From patchwork Wed Sep 18 08:47:48 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: 11149907 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A56CD912 for ; Wed, 18 Sep 2019 08:47:58 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 82CC921897 for ; Wed, 18 Sep 2019 08:47:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="pjroe6xr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82CC921897 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+patchwork-linux-mediatek=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ks8PsbxBXUwqp6aOqKOKlCMBcQlekZvK2WN44jumwXU=; b=pjroe6xr++cV1m qTtV5PxU6pxjNcDOSSUWomC7tpxqSr9ARQgwsb/Oy+O51eaQVvF8CF40yXBToWIGulNm8z3Y6J/4s aHMXDCfthjZKgLsIChfTyxs0GbOCmqg8I0Ufmh4dAd4zDiUFroHNjL9upXMQSXK1hCtNC5Zd9Lzu/ 7wtpwdINV1qW4A+s63/GGkx4UdZSIBGiQVkszRxJ6ksUx9YY3P0g69lzS4txWgYGthVDAQKPUStF1 RyqCkOjRrcxJ1I5Bqf5gFy70Vz2yaUso9ty1E9oi6X/2RJYDGNfeMoQW4VeEGYO9FmkzlMXZugGCb YoE/BZSeEGpvGHGiO3pw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iAVd0-0005oT-4V; Wed, 18 Sep 2019 08:47:58 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iAVcx-0005nN-Hl for linux-mediatek@lists.infradead.org; Wed, 18 Sep 2019 08:47:57 +0000 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 1iAVcr-0001B8-T8; Wed, 18 Sep 2019 10:47:49 +0200 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1iAVcq-0007mf-Bu; Wed, 18 Sep 2019 10:47:48 +0200 Date: Wed, 18 Sep 2019 10:47:48 +0200 From: Uwe =?iso-8859-1?q?Kleine-K=F6nig?= To: Peter Rosin , Rob Herring , Frank Rowand Subject: [PATCH v2] of: restore old handling of cells_name=NULL in of_*_phandle_with_args() Message-ID: <20190918084748.hnjkiq7wc5b35wjh@pengutronix.de> References: <20190918063837.8196-1-u.kleine-koenig@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) 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: linux-mediatek@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190918_014755_589160_B9CDFDB7 X-CRM114-Status: GOOD ( 24.03 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "devicetree@vger.kernel.org" , Geert Uytterhoeven , Robin Murphy , Joerg Roedel , "linux-kernel@vger.kernel.org" , "linux-mediatek@lists.infradead.org" , "kernel@pengutronix.de" , Matthias Brugger , Geert Uytterhoeven , Will Deacon , "linux-arm-kernel@lists.infradead.org" , Marek Szyprowski Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+patchwork-linux-mediatek=patchwork.kernel.org@lists.infradead.org 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 --- On Wed, Sep 18, 2019 at 08:01:05AM +0000, Peter Rosin wrote: > On 2019-09-18 08:38, Uwe Kleine-König wrote: > > 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) { > > A couple of nits. > > I don't know if there are other considerations, but in the previous two > hunks you use !cells_name instead of comparing explicitly with NULL. > Personally, I find the shorter form more readable, and in the name of > consistency bla bla... Ack, changed to !cells_name here, too. > > Also, the comment explaining this NULL-check didn't really make sense > to me until I realized that knowing the cell count to be zero makes > counting trivial. Something along those lines should perhaps be in the > comment? You're right, I extended the comment a bit. > But as I said, these are nits. Feel free to ignore. I considered resending already anyhow as I fatfingerd my email address. this is fixed now, too. Additionally I fixed a typo in one of the comments. Thanks for your feedback. Best regards Uwe drivers/of/base.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-) diff --git a/drivers/of/base.c b/drivers/of/base.c index 2f25d2dfecfa..1d667eb730e1 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 is 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 +1779,23 @@ 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. This makes + * counting the phandles trivial as each 32bit word in the list is a + * phandle and no arguments are to consider. So we don't iterate through + * the list but just use the length to determine the phandle count. + */ + if (!cells_name) { + 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;