Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966734AbeAOMqB (ORCPT + 1 other); Mon, 15 Jan 2018 07:46:01 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:48872 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966699AbeAOMp6 (ORCPT ); Mon, 15 Jan 2018 07:45:58 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Torvalds , Josh Poimboeuf , Jessica Yu , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , David Woodhouse Subject: [PATCH 4.9 81/96] objtool, modules: Discard objtool annotation sections for modules Date: Mon, 15 Jan 2018 13:35:20 +0100 Message-Id: <20180115123410.917847953@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180115123404.270241256@linuxfoundation.org> References: <20180115123404.270241256@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josh Poimboeuf commit e390f9a9689a42f477a6073e2e7df530a4c1b740 upstream. The '__unreachable' and '__func_stack_frame_non_standard' sections are only used at compile time. They're discarded for vmlinux but they should also be discarded for modules. Since this is a recurring pattern, prefix the section names with ".discard.". It's a nice convention and vmlinux.lds.h already discards such sections. Also remove the 'a' (allocatable) flag from the __unreachable section since it doesn't make sense for a discarded section. Suggested-by: Linus Torvalds Signed-off-by: Josh Poimboeuf Cc: Jessica Yu Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends") Link: http://lkml.kernel.org/r/20170301180444.lhd53c5tibc4ns77@treble Signed-off-by: Ingo Molnar [dwmw2: Remove the unreachable part in backporting since it's not here yet] Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- include/linux/frame.h | 2 +- scripts/mod/modpost.c | 1 + scripts/module-common.lds | 5 ++++- tools/objtool/builtin-check.c | 2 +- 4 files changed, 7 insertions(+), 3 deletions(-) --- a/include/linux/frame.h +++ b/include/linux/frame.h @@ -11,7 +11,7 @@ * For more information, see tools/objtool/Documentation/stack-validation.txt. */ #define STACK_FRAME_NON_STANDARD(func) \ - static void __used __section(__func_stack_frame_non_standard) \ + static void __used __section(.discard.func_stack_frame_non_standard) \ *__func_stack_frame_non_standard_##func = func #else /* !CONFIG_STACK_VALIDATION */ --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -838,6 +838,7 @@ static const char *const section_white_l ".cmem*", /* EZchip */ ".fmt_slot*", /* EZchip */ ".gnu.lto*", + ".discard.*", NULL }; --- a/scripts/module-common.lds +++ b/scripts/module-common.lds @@ -4,7 +4,10 @@ * combine them automatically. */ SECTIONS { - /DISCARD/ : { *(.discard) } + /DISCARD/ : { + *(.discard) + *(.discard.*) + } __ksymtab 0 : { *(SORT(___ksymtab+*)) } __ksymtab_gpl 0 : { *(SORT(___ksymtab_gpl+*)) } --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -1229,7 +1229,7 @@ int cmd_check(int argc, const char **arg INIT_LIST_HEAD(&file.insn_list); hash_init(file.insn_hash); - file.whitelist = find_section_by_name(file.elf, "__func_stack_frame_non_standard"); + file.whitelist = find_section_by_name(file.elf, ".discard.func_stack_frame_non_standard"); file.rodata = find_section_by_name(file.elf, ".rodata"); file.ignore_unreachables = false; file.c_file = find_section_by_name(file.elf, ".comment");