From patchwork Mon Aug 12 14:04:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 818737 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 55FE117F4F2; Mon, 12 Aug 2024 14:09:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=79.96.170.134 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723471776; cv=none; b=BF/ZUe8EuPW02OTM9XXAd0ERM39ZDLukXufhT1pCoAumP15M2fj5Fk1WupT0IF2VU4MLhOC5HeCze7dnrdrS63qGMRpggTiRqAY1yHsD2k1IyXm58S41JlsTKEtWz53bchlxSaK62B1s4e4FGVSV7tIVXD4UNWzDg/DvZWpNbUk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723471776; c=relaxed/simple; bh=cKY0anN3ZJZFbMAXGyDYNJKkKnybGeIoM+WSXcqfNeQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=YuXqF//yIxzfKi1+9AHv/Mtt2cKRDQXkpmmQNAKdFcLIiNBQZiJ1UXAo3W6tyiPr2WD91TYJFKHriC39DtqfBU9thgl8aWBwnYOlyvD3qppOFHK6j/YGPsE8NDYNAtPPJo3dzb/g1gt89bKAJ+BOzNUTU2sqPxtVbD6GuIGcny4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net; spf=pass smtp.mailfrom=rjwysocki.net; dkim=fail (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b=ckxUKGAu reason="signature verification failed"; arc=none smtp.client-ip=79.96.170.134 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b="ckxUKGAu" Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 6.2.0) id 01e34b93c51094a0; Mon, 12 Aug 2024 16:09:32 +0200 Received: from kreacher.localnet (unknown [195.136.19.94]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by cloudserver094114.home.pl (Postfix) with ESMTPSA id EBDA56F0D6A; Mon, 12 Aug 2024 16:09:31 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rjwysocki.net; s=dkim; t=1723471772; bh=cKY0anN3ZJZFbMAXGyDYNJKkKnybGeIoM+WSXcqfNeQ=; h=From:Subject:Date; b=ckxUKGAuOT/kqe/o7x836A7hWh/PessHF88KZEaPEoujfc4lGvJrDgbx8s6UBezQw R54Q8deIQKIKTkm5+Lfr1wEJi+WLQMLiMzX6Np526QYx8B/Yutnuh4zpzRjaoS3grn lqUBs84whkOIJQ0K4ss0jky3ySZNyy4LyC9at8KIblGIWa0lD/CaoM/08b/W5wXIR5 13TpF+c2KMz17vZC2S4JgeZ1fjXAkNrDRwuZKKCeF3e2f1CbJ0vYfHE1zfPWQzF1kx jMZwS75lSyF3WIlmeNrBNSXWLu+76XGQN2Mo10oTUmeYDSCizhAmQWMizHWRItMn6S /kzqoT1E9uCRw== From: "Rafael J. Wysocki" To: Linux PM Cc: LKML , Daniel Lezcano , Lukasz Luba , Zhang Rui Subject: [PATCH v2 07/17] thermal: core: Move thermal zone locking out of bind/unbind functions Date: Mon, 12 Aug 2024 16:04:38 +0200 Message-ID: <4611405.cEBGB3zze1@rjwysocki.net> In-Reply-To: <114901234.nniJfEyVGO@rjwysocki.net> References: <114901234.nniJfEyVGO@rjwysocki.net> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CLIENT-IP: 195.136.19.94 X-CLIENT-HOSTNAME: 195.136.19.94 X-VADE-SPAMSTATE: spam:low X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeeftddruddttddgjeefucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecujffqoffgrffnpdggtffipffknecuuegrihhlohhuthemucduhedtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenogfuphgrmhfkphculdeftddtmdenucfjughrpefhvfevufffkfgjfhgggfgtsehtufertddttdejnecuhfhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqnecuggftrfgrthhtvghrnhepvdffueeitdfgvddtudegueejtdffteetgeefkeffvdeftddttdeuhfegfedvjefhnecukfhppeduleehrddufeeirdduledrleegnecuufhprghmkfhppeduleehrddufeeirdduledrleegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepudelhedrudefiedrudelrdelgedphhgvlhhopehkrhgvrggthhgvrhdrlhhotggrlhhnvghtpdhmrghilhhfrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqedpnhgspghrtghpthhtohephedprhgtphhtthhopehlihhnuhigqdhpmhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopegurghnihgvlhdrlhgviigtrghnoheslhhinhgrrhhordhorhhgpdhrtghpthhtoheplhhukhgrshiirdhluhgsrgesrghrmhdrtghomhdprhgtphhtthhopehruhhirdiihhgrnhhgsehinhhtvghlrdgtohhm X-DCC--Metrics: v370.home.net.pl 1024; Body=5 Fuz1=5 Fuz2=5 From: Rafael J. Wysocki Since thermal_bind_cdev_to_trip() and thermal_unbind_cdev_from_trip() acquire the thermal zone lock, the locking rules for their callers get complicated. In particular, the thermal zone lock cannot be acquired in any code path leading to one of these functions even though it might be useful to do so. To address this, remove the thermal zone locking from both these functions, add lockdep assertions for the thermal zone lock to both of them and make their callers acquire the thermal zone lock instead. No intentional functional impact. Signed-off-by: Rafael J. Wysocki --- v1 -> v2: No changes --- drivers/acpi/thermal.c | 2 +- drivers/thermal/thermal_core.c | 30 ++++++++++++++++++++++-------- 2 files changed, 23 insertions(+), 9 deletions(-) Index: linux-pm/drivers/thermal/thermal_core.c =================================================================== --- linux-pm.orig/drivers/thermal/thermal_core.c +++ linux-pm/drivers/thermal/thermal_core.c @@ -789,6 +789,7 @@ int thermal_bind_cdev_to_trip(struct the int result; lockdep_assert_held(&thermal_list_lock); + lockdep_assert_held(&tz->lock); if (list_empty(&tz->node) || list_empty(&cdev->node)) return -EINVAL; @@ -851,7 +852,6 @@ int thermal_bind_cdev_to_trip(struct the if (result) goto remove_trip_file; - mutex_lock(&tz->lock); mutex_lock(&cdev->lock); list_for_each_entry(instance, &td->thermal_instances, trip_node) { @@ -868,7 +868,6 @@ int thermal_bind_cdev_to_trip(struct the thermal_governor_update_tz(tz, THERMAL_TZ_BIND_CDEV); mutex_unlock(&cdev->lock); - mutex_unlock(&tz->lock); return 0; @@ -892,11 +891,19 @@ int thermal_zone_bind_cooling_device(str unsigned long upper, unsigned long lower, unsigned int weight) { + int ret; + if (trip_index < 0 || trip_index >= tz->num_trips) return -EINVAL; - return thermal_bind_cdev_to_trip(tz, &tz->trips[trip_index].trip, cdev, - upper, lower, weight); + mutex_lock(&tz->lock); + + ret = thermal_bind_cdev_to_trip(tz, &tz->trips[trip_index].trip, cdev, + upper, lower, weight); + + mutex_unlock(&tz->lock); + + return ret; } EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device); @@ -919,7 +926,8 @@ int thermal_unbind_cdev_from_trip(struct struct thermal_trip_desc *td = trip_to_trip_desc(trip); struct thermal_instance *pos, *next; - mutex_lock(&tz->lock); + lockdep_assert_held(&tz->lock); + mutex_lock(&cdev->lock); list_for_each_entry_safe(pos, next, &td->thermal_instances, trip_node) { @@ -930,13 +938,11 @@ int thermal_unbind_cdev_from_trip(struct thermal_governor_update_tz(tz, THERMAL_TZ_UNBIND_CDEV); mutex_unlock(&cdev->lock); - mutex_unlock(&tz->lock); goto free; } } mutex_unlock(&cdev->lock); - mutex_unlock(&tz->lock); return -ENODEV; @@ -954,10 +960,18 @@ int thermal_zone_unbind_cooling_device(s int trip_index, struct thermal_cooling_device *cdev) { + int ret; + if (trip_index < 0 || trip_index >= tz->num_trips) return -EINVAL; - return thermal_unbind_cdev_from_trip(tz, &tz->trips[trip_index].trip, cdev); + mutex_lock(&tz->lock); + + ret = thermal_unbind_cdev_from_trip(tz, &tz->trips[trip_index].trip, cdev); + + mutex_unlock(&tz->lock); + + return ret; } EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device); Index: linux-pm/drivers/acpi/thermal.c =================================================================== --- linux-pm.orig/drivers/acpi/thermal.c +++ linux-pm/drivers/acpi/thermal.c @@ -609,7 +609,7 @@ static int acpi_thermal_bind_unbind_cdev .thermal = thermal, .cdev = cdev, .bind = bind }; - return for_each_thermal_trip(thermal, bind_unbind_cdev_cb, &bd); + return thermal_zone_for_each_trip(thermal, bind_unbind_cdev_cb, &bd); } static int