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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B2CB0ECE58C for ; Mon, 7 Oct 2019 11:24:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8407E21655 for ; Mon, 7 Oct 2019 11:24:46 +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="ln7OQiCh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727816AbfJGLXl (ORCPT ); Mon, 7 Oct 2019 07:23:41 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:50164 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727416AbfJGLXi (ORCPT ); Mon, 7 Oct 2019 07:23:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=1IsSSBvH0bWyxSaxdNIgTM20UtTECgRXhk8ujqL31QU=; b=ln7OQiChV8SzaEzmuUjMfcpQlP soSfwn/4/dANdg5CQKqtUnOckCwNceq/8QgfoHqaTESTDUrr4DLaLNp5RZjowoB5IH+Lg8LkzwRMv yhSZ1kI2YXhHpD6gqAu67hHT609cOZpbbqNcLkob3E2tVkxtpf10OrkDbkD3/EFulYCxu+zIvN819 UpuK4Gg5MqrY36TPhgZRlegqddBUMYG70Ahd/M/MSxZJR0Q+5oK/I3CiGt/8i8mXLdMS9oE2ybl6Y +9jZEUDSEdEXgZ1nY+tcsvpMpNoON9HNM7wnHd4fxAXy/QIXmiGuQH0axY6VQoWiIqUDEawOE5ltI 3QLp6f5w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHR6u-0003Fy-OG; Mon, 07 Oct 2019 11:23:28 +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 06693307058; Mon, 7 Oct 2019 13:22:36 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 94B5520244E26; Mon, 7 Oct 2019 13:23:26 +0200 (CEST) Message-Id: <20191007082700.20088974.3@infradead.org> User-Agent: quilt/0.65 Date: Mon, 07 Oct 2019 10:25:45 +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 Subject: [PATCH v2 4/4] jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved References: <20191007082541.64146933.7@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) --- 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)