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 59C5B5102A; Mon, 11 Dec 2023 18:49:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="h7ZXiqYJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BB23C433C9; Mon, 11 Dec 2023 18:49:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1702320566; bh=CBwq/L8/T1wptKzJuFPxhGXrhgXQtUBWVhMhb+JRjzc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h7ZXiqYJChC90vuiWm05E5gEacwbp15rsTB40ZsmLsHrLz8clCN4TToREkbWLBRAQ 3BnOwAv/nabX7qgNoaiswiYRtHMAwDp0KMV1EYLDlr+Zs5h5DDEz++Uxk5c1EykuMT YdHc6GLJRrSHOwhjOSA4lFNVpaupMxnsMwDHa874= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, urbinek@gmail.com, Armin Wolf , Guenter Roeck , Sasha Levin Subject: [PATCH 6.1 080/194] hwmon: (acpi_power_meter) Fix 4.29 MW bug Date: Mon, 11 Dec 2023 19:21:10 +0100 Message-ID: <20231211182040.048013997@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231211182036.606660304@linuxfoundation.org> References: <20231211182036.606660304@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Armin Wolf [ Upstream commit 1fefca6c57fb928d2131ff365270cbf863d89c88 ] The ACPI specification says: "If an error occurs while obtaining the meter reading or if the value is not available then an Integer with all bits set is returned" Since the "integer" is 32 bits in case of the ACPI power meter, userspace will get a power reading of 2^32 * 1000 miliwatts (~4.29 MW) in case of such an error. This was discovered due to a lm_sensors bugreport (https://github.com/lm-sensors/lm-sensors/issues/460). Fix this by returning -ENODATA instead. Tested-by: Fixes: de584afa5e18 ("hwmon driver for ACPI 4.0 power meters") Signed-off-by: Armin Wolf Link: https://lore.kernel.org/r/20231124182747.13956-1-W_Armin@gmx.de Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/acpi_power_meter.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c index 0962c12eba5a0..2147afb725581 100644 --- a/drivers/hwmon/acpi_power_meter.c +++ b/drivers/hwmon/acpi_power_meter.c @@ -31,6 +31,7 @@ #define POWER_METER_CAN_NOTIFY (1 << 3) #define POWER_METER_IS_BATTERY (1 << 8) #define UNKNOWN_HYSTERESIS 0xFFFFFFFF +#define UNKNOWN_POWER 0xFFFFFFFF #define METER_NOTIFY_CONFIG 0x80 #define METER_NOTIFY_TRIP 0x81 @@ -348,6 +349,9 @@ static ssize_t show_power(struct device *dev, update_meter(resource); mutex_unlock(&resource->lock); + if (resource->power == UNKNOWN_POWER) + return -ENODATA; + return sprintf(buf, "%llu\n", resource->power * 1000); } -- 2.42.0