyiJNb5ZJD3XUNySU2+GGj7MeO0T4mSWDQ5rIqPzB7XL75c7OP6IL02n7H+dIG0lIznBViflr8T 43boW931C0WXhFyKx64eW1xjQeBCA6FQ5p2hS9M6c/jT61Uxc2Z1cWfwdVGhpG70yEW3LnwCHKoYI ViYOraIFSGmxnXLOjDjlYX0OhdRBdurI3IWta1dtOgoioK7oNwMxW9SuchWMlp/S5QHPGVqnpBicE GmZsAnzjzjSaTzVgCm3RQ3SuaJJirAJtWrolW4souTNh79BX5xg7uHA/oT1HfAY12n5ZnQ6b5F0Ow n58zekpw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1u1ydM-00000002WD3-3Lmw; Tue, 08 Apr 2025 02:24:16 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1u1ydI-00000002WCT-01GF for kexec@lists.infradead.org; Tue, 08 Apr 2025 02:24:13 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744079049; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=K7shp0i8xV6W4sEMIfoyEtGIoaU0RHBOh45LNxxy8wY=; b=L+iJlWyIqx4QEZnEj95ZK1PDBxNbgHCIqHFTjIWi5Y6BKVih2xc371XTGV2fjmWgoEET1T LXlA8KvcQ6JGi8txrSix5vo3wmjdzCYg04AO5xuY6vTE7ieWCblQ1A2JN8aKpxTH/XZUvU 1kGx01C4fCl6tt4L1nqmETadvzKScd0= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-475-fVNTxx_CPL6CJ9AhxUkyVA-1; Mon, 07 Apr 2025 22:24:04 -0400 X-MC-Unique: fVNTxx_CPL6CJ9AhxUkyVA-1 X-Mimecast-MFC-AGG-ID: fVNTxx_CPL6CJ9AhxUkyVA_1744079042 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0CEC01956048; Tue, 8 Apr 2025 02:24:01 +0000 (UTC) Received: from localhost (unknown [10.72.112.61]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 71DE6180B48C; Tue, 8 Apr 2025 02:23:58 +0000 (UTC) Date: Tue, 8 Apr 2025 10:23:53 +0800 From: Baoquan He To: steven chen Cc: zohar@linux.ibm.com, stefanb@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, ebiederm@xmission.com, paul@paul-moore.com, code@tyhicks.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, madvenka@linux.microsoft.com, nramas@linux.microsoft.com, James.Bottomley@hansenpartnership.com, vgoyal@redhat.com, dyoung@redhat.com Subject: Re: [PATCH v11 1/9] ima: rename variable the set_file "file" to "ima_kexec_file" Message-ID: References: <20250402124725.5601-1-chenste@linux.microsoft.com> <20250402124725.5601-2-chenste@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250402124725.5601-2-chenste@linux.microsoft.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250407_192412_131384_B85A4EE6 X-CRM114-Status: GOOD ( 30.60 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On 04/02/25 at 05:47am, steven chen wrote: > The current kernel behavior is IMA measurements snapshot is taken at > kexec 'load' and not at kexec 'execute'. IMA log is then carried > over to the new kernel after kexec 'execute'. However, the time gap > between kexec load and kexec reboot can be very long. During this > time window, new events extended into TPM PCRs miss the chance > to be carried over to the second kernel. > > To address the above, the following approach is proposed: > - Allocate the necessary buffer during the kexec load phase. > - Populate this buffer with the IMA measurements during > the kexec execute phase. > > In the current implementation, a local variable "file" of type seq_file > is used in the API ima_dump_measurement_list() to store the IMA measurements > to be carried over across kexec system call. To make this buffer accessible > at kexec 'execute' time, rename it to "ima_kexec_file" before making it > a file variable to better reflect its purpose. > > Renaming the local variable "file" of type seq_file defined in the > ima_dump_measurement_list function to "ima_kexec_file" will improve code > readability and maintainability by making the variable's role more explicit. Seems it's clearer with below paragraph to replace the whole log: ===== Rename the local variable "file" of type seq_file defined in the ima_dump_measurement_list function to "ima_kexec_file" to improve code readability and maintainability by making the variable's role more explicit. ===== The code change looks good to me. > > Suggested-by: Mimi Zohar > Signed-off-by: steven chen > Reviewed-by: Stefan Berger If there's code change in patch content, the reviewing tag should be reset so that reviewing is taken again on the new change. > --- > security/integrity/ima/ima_kexec.c | 31 +++++++++++++++--------------- > 1 file changed, 16 insertions(+), 15 deletions(-) > > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c > index 9d45f4d26f73..650beb74346c 100644 > --- a/security/integrity/ima/ima_kexec.c > +++ b/security/integrity/ima/ima_kexec.c > @@ -18,30 +18,30 @@ > static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > unsigned long segment_size) > { > + struct seq_file ima_kexec_file; > struct ima_queue_entry *qe; > - struct seq_file file; > struct ima_kexec_hdr khdr; > int ret = 0; > > /* segment size can't change between kexec load and execute */ > - file.buf = vmalloc(segment_size); > - if (!file.buf) { > + ima_kexec_file.buf = vmalloc(segment_size); > + if (!ima_kexec_file.buf) { > ret = -ENOMEM; > goto out; > } > > - file.file = NULL; > - file.size = segment_size; > - file.read_pos = 0; > - file.count = sizeof(khdr); /* reserved space */ > + ima_kexec_file.file = NULL; > + ima_kexec_file.size = segment_size; > + ima_kexec_file.read_pos = 0; > + ima_kexec_file.count = sizeof(khdr); /* reserved space */ > > memset(&khdr, 0, sizeof(khdr)); > khdr.version = 1; > /* This is an append-only list, no need to hold the RCU read lock */ > list_for_each_entry_rcu(qe, &ima_measurements, later, true) { > - if (file.count < file.size) { > + if (ima_kexec_file.count < ima_kexec_file.size) { > khdr.count++; > - ima_measurements_show(&file, qe); > + ima_measurements_show(&ima_kexec_file, qe); > } else { > ret = -EINVAL; > break; > @@ -55,23 +55,24 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, > * fill in reserved space with some buffer details > * (eg. version, buffer size, number of measurements) > */ > - khdr.buffer_size = file.count; > + khdr.buffer_size = ima_kexec_file.count; > if (ima_canonical_fmt) { > khdr.version = cpu_to_le16(khdr.version); > khdr.count = cpu_to_le64(khdr.count); > khdr.buffer_size = cpu_to_le64(khdr.buffer_size); > } > - memcpy(file.buf, &khdr, sizeof(khdr)); > + memcpy(ima_kexec_file.buf, &khdr, sizeof(khdr)); > > print_hex_dump_debug("ima dump: ", DUMP_PREFIX_NONE, 16, 1, > - file.buf, file.count < 100 ? file.count : 100, > + ima_kexec_file.buf, ima_kexec_file.count < 100 ? > + ima_kexec_file.count : 100, > true); > > - *buffer_size = file.count; > - *buffer = file.buf; > + *buffer_size = ima_kexec_file.count; > + *buffer = ima_kexec_file.buf; > out: > if (ret == -EINVAL) > - vfree(file.buf); > + vfree(ima_kexec_file.buf); > return ret; > } > > -- > 2.25.1 >