From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7574881732; Sun, 20 Apr 2025 13:03:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745154189; cv=none; b=iF5C6USf4V0TBkLpY0t5GhVJTQgtkgzlBRsAKo9kiZv8GCMBVkUkhxhnz6VR4Evijy1zQwvMFBGD+yRPJFLXKacqi7W+3aowk0hfn3I1cpnGIU98TYeoNMrQeEoKX8r6NTtORT4B3OdKuNSdmsa2ZCA7BZ9Vt41rzJKTPk+BZQ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745154189; c=relaxed/simple; bh=8zRLSSRZai+b1opyOznQG0sQaxVT0Mf20jczAZ7OEic=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HWr8qc7Go4wnnD5Q1gASHJ1uEmMFbWi8cbC1rv0jwC1dfJzLTltVYokGMXPphY4Yc8Vk9UbEDFeLUDwk0NusvNZU47E7IwtQUMcKG3Qx6C/slM2PxZgh3xwEtcpDLh+fgj6XOCesBjHtWhfEqeFdJpIlxoaaHJwJa3B9ktAb8as= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=bfxeURb1; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="bfxeURb1" Received: from [100.70.200.26] (unknown [20.114.144.49]) by linux.microsoft.com (Postfix) with ESMTPSA id B007E21165A5; Sun, 20 Apr 2025 06:03:05 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B007E21165A5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1745154187; bh=fhpLVOWEQiBjCCnkJmayCrcPxfbCn5Ps77LhW/efDII=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=bfxeURb10LnMYzKHDU3I5KE7vfBqNVXcdX73dIcqtHUdWdlsCku8O74+nr0BczmH7 HdzIdQhw48R/Adsh0EcCCdSU+tSqNpSjoncm7P4zo9yH/eLqCIOHvX0iwGpEgKuPGG T7I0aMeEDv64fFcBA7aGbX4L5aXUPyfgn4rIrJO0= Message-ID: Date: Sun, 20 Apr 2025 06:03:03 -0700 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v12 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: <20250416021028.1403-1-chenste@linux.microsoft.com> <20250416021028.1403-9-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 On 4/18/2025 1:14 AM, Baoquan He wrote: > 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 > ^^^^^^^^^^^^^^^^ Hi Baoquan, I will add Co-developed-by tag in next version. >> 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, I will add the contributor's tag in next version. Thanks > 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 >>