From mboxrd@z Thu Jan 1 00:00:00 1970 From: Timur Tabi Subject: Re: [PATCH 3/3] pinctrl: qcom: Don't allow protected pins to be requested Date: Mon, 22 Jan 2018 07:55:39 -0600 Message-ID: References: <20180110015848.11480-1-sboyd@codeaurora.org> <20180110015848.11480-4-sboyd@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180110015848.11480-4-sboyd@codeaurora.org> Content-Language: en-US Sender: linux-arm-msm-owner@vger.kernel.org To: Stephen Boyd , Linus Walleij Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Andy Shevchenko , Bjorn Andersson , linux-gpio@vger.kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org On 1/9/18 7:58 PM, Stephen Boyd wrote: > + ret = device_property_read_u16_array(pctrl->dev, "gpios", tmp, > + len); > + if (ret < 0) { > + dev_err(pctrl->dev, "could not read list of GPIOs\n"); > + kfree(tmp); > + return ret; > + } Just FYI, I'm still going to have to parse "gpios" in my pinctrl-qdf2xxx.c driver, even though you're also parsing it here. That's because I need to make sure that the msm_pingroup array only contains "approve" addresses in its ctl_reg fields. + for (i = 0; i < avail_gpios; i++) { + unsigned int gpio = gpios[i]; + + groups[gpio].npins = 1; + snprintf(names[i], NAME_SIZE, "gpio%u", gpio); + pins[gpio].name = names[i]; + groups[gpio].name = names[i]; + + groups[gpio].ctl_reg = 0x10000 * gpio; ^^^^ I do this because I need to make sure that "unapproved" physical addresses are never store anywhere in groups[]. That way, it's impossible for the driver to cause an XPU violation -- the worst that can happen is a null pointer dereference. -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.