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=-3.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 98706C433DF for ; Wed, 24 Jun 2020 15:52:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76940206F7 for ; Wed, 24 Jun 2020 15:52:13 +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="FHACZ8Ok" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404659AbgFXPwL (ORCPT ); Wed, 24 Jun 2020 11:52:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404606AbgFXPvx (ORCPT ); Wed, 24 Jun 2020 11:51:53 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B5CBC061573 for ; Wed, 24 Jun 2020 08:51:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; 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=2Qsfk0HOB3x9nc2pqsOJnCHVpv340CkHcue6gSdP15s=; b=FHACZ8OkiEyxYLkMEia3AT7amH 5uhJITj4XXLZaUpJMFC7LUy6dw9gFmR1fUdu1v8f4frCmbhl/obmB12hoWrXjjmPEpyQ2W2QRHEta lhOsQ6MOs0g+Meosuchl49q8O2WXcdIDYD94/Tela2/OY/YYqr2KwO7Hr4XiRP6pnqZRP380W2P+9 /iucd+rpRYliYvf7HH++pl3b0CU3q2OiADmtqjzeQathc4e9Qie+C+ak65350YCzoNV4nTwKvrDnb ssrOFZOFZ2bnj1yM1hac4bHSsbcgTlS0OM6Ir+IrixqOWgXRNYZVVx+O9zX5VSQ3c2AMTR6a1tFD9 BYShSSLw==; 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 1jo7gC-0001cX-7f; Wed, 24 Jun 2020 15:51:16 +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 EA88A3007CD; Wed, 24 Jun 2020 17:51:13 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id D97B4236E775B; Wed, 24 Jun 2020 17:51:13 +0200 (CEST) Message-ID: <20200624154156.969420584@infradead.org> User-Agent: quilt/0.66 Date: Wed, 24 Jun 2020 17:30:28 +0200 From: Peter Zijlstra To: x86@kernel.org Cc: peterz@infradead.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, mhiramat@kernel.org, bristot@redhat.com, jbaron@akamai.com, torvalds@linux-foundation.org, tglx@linutronix.de, mingo@kernel.org, namit@vmware.com, hpa@zytor.com, luto@kernel.org, ard.biesheuvel@linaro.org, jpoimboe@redhat.com, pbonzini@redhat.com, mathieu.desnoyers@efficios.com, linux@rasmusvillemoes.dk Subject: [PATCH v5 04/17] jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved References: <20200624153024.794671356@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nothing ensures the module exists while we're iterating mod->jump_entries in __jump_label_mod_text_reserved(), take a module reference to ensure the module sticks around. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Steven Rostedt (VMware) --- kernel/jump_label.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -539,19 +539,25 @@ static void static_key_set_mod(struct st static int __jump_label_mod_text_reserved(void *start, void *end) { struct module *mod; + int ret; preempt_disable(); mod = __module_text_address((unsigned long)start); WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod); + if (!try_module_get(mod)) + mod = NULL; preempt_enable(); if (!mod) return 0; - - return __jump_label_text_reserved(mod->jump_entries, + ret = __jump_label_text_reserved(mod->jump_entries, mod->jump_entries + mod->num_jump_entries, start, end); + + module_put(mod); + + return ret; } static void __jump_label_mod_update(struct static_key *key)