From patchwork Tue Sep 15 14:13:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 263964 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=-12.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 E07D6C433E2 for ; Tue, 15 Sep 2020 23:15:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5C47206B7 for ; Tue, 15 Sep 2020 23:15:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600211750; bh=IzH0ezexaof8uOk76+O12OrvbCwbKPqp+FmwFtCIyoI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XQN//gM2aKS4M/E9uzwJ7VZHYnppjpMuBzEbfqcMjJ7Cb31L77xu2VDJ9ssl7FwTL Quy9rc90rcSPT+bC9SeNnxzNocgmi3eZ+gs/17DHfTCJ0GR/Kp/pUSrHranldZNBBn fF/KeM4FVeEFfsqogZYpQh7fDfvhg+TzJ/6U9jI4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727277AbgIOXPr (ORCPT ); Tue, 15 Sep 2020 19:15:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:48812 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727239AbgIOOj2 (ORCPT ); Tue, 15 Sep 2020 10:39:28 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 721DC224DE; Tue, 15 Sep 2020 14:29:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600180165; bh=IzH0ezexaof8uOk76+O12OrvbCwbKPqp+FmwFtCIyoI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hAfEZMspSCHIL+g8HLBv4Hrggbqz6SVFNrobdP4cRLnD1kvqzysAPc8CErKlLWjL7 +dMsS2MkWw7D3j+RYm0a46Jo9zqfo56j+8uvUEVVjNurhgkSBeCS/gPufGF6A2CV1g kxuVo8wsxo4sZiE5HMb7hu5NOopkWIAAtDp77Diw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?utf-8?b?TWljaGHFgiBNaXJvc8WCYXc=?= , Mark Brown Subject: [PATCH 5.8 134/177] regulator: push allocations in create_regulator() outside of lock Date: Tue, 15 Sep 2020 16:13:25 +0200 Message-Id: <20200915140700.074033733@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200915140653.610388773@linuxfoundation.org> References: <20200915140653.610388773@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Michał Mirosław commit 87fe29b61f9522a3d7b60a4580851f548558186f upstream. Move all allocations outside of the regulator_lock()ed section. ====================================================== WARNING: possible circular locking dependency detected 5.7.13+ #535 Not tainted ------------------------------------------------------ f2fs_discard-179:7/702 is trying to acquire lock: c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0 but task is already holding lock: cb95b080 (&dcc->cmd_lock){+.+.}-{3:3}, at: __issue_discard_cmd+0xec/0x5f8 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: [...] -> #3 (fs_reclaim){+.+.}-{0:0}: fs_reclaim_acquire.part.11+0x40/0x50 fs_reclaim_acquire+0x24/0x28 __kmalloc_track_caller+0x54/0x218 kstrdup+0x40/0x5c create_regulator+0xf4/0x368 regulator_resolve_supply+0x1a0/0x200 regulator_register+0x9c8/0x163c [...] other info that might help us debug this: Chain exists of: regulator_list_mutex --> &sit_i->sentry_lock --> &dcc->cmd_lock [...] Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking") Signed-off-by: Michał Mirosław Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/6eebc99b2474f4ffaa0405b15178ece0e7e4f608.1597195321.git.mirq-linux@rere.qmqm.pl Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/regulator/core.c | 53 ++++++++++++++++++++++++----------------------- 1 file changed, 28 insertions(+), 25 deletions(-) --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1579,44 +1579,53 @@ static struct regulator *create_regulato const char *supply_name) { struct regulator *regulator; - char buf[REG_STR_SIZE]; - int err, size; + int err; + + if (dev) { + char buf[REG_STR_SIZE]; + int size; + + size = snprintf(buf, REG_STR_SIZE, "%s-%s", + dev->kobj.name, supply_name); + if (size >= REG_STR_SIZE) + return NULL; + + supply_name = kstrdup(buf, GFP_KERNEL); + if (supply_name == NULL) + return NULL; + } else { + supply_name = kstrdup_const(supply_name, GFP_KERNEL); + if (supply_name == NULL) + return NULL; + } regulator = kzalloc(sizeof(*regulator), GFP_KERNEL); - if (regulator == NULL) + if (regulator == NULL) { + kfree(supply_name); return NULL; + } - regulator_lock(rdev); regulator->rdev = rdev; + regulator->supply_name = supply_name; + + regulator_lock(rdev); list_add(®ulator->list, &rdev->consumer_list); + regulator_unlock(rdev); if (dev) { regulator->dev = dev; /* Add a link to the device sysfs entry */ - size = snprintf(buf, REG_STR_SIZE, "%s-%s", - dev->kobj.name, supply_name); - if (size >= REG_STR_SIZE) - goto overflow_err; - - regulator->supply_name = kstrdup(buf, GFP_KERNEL); - if (regulator->supply_name == NULL) - goto overflow_err; - err = sysfs_create_link_nowarn(&rdev->dev.kobj, &dev->kobj, - buf); + supply_name); if (err) { rdev_dbg(rdev, "could not add device link %s err %d\n", dev->kobj.name, err); /* non-fatal */ } - } else { - regulator->supply_name = kstrdup_const(supply_name, GFP_KERNEL); - if (regulator->supply_name == NULL) - goto overflow_err; } - regulator->debugfs = debugfs_create_dir(regulator->supply_name, + regulator->debugfs = debugfs_create_dir(supply_name, rdev->debugfs); if (!regulator->debugfs) { rdev_dbg(rdev, "Failed to create debugfs directory\n"); @@ -1641,13 +1650,7 @@ static struct regulator *create_regulato _regulator_is_enabled(rdev)) regulator->always_on = true; - regulator_unlock(rdev); return regulator; -overflow_err: - list_del(®ulator->list); - kfree(regulator); - regulator_unlock(rdev); - return NULL; } static int _regulator_get_enable_time(struct regulator_dev *rdev)