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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 B5D7AC433B4 for ; Thu, 6 May 2021 19:42:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 976CD61289 for ; Thu, 6 May 2021 19:42:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235687AbhEFTnx (ORCPT ); Thu, 6 May 2021 15:43:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235628AbhEFTnu (ORCPT ); Thu, 6 May 2021 15:43:50 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD0DDC061761 for ; Thu, 6 May 2021 12:42:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=hhyxUtgR+B7x+kVwQUha59XgAwJqFT7lXBFEsYsowC8=; b=FYz67lt2uLfSCElARaIMcxCp52 mN05C2AkGfg/3XYibjBpK/EFm4bU+Pu+kXcXuJ5XIDVQI5xAi3S6EXsMVMjGlQlPp2FEWLwxScY7u lAByljCmH2241f3eWr0jjyi1AyGWuFFJJJ9PC0TtFjvwIJyyQyxgRkUS4rg2eSVArz/iMtbvPvj2t 7rn5FwOU06CywuH2DVeiZxKUfOd8gFgxXQtXhWuFIeJW7uhOdSxqofAo11nUYlSbjHs+aOTBfl/GI +a+wccHgoNLCuTHlmubkIRMAVqXfw67i+tSvQeWPl1AfCtKKo4ONzkuZBfJ91o1l7Gev7CCQ3/C+v Yw6wQbkg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lejtT-005BM8-8s; Thu, 06 May 2021 19:42:43 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 25C6A300365; Thu, 6 May 2021 21:42:39 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id C8FC820B96F91; Thu, 6 May 2021 21:42:38 +0200 (CEST) Message-ID: <20210506194158.091028792@infradead.org> User-Agent: quilt/0.66 Date: Thu, 06 May 2021 21:34:03 +0200 From: Peter Zijlstra To: x86@kernel.org, jpoimboe@redhat.com, jbaron@akamai.com, rostedt@goodmis.org, ardb@kernel.org Cc: linux-kernel@vger.kernel.org, peterz@infradead.org Subject: [PATCH 11/13] objtool: Rewrite jump_label instructions References: <20210506193352.719596001@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When a jump_entry::key has bit1 set, rewrite the instruction to be a NOP. This allows the compiler/assembler to emit JMP (and thus decide on which encoding to use). Signed-off-by: Peter Zijlstra (Intel) --- tools/objtool/check.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1223,6 +1223,20 @@ static int handle_jump_alt(struct objtoo return -1; } + if (special_alt->key_addend & 2) { + struct reloc *reloc = insn_reloc(file, orig_insn); + + if (reloc) { + reloc->type = R_NONE; + elf_write_reloc(file->elf, reloc); + } + elf_write_insn(file->elf, orig_insn->sec, + orig_insn->offset, orig_insn->len, + arch_nop_insn(orig_insn->len)); + orig_insn->type = INSN_NOP; + return 0; + } + *new_insn = list_next_entry(orig_insn, list); return 0; }