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 X-Spam-Level: X-Spam-Status: No, score=-17.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0515C433E6 for ; Wed, 27 Jan 2021 18:44:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6D2A601FB for ; Wed, 27 Jan 2021 18:44:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229950AbhA0SoL (ORCPT ); Wed, 27 Jan 2021 13:44:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:59056 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232828AbhA0SoK (ORCPT ); Wed, 27 Jan 2021 13:44:10 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6B141601FB; Wed, 27 Jan 2021 18:43:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611773008; bh=GZ0Dc/tE/vX/hQMmkRpmanBmWtj6NrDessKfg0CzNQc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hq9cayECysR7wC0JyvXib4KeHkGCaDldIGwVp3rDHBgGkQ1LymJfYzNCHYTWnOteh D/a4R7QdG6BOOOf3X8N/DYX4m5Ylj8hR8GIRpKFTInswxgi9aim5djfTEopswbiYBh 5cA3sd60j8+bOtwsXdyKysCNG6+ZDeOICgWE8vnTanfwhOSE9JVUDFtyd3gYWECdt5 uJ23zMZoj7kUW4bL5vIrmLcZeFPgxo+vAXyEmEU1WFwVLyjQQDigv+6af5vmTVauJf vhk8QGF8ckom1KSdAuAF9nbs/lM+XOOP1TzBNrf9cDTNKAeVMosfDtKRDoEL8tGPUi Tv/6eJXRVeqfg== Date: Wed, 27 Jan 2021 18:43:20 +0000 From: Will Deacon To: Lakshmi Ramasubramanian Cc: zohar@linux.ibm.com, bauerman@linux.ibm.com, robh@kernel.org, takahiro.akashi@linaro.org, gregkh@linuxfoundation.org, catalin.marinas@arm.com, mpe@ellerman.id.au, james.morse@arm.com, sashal@kernel.org, benh@kernel.crashing.org, paulus@samba.org, frowand.list@gmail.com, vincenzo.frascino@arm.com, mark.rutland@arm.com, dmitry.kasatkin@gmail.com, jmorris@namei.org, serge@hallyn.com, pasha.tatashin@soleen.com, allison@lohutok.net, masahiroy@kernel.org, bhsharma@redhat.com, mbrugger@suse.com, hsinyi@chromium.org, tao.li@vivo.com, christophe.leroy@c-s.fr, prsriva@linux.microsoft.com, balajib@linux.microsoft.com, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v15 09/10] arm64: Call kmalloc() to allocate DTB buffer Message-ID: <20210127184319.GA676@willie-the-truck> References: <20210115173017.30617-1-nramas@linux.microsoft.com> <20210115173017.30617-10-nramas@linux.microsoft.com> <20210127165208.GA358@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Wed, Jan 27, 2021 at 09:59:38AM -0800, Lakshmi Ramasubramanian wrote: > On 1/27/21 8:52 AM, Will Deacon wrote: > > Hi Will, > > > On Fri, Jan 15, 2021 at 09:30:16AM -0800, Lakshmi Ramasubramanian wrote: > > > create_dtb() function allocates kernel virtual memory for > > > the device tree blob (DTB). This is not consistent with other > > > architectures, such as powerpc, which calls kmalloc() for allocating > > > memory for the DTB. > > > > > > Call kmalloc() to allocate memory for the DTB, and kfree() to free > > > the allocated memory. > > > > > > Co-developed-by: Prakhar Srivastava > > > Signed-off-by: Prakhar Srivastava > > > Signed-off-by: Lakshmi Ramasubramanian > > > --- > > > arch/arm64/kernel/machine_kexec_file.c | 12 +++++++----- > > > 1 file changed, 7 insertions(+), 5 deletions(-) > > > > > > diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c > > > index 7de9c47dee7c..51c40143d6fa 100644 > > > --- a/arch/arm64/kernel/machine_kexec_file.c > > > +++ b/arch/arm64/kernel/machine_kexec_file.c > > > @@ -29,7 +29,7 @@ const struct kexec_file_ops * const kexec_file_loaders[] = { > > > int arch_kimage_file_post_load_cleanup(struct kimage *image) > > > { > > > - vfree(image->arch.dtb); > > > + kfree(image->arch.dtb); > > > image->arch.dtb = NULL; > > > vfree(image->arch.elf_headers); > > > @@ -59,19 +59,21 @@ static int create_dtb(struct kimage *image, > > > + cmdline_len + DTB_EXTRA_SPACE; > > > for (;;) { > > > - buf = vmalloc(buf_size); > > > + buf = kmalloc(buf_size, GFP_KERNEL); > > > > Is there a functional need for this patch? I build the 'dtbs' target just > > now and sdm845-db845c.dtb is approaching 100K, which feels quite large > > for kmalloc(). > > Changing the allocation from vmalloc() to kmalloc() would help us further > consolidate the DTB setup code for powerpc and arm64. Ok, but at the risk of allocation failure. Can powerpc use vmalloc() instead? Will