From patchwork Fri Oct 13 11:58:46 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frederic Weisbecker X-Patchwork-Id: 152541 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:612c:2908:b0:403:3b70:6f57 with SMTP id ib8csp1834268vqb; Fri, 13 Oct 2023 04:59:26 -0700 (PDT) X-Google-Smtp-Source: AGHT+IENTDFxfDQW9WDZJHgEWC7PiGb0tNX6+AlA0ov9rtgu2VKV++mLsZ86AhkD5/MPJym1zMfg X-Received: by 2002:a05:6a00:1d22:b0:693:38c5:4d6d with SMTP id a34-20020a056a001d2200b0069338c54d6dmr29428469pfx.2.1697198365982; Fri, 13 Oct 2023 04:59:25 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1697198365; cv=none; d=google.com; s=arc-20160816; b=Lg0pQVgUIwwUYPN+rKHoc8gKRHezR5+ORdCCHbrGaz2lkbZgiskkOEv2Ac2vwAu5kW DGIxe3nWzrly7oUNGLQZuizS1yOSjZiuATE+St4iFU44lR293LE4qVCo2myUFuhnMMKV Z+HWSSWk6Fpe6HOQMDFPQsd9ek/bn8VlV1dkBwm91+n9461cr4Pi3mO6UDliJ0QjPtEX PwClk+fJ8AxOf9w2foQsGENDRrOSZp5mE2/dk+tX26d0eP3gbSUHkU28+VCv5bo/dPle YExRXbFQc/c4ggvq9oXU/C+efOmuBpCyIQtwgVGgN3zP/OeC1aiBX4d7+Qy1LntZOEXR YJ2Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=G2DFeqo0EWOzNIlwMQ1whDCqR/8K+r/TDi9s97w3xgM=; fh=QyKVx5sQ6a0Rye+jmuSl6ocZCOg2PmQ9bDVx4c3R8jE=; b=zctqUcXSY2OHtp1nzfuTYLnk1aR6rP+4Q3teOtr3tlx2W0Pq4zt1aJOxz+XE3XKNMi OGLNrC7V6xOzcBv1jyR7JHzSx5iaysSuWQg1kQEFvc+C6tSF6VU1pDdFBPqICeKheyWm Q7etd5PFVJ9iMwjxT8dG77d+WeFpgCzL1VwlXDUvFG25js8ph7wKxUv2le2TaNKJa7Mg hbqQEWj1MvjwclXgKBpLBLEE0t4a3OwUIqCDrKrKWMOXbY4GzmIXfTGyuToaaprqoOpE ONNgkLF9tDIrVQ/g9f7P010hsv3E0jbsIPHyI4gVcW6REKL9xV+cxR1G/3wcuMFy6oLH 3meA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=ST+LcM3k; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from snail.vger.email (snail.vger.email. [23.128.96.37]) by mx.google.com with ESMTPS id cb4-20020a056a00430400b00690d8405fe6si3208566pfb.317.2023.10.13.04.59.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Oct 2023 04:59:25 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=ST+LcM3k; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by snail.vger.email (Postfix) with ESMTP id 50BC7830C324; Fri, 13 Oct 2023 04:59:25 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at snail.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231479AbjJML7T (ORCPT + 19 others); Fri, 13 Oct 2023 07:59:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231591AbjJML7Q (ORCPT ); Fri, 13 Oct 2023 07:59:16 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 538FDA9; Fri, 13 Oct 2023 04:59:14 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0BB0C433C7; Fri, 13 Oct 2023 11:59:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697198353; bh=QSG6hSbymQR94WKaIKBPaZ45C4sCdjinqu5taG9tkdg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ST+LcM3kTPie/f4gkDT0cUkbNWb3QyNRsKSk10jgGlWr2PeS6+U3wSok2DF0IK8La 8ZTxGilr1I71zi49J1hyWv7bt5fSBDMpDN//3E6k1a/7JX1D0WtmJXYthV+Qf8IoNv 65GP3qfrkDMIwm86TZDVQzthXMGFfj7HhJQyQyiLtJUljR29rwm9JTBUwI7cXFHr4M 3a6TYfvLFkoIQpcw+mY8P4O2BKsANgaxt0QMm43q2UNT3TkRxioGLnKaoBNk1jBrdM AexJvDe+NCk41waI36+jQlFhjh6yAnGPsaSF0ikKnmWxq/Bl0AhB+pElrcO8eabFRt 20IMFX6kyDcCw== From: Frederic Weisbecker To: LKML Cc: "Joel Fernandes (Google)" , Boqun Feng , Josh Triplett , Mathieu Desnoyers , Neeraj Upadhyay , "Paul E . McKenney" , Steven Rostedt , Uladzislau Rezki , rcu , Frederic Weisbecker Subject: [PATCH 02/18] srcu: Fix error handling in init_srcu_struct_fields() Date: Fri, 13 Oct 2023 13:58:46 +0200 Message-Id: <20231013115902.1059735-3-frederic@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231013115902.1059735-1-frederic@kernel.org> References: <20231013115902.1059735-1-frederic@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (snail.vger.email [0.0.0.0]); Fri, 13 Oct 2023 04:59:25 -0700 (PDT) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1779641474014052929 X-GMAIL-MSGID: 1779641474014052929 From: "Joel Fernandes (Google)" The current error handling in init_srcu_struct_fields() is a bit inconsistent. If init_srcu_struct_nodes() fails, the function either returns -ENOMEM or 0 depending on whether ssp->sda_is_static is true or false. This can make init_srcu_struct_fields() return 0 even if memory allocation failed! Simplify the error handling by always returning -ENOMEM if either init_srcu_struct_nodes() or the per-CPU allocation fails. This makes the control flow easier to follow and avoids the inconsistent return values. Add goto labels to avoid duplicating the error cleanup code. Link: https://lore.kernel.org/r/20230404003508.GA254019@google.com Signed-off-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker --- kernel/rcu/srcutree.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 20d7a238d675..f1a905200fc2 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -255,29 +255,31 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static) ssp->srcu_sup->sda_is_static = is_static; if (!is_static) ssp->sda = alloc_percpu(struct srcu_data); - if (!ssp->sda) { - if (!is_static) - kfree(ssp->srcu_sup); - return -ENOMEM; - } + if (!ssp->sda) + goto err_free_sup; init_srcu_struct_data(ssp); ssp->srcu_sup->srcu_gp_seq_needed_exp = 0; ssp->srcu_sup->srcu_last_gp_end = ktime_get_mono_fast_ns(); if (READ_ONCE(ssp->srcu_sup->srcu_size_state) == SRCU_SIZE_SMALL && SRCU_SIZING_IS_INIT()) { - if (!init_srcu_struct_nodes(ssp, GFP_ATOMIC)) { - if (!ssp->srcu_sup->sda_is_static) { - free_percpu(ssp->sda); - ssp->sda = NULL; - kfree(ssp->srcu_sup); - return -ENOMEM; - } - } else { - WRITE_ONCE(ssp->srcu_sup->srcu_size_state, SRCU_SIZE_BIG); - } + if (!init_srcu_struct_nodes(ssp, GFP_ATOMIC)) + goto err_free_sda; + WRITE_ONCE(ssp->srcu_sup->srcu_size_state, SRCU_SIZE_BIG); } ssp->srcu_sup->srcu_ssp = ssp; smp_store_release(&ssp->srcu_sup->srcu_gp_seq_needed, 0); /* Init done. */ return 0; + +err_free_sda: + if (!is_static) { + free_percpu(ssp->sda); + ssp->sda = NULL; + } +err_free_sup: + if (!is_static) { + kfree(ssp->srcu_sup); + ssp->srcu_sup = NULL; + } + return -ENOMEM; } #ifdef CONFIG_DEBUG_LOCK_ALLOC