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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 64CD4C11F67 for ; Tue, 29 Jun 2021 20:36:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B5D561CA1 for ; Tue, 29 Jun 2021 20:36:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235513AbhF2Uip (ORCPT ); Tue, 29 Jun 2021 16:38:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234054AbhF2Uio (ORCPT ); Tue, 29 Jun 2021 16:38:44 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 204B9C061760; Tue, 29 Jun 2021 13:36:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=LVxbuLMLcRpyjQRz1kncVZYfUbiUuDqHXsL23IYKsAY=; b=Kp5YrV6NDDHSjE90/fqu4gF+1L EX6fRw/AgoFU14R9swh3NPg1FeGggmsk/CWWtLVQ7XIPZ1Ndd3lDcok/Ps00f/48iAxQ1XfzROkob U5K/7U1o+5mpcRTGMZZ4YE2uZocZED5W6nlhtTs81cm6KVGzkRadLWUqvPf8lLq3ZUYGWEdNV/5Xg KokSW396SlHuQ+ESiF9Qxm2UgzJT09DEizVi4nPDcJKP166rO00MXwUu3HUBNQrq0jZNrHh4qXbkV HTIn5iOZcuQa0oU8AxcXFNohLBUoNkqctZC+Tj8ycp5HuzNT1+16P8Co+5g+8t8J6gKmAmXx01ud4 QHvx9oEw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lyKSH-004VrN-JG; Tue, 29 Jun 2021 20:35:42 +0000 Date: Tue, 29 Jun 2021 21:35:37 +0100 From: Matthew Wilcox To: Peter Zijlstra Cc: Josh Poimboeuf , linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org, Ingo Molnar , x86@kernel.org, masahiroy@kernel.org, michal.lkml@markovi.net, Linus Torvalds Subject: Re: [tip: objtool/core] jump_label, x86: Allow short NOPs Message-ID: References: <20210506194158.216763632@infradead.org> <162082558708.29796.10992563428983424866.tip-bot2@tip-bot2> <20210518195004.GD21560@worktop.programming.kicks-ass.net> <20210518202443.GA48949@worktop.programming.kicks-ass.net> <20210519004411.xpx4i6qcnfpyyrbj@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 29, 2021 at 09:01:25PM +0100, Matthew Wilcox wrote: > So this got merged without the corresponding Kbuild update being merged, > and my kernel failed to boot. Bisect got as far as > > $ git bisect good > Bisecting: 4 revisions left to test after this (roughly 2 steps) > [ab3257042c26d0cd44793c741e2f89bf38b21fe8] jump_label, x86: Allow short NOPs > > before my sluggish memory remembered this thread from six weeks ago. > > So if anybody else hits this, do a make clean. Actually, this is a different bug with the same symptom. Applying the patch from Peter, and running it: $ ./.build_test_kernel-x86_64/tools/objtool/objtool check -abdJsuld .build_test_kernel-x86_64/vmlinux.o nr_sections: 15446 section_bits: 13 nr_symbols: 116448 symbol_bits: 16 max_reloc: 8031700 tot_reloc: 12477754 reloc_bits: 19 nr_insns: 2523443 .build_test_kernel-x86_64/vmlinux.o: warning: objtool: want_init_on_free()+0x0: jump-label unpatched This is against a freshly built kernel -- i removed the build directory, copied in a .config file and built a fresh kernel.