From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 7A17C26B2AF for ; Fri, 18 Apr 2025 08:15:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744964111; cv=none; b=R9TGTFKM4SYGWrbUqRwZp8UDDPWEv8Mx9pDNUdtKJVYTyVr4Q5uOFOf7Xde+S6wE7G3z9qsQaXwQqBaQvYaV5VdG5UtWoiFeVkAK207rastUKCSIl9j7OqR0Cvt8h0y10JOTxA9eLY2B1k8sCNvH2xW4O2LNBG76XWlGks3uPic= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744964111; c=relaxed/simple; bh=rX7D5fJ6dxuaIJHo2NjKN2s6bX97dO1N9qsbOAQFqWc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HZXPMKq3SwmXBw/UzaLqVmzSvLI0rZbk5Rre95QSfn1c3Lc2uIab0mFgpz9CtOep/k3scP4uSyGvJaElUNDkVDg7jWiLezCO6ytJgYX/zNDGA+rlkh+IXh2+qlss+zqFam6IkTmfQfAFbNOVm6gELijHQeMdsKHliu9X2MuMgwM= 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=FIhlV2Zb; arc=none smtp.client-ip=170.10.133.124 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="FIhlV2Zb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744964108; 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=oGpLEGpFPjLHr2TI5L2WF5TxWp0RKlr+m9WjaH1iqOo=; b=FIhlV2ZbWANAYSpvFAfkH+Olh/8PS0/DQz8XfYFWlc5bDh3x+J+j1iU51tVNb0911KmJHU PZoYXCwIjHN1USe1umFPpT3OoZqmIpsJy1x48QGW4dOU/hWB1T4VsinkW9HTgECBNEVqlw mTJmSh6H4xKSke+wKLQAYdOYdAsgnVI= 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-586-SJ0K13ASMYa3gF71ua8eWQ-1; Fri, 18 Apr 2025 04:15:04 -0400 X-MC-Unique: SJ0K13ASMYa3gF71ua8eWQ-1 X-Mimecast-MFC-AGG-ID: SJ0K13ASMYa3gF71ua8eWQ_1744964102 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 4C8E819560AB; Fri, 18 Apr 2025 08:15:01 +0000 (UTC) Received: from localhost (unknown [10.72.112.33]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id EB5B519560A3; Fri, 18 Apr 2025 08:14:58 +0000 (UTC) Date: Fri, 18 Apr 2025 16:14:54 +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 v12 8/9] ima: make the kexec extra memory configurable Message-ID: References: <20250416021028.1403-1-chenste@linux.microsoft.com> <20250416021028.1403-9-chenste@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20250416021028.1403-9-chenste@linux.microsoft.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On 04/15/25 at 07:10pm, steven chen wrote: > From: Steven Chen > > 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 > --- > security/integrity/ima/Kconfig | 11 +++++++++++ > security/integrity/ima/ima_kexec.c | 16 +++++++++++----- > 2 files changed, 22 insertions(+), 5 deletions(-) The contributor's tag need be updated too, otherwise, Acked-by: Baoquan He > > diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig > index 475c32615006..976e75f9b9ba 100644 > --- a/security/integrity/ima/Kconfig > +++ b/security/integrity/ima/Kconfig > @@ -321,4 +321,15 @@ 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" > + range 0 40 > + depends on IMA_KEXEC > + default 0 > + 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 ed867734ee70..d1c9d369ba08 100644 > --- a/security/integrity/ima/ima_kexec.c > +++ b/security/integrity/ima/ima_kexec.c > @@ -118,6 +118,7 @@ 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; > @@ -125,15 +126,20 @@ 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"); > -- > 2.43.0 >