From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756028Ab2AWXtE (ORCPT ); Mon, 23 Jan 2012 18:49:04 -0500 Received: from cantor2.suse.de ([195.135.220.15]:42563 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755948Ab2AWXs6 (ORCPT ); Mon, 23 Jan 2012 18:48:58 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Mon Jan 23 15:40:27 2012 Message-Id: <20120123234027.211952075@clark.kroah.org> User-Agent: quilt/0.50-11.1 Date: Mon, 23 Jan 2012 15:39:36 -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, David Daney , Steven Rostedt Subject: [50/90] recordmcount: Fix handling of elf64 big-endian objects. In-Reply-To: <20120123234211.GA19504@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Daney commit 2e885057b7f75035f0b85e02f737891482815a81 upstream. In ELF64, the sh_flags field is 64-bits wide. recordmcount was erroneously treating it as a 32-bit wide field. For little endian objects this works because the flags of interest (SHF_EXECINSTR) reside in the lower 32 bits of the word, and you get the same result with either a 32-bit or 64-bit read. Big endian objects on the other hand do not work at all with this error. The fix: Correctly treat sh_flags as 64-bits wide in elf64 objects. The symptom I observed was that my __start_mcount_loc..__stop_mcount_loc was empty even though ftrace function tracing was enabled. Link: http://lkml.kernel.org/r/1324345362-12230-1-git-send-email-ddaney.cavm@gmail.com Signed-off-by: David Daney Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- scripts/recordmcount.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/scripts/recordmcount.h +++ b/scripts/recordmcount.h @@ -462,7 +462,7 @@ __has_rel_mcount(Elf_Shdr const *const r succeed_file(); } if (w(txthdr->sh_type) != SHT_PROGBITS || - !(w(txthdr->sh_flags) & SHF_EXECINSTR)) + !(_w(txthdr->sh_flags) & SHF_EXECINSTR)) return NULL; return txtname; }