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 37D82327C03; Wed, 3 Dec 2025 15:59:24 +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=1764777564; cv=none; b=P8F7zENnoc0UdzwxnWX5x4YPF3rC+c34ajSElh2AajQYl0W5HyYeJz/uqCA1y1aLdtbPPEfmU5iwC+nyPuDQLBFL0SGL4ic5SFrOtklhMT2xMldWXVlziJn7le1bZroBRbA0NAYNBNfsfEGEhJ59I/cQ4aJgeFIkGxkkHAZbtUM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764777564; c=relaxed/simple; bh=UI4GVS/wYL2myiWPBEogXyWF/7a3NEBXW/ERz1sq6IM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iJo35V7wTN5lYEWaJXqoOHXZVBqG1vt/7LRfg046F8AdjSEoNnMhEfKDJ+Sf6vldOm/U8BRC0PhmnePs+piVcZsZpG879frcKKPRpdBRRmVCmr+EeLorOyXGIeaOa8Bn0io+7glJxdAkqojsNH3ULe/C2bmiC1Xrn6ea3LEw9c8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yMwFnZU6; 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="yMwFnZU6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 993E7C116B1; Wed, 3 Dec 2025 15:59:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764777564; bh=UI4GVS/wYL2myiWPBEogXyWF/7a3NEBXW/ERz1sq6IM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yMwFnZU6Ms9RFGh8IYapHM18ssyE7Mlvg9emFyqcsq42+5OHWenbDxqQAGuej0a/F LtHXifhqGgYwamR659lLXzbI41DU8eFUspDGoe8VF1FxFRr9Qe3tYTT5BylHhyyvfJ hHkl4tLQ9nIpwsfwcTUYHHb1HWUTNeYTE/ZU0wfM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 5.15 078/392] cpuidle: Fail cpuidle device registration if there is one already Date: Wed, 3 Dec 2025 16:23:48 +0100 Message-ID: <20251203152416.974983473@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152414.082328008@linuxfoundation.org> References: <20251203152414.082328008@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 5.15-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 ef2ea1b12cd84..e371d6972f8d9 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -597,8 +597,14 @@ 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; @@ -610,7 +616,7 @@ 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