From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E0243248883; Tue, 11 Nov 2025 01:01:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762822911; cv=none; b=KimKnNcsJyHrSj/mbvtNy5eO95jgdJlGPkwCj5/j4+lUWwhSuHeMOedFH5vECaYmnfGrWz90MKo7+jQEkh0xnecCv6pQCE8GQqeoCkRSzYWRnt7U824z442AuAXsl3N2HA3PiZdfvvzxYhHHwgOTVV+0wVi8ljDqHUL5BQDOAPo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762822911; c=relaxed/simple; bh=BL66hqJbd6jceZrX4jOzrgW9sonc1eunku/WQBpSvdw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mVIrJgg+TGCtE6/JLfwJQu+rGmXI6hVIPJmjI6WOkvCq98BQgmJsH4ArMCd9zRcCWZMcQQgDs7+6rvgVEPqgCdUB8IcKHKOMVq+KvlGoiw9hHdHfpeaKD6MiumwnaJGu0IrVrXp8iqsr/APsklSLuGuxj4ZQK8H2RauLBPXzSSM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Chf6U6BR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Chf6U6BR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 764C3C16AAE; Tue, 11 Nov 2025 01:01:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1762822910; bh=BL66hqJbd6jceZrX4jOzrgW9sonc1eunku/WQBpSvdw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Chf6U6BRMr2/RkLK5LSOB+ebqPN8sVk5AW4QRI3GMEJfkGSFFt9eS4WKxPPkYoDTF YD42PBbAdJQ04/4qBpzW+9e1p/QjX8ScaSbJoctEwYtDeb62ntgpJQUjYh1+aaymCs Ksy9q9CjlZHFy2hi6/XiOx8QtFRZOwuSTdhrZNHc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 6.17 194/849] cpuidle: Fail cpuidle device registration if there is one already Date: Tue, 11 Nov 2025 09:36:04 +0900 Message-ID: <20251111004541.132988662@linuxfoundation.org> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251111004536.460310036@linuxfoundation.org> References: <20251111004536.460310036@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rafael J. Wysocki [ Upstream commit 7b1b7961170e4fcad488755e5ffaaaf9bd527e8f ] Refuse to register a cpuidle device if the given CPU has a cpuidle device already and print a message regarding it. Without this, an attempt to register a new cpuidle device without unregistering the existing one leads to the removal of the existing cpuidle device without removing its sysfs interface. Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/cpuidle/cpuidle.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 0835da449db8b..56132e843c991 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -635,8 +635,14 @@ static void __cpuidle_device_init(struct cpuidle_device *dev) static int __cpuidle_register_device(struct cpuidle_device *dev) { struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); + unsigned int cpu = dev->cpu; int i, ret; + if (per_cpu(cpuidle_devices, cpu)) { + pr_info("CPU%d: cpuidle device already registered\n", cpu); + return -EEXIST; + } + if (!try_module_get(drv->owner)) return -EINVAL; @@ -648,7 +654,7 @@ static int __cpuidle_register_device(struct cpuidle_device *dev) dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_USER; } - per_cpu(cpuidle_devices, dev->cpu) = dev; + per_cpu(cpuidle_devices, cpu) = dev; list_add(&dev->device_list, &cpuidle_detected_devices); ret = cpuidle_coupled_register_device(dev); -- 2.51.0