From patchwork Wed Jul 6 18:44:25 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rafael Wysocki X-Patchwork-Id: 950852 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p66IhxiI029986 for ; Wed, 6 Jul 2011 18:44:00 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754888Ab1GFSn4 (ORCPT ); Wed, 6 Jul 2011 14:43:56 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:33329 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754850Ab1GFSn4 (ORCPT ); Wed, 6 Jul 2011 14:43:56 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by ogre.sisk.pl (Postfix) with ESMTP id 0911D1A764F; Wed, 6 Jul 2011 20:18:19 +0200 (CEST) Received: from ogre.sisk.pl ([127.0.0.1]) by localhost (ogre.sisk.pl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 04670-04; Wed, 6 Jul 2011 20:17:53 +0200 (CEST) Received: from ferrari.rjw.lan (220-bem-13.acn.waw.pl [82.210.184.220]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ogre.sisk.pl (Postfix) with ESMTP id 7B624199858; Wed, 6 Jul 2011 20:17:53 +0200 (CEST) From: "Rafael J. Wysocki" To: Len Brown Subject: [Resend/Update][PATCH] ACPI: Fix lockdep false positives in acpi_power_off() Date: Wed, 6 Jul 2011 20:44:25 +0200 User-Agent: KMail/1.13.6 (Linux/3.0.0-rc5+; KDE/4.6.0; x86_64; ; ) Cc: Florian Mickler , Andrea Righi , Peter Zijlstra , Ingo Molnar , Borislav Petkov , Maciej Rutecki , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org References: <1309684450-24549-1-git-send-email-andrea@betterlinux.com> <201107050132.11996.rjw@sisk.pl> <20110705100358.6857b235@schatten.dmk.lab> In-Reply-To: <20110705100358.6857b235@schatten.dmk.lab> MIME-Version: 1.0 Message-Id: <201107062044.25387.rjw@sisk.pl> X-Virus-Scanned: amavisd-new at ogre.sisk.pl using MkS_Vir for Linux Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Wed, 06 Jul 2011 18:44:01 +0000 (UTC) From: Rafael J. Wysocki Subject: ACPI: Fix lockdep false positives in acpi_power_off() All ACPICA locks are allocated by the same function, acpi_os_create_lock(), with the help of a local variable called "lock". Thus, when lockdep is enabled, it uses "lock" as the name of all those locks and regards them as instances of the same lock, which causes it to report possible locking problems with them when there aren't any. To work around this problem, define acpi_os_create_lock() as a macro and make it pass its argument to spin_lock_init(), so that lockdep uses it as the name of the new lock. Define this macron in a Linux-specific file, to minimize the resulting modifications of the OS-independent ACPICA parts. This change is based on an earlier patch from Andrea Righi and it addresses a regression from 2.6.39 tracked as https://bugzilla.kernel.org/show_bug.cgi?id=38152 Signed-off-by: Rafael J. Wysocki Reported-and-tested-by: Borislav Petkov Tested-by: Andrea Righi Reviewed-by: Florian Mickler --- drivers/acpi/osl.c | 17 ----------------- include/acpi/acpiosxf.h | 3 +++ include/acpi/platform/aclinux.h | 18 ++++++++++++++++++ 3 files changed, 21 insertions(+), 17 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux-2.6/drivers/acpi/osl.c =================================================================== --- linux-2.6.orig/drivers/acpi/osl.c +++ linux-2.6/drivers/acpi/osl.c @@ -1333,23 +1333,6 @@ int acpi_resources_are_enforced(void) EXPORT_SYMBOL(acpi_resources_are_enforced); /* - * Create and initialize a spinlock. - */ -acpi_status -acpi_os_create_lock(acpi_spinlock *out_handle) -{ - spinlock_t *lock; - - lock = ACPI_ALLOCATE(sizeof(spinlock_t)); - if (!lock) - return AE_NO_MEMORY; - spin_lock_init(lock); - *out_handle = lock; - - return AE_OK; -} - -/* * Deallocate the memory for a spinlock. */ void acpi_os_delete_lock(acpi_spinlock handle) Index: linux-2.6/include/acpi/acpiosxf.h =================================================================== --- linux-2.6.orig/include/acpi/acpiosxf.h +++ linux-2.6/include/acpi/acpiosxf.h @@ -98,8 +98,11 @@ acpi_os_table_override(struct acpi_table /* * Spinlock primitives */ + +#ifndef acpi_os_create_lock acpi_status acpi_os_create_lock(acpi_spinlock *out_handle); +#endif void acpi_os_delete_lock(acpi_spinlock handle); Index: linux-2.6/include/acpi/platform/aclinux.h =================================================================== --- linux-2.6.orig/include/acpi/platform/aclinux.h +++ linux-2.6/include/acpi/platform/aclinux.h @@ -159,6 +159,24 @@ static inline void *acpi_os_acquire_obje } while (0) #endif +/* + * When lockdep is enabled, the spin_lock_init() macro stringifies it's + * argument and uses that as a name for the lock in debugging. + * By executing spin_lock_init() in a macro the key changes from "lock" for + * all locks to the name of the argument of acpi_os_create_lock(), which + * prevents lockdep from reporting false positives for ACPICA locks. + */ +#define acpi_os_create_lock(__handle) \ +({ \ + spinlock_t *lock = ACPI_ALLOCATE(sizeof(*lock)); \ + \ + if (lock) { \ + *(__handle) = lock; \ + spin_lock_init(*(__handle)); \ + } \ + lock ? AE_OK : AE_NO_MEMORY; \ +}) + #endif /* __KERNEL__ */ #endif /* __ACLINUX_H__ */