From patchwork Wed Sep 18 06:38:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 1163769 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=devicetree-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46Y9L44RXjz9sNw for ; Wed, 18 Sep 2019 16:38:52 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725834AbfIRGiv (ORCPT ); Wed, 18 Sep 2019 02:38:51 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:45727 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726116AbfIRGiv (ORCPT ); Wed, 18 Sep 2019 02:38:51 -0400 Received: from pty.hi.pengutronix.de ([2001:67c:670:100:1d::c5]) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iATc2-0003Vb-Bq; Wed, 18 Sep 2019 08:38:50 +0200 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1iATby-0003FW-Lw; Wed, 18 Sep 2019 08:38:46 +0200 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Rob Herring , Frank Rowand Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, kernel@pengutronix.de, Will Deacon , Robin Murphy , Joerg Roedel , Matthias Brugger , Geert Uytterhoeven , Peter Rosin , Marek Szyprowski , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Geert Uytterhoeven Subject: [PATCH] of: restore old handling of cells_name=NULL in of_*_phandle_with_args() Date: Wed, 18 Sep 2019 08:38:37 +0200 Message-Id: <20190918063837.8196-1-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c5 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: devicetree@vger.kernel.org Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: Uwe Kleine-König Before commit e42ee61017f5 ("of: Let of_for_each_phandle fallback to non-negative cell_count") the iterator functions calling of_for_each_phandle assumed a cell count of 0 if cells_name was NULL. This corner case was missed when implementing the fallback logic in e42ee61017f5 and resulted in an endless loop. Restore the old behaviour of of_count_phandle_with_args() and of_parse_phandle_with_args() and add a check to of_phandle_iterator_init() to prevent a similar failure as a safety precaution. of_parse_phandle_with_args_map() doesn't need a similar fix as cells_name isn't NULL there. Affected drivers are: - drivers/base/power/domain.c - drivers/base/power/domain.c - drivers/clk/ti/clk-dra7-atl.c - drivers/hwmon/ibmpowernv.c - drivers/i2c/muxes/i2c-demux-pinctrl.c - drivers/iommu/mtk_iommu.c - drivers/net/ethernet/freescale/fman/mac.c - drivers/opp/of.c - drivers/perf/arm_dsu_pmu.c - drivers/regulator/of_regulator.c - drivers/remoteproc/imx_rproc.c - drivers/soc/rockchip/pm_domains.c - sound/soc/fsl/imx-audmix.c - sound/soc/fsl/imx-audmix.c - sound/soc/meson/axg-card.c - sound/soc/samsung/tm2_wm5110.c - sound/soc/samsung/tm2_wm5110.c Thanks to Geert Uytterhoeven for reporting the issue, Peter Rosin for helping pinpoint the actual problem and the testers for confirming this fix. Fixes: e42ee61017f5 ("of: Let of_for_each_phandle fallback to non-negative cell_count") Tested-by: Marek Szyprowski Tested-by: Geert Uytterhoeven Signed-off-by: Uwe Kleine-König --- Hello, compared to the untested patch I sent yesterday I also fixed of_parse_phandle_with_args which has three users that pass cells_name=NULL. (i.e. drivers/clk/ti/clk-dra7-atl.c, sound/soc/fsl/imx-audmix.c, sound/soc/samsung/tm2_wm5110.c) I didn't look closely, but maybe these could be converted to use of_parse_phandle as there are no arguments to be processed with no cells_name?! Best regards Uwe drivers/of/base.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/drivers/of/base.c b/drivers/of/base.c index 2f25d2dfecfa..25ee07c0a3cd 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1286,6 +1286,13 @@ int of_phandle_iterator_init(struct of_phandle_iterator *it, memset(it, 0, sizeof(*it)); + /* + * one of cell_count or cells_name must be provided to determine the + * argument length. + */ + if (cell_count < 0 && !cells_name) + return -EINVAL; + list = of_get_property(np, list_name, &size); if (!list) return -ENOENT; @@ -1512,10 +1519,17 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na const char *cells_name, int index, struct of_phandle_args *out_args) { + int cell_count = -1; + if (index < 0) return -EINVAL; - return __of_parse_phandle_with_args(np, list_name, cells_name, -1, - index, out_args); + + /* If cells_name if NULL we assume a cell count of 0 */ + if (!cells_name) + cell_count = 0; + + return __of_parse_phandle_with_args(np, list_name, cells_name, + cell_count, index, out_args); } EXPORT_SYMBOL(of_parse_phandle_with_args); @@ -1765,6 +1779,18 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na struct of_phandle_iterator it; int rc, cur_index = 0; + /* If cells_name is NULL we assume a cell count of 0 */ + if (cells_name == NULL) { + const __be32 *list; + int size; + + list = of_get_property(np, list_name, &size); + if (!list) + return -ENOENT; + + return size / sizeof(*list); + } + rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1); if (rc) return rc;