From nobody Sun Dec 14 14:12:48 2025 Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) (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 0017D158524; Tue, 4 Feb 2025 06:53:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.69.126.157 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738651994; cv=none; b=erfJYVy4929V8hVarhQx522GLnx3lckIhuhT3sF/q5zcEvMHiJ/Mirl3F5B8xPn6ladGlIHZPFdxP7w8hvYhlJDukH8u6X1XSqLsVFrHFZg5+X44vVhrFXnp2rgFGIG+958e4NbhJFL3zVJ48/35PDt4MUHF5+qDkQwIYPg8Rg8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738651994; c=relaxed/simple; bh=8o4oNcfMbl5apVwsKTboT/C2NPZBgsAaBH5eEBfrt/c=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=h+PVxZc9t/FP+01P7RISgfHJ1C4QZb6xwuv/1QbSXhWBGjhZedLjJIGPoJmFH1yfFAkxHj4NnhRQ661V0XrrVb8OtlT3lbRETa0Qz6m2rHFZLRx1cCZ93sl8eQc+r09PVDnExT0SDDsACc55TocKSOanUyM8feaIwpK1ZyRFlVo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weissschuh.net; spf=pass smtp.mailfrom=weissschuh.net; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b=el64BpR/; arc=none smtp.client-ip=159.69.126.157 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b="el64BpR/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=weissschuh.net; s=mail; t=1738651982; bh=8o4oNcfMbl5apVwsKTboT/C2NPZBgsAaBH5eEBfrt/c=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=el64BpR/F9AGD97NSmKAhZXtLVaMPXocgKTj9jv0zQ43wKPc2upHptB4MrTFiN1PR 8IoZcdHFiFfqBsrS1qs0LTqHmsoJAhSacN91gZ6+tRS62AH078Vx40fQ6C9QDHuV9C v0IcxmzRfssEgPXe1sR/yDaJ1UtUcKTsGNCDviJw= From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Date: Tue, 04 Feb 2025 07:52:51 +0100 Subject: [PATCH v2 2/2] locking/mutex: Mark devm_mutex_init() as __must_check Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250204-must_check-devm_mutex_init-v2-2-7b6271c4b7e6@weissschuh.net> References: <20250204-must_check-devm_mutex_init-v2-0-7b6271c4b7e6@weissschuh.net> In-Reply-To: <20250204-must_check-devm_mutex_init-v2-0-7b6271c4b7e6@weissschuh.net> To: Peter Zijlstra , Ingo Molnar , Will Deacon , Waiman Long , Boqun Feng , Pavel Machek , Lee Jones , Vicentiu Galanopulo Cc: Andy Shevchenko , linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1738651981; l=2054; i=linux@weissschuh.net; s=20221212; h=from:subject:message-id; bh=8o4oNcfMbl5apVwsKTboT/C2NPZBgsAaBH5eEBfrt/c=; b=i2FB1C+6Hk6bvSnTgIrPAVu13VpecclEIRL+TbUqweG0T5nwPZh0q38d71SvN/gAA3ANJqQZa QrE1BvjpaddBw5ZxsfQGKvUGznhrozy3OwSYaZ9FIRfXTtzQ2qkm/Ly X-Developer-Key: i=linux@weissschuh.net; a=ed25519; pk=KcycQgFPX2wGR5azS7RhpBqedglOZVgRPfdFSPB1LNw= Even if it's not critical, the avoidance of checking the error code from devm_mutex_init() call today diminishes the point of using devm variant of it. Tomorrow it may even leak something. Enforce all callers checking the return value through the compiler. As devm_mutex_init() itself is a macro which can not be annotated, annotate __devm_mutex_init() instead. Unfortunately __must_check/warn_unused_result don't propagate through statement expression. To work around this move the statement expression into the argument list of the call to __devm_mutex_init() so devm_mutex_init() directly expands to __devm_mutex_init(). Signed-off-by: Thomas Wei=C3=9Fschuh --- include/linux/mutex.h | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/include/linux/mutex.h b/include/linux/mutex.h index 2bf91b57591b49e4668752e773419ae945f124da..65b28c9e6efc123982d923d1ed1= 71eae471c82c1 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -126,11 +126,11 @@ do { \ =20 #ifdef CONFIG_DEBUG_MUTEXES =20 -int __devm_mutex_init(struct device *dev, struct mutex *lock); +int __must_check __devm_mutex_init(struct device *dev, struct mutex *lock); =20 #else =20 -static inline int __devm_mutex_init(struct device *dev, struct mutex *lock) +static inline int __must_check __devm_mutex_init(struct device *dev, struc= t mutex *lock) { /* * When CONFIG_DEBUG_MUTEXES is off mutex_destroy() is just a nop so @@ -141,13 +141,12 @@ static inline int __devm_mutex_init(struct device *de= v, struct mutex *lock) =20 #endif =20 -#define devm_mutex_init(dev, mutex) \ -({ \ - typeof(mutex) mutex_ =3D (mutex); \ - \ - mutex_init(mutex_); \ - __devm_mutex_init(dev, mutex_); \ -}) +#define devm_mutex_init(dev, mutex) __devm_mutex_init(dev, ({ \ + typeof(mutex) mutex_ =3D (mutex); \ + \ + mutex_init(mutex_); \ + mutex_; \ +})) =20 /* * See kernel/locking/mutex.c for detailed documentation of these APIs. --=20 2.48.1