From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756000Ab3JKBkT (ORCPT ); Thu, 10 Oct 2013 21:40:19 -0400 Received: from smtp.outflux.net ([198.145.64.163]:50814 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752324Ab3JKBkS (ORCPT ); Thu, 10 Oct 2013 21:40:18 -0400 Date: Thu, 10 Oct 2013 18:39:54 -0700 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Kees Cook , Michael Davidson , Cong Ding Subject: [PATCH v2] x86, relocs: add more per-cpu gold special cases Message-ID: <20131011013954.GA28902@www.outflux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michael Davidson The "gold" linker doesn't seem to put some additional per-cpu cases in the right place. Add these to the per-cpu check. Without this, the kASLR patch series fails to correctly apply relocations, and fails to boot. Signed-off-by: Michael Davidson Signed-off-by: Kees Cook --- v2: - clean up attribution for clarity; HPA. --- arch/x86/tools/relocs.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index f7bab68..71a2533 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -722,15 +722,23 @@ static void percpu_init(void) /* * Check to see if a symbol lies in the .data..percpu section. - * For some as yet not understood reason the "__init_begin" - * symbol which immediately preceeds the .data..percpu section - * also shows up as it it were part of it so we do an explict - * check for that symbol name and ignore it. + * + * The linker incorrectly associates some symbols with the + * .data..percpu section so we also need to check the symbol + * name to make sure that we classify the symbol correctly. + * + * The GNU linker incorrectly associates: + * __init_begin + * + * The "gold" linker incorrectly associates: + * init_per_cpu__irq_stack_union + * init_per_cpu__gdt_page */ static int is_percpu_sym(ElfW(Sym) *sym, const char *symname) { return (sym->st_shndx == per_cpu_shndx) && - strcmp(symname, "__init_begin"); + strcmp(symname, "__init_begin") && + strncmp(symname, "init_per_cpu_", 13); } -- 1.7.9.5 -- Kees Cook Chrome OS Security