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 3F56AC369A2 for ; Thu, 10 Apr 2025 17:56:43 +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:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=vxXwkdEOn7BTRh/cnvKn+B0GcVvl6i4koOpR5p1bqWc=; b=zHVmzKfwrWwNYzeEiEu+fsu8vb 3zaNeO8sByHJ5VkS7xChQ1KoJHWillzUSJ4gstkVzN0q4NknwKe+sgrCcQdIcgM/P8VOsqxgsdptY JVK9NGwE0ErTvxSZOiR9DGFysEgqi+tSyDzkjsgMg3B8whybpHMvoruL3NXWmAMi07EhzQkUqfCi+ 4PY3YHETyjd0J6u52dpCIVJazc1rUMsJzRfx/IQm9WKu7uiCT6cgZK43pt35NOxbhNu+fs6gi6c9C QMzNKcxBzhPML35UPL/17ofbDKSojZlobjOyzApfSX9uy1K5J1pAhLKbNV3WLg0L0lZTWjN6HUE7q oE/CLE8Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u2w8m-0000000BSgm-0SDV; Thu, 10 Apr 2025 17:56:40 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u2vFi-0000000BIOz-1sc0 for kexec@lists.infradead.org; Thu, 10 Apr 2025 16:59:47 +0000 Received: from [100.70.65.11] (unknown [20.110.218.7]) by linux.microsoft.com (Postfix) with ESMTPSA id C81DA2113E87; Thu, 10 Apr 2025 09:59:43 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C81DA2113E87 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1744304385; bh=vxXwkdEOn7BTRh/cnvKn+B0GcVvl6i4koOpR5p1bqWc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=JHT8LCdCXgjdyTqcygVEM0A4oBfxyGSsACAFVgSqpF/r46yj9ypHpbSf9+HHuLb0X pmX4Hwe5MUrRUG6uvpniItcbSKg3gVhZwQfhXHOUMDNCscbXA/4LlNcntMgVGA1fl7 7Dm1oub7U52nP9dRwCvWoI+slg2g3jGZNsdYjDak= Message-ID: <8b5e5495-4b11-4acc-8df1-fb94b2a34f0f@linux.microsoft.com> Date: Thu, 10 Apr 2025 09:59:41 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 8/9] ima: make the kexec extra memory configurable To: Baoquan He 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 References: <20250402124725.5601-1-chenste@linux.microsoft.com> <20250402124725.5601-9-chenste@linux.microsoft.com> Content-Language: en-US From: steven chen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250410_095946_540552_9601E6FD X-CRM114-Status: GOOD ( 18.91 ) 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 4/10/2025 2:54 AM, Baoquan He wrote: > On 04/02/25 at 05:47am, steven chen wrote: >> The extra memory allocated for carrying the IMA measurement list across >> kexec is hard-coded as half a PAGE. Make it configurable. >> >> Define a Kconfig option, IMA_KEXEC_EXTRA_MEMORY_KB, to configure the >> extra memory (in kb) to be allocated for IMA measurements added during >> kexec soft reboot. Ensure the default value of the option is set such >> that extra half a page of memory for additional measurements is allocated >> for the additional measurements. >> >> Update ima_add_kexec_buffer() function to allocate memory based on the >> Kconfig option value, rather than the currently hard-coded one. >> >> Suggested-by: Stefan Berger >> Signed-off-by: Tushar Sugandhi >> Signed-off-by: steven chen >> Reviewed-by: Stefan Berger >> Reviewed-by: Mimi Zohar >> --- >> security/integrity/ima/Kconfig | 10 ++++++++++ >> security/integrity/ima/ima_kexec.c | 16 +++++++++++----- >> 2 files changed, 21 insertions(+), 5 deletions(-) >> >> diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig >> index 475c32615006..d73c96c3c1c9 100644 >> --- a/security/integrity/ima/Kconfig >> +++ b/security/integrity/ima/Kconfig >> @@ -321,4 +321,14 @@ config IMA_DISABLE_HTABLE >> help >> This option disables htable to allow measurement of duplicate records. >> >> +config IMA_KEXEC_EXTRA_MEMORY_KB >> + int "Extra memory for IMA measurements added during kexec soft reboot" >> + depends on IMA_KEXEC >> + default 0 > Usually a new Kconfig item which accepts a range should define the range > boundary, otherwise it's not clear to people how large or how small it > can be set. For example, can I set it as value of 1<<40? We should at > least estimate a possible upper limit for it for other people's > reference. My personal opinion. Hi Baoquan, How about I set range 2-40? Default set as 2, same as the fixed setting. Thanks, Steven > The rest looks good to me. > > >> + help >> + IMA_KEXEC_EXTRA_MEMORY_KB determines the extra memory to be >> + allocated (in kb) for IMA measurements added during kexec soft reboot. >> + If set to the default value of 0, an extra half page of memory for those >> + additional measurements will be allocated. >> + >> endif > ...snip...