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Commit b5bfd16f authored by Liam Mark's avatar Liam Mark
Browse files

iommu: iommu-debug: cleanup iommu debug 



Only expose debugfs nodes for test devices.
Restrict secure attach to a valid vmid.
Add clock reference counting to make code more robust.
Restrict address printing with kptr_restrict.

Change-Id: Ibf90068d778b0156e3bb42287af5dda3864da5fc
Signed-off-by: default avatarLiam Mark <lmark@codeaurora.org>
Signed-off-by: default avatarPatrick Daly <pdaly@codeaurora.org>
parent 778f546f

drivers/iommu/iommu-debug.c

+25 −1
Original line number Diff line number Diff line
@@ -170,6 +170,8 @@ struct iommu_debug_device { 
	u64 phys;

	size_t len;

	struct list_head list;

	struct mutex clk_lock;

	unsigned int clk_count;

};



static int iommu_debug_build_phoney_sg_table(struct device *dev,
@@ -1278,7 +1280,7 @@ static int iommu_debug_attach_do_attach(struct iommu_debug_device *ddev, 
	}



	ddev->domain->is_debug_domain = true;



	val = VMID_CP_CAMERA;

	if (is_secure && iommu_domain_set_attr(ddev->domain,

					       DOMAIN_ATTR_SECURE_VMID,

					       &val)) {
@@ -1638,6 +1640,10 @@ static ssize_t iommu_debug_atos_read(struct file *file, char __user *ubuf, 
	ssize_t retval;

	size_t buflen;



	if (kptr_restrict != 0) {

		pr_err("kptr_restrict needs to be disabled.\n");

		return -EPERM;

	}

	if (!ddev->domain) {

		pr_err("No domain. Did you already attach?\n");

		return -EINVAL;
@@ -2132,20 +2138,34 @@ static ssize_t iommu_debug_config_clocks_write(struct file *file, 
		return -EFAULT;

	}



	mutex_lock(&ddev->clk_lock);

	switch (buf) {

	case '0':

		if (ddev->clk_count == 0) {

			dev_err(dev, "Config clocks already disabled\n");

			break;

		}



		if (--ddev->clk_count > 0)

			break;



		dev_err(dev, "Disabling config clocks\n");

		iommu_disable_config_clocks(ddev->domain);

		break;

	case '1':

		if (ddev->clk_count++ > 0)

			break;



		dev_err(dev, "Enabling config clocks\n");

		if (iommu_enable_config_clocks(ddev->domain))

			dev_err(dev, "Failed!\n");

		break;

	default:

		dev_err(dev, "Invalid value. Should be 0 or 1.\n");

		mutex_unlock(&ddev->clk_lock);

		return -EINVAL;

	}

	mutex_unlock(&ddev->clk_lock);



	return count;

}
@@ -2195,6 +2215,9 @@ static int snarf_iommu_devices(struct device *dev, void *ignored) 
	if (!of_find_property(dev->of_node, "iommus", NULL))

		return 0;



	if (!of_device_is_compatible(dev->of_node, "iommu-debug-test"))

		return 0;



	/* Hold a reference count */

	if (!iommu_group_get(dev))

		return 0;
@@ -2203,6 +2226,7 @@ static int snarf_iommu_devices(struct device *dev, void *ignored) 
	if (!ddev)

		return -ENODEV;



	mutex_init(&ddev->clk_lock);

	ddev->dev = dev;

	dir = debugfs_create_dir(dev_name(dev), debugfs_tests_dir);

	if (!dir) {