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 X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6034BC43331 for ; Wed, 1 Apr 2020 18:50:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2F6FF206F5 for ; Wed, 1 Apr 2020 18:50:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Dzsjusu5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732500AbgDASuE (ORCPT ); Wed, 1 Apr 2020 14:50:04 -0400 Received: from merlin.infradead.org ([205.233.59.134]:60522 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732279AbgDASuD (ORCPT ); Wed, 1 Apr 2020 14:50:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=5gIoccWgwG0UTBdqO685OvdtFiV1jZqp8Lt6I3tMn5E=; b=Dzsjusu5pglcXVvT6J0lYNgX8V RcGUXFdinq9nGxJ/EvCtHdxS8HYBkhhbMsQLBLXpMjjUl8Yzc7xriIRnIsUYlZ9aK983GjBjfClXW 2gr8CAJdmi2r+tTyspmOYEZT1TCP48oE6tRDXZAyeanOrmVcdwZG4Vme10GReLvdHs4cQZF132M51 Yg7pOabZoT6Dd3jHfswrkgZcBzesXzMgQDQkxIJjvJ51Th9XGB7en6rnK1KVB7iDvJURyhyJxSnno JXEKmHXzx8A3nCVLxSqZsGJkCT3HRGhVAxTaWD7eghcZEKFh8CMQsm0U2O2ahs3/wwFwoSxmOGFwA 8lLHCdiQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jJiR1-0007PY-Jy; Wed, 01 Apr 2020 18:49:56 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 495AA3025C3; Wed, 1 Apr 2020 20:49:53 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2299920418979; Wed, 1 Apr 2020 20:49:53 +0200 (CEST) Date: Wed, 1 Apr 2020 20:49:53 +0200 From: Peter Zijlstra To: Josh Poimboeuf Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Miroslav Benes , Julien Thierry , Nick Desaulniers , Dmitry Golovin , Nathan Chancellor Subject: Re: [PATCH 3/5] objtool: Support Clang non-section symbols in ORC generation Message-ID: <20200401184953.GZ20730@hirez.programming.kicks-ass.net> References: <9a9cae7fcf628843aabe5a086b1a3c5bf50f42e8.1585761021.git.jpoimboe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9a9cae7fcf628843aabe5a086b1a3c5bf50f42e8.1585761021.git.jpoimboe@redhat.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 01, 2020 at 01:23:27PM -0500, Josh Poimboeuf wrote: > @@ -105,8 +100,32 @@ static int create_orc_entry(struct elf *elf, struct section *u_sec, struct secti > } > memset(rela, 0, sizeof(*rela)); > > - rela->sym = insn_sec->sym; > - rela->addend = insn_off; > + if (insn_sec->sym) { > + rela->sym = insn_sec->sym; > + rela->addend = insn_off; > + } else { > + /* > + * The Clang assembler doesn't produce section symbols, so we > + * have to reference the function symbol instead: > + */ > + rela->sym = find_symbol_containing(insn_sec, insn_off); It's a good thing I made that a lot faster I suppose ;-) > + if (!rela->sym) { > + /* > + * Hack alert. This happens when we need to reference > + * the NOP pad insn immediately after the function. > + */ > + rela->sym = find_symbol_containing(insn_sec, > + insn_off - 1); Urgh, when does that happen? > + } > + if (!rela->sym) { > + WARN("missing symbol for insn at offset 0x%lx\n", > + insn_off); > + return -1; > + } > + > + rela->addend = insn_off - rela->sym->offset; > + } > + > rela->type = R_X86_64_PC32; > rela->offset = idx * sizeof(int); > rela->sec = ip_relasec; > -- > 2.21.1 >