From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 966ED15B543 for ; Thu, 20 Mar 2025 02:52:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742439176; cv=none; b=XxGlAl7vtlJ9HwvWzYaieY4ej9BcIHDZh5VZxA7bN2JUWgYiFmMXXPWo+0xzB7JvsKTuLYwg/s2Sz8fFFD7vX/0Glg6tifnf4r/RwENdzd07TQKtDZvADHiMSaL0WylRcf1zDNDSJgsjLCZIhnnuTMpDAt4GxBWmcjevdywxqzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742439176; c=relaxed/simple; bh=vg4+ggxmuzeKTljMhEG1Oo/JmSE8/6fLfiQV1X3qNsY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AJ2CtmcCQJPxuyG5OyvjiWto02OwcYNtDCLIFgoGwWg6lbNkka3qBOdApTx8VYQlcy8IJ7S1lHr9gZDUX18VPgVWtxeQM8LXW2Tj1P9sOlpH4ASfLky/rnwf9K2ZbAsn3St9YMBS8lLcBURR7lfEAlMacNROFk/gxG7BXRwh76c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=N3ccJmrU; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="N3ccJmrU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1742439173; 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=llxsDGyF5OTS0kLxtrZq1xxBUU0ow8OofIklAK3fpNU=; b=N3ccJmrUh2Qv6PDYr1LkgrCeJNaj+nfS8IbXJVZV8WJczUgHZmvarH0oeF5hyU0gP8Bgjh YUdWeycoMUthhT7ppotbZ3XqXjWDZR5s+5LdktA+xs3xlkcEA9/v7PmAXKM3Gt6K/tUGiH mr18kvPDfpIaTdKRkzeRjQvF0B5ETMA= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-121-BuMgurEROi-9O3Ip2yolXw-1; Wed, 19 Mar 2025 22:52:49 -0400 X-MC-Unique: BuMgurEROi-9O3Ip2yolXw-1 X-Mimecast-MFC-AGG-ID: BuMgurEROi-9O3Ip2yolXw_1742439167 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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 74EC41800875; Thu, 20 Mar 2025 02:52:46 +0000 (UTC) Received: from localhost (unknown [10.72.112.30]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E66BA180174E; Thu, 20 Mar 2025 02:52:42 +0000 (UTC) Date: Thu, 20 Mar 2025 10:52:38 +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 v10 7/8] ima: make the kexec extra memory configurable Message-ID: References: <20250318010448.954-1-chenste@linux.microsoft.com> <20250318010448.954-8-chenste@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250318010448.954-8-chenste@linux.microsoft.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On 03/17/25 at 06:04pm, 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 Is there range for this memory, e.g [0, max] and max will be a value according to our current perception? > + 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 > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c > index c390c745f882..0f214e41dd33 100644 > --- a/security/integrity/ima/ima_kexec.c > +++ b/security/integrity/ima/ima_kexec.c > @@ -131,6 +131,7 @@ void ima_add_kexec_buffer(struct kimage *image) > .buf_min = 0, .buf_max = ULONG_MAX, > .top_down = true }; > unsigned long binary_runtime_size; > + unsigned long extra_memory; > > /* use more understandable variable names than defined in kbuf */ > size_t kexec_buffer_size = 0; > @@ -138,15 +139,20 @@ void ima_add_kexec_buffer(struct kimage *image) > int ret; > > /* > - * Reserve an extra half page of memory for additional measurements > - * added during the kexec load. > + * Reserve extra memory for measurements added during kexec. > */ > - binary_runtime_size = ima_get_binary_runtime_size(); > + if (CONFIG_IMA_KEXEC_EXTRA_MEMORY_KB <= 0) > + extra_memory = PAGE_SIZE / 2; > + else > + extra_memory = CONFIG_IMA_KEXEC_EXTRA_MEMORY_KB * 1024; > + > + binary_runtime_size = ima_get_binary_runtime_size() + extra_memory; > + > if (binary_runtime_size >= ULONG_MAX - PAGE_SIZE) > kexec_segment_size = ULONG_MAX; > else > - kexec_segment_size = ALIGN(ima_get_binary_runtime_size() + > - PAGE_SIZE / 2, PAGE_SIZE); > + kexec_segment_size = ALIGN(binary_runtime_size, PAGE_SIZE); > + > if ((kexec_segment_size == ULONG_MAX) || > ((kexec_segment_size >> PAGE_SHIFT) > totalram_pages() / 2)) { > pr_err("Binary measurement list too large.\n"); > -- > 2.25.1 > >