From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751561AbbAVHOd (ORCPT ); Thu, 22 Jan 2015 02:14:33 -0500 Received: from mail-pd0-f179.google.com ([209.85.192.179]:51835 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750811AbbAVHO0 (ORCPT ); Thu, 22 Jan 2015 02:14:26 -0500 Message-ID: <54C0A357.4070701@gmail.com> Date: Thu, 22 Jan 2015 15:14:31 +0800 From: Chung-Lin Tang User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org CC: Ley Foon Tan , Tobias Klauser , cltang@codesourcery.com Subject: [PATCH] nios2: __kuser_sigtramp placement fix Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The address of __kuser_sigtramp is wrong by one word, due to padding __kuser_cmpxchg to fully 64 bytes. The version word at the start of the page displaces __kuser_sigtramp to 0x1044, instead of the intended 0x1040. Fixed by counting the 64-byte frame from the start of the page instead of __kuser_cmpxchg. This shortens the __kuser_cmpxchg frame to 60-bytes, but that's likely enough. The zero-byte padding parts of the kuser_pad macro has been removed, due to the .if command refusing to behave properly when there are other .word directives in between. Probably a binutils gas bug. Thanks, Chung-Lin Cc: Ley Foon Tan Cc: Tobias Klauser Signed-off-by: Chung-Lin Tang diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S index 0bdfd13..3224839 100644 --- a/arch/nios2/kernel/entry.S +++ b/arch/nios2/kernel/entry.S @@ -492,14 +492,7 @@ ENTRY(ret_from_kernel_thread) /* Filling pads with undefined instructions. */ .macro kuser_pad sym size - .if ((. - \sym) & 3) - .rept (4 - (. - \sym) & 3) - .byte 0 - .endr - .endif - .rept ((\size - (. - \sym)) / 4) - .word 0xdeadbeef - .endr + .fill ((\size - (. - \sym)) / 4), 4, 0xdeadbeef .endm .align 6 @@ -526,7 +519,10 @@ cmpxchg_stw: cmpxchg_ret: ret - kuser_pad __kuser_cmpxchg, 64 + /* The first 64-byte frame contains the version word, so note + that the first padding entry is based from the start of the kuser + page, instead of __kuser_cmpxchg. */ + kuser_pad __kuser_helper_start, 64 .globl __kuser_sigtramp __kuser_sigtramp: