From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72616C433FE for ; Tue, 22 Mar 2022 13:16:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233774AbiCVNRi (ORCPT ); Tue, 22 Mar 2022 09:17:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233647AbiCVNRg (ORCPT ); Tue, 22 Mar 2022 09:17:36 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5DFA8443ED; Tue, 22 Mar 2022 06:16:08 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A58F31042; Tue, 22 Mar 2022 06:16:07 -0700 (PDT) Received: from FVFF77S0Q05N (unknown [10.57.92.214]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 50FFA3F73B; Tue, 22 Mar 2022 06:16:05 -0700 (PDT) Date: Tue, 22 Mar 2022 13:15:58 +0000 From: Mark Rutland To: Masami Hiramatsu Cc: Peter Zijlstra , Stephen Rothwell , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Linux Kernel Mailing List , Linux Next Mailing List , rostedt@goodmis.org, ast@kernel.org, hjl.tools@gmail.com, rick.p.edgecombe@intel.com, rppt@kernel.org, linux-toolchains@vger.kernel.org, Andrew.Cooper3@citrix.com, ndesaulniers@google.com Subject: Re: linux-next: build warnings after merge of the tip tree Message-ID: References: <20220321140327.777f9554@canb.auug.org.au> <20220322143136.0e78366c3521b54b7b9385b8@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220322143136.0e78366c3521b54b7b9385b8@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On Tue, Mar 22, 2022 at 02:31:36PM +0900, Masami Hiramatsu wrote: > On Mon, 21 Mar 2022 17:48:54 +0100 > Peter Zijlstra wrote: > > > On Mon, Mar 21, 2022 at 02:04:05PM +0100, Peter Zijlstra wrote: > > > On Mon, Mar 21, 2022 at 01:55:49PM +0100, Peter Zijlstra wrote: > > > > On Mon, Mar 21, 2022 at 02:03:27PM +1100, Stephen Rothwell wrote: > > > > > Hi all, > > > > > > > > > > After merging the tip tree, today's linux-next build (x864 allmodconfig) > > > > > produced these new warnings: > > > > > > > > > > vmlinux.o: warning: objtool: arch_rethook_prepare()+0x55: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: arch_rethook_trampoline_callback()+0x3e: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: unwind_next_frame()+0x93e: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: unwind_next_frame()+0x5f2: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: unwind_next_frame()+0x4a7: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: __rethook_find_ret_addr()+0x81: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: __rethook_find_ret_addr()+0x90: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: rethook_trampoline_handler()+0x8c: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > vmlinux.o: warning: objtool: rethook_trampoline_handler()+0x9b: relocation to !ENDBR: arch_rethook_trampoline+0x0 > > > > > > > > Hurmph, lemme go figure out where that code comes from, I've not seen > > > > those. > > > > > > Ahh, something tracing. I'll go do some patches on top of it. > > > > The below gets rid of the objtool warnings. > > Yes, I confirmed that. > > > But I still think it's fairly terrible to get a (flawed) carbon copy of > > the kretprobe code. > > Indeed. I would like to replace the trampoline code of kretprobe with > rethook, eventually. There is no reason why we keep the clone. > (But I need more arch maintainers help for that, there are too many > archs implemented kretprobes) FWIW, I'm more than happy to help on the arm64 side if you could Cc me for that; I'm aware of other things in this area I'd like to clean up for backtracing, too. Thanks, Mark.