From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753927AbaCKAhs (ORCPT ); Mon, 10 Mar 2014 20:37:48 -0400 Received: from terminus.zytor.com ([198.137.202.10]:55724 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753364AbaCKAhq (ORCPT ); Mon, 10 Mar 2014 20:37:46 -0400 Date: Mon, 10 Mar 2014 17:36:43 -0700 From: tip-bot for Mathias Krause Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, brgerst@gmail.com, peterz@infradead.org, rostedt@goodmis.org, akpm@linux-foundation.org, minipli@googlemail.com, ak@linux.intel.com, tglx@linutronix.de, hpa@linux.intel.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, brgerst@gmail.com, peterz@infradead.org, rostedt@goodmis.org, akpm@linux-foundation.org, minipli@googlemail.com, ak@linux.intel.com, tglx@linutronix.de, hpa@linux.intel.com In-Reply-To: <1394178752-18047-1-git-send-email-minipli@googlemail.com> References: <1394178752-18047-1-git-send-email-minipli@googlemail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/threadinfo] x86, threadinfo: Redo "x86: Use inline assembler to get sp" Git-Commit-ID: 6cce16f99d7be23cec7cabdf32a8166eec6e5393 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 6cce16f99d7be23cec7cabdf32a8166eec6e5393 Gitweb: http://git.kernel.org/tip/6cce16f99d7be23cec7cabdf32a8166eec6e5393 Author: Mathias Krause AuthorDate: Fri, 7 Mar 2014 08:52:32 +0100 Committer: H. Peter Anvin CommitDate: Mon, 10 Mar 2014 17:32:01 -0700 x86, threadinfo: Redo "x86: Use inline assembler to get sp" This patch restores the changes of commit dff38e3e93 "x86: Use inline assembler instead of global register variable to get sp". They got lost in commit 198d208df4 "x86: Keep thread_info on thread stack in x86_32" while moving the code to arch/x86/kernel/irq_32.c. Quoting Andi from commit dff38e3e93: """ LTO in gcc 4.6/47. has trouble with global register variables. They were used to read the stack pointer. Use a simple inline assembler statement with a mov instead. This also helps LLVM/clang, which does not support global register variables. """ Cc: Steven Rostedt Cc: Andrew Morton Cc: Peter Zijlstra Cc: Brian Gerst Cc: Andi Kleen Signed-off-by: Mathias Krause Link: http://lkml.kernel.org/r/1394178752-18047-1-git-send-email-minipli@googlemail.com Signed-off-by: H. Peter Anvin --- arch/x86/kernel/irq_32.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 988dc8b..63ce838 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -70,7 +70,11 @@ static void call_on_stack(void *func, void *stack) } /* how to get the current stack pointer from C */ -register unsigned long current_stack_pointer asm("esp") __used; +#define current_stack_pointer ({ \ + unsigned long sp; \ + asm("mov %%esp,%0" : "=g" (sp)); \ + sp; \ +}) static inline void *current_stack(void) {