Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752524AbdHPWrC (ORCPT ); Wed, 16 Aug 2017 18:47:02 -0400 Received: from mail-qk0-f176.google.com ([209.85.220.176]:37966 "EHLO mail-qk0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752444AbdHPWq7 (ORCPT ); Wed, 16 Aug 2017 18:46:59 -0400 From: Laura Abbott To: Kees Cook Cc: Laura Abbott , kernel-hardening@lists.openwall.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Daniel Micay , Laura Abbott Subject: [PATCHv2 1/2] init: Move stack canary initialization after setup_arch Date: Wed, 16 Aug 2017 15:46:49 -0700 Message-Id: <20170816224650.1089-2-labbott@redhat.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170816224650.1089-1-labbott@redhat.com> References: <20170816224650.1089-1-labbott@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1351 Lines: 47 From: Laura Abbott Stack canary intialization involves getting a random number. Getting this random number may involve accessing caches or other architectural specific features which are not available until after the architecture is setup. Move the stack canary initialization later to accomodate this. Signed-off-by: Laura Abbott Signed-off-by: Laura Abbott --- v2: Also moved add_latent_entropy per suggestion of Kees. --- init/main.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/init/main.c b/init/main.c index 052481fbe363..21d599eaad06 100644 --- a/init/main.c +++ b/init/main.c @@ -515,12 +515,6 @@ asmlinkage __visible void __init start_kernel(void) smp_setup_processor_id(); debug_objects_early_init(); - /* - * Set up the initial canary ASAP: - */ - add_latent_entropy(); - boot_init_stack_canary(); - cgroup_init_early(); local_irq_disable(); @@ -534,6 +528,11 @@ asmlinkage __visible void __init start_kernel(void) page_address_init(); pr_notice("%s", linux_banner); setup_arch(&command_line); + /* + * Set up the the initial canary and entropy after arch + */ + add_latent_entropy(); + boot_init_stack_canary(); mm_init_cpumask(&init_mm); setup_command_line(command_line); setup_nr_cpu_ids(); -- 2.13.0