From patchwork Fri Apr 8 18:48:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 12807118 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 2D0D5C433EF for ; Fri, 8 Apr 2022 18:49:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238956AbiDHSvm (ORCPT ); Fri, 8 Apr 2022 14:51:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233108AbiDHSvk (ORCPT ); Fri, 8 Apr 2022 14:51:40 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C39791CA13B; Fri, 8 Apr 2022 11:49:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649443775; x=1680979775; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=daPwwK0cfexVVreME76t5ptpRPDPiAG+S6sEydOhfxY=; b=JGaKDt/JaI4db+ZwLiJLGGlGjLdS55E2XMqWRHvxzB+PX+OlAuzeZFsB uX4enU52ksMigvPp/WW+stbVPflOWvX6EDkGYs6qHV/3z4Om3H47PO63V /bDfppa0fv7Zz0MwSYp/tAkcWFK9OJSzk2QVZvy7fND4JJvCu6TxiogUW 9AYnlMcedEanlCBc1hZxQ8yvSi1oXL+ztF8ETEbCow3mueFftQr3x20c0 OmjMhKuk7EV8ewSUdBZ7Oqty9WGGS9Yq7QnvMauTdEXPC51YR0yUlfprG VBHrePoI7z029+lClNjWs41QB7Uhpw1yTLmZvbqX+UF7bn6pZANzMsXtJ Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10311"; a="348099328" X-IronPort-AV: E=Sophos;i="5.90,245,1643702400"; d="scan'208";a="348099328" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Apr 2022 11:49:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,245,1643702400"; d="scan'208";a="852173965" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga005.fm.intel.com with ESMTP; 08 Apr 2022 11:49:31 -0700 Received: by black.fi.intel.com (Postfix, from userid 1003) id 2969C144; Fri, 8 Apr 2022 21:48:46 +0300 (EEST) From: Andy Shevchenko To: Andy Shevchenko , Rob Herring , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Cc: Daniel Scally , Heikki Krogerus , Sakari Ailus , Greg Kroah-Hartman , "Rafael J. Wysocki" , Rob Herring , Frank Rowand , Len Brown , =?utf-8?q?Nuno_S=C3=A1?= , Michael Walle Subject: [PATCH v6 1/5] device property: Allow error pointer to be passed to fwnode APIs Date: Fri, 8 Apr 2022 21:48:40 +0300 Message-Id: <20220408184844.22829-1-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@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 Tested-by: Nuno Sá Acked-by: Nuno Sá Reviewed-by: Sakari Ailus Reviewed-by: Heikki Krogerus Signed-off-by: Andy Shevchenko Tested-by: Michael Walle --- v6: added tag (Michael), avoid shadowing error code (Michael) drivers/base/property.c | 89 +++++++++++++++++++++++------------------ include/linux/fwnode.h | 10 ++--- 2 files changed, 56 insertions(+), 43 deletions(-) diff --git a/drivers/base/property.c b/drivers/base/property.c index 3560c4419d11..6ecc1398b0ba 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -47,12 +47,14 @@ 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) + return ret; + + return fwnode_call_bool_op(fwnode->secondary, property_present, propname); } EXPORT_SYMBOL_GPL(fwnode_property_present); @@ -232,15 +234,16 @@ 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 +374,16 @@ 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 +485,19 @@ 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); + if (IS_ERR_OR_NULL(fwnode->secondary)) + return ret; - 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); @@ -635,12 +644,13 @@ EXPORT_SYMBOL_GPL(fwnode_count_parents); struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode, unsigned int depth) { - unsigned int i; - fwnode_handle_get(fwnode); - for (i = 0; i < depth && fwnode; i++) + do { + if (depth-- == 0) + break; fwnode = fwnode_get_next_parent(fwnode); + } while (fwnode); return fwnode; } @@ -659,17 +669,17 @@ EXPORT_SYMBOL_GPL(fwnode_get_nth_parent); bool fwnode_is_ancestor_of(struct fwnode_handle *test_ancestor, struct fwnode_handle *test_child) { - if (!test_ancestor) + if (IS_ERR_OR_NULL(test_ancestor)) return false; fwnode_handle_get(test_child); - while (test_child) { + do { if (test_child == test_ancestor) { fwnode_handle_put(test_child); return true; } test_child = fwnode_get_next_parent(test_child); - } + } while (test_child); return false; } @@ -698,7 +708,7 @@ 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 +732,16 @@ 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 +808,9 @@ 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; @@ -958,14 +971,14 @@ 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 6ab69871b06d..9a81c4410b9f 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -153,12 +153,12 @@ 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) ? \