From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120217005510.084150159@linuxfoundation.org> Date: Thu, 16 Feb 2012 16:55:11 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Clark Williams , Eric Dumazet , Corey Ashford , Ingo Molnar , Paul Mackerras , Peter Zijlstra , Jiri Olsa , Arnaldo Carvalho de Melo Subject: [02/15] perf tools: Fix perf stack to non executable on x86_64 In-Reply-To: <20120217005650.GA17119@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Olsa commit 7a0153ee15575a4d07b5da8c96b79e0b0fd41a12 upstream. By adding following objects: bench/mem-memcpy-x86-64-asm.o the x86_64 perf binary ended up with executable stack. The reason was that above object are assembler sourced and is 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 object, with all flags disabled, thus omiting this object from linker stack flags decision. Problem introduced in: $ git describe ea7872b v2.6.37-rc2-19-gea7872b Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=783570 Reported-by: Clark Williams Acked-by: Eric Dumazet Cc: Corey Ashford Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1328100848-5630-1-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa [ committer note: Backported fix to perf/urgent (3.3-rc2+) ] Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/perf/bench/mem-memcpy-x86-64-asm.S | 6 ++++++ 1 file changed, 6 insertions(+) --- a/tools/perf/bench/mem-memcpy-x86-64-asm.S +++ b/tools/perf/bench/mem-memcpy-x86-64-asm.S @@ -1,2 +1,8 @@ #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