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SubjectRe: [PATCH 3/3] pinctrl: qcom: Don't allow protected pins to be requested
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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.

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