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=-12.8 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,USER_AGENT_GIT autolearn=unavailable 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 CE9F7C4363D for ; Sun, 4 Oct 2020 02:41:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A82F420657 for ; Sun, 4 Oct 2020 02:41:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726893AbgJDClD (ORCPT ); Sat, 3 Oct 2020 22:41:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726195AbgJDCjb (ORCPT ); Sat, 3 Oct 2020 22:39:31 -0400 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E1D4C0613D0; Sat, 3 Oct 2020 19:39:31 -0700 (PDT) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kOtvu-00BUpm-0z; Sun, 04 Oct 2020 02:39:30 +0000 From: Al Viro To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Marc Zyngier Subject: [RFC PATCH 05/27] untangling ep_call_nested(): take pushing cookie into a helper Date: Sun, 4 Oct 2020 03:39:07 +0100 Message-Id: <20201004023929.2740074-5-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201004023929.2740074-1-viro@ZenIV.linux.org.uk> References: <20201004023608.GM3421308@ZenIV.linux.org.uk> <20201004023929.2740074-1-viro@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro Signed-off-by: Al Viro --- fs/eventpoll.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 43aecae0935c..bd2cc78c47c8 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -424,6 +424,21 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi) #endif /* CONFIG_NET_RX_BUSY_POLL */ +static bool ep_push_nested(void *cookie) +{ + int i; + + if (nesting > EP_MAX_NESTS) /* too deep nesting */ + return false; + + for (i = 0; i < nesting; i++) { + if (cookies[i] == cookie) /* loop detected */ + return false; + } + cookies[nesting++] = cookie; + return true; +} + /** * ep_call_nested - Perform a bound (possibly) nested call, by checking * that the recursion limit is not exceeded, and that @@ -440,17 +455,10 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi) static int ep_call_nested(int (*nproc)(void *, void *, int), void *priv, void *cookie) { - int error, i; + int error; - if (nesting > EP_MAX_NESTS) /* too deep nesting */ + if (!ep_push_nested(cookie)) return -1; - - for (i = 0; i < nesting; i++) { - if (cookies[i] == cookie) /* loop detected */ - return -1; - } - cookies[nesting++] = cookie; - /* Call the nested function */ error = (*nproc)(priv, cookie, nesting - 1); nesting--; -- 2.11.0