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=-9.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 B642FC4727C for ; Tue, 22 Sep 2020 00:27:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A09C23A84 for ; Tue, 22 Sep 2020 00:27:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729257AbgIVA1C (ORCPT ); Mon, 21 Sep 2020 20:27:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:55428 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729220AbgIVA1B (ORCPT ); Mon, 21 Sep 2020 20:27:01 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EE17523A9A; Tue, 22 Sep 2020 00:27:00 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94) (envelope-from ) id 1kKW95-001raD-W8; Mon, 21 Sep 2020 20:27:00 -0400 Message-ID: <20200922002659.875259952@goodmis.org> User-Agent: quilt/0.66 Date: Mon, 21 Sep 2020 20:26:23 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Adrian Hunter Subject: [for-linus][PATCH 3/8] ftrace: Fix missing synchronize_rcu() removing trampoline from kallsyms References: <20200922002620.231334654@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Adrian Hunter Add synchronize_rcu() after list_del_rcu() in ftrace_remove_trampoline_from_kallsyms() to protect readers of ftrace_ops_trampoline_list (in ftrace_get_trampoline_kallsym) which is used when kallsyms is read. Link: https://lkml.kernel.org/r/20200901091617.31837-1-adrian.hunter@intel.com Fixes: fc0ea795f53c8d ("ftrace: Add symbols for ftrace trampolines") Signed-off-by: Adrian Hunter Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ftrace.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 656d7cb5a78c..e9f893388245 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2782,6 +2782,7 @@ static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops) { lockdep_assert_held(&ftrace_lock); list_del_rcu(&ops->list); + synchronize_rcu(); } /* -- 2.28.0