From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756294Ab2BAMyc (ORCPT ); Wed, 1 Feb 2012 07:54:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:16419 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754258Ab2BAMyb (ORCPT ); Wed, 1 Feb 2012 07:54:31 -0500 From: Jiri Olsa To: acme@redhat.com, a.p.zijlstra@chello.nl, mingo@elte.hu, paulus@samba.org, cjashfor@linux.vnet.ibm.com Cc: linux-kernel@vger.kernel.org, Jiri Olsa Subject: [PATCH] perf, tool: Fix perf stack to non executable on x86_64 Date: Wed, 1 Feb 2012 13:54:08 +0100 Message-Id: <1328100848-5630-1-git-send-email-jolsa@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org By adding following objects: bench/mem-memset-x86-64-asm.o bench/mem-memcpy-x86-64-asm.o the x86_64 perf binary ended up with executable stack. The reason was that above objects are assembler sourced and are missing the GNU-stack note section. In such case the linker assumes that the final binary should not be restricted at all and mark the stack as RWX. Adding section ".note.GNU-stack" definition to mentioned objects, with all flags disabled, thus omiting those objects from linker stack flags decision. Signed-off-by: Jiri Olsa --- tools/perf/bench/mem-memcpy-x86-64-asm.S | 7 +++++++ tools/perf/bench/mem-memset-x86-64-asm.S | 7 +++++++ 2 files changed, 14 insertions(+), 0 deletions(-) diff --git a/tools/perf/bench/mem-memcpy-x86-64-asm.S b/tools/perf/bench/mem-memcpy-x86-64-asm.S index a20780b..a6c8909 100644 --- a/tools/perf/bench/mem-memcpy-x86-64-asm.S +++ b/tools/perf/bench/mem-memcpy-x86-64-asm.S @@ -4,3 +4,10 @@ #define Lmemcpy_c globl memcpy_c; memcpy_c #define Lmemcpy_c_e globl memcpy_c_e; memcpy_c_e #include "../../../arch/x86/lib/memcpy_64.S" + +/* + * We need to provide note.GNU-stack section, saying that we want + * NOT executable stack. Otherwise the final linking will assume that + * the ELF stack should not be restricted at all and set it RWX. + */ +.section .note.GNU-stack,"",@progbits diff --git a/tools/perf/bench/mem-memset-x86-64-asm.S b/tools/perf/bench/mem-memset-x86-64-asm.S index cb92170..9e5af89 100644 --- a/tools/perf/bench/mem-memset-x86-64-asm.S +++ b/tools/perf/bench/mem-memset-x86-64-asm.S @@ -4,3 +4,10 @@ #define Lmemset_c globl memset_c; memset_c #define Lmemset_c_e globl memset_c_e; memset_c_e #include "../../../arch/x86/lib/memset_64.S" + +/* + * We need to provide note.GNU-stack section, saying that we want + * NOT executable stack. Otherwise the final linking will assume that + * the ELF stack should not be restricted at all and set it RWX. + */ +.section .note.GNU-stack,"",@progbits -- 1.7.1