From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934104AbdAFRed (ORCPT ); Fri, 6 Jan 2017 12:34:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56448 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752980AbdAFReZ (ORCPT ); Fri, 6 Jan 2017 12:34:25 -0500 Date: Fri, 6 Jan 2017 11:34:23 -0600 From: Josh Poimboeuf To: Arnd Bergmann Cc: linux-kernel@vger.kernel.org Subject: Re: objtool warning for wanxl_pci_init_one with gcc-7 Message-ID: <20170106173423.xlmkwtb3iewduqq3@treble> References: <2838744.OLG82KjLgW@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <2838744.OLG82KjLgW@wuerfel> User-Agent: Mutt/1.6.0.1 (2016-04-01) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Fri, 06 Jan 2017 17:34:25 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 04, 2017 at 12:19:20PM +0100, Arnd Bergmann wrote: > Hi Josh, > > I'm getting a new warning with the latest gcc-7 snapshot, I think this > is a false positive: > > drivers/net/wan/wanxl.o: warning: objtool: wanxl_pci_init_one()+0x9d2: sibling call from callable instruction with changed frame pointer > > # /git/arm-soc/drivers/net/wan/wanxl.c:133: switch((value >> STATUS_CABLE_PM_SHIFT) & 0x7) { > movl %eax, %ecx # value, _314 > movl %eax, %r10d # value, _224 > movq (%r15), %rdi # MEM[base: _546, offset: 0B], pretmp_490 > shrl $5, %ecx #, _314 > andl $8, %r10d #, _224 > movl %ecx, %edx # _314, tmp377 > andl $7, %edx #, tmp377 > jmp *(%r14,%rdx,8) # > .section .rodata > .align 8 > .align 4 > .L280: > .quad .L278 > .quad .L278 > .quad .L279 > .quad .L281 > .quad .L282 > .quad .L305 > .quad .L278 > .quad .L306 > .text Thanks Arnd, will take a look at it. This reminds me that I need to ping the gcc guys about better annotations of switch statement jump tables. -- Josh