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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 D1126C06510 for ; Tue, 2 Jul 2019 16:50:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B39BC21851 for ; Tue, 2 Jul 2019 16:50:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727059AbfGBQuN (ORCPT ); Tue, 2 Jul 2019 12:50:13 -0400 Received: from foss.arm.com ([217.140.110.172]:53372 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726150AbfGBQuN (ORCPT ); Tue, 2 Jul 2019 12:50:13 -0400 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 3F59828; Tue, 2 Jul 2019 09:50:12 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 56DA13F246; Tue, 2 Jul 2019 09:50:11 -0700 (PDT) Date: Tue, 2 Jul 2019 17:50:09 +0100 From: Mark Rutland To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Masami Hiramatsu , Catalin Marinas Subject: Re: [for-next][PATCH 12/16] kprobes: Initialize kprobes at postcore_initcall Message-ID: <20190702165008.GC34718@lakrids.cambridge.arm.com> References: <20190526191828.466305460@goodmis.org> <20190526191848.266163206@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190526191848.266163206@goodmis.org> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 26, 2019 at 03:18:40PM -0400, Steven Rostedt wrote: > From: Masami Hiramatsu > > Initialize kprobes at postcore_initcall level instead of module_init > since kprobes is not a module, and it depends on only subsystems > initialized in core_initcall. > This will allow ftrace kprobe event to add new events when it is > initializing because ftrace kprobe event is initialized at > later initcall level. > > Link: http://lkml.kernel.org/r/155851394736.15728.13626739508905120098.stgit@devnote2 > > Signed-off-by: Masami Hiramatsu > Signed-off-by: Steven Rostedt (VMware) > --- > kernel/kprobes.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index b1ea30a5540e..54aaaad00a47 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -2289,6 +2289,7 @@ static int __init init_kprobes(void) > init_test_probes(); > return err; > } > +postcore_initcall(init_kprobes); As a heads-up, this is causing boot-time failures on arm64. On arm64 kprobes depends on the BRK handler we register in debug_traps_init(), which is an arch_initcall. As of this change, init_krprobes() calls init_test_probes() before that's registered, so we end up hitting a BRK before we can handle it. Thanks, Mark. > > #ifdef CONFIG_DEBUG_FS > static void report_probe(struct seq_file *pi, struct kprobe *p, > @@ -2614,5 +2615,3 @@ static int __init debugfs_kprobe_init(void) > > late_initcall(debugfs_kprobe_init); > #endif /* CONFIG_DEBUG_FS */ > - > -module_init(init_kprobes); > -- > 2.20.1 > >