From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C80B3C433EF for ; Mon, 7 Mar 2022 20:29:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239345AbiCGUao (ORCPT ); Mon, 7 Mar 2022 15:30:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234979AbiCGUak (ORCPT ); Mon, 7 Mar 2022 15:30:40 -0500 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2309574A7; Mon, 7 Mar 2022 12:29:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1646684985; x=1678220985; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=uQIjKu/qjwzFXGSLSmIUdR//ml6vKPhPZdbrnXFYAAU=; b=WszdeIccC+fM0JlGUdqh9MzZypJsV7RpzqtRNjOHgRUey77RoscLzTuG VCZtQly5E1ycMxLBYhdziW2+ZVeE56L+4Oc3DdaOU95nZ6bh45Pf3B5XV KYanFbpfr1b8xFyUpp8JbdWrpbzwNptHckzaQZG9jc6hLq77eRPusbGnp oCTE8QwsqJNuKnXrWHcYAM+7uIdnaYA5VY21nWyIHYHAc+BbuZe2OHAKg i7/YvAhZf1VJKS0pNLFhLe3lh5f4TDXE85xm8cBsnTw7mdP7ar2As5ULE Af3WDyThPxCQjb9wK4ucqJCF1l8zFGumVfBVqphZ8azCY4grmpRnlkZEy g==; X-IronPort-AV: E=McAfee;i="6200,9189,10279"; a="234451976" X-IronPort-AV: E=Sophos;i="5.90,163,1643702400"; d="scan'208";a="234451976" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Mar 2022 12:29:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,163,1643702400"; d="scan'208";a="509838533" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga002.jf.intel.com with ESMTP; 07 Mar 2022 12:29:40 -0800 Received: by black.fi.intel.com (Postfix, from userid 1003) id E5A551D6; Mon, 7 Mar 2022 22:29:58 +0200 (EET) From: Andy Shevchenko To: Andy Shevchenko , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Daniel Scally , Heikki Krogerus , Sakari Ailus , Greg Kroah-Hartman , "Rafael J. Wysocki" , Len Brown , =?UTF-8?q?Nuno=20S=C3=A1?= Subject: [PATCH v3 1/1] device property: Allow error pointer to be passed to fwnode APIs Date: Mon, 7 Mar 2022 22:29:49 +0200 Message-Id: <20220307202949.75300-1-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some of the fwnode APIs might return an error pointer instead of NULL or valid fwnode handle. The result of such API call may be considered optional and hence the test for it is usually done in a form of fwnode = fwnode_find_reference(...); if (IS_ERR(fwnode)) ...error handling... Nevertheless the resulting fwnode may have bumped the reference count and hence caller of the above API is obliged to call fwnode_handle_put(). Since fwnode may be not valid either as NULL or error pointer the check has to be performed there. This approach uglifies the code and adds a point of making a mistake, i.e. forgetting about error point case. To prevent this, allow an error pointer to be passed to the fwnode APIs. Fixes: 83b34afb6b79 ("device property: Introduce fwnode_find_reference()") Reported-by: Nuno Sá Signed-off-by: Andy Shevchenko Tested-by: Nuno Sá --- v3: dropped test of secondary fwnode (Nuno), added tag (Nuno), amended commit message v2: adjusted the entire fwnode API (Sakari) Nuno, can you re-test this with the ltc2983 series to be sure it is still okay? drivers/base/property.c | 76 +++++++++++++++++++++++------------------ include/linux/fwnode.h | 10 +++--- 2 files changed, 48 insertions(+), 38 deletions(-) diff --git a/drivers/base/property.c b/drivers/base/property.c index c0e94cce9c29..635a0e556a4f 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -9,6 +9,7 @@ #include #include +#include #include #include #include @@ -47,12 +48,14 @@ bool fwnode_property_present(const struct fwnode_handle *fwnode, { bool ret; + if (IS_ERR_OR_NULL(fwnode)) + return false; + ret = fwnode_call_bool_op(fwnode, property_present, propname); - if (ret == false && !IS_ERR_OR_NULL(fwnode) && - !IS_ERR_OR_NULL(fwnode->secondary)) - ret = fwnode_call_bool_op(fwnode->secondary, property_present, - propname); - return ret; + if (ret == true) + return ret; + + return fwnode_call_bool_op(fwnode->secondary, property_present, propname); } EXPORT_SYMBOL_GPL(fwnode_property_present); @@ -232,15 +235,16 @@ static int fwnode_property_read_int_array(const struct fwnode_handle *fwnode, { int ret; + if (IS_ERR_OR_NULL(fwnode)) + return -EINVAL; + ret = fwnode_call_int_op(fwnode, property_read_int_array, propname, elem_size, val, nval); - if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) && - !IS_ERR_OR_NULL(fwnode->secondary)) - ret = fwnode_call_int_op( - fwnode->secondary, property_read_int_array, propname, - elem_size, val, nval); + if (ret != -EINVAL) + return ret; - return ret; + return fwnode_call_int_op(fwnode->secondary, property_read_int_array, propname, + elem_size, val, nval); } /** @@ -371,14 +375,16 @@ int fwnode_property_read_string_array(const struct fwnode_handle *fwnode, { int ret; + if (IS_ERR_OR_NULL(fwnode)) + return -EINVAL; + ret = fwnode_call_int_op(fwnode, property_read_string_array, propname, val, nval); - if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) && - !IS_ERR_OR_NULL(fwnode->secondary)) - ret = fwnode_call_int_op(fwnode->secondary, - property_read_string_array, propname, - val, nval); - return ret; + if (ret != -EINVAL) + return ret; + + return fwnode_call_int_op(fwnode->secondary, property_read_string_array, propname, + val, nval); } EXPORT_SYMBOL_GPL(fwnode_property_read_string_array); @@ -480,15 +486,16 @@ int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode, { int ret; + if (IS_ERR_OR_NULL(fwnode)) + return -ENOENT; + ret = fwnode_call_int_op(fwnode, get_reference_args, prop, nargs_prop, nargs, index, args); + if (ret == 0) + return ret; - if (ret < 0 && !IS_ERR_OR_NULL(fwnode) && - !IS_ERR_OR_NULL(fwnode->secondary)) - ret = fwnode_call_int_op(fwnode->secondary, get_reference_args, - prop, nargs_prop, nargs, index, args); - - return ret; + return fwnode_call_int_op(fwnode->secondary, get_reference_args, prop, nargs_prop, + nargs, index, args); } EXPORT_SYMBOL_GPL(fwnode_property_get_reference_args); @@ -698,7 +705,7 @@ fwnode_get_next_available_child_node(const struct fwnode_handle *fwnode, { struct fwnode_handle *next_child = child; - if (!fwnode) + if (IS_ERR_OR_NULL(fwnode)) return NULL; do { @@ -722,16 +729,16 @@ struct fwnode_handle *device_get_next_child_node(struct device *dev, const struct fwnode_handle *fwnode = dev_fwnode(dev); struct fwnode_handle *next; + if (IS_ERR_OR_NULL(fwnode)) + return NULL; + /* Try to find a child in primary fwnode */ next = fwnode_get_next_child_node(fwnode, child); if (next) return next; /* When no more children in primary, continue with secondary */ - if (fwnode && !IS_ERR_OR_NULL(fwnode->secondary)) - next = fwnode_get_next_child_node(fwnode->secondary, child); - - return next; + return fwnode_get_next_child_node(fwnode->secondary, child); } EXPORT_SYMBOL_GPL(device_get_next_child_node); @@ -798,6 +805,9 @@ EXPORT_SYMBOL_GPL(fwnode_handle_put); */ bool fwnode_device_is_available(const struct fwnode_handle *fwnode) { + if (IS_ERR_OR_NULL(fwnode)) + return false; + if (!fwnode_has_op(fwnode, device_is_available)) return true; @@ -988,14 +998,14 @@ fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode, parent = fwnode_graph_get_port_parent(prev); else parent = fwnode; + if (IS_ERR_OR_NULL(parent)) + return NULL; ep = fwnode_call_ptr_op(parent, graph_get_next_endpoint, prev); + if (ep) + return ep; - if (IS_ERR_OR_NULL(ep) && - !IS_ERR_OR_NULL(parent) && !IS_ERR_OR_NULL(parent->secondary)) - ep = fwnode_graph_get_next_endpoint(parent->secondary, NULL); - - return ep; + return fwnode_graph_get_next_endpoint(parent->secondary, NULL); } EXPORT_SYMBOL_GPL(fwnode_graph_get_next_endpoint); diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 3a532ba66f6c..7defac04f9a3 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -148,12 +148,12 @@ struct fwnode_operations { int (*add_links)(struct fwnode_handle *fwnode); }; -#define fwnode_has_op(fwnode, op) \ - ((fwnode) && (fwnode)->ops && (fwnode)->ops->op) +#define fwnode_has_op(fwnode, op) \ + (!IS_ERR_OR_NULL(fwnode) && (fwnode)->ops && (fwnode)->ops->op) + #define fwnode_call_int_op(fwnode, op, ...) \ - (fwnode ? (fwnode_has_op(fwnode, op) ? \ - (fwnode)->ops->op(fwnode, ## __VA_ARGS__) : -ENXIO) : \ - -EINVAL) + (fwnode_has_op(fwnode, op) ? \ + (fwnode)->ops->op(fwnode, ## __VA_ARGS__) : (IS_ERR_OR_NULL(fwnode) ? -EINVAL : -ENXIO)) #define fwnode_call_bool_op(fwnode, op, ...) \ (fwnode_has_op(fwnode, op) ? \ -- 2.34.1