From patchwork Sat Jun 1 22:27:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Fernandes X-Patchwork-Id: 10971519 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D2ACC6C5 for ; Sat, 1 Jun 2019 22:28:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C368E28CD4 for ; Sat, 1 Jun 2019 22:28:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B61D428CE8; Sat, 1 Jun 2019 22:28:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id AAE3528CD4 for ; Sat, 1 Jun 2019 22:28:25 +0000 (UTC) Received: (qmail 7880 invoked by uid 550); 1 Jun 2019 22:28:10 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 7760 invoked from network); 1 Jun 2019 22:28:08 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rqX2p4uQomvAAMxsp9TEtCWxlekRzsNAShlcKhjjs7M=; b=u9hyOmtkHjFodsqyuMvifQjLEIbjbOOqfRSX3tNRi9E8HhOlBJLdxvNGwOW85TGM/d /w6VDCUiwLJcv7Fb35zChbFxWc5Oe2xie9SV8/YjahmmS9P/twVmlQw2oBBNNunqlPpK BZ1sImNKFFdkr8E6qsjV9GEwobbs6bVeqYvoY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rqX2p4uQomvAAMxsp9TEtCWxlekRzsNAShlcKhjjs7M=; b=ljZqiJXnyirtWE/Uk24MKXzeECqNaCuKXFmpRAtNZ8e1z4mi26H0UwDq55WbMRiYJv tg0y4ytnY4WGWgFYG6dWzQ6HF3v3eJtzFp7kiRcMGWHZma1h5HzvDUgOmfrwP+rQohqq 28+oDDjUjC9dYkI5LbYDNgLuXn63QuzjNUTQrXNWj4TvKdi5iIN4es2KVDJ9yzv/Z7ph uRcCaP6nGmq61wkLoL1ttyNKBPbcP9XzoFR5xxwDq/o6YeeJswpZa3WeiYOW+n08D/e1 kkqXvLLVsCggvcsuQ3K2DRspd/7yxnnNiDb7xfNiwQm0H9skMOFYgpdG7A1QF512yOoY DRqA== X-Gm-Message-State: APjAAAXViE6fvaE3PNYm5dy/yx8WHEctyhvu8AgPTMYOhZOV+TYoUdOD 6YEoLHtDmEiU/8ODITGkLiTj0A== X-Google-Smtp-Source: APXvYqyiCQj6LH72QpZ9kXjISAU3j1wiZHQ9UAorgqFGuK1ddmmKcw5Ut1EOXcWf5lfwMy2Ph2ZgdQ== X-Received: by 2002:a17:90b:d88:: with SMTP id bg8mr5074839pjb.70.1559428076902; Sat, 01 Jun 2019 15:27:56 -0700 (PDT) From: "Joel Fernandes (Google)" To: linux-kernel@vger.kernel.org Cc: "Joel Fernandes (Google)" , Alexey Kuznetsov , Bjorn Helgaas , Borislav Petkov , "David S. Miller" , edumazet@google.com, Greg Kroah-Hartman , Hideaki YOSHIFUJI , "H. Peter Anvin" , Ingo Molnar , Josh Triplett , keescook@chromium.org, kernel-hardening@lists.openwall.com, Lai Jiangshan , Len Brown , linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, Mathieu Desnoyers , neilb@suse.com, netdev@vger.kernel.org, oleg@redhat.com, "Paul E. McKenney" , Pavel Machek , peterz@infradead.org, "Rafael J. Wysocki" , rcu@vger.kernel.org, Steven Rostedt , Tejun Heo , Thomas Gleixner , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)) Subject: [RFC 3/6] driver/core: Convert to use built-in RCU list checking Date: Sat, 1 Jun 2019 18:27:35 -0400 Message-Id: <20190601222738.6856-4-joel@joelfernandes.org> X-Mailer: git-send-email 2.22.0.rc1.311.g5d7573a151-goog In-Reply-To: <20190601222738.6856-1-joel@joelfernandes.org> References: <20190601222738.6856-1-joel@joelfernandes.org> MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP list_for_each_entry_rcu has built-in RCU and lock checking. Make use of it in driver core. Signed-off-by: Joel Fernandes (Google) --- drivers/base/base.h | 1 + drivers/base/core.c | 10 ++++++++++ drivers/base/power/runtime.c | 15 ++++++++++----- 3 files changed, 21 insertions(+), 5 deletions(-) diff --git a/drivers/base/base.h b/drivers/base/base.h index b405436ee28e..0d32544b6f91 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -165,6 +165,7 @@ static inline int devtmpfs_init(void) { return 0; } /* Device links support */ extern int device_links_read_lock(void); extern void device_links_read_unlock(int idx); +extern int device_links_read_lock_held(void); extern int device_links_check_suppliers(struct device *dev); extern void device_links_driver_bound(struct device *dev); extern void device_links_driver_cleanup(struct device *dev); diff --git a/drivers/base/core.c b/drivers/base/core.c index fd7511e04e62..6c5ca9685647 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -68,6 +68,11 @@ void device_links_read_unlock(int idx) { srcu_read_unlock(&device_links_srcu, idx); } + +int device_links_read_lock_held(void) +{ + return srcu_read_lock_held(&device_links_srcu); +} #else /* !CONFIG_SRCU */ static DECLARE_RWSEM(device_links_lock); @@ -91,6 +96,11 @@ void device_links_read_unlock(int not_used) { up_read(&device_links_lock); } + +int device_links_read_lock_held(void) +{ + return lock_is_held(&device_links_lock); +} #endif /* !CONFIG_SRCU */ /** diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 952a1e7057c7..7a10e8379a70 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -287,7 +287,8 @@ static int rpm_get_suppliers(struct device *dev) { struct device_link *link; - list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) { + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, + device_links_read_lock_held()) { int retval; if (!(link->flags & DL_FLAG_PM_RUNTIME) || @@ -309,7 +310,8 @@ static void rpm_put_suppliers(struct device *dev) { struct device_link *link; - list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) { + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, + device_links_read_lock_held()) { if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND) continue; @@ -1640,7 +1642,8 @@ void pm_runtime_clean_up_links(struct device *dev) idx = device_links_read_lock(); - list_for_each_entry_rcu(link, &dev->links.consumers, s_node) { + list_for_each_entry_rcu(link, &dev->links.consumers, s_node, + device_links_read_lock_held()) { if (link->flags & DL_FLAG_STATELESS) continue; @@ -1662,7 +1665,8 @@ void pm_runtime_get_suppliers(struct device *dev) idx = device_links_read_lock(); - list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, + device_links_read_lock_held()) if (link->flags & DL_FLAG_PM_RUNTIME) { link->supplier_preactivated = true; refcount_inc(&link->rpm_active); @@ -1683,7 +1687,8 @@ void pm_runtime_put_suppliers(struct device *dev) idx = device_links_read_lock(); - list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, + device_links_read_lock_held()) if (link->supplier_preactivated) { link->supplier_preactivated = false; if (refcount_dec_not_one(&link->rpm_active))