From patchwork Mon Jan 13 13:48:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Zhang, Rui" X-Patchwork-Id: 309842 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id A7C5C2C008F for ; Tue, 14 Jan 2014 00:48:16 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751534AbaAMNsP (ORCPT ); Mon, 13 Jan 2014 08:48:15 -0500 Received: from mga01.intel.com ([192.55.52.88]:60261 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751029AbaAMNsO (ORCPT ); Mon, 13 Jan 2014 08:48:14 -0500 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 13 Jan 2014 05:48:14 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.95,653,1384329600"; d="scan'208";a="464293307" Received: from unknown (HELO rzhang1-mobl4.ccr.corp.intel.com) ([10.255.21.146]) by fmsmga002.fm.intel.com with ESMTP; 13 Jan 2014 05:48:11 -0800 From: Zhang Rui To: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, linux-spi@vger.kernel.org Cc: rjw@rjwysocki.net, grant.likely@secretlab.ca, jarkko.nikula@linux.intel.com, mika.westerberg@linux.intel.com, Zhang Rui Subject: [PATCH 1/4] ACPI: fix create_modalias() return value handling Date: Mon, 13 Jan 2014 21:48:09 +0800 Message-Id: <1389620889-3818-1-git-send-email-rui.zhang@intel.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Currently, create_modalias() handles the output truncated case in an improper way (return -EINVAL). Plus, acpi_device_uevent() and acpi_device_modalias_show() do improper check for the create_modalias() return value as well. This patch fixes create_modalias() to return -EINVAL if there is an output error, return -ENOMEM if the output is truncated, and also fixes both acpi_device_uevent() and acpi_device_modalias_show() to do proper return value check. Signed-off-by: Zhang Rui --- drivers/acpi/scan.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index fd39459..c925321 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -85,6 +85,9 @@ int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler, * Creates hid/cid(s) string needed for modalias and uevent * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get: * char *modalias: "acpi:IBM0001:ACPI0001" + * Return: 0: no _HID and no _CID + * -EINVAL: output error + * -ENOMEM: output is truncated */ static int create_modalias(struct acpi_device *acpi_dev, char *modalias, int size) @@ -101,8 +104,10 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias, list_for_each_entry(id, &acpi_dev->pnp.ids, list) { count = snprintf(&modalias[len], size, "%s:", id->id); - if (count < 0 || count >= size) - return -EINVAL; + if (count < 0) + return EINVAL; + if (count >= size) + return -ENOMEM; len += count; size -= count; } @@ -116,10 +121,9 @@ acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, cha struct acpi_device *acpi_dev = to_acpi_device(dev); int len; - /* Device has no HID and no CID or string is >1024 */ len = create_modalias(acpi_dev, buf, 1024); if (len <= 0) - return 0; + return len; buf[len++] = '\n'; return len; } @@ -782,8 +786,8 @@ static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env) return -ENOMEM; len = create_modalias(acpi_dev, &env->buf[env->buflen - 1], sizeof(env->buf) - env->buflen); - if (len >= (sizeof(env->buf) - env->buflen)) - return -ENOMEM; + if (len <= 0) + return len; env->buflen += len; return 0; }