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Commit cd180699 authored by Swathi Sridhar's avatar Swathi Sridhar
Browse files

iommu: iommu-debug: Fix race conditions in iommu debug 



With the current support, concurrent iommu debug calls
to the test device/debug domain can result in multiple
race conditions between attach, map, unmap and detach
calls.Hence introduce a new lock in the iommu_debug_device
structure to serialize iommu calls to the test device.

Change-Id: I94cd36eeaba4208972fdfa49ca4446a08d53b334
Signed-off-by: default avatarSwathi Sridhar <swatsrid@codeaurora.org>
parent 6c457fab

drivers/iommu/iommu-debug.c

+61 −9
Original line number Diff line number Diff line
@@ -172,6 +172,7 @@ struct iommu_debug_device { 
	struct list_head list;

	struct mutex clk_lock;

	unsigned int clk_count;

	struct mutex debug_dev_lock;

};



static int iommu_debug_build_phoney_sg_table(struct device *dev,
@@ -435,8 +436,10 @@ static int iommu_debug_profiling_show(struct seq_file *s, void *ignored) 
	int htw_disable = 1, atomic = 1;

	void *attr_values[] = { &htw_disable, &atomic };



	mutex_lock(&ddev->debug_dev_lock);

	iommu_debug_device_profiling(s, ddev->dev, attrs, attr_values,

				     ARRAY_SIZE(attrs), sizes);

	mutex_unlock(&ddev->debug_dev_lock);



	return 0;

}
@@ -466,9 +469,10 @@ static int iommu_debug_secure_profiling_show(struct seq_file *s, void *ignored) 
	int one = 1, secure_vmid = VMID_CP_PIXEL;

	void *attr_values[] = { &one, &secure_vmid };



	mutex_lock(&ddev->debug_dev_lock);

	iommu_debug_device_profiling(s, ddev->dev, attrs, attr_values,

				     ARRAY_SIZE(attrs), sizes);



	mutex_unlock(&ddev->debug_dev_lock);

	return 0;

}
@@ -497,9 +501,10 @@ static int iommu_debug_profiling_fast_show(struct seq_file *s, void *ignored) 
	int one = 1;

	void *attr_values[] = { &one, &one };



	mutex_lock(&ddev->debug_dev_lock);

	iommu_debug_device_profiling(s, ddev->dev, attrs, attr_values,

				     ARRAY_SIZE(attrs), sizes);



	mutex_unlock(&ddev->debug_dev_lock);

	return 0;

}
@@ -1315,6 +1320,7 @@ static ssize_t __iommu_debug_dma_attach_write(struct file *file, 
	ssize_t retval = -EINVAL;

	int val;



	mutex_lock(&ddev->debug_dev_lock);

	if (kstrtoint_from_user(ubuf, count, 0, &val)) {

		pr_err("Invalid format. Expected a hex or decimal integer");

		retval = -EFAULT;
@@ -1363,11 +1369,13 @@ static ssize_t __iommu_debug_dma_attach_write(struct file *file, 
		pr_err("Detached\n");

	}

	retval = count;

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;



out_release_mapping:

	arm_iommu_release_mapping(dma_mapping);

out:

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;

}
@@ -1382,6 +1390,7 @@ static ssize_t __iommu_debug_attach_write(struct file *file, 
	ssize_t retval;

	int val;



	mutex_lock(&ddev->debug_dev_lock);

	if (kstrtoint_from_user(ubuf, count, 0, &val)) {

		pr_err("Invalid format. Expected a hex or decimal integer");

		retval = -EFAULT;
@@ -1421,6 +1430,7 @@ static ssize_t __iommu_debug_attach_write(struct file *file, 


	retval = count;

out:

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;

}
@@ -1585,17 +1595,23 @@ static ssize_t iommu_debug_pte_read(struct file *file, char __user *ubuf, 
		pr_err("kptr_restrict needs to be disabled.\n");

		return -EPERM;

	}



	mutex_lock(&ddev->debug_dev_lock);

	if (!dev->archdata.mapping) {

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

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}

	if (!dev->archdata.mapping->domain) {

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

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}



	if (*offset)

	if (*offset) {

		mutex_unlock(&ddev->debug_dev_lock);

		return 0;

	}



	memset(buf, 0, sizeof(buf));
@@ -1615,7 +1631,7 @@ static ssize_t iommu_debug_pte_read(struct file *file, char __user *ubuf, 
		*offset = 1;	/* non-zero means we're done */

		retval = buflen;

	}



	mutex_unlock(&ddev->debug_dev_lock);

	return retval;

}
@@ -1656,13 +1672,18 @@ static ssize_t iommu_debug_atos_read(struct file *file, char __user *ubuf, 
		pr_err("kptr_restrict needs to be disabled.\n");

		return -EPERM;

	}



	mutex_lock(&ddev->debug_dev_lock);

	if (!ddev->domain) {

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

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}



	if (*offset)

	if (*offset) {

		mutex_unlock(&ddev->debug_dev_lock);

		return 0;

	}



	memset(buf, 0, 100);
@@ -1685,6 +1706,7 @@ static ssize_t iommu_debug_atos_read(struct file *file, char __user *ubuf, 
		retval = buflen;

	}



	mutex_unlock(&ddev->debug_dev_lock);

	return retval;

}
@@ -1708,18 +1730,23 @@ static ssize_t iommu_debug_dma_atos_read(struct file *file, char __user *ubuf, 
		pr_err("kptr_restrict needs to be disabled.\n");

		return -EPERM;

	}



	mutex_lock(&ddev->debug_dev_lock);

	if (!dev->archdata.mapping) {

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

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}

	if (!dev->archdata.mapping->domain) {

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

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}



	if (*offset)

	if (*offset) {

		mutex_unlock(&ddev->debug_dev_lock);

		return 0;



	}

	memset(buf, 0, sizeof(buf));



	phys = iommu_iova_to_phys_hard(dev->archdata.mapping->domain,
@@ -1737,7 +1764,7 @@ static ssize_t iommu_debug_dma_atos_read(struct file *file, char __user *ubuf, 
		*offset = 1;	/* non-zero means we're done */

		retval = buflen;

	}



	mutex_unlock(&ddev->debug_dev_lock);

	return retval;

}
@@ -1765,8 +1792,10 @@ static ssize_t iommu_debug_map_write(struct file *file, const char __user *ubuf, 
		return -EINVAL;

	}



	mutex_lock(&ddev->debug_dev_lock);

	if (!ddev->domain) {

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

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}
@@ -1815,10 +1844,12 @@ static ssize_t iommu_debug_map_write(struct file *file, const char __user *ubuf, 
	pr_err("Mapped %pa to %pa (len=0x%zx, prot=0x%x)\n",

	       &iova, &phys, size, prot);

out:

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;



invalid_format:

	pr_err("Invalid format. Expected: iova,phys,len,prot where `prot' is the bitwise OR of IOMMU_READ, IOMMU_WRITE, etc.\n");

	mutex_unlock(&ddev->debug_dev_lock);

	return -EINVAL;

}
@@ -1856,6 +1887,7 @@ static ssize_t iommu_debug_dma_map_write(struct file *file, 
		return -EINVAL;

	}



	mutex_lock(&ddev->debug_dev_lock);

	if (!dev->archdata.mapping) {

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

		retval = -EINVAL;
@@ -1924,14 +1956,17 @@ static ssize_t iommu_debug_dma_map_write(struct file *file, 
	ddev->iova = iova;

		pr_err("Saved iova=%pa for future PTE commands\n", &iova);

out:

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;



invalid_format:

	pr_err("Invalid format. Expected: addr,len,dma attr where 'dma attr' is\n0: normal mapping\n1: force coherent\n2: force non-cohernet\n3: use system cache\n");

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;



invalid_addr:

	pr_err("Invalid addr given! Address should be within 1MB size from start addr returned by doing 'cat test_virt_addr'.\n");

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;

}
@@ -1997,8 +2032,10 @@ static ssize_t iommu_debug_unmap_write(struct file *file, 
		return -EINVAL;

	}



	mutex_lock(&ddev->debug_dev_lock);

	if (!ddev->domain) {

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

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}
@@ -2027,16 +2064,19 @@ static ssize_t iommu_debug_unmap_write(struct file *file, 
	if (unmapped != size) {

		pr_err("iommu_unmap failed. Expected to unmap: 0x%zx, unmapped: 0x%zx",

		       size, unmapped);

		mutex_unlock(&ddev->debug_dev_lock);

		return -EIO;

	}



	retval = count;

	pr_err("Unmapped %pa (len=0x%zx)\n", &iova, size);

out:

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;



invalid_format:

	pr_err("Invalid format. Expected: iova,len\n");

	mutex_unlock(&ddev->debug_dev_lock);

	return -EINVAL;

}
@@ -2064,6 +2104,7 @@ static ssize_t iommu_debug_dma_unmap_write(struct file *file, 
		return -EINVAL;

	}



	mutex_lock(&ddev->debug_dev_lock);

	if (!dev->archdata.mapping) {

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

		retval = -EINVAL;
@@ -2118,10 +2159,12 @@ static ssize_t iommu_debug_dma_unmap_write(struct file *file, 
	retval = count;

	pr_err("Unmapped %pa (len=0x%zx)\n", &iova, size);

out:

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;



invalid_format:

	pr_err("Invalid format. Expected: iova,len, dma attr\n");

	mutex_unlock(&ddev->debug_dev_lock);

	return retval;

}
@@ -2144,13 +2187,16 @@ static ssize_t iommu_debug_config_clocks_write(struct file *file, 
		return -EINVAL;

	}



	mutex_lock(&ddev->debug_dev_lock);

	if (!ddev->domain) {

		dev_err(dev, "No domain. Did you already attach?\n");

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}



	if (copy_from_user(&buf, ubuf, 1)) {

		dev_err(dev, "Couldn't copy from user\n");

		mutex_unlock(&ddev->debug_dev_lock);

		return -EFAULT;

	}
@@ -2179,10 +2225,11 @@ static ssize_t iommu_debug_config_clocks_write(struct file *file, 
	default:

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

		mutex_unlock(&ddev->clk_lock);

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}

	mutex_unlock(&ddev->clk_lock);



	mutex_unlock(&ddev->debug_dev_lock);

	return count;

}
@@ -2198,17 +2245,21 @@ static ssize_t iommu_debug_trigger_fault_write( 
	struct iommu_debug_device *ddev = file->private_data;

	unsigned long flags;



	mutex_lock(&ddev->debug_dev_lock);

	if (!ddev->domain) {

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

		mutex_unlock(&ddev->debug_dev_lock);

		return -EINVAL;

	}



	if (kstrtoul_from_user(ubuf, count, 0, &flags)) {

		pr_err("Invalid flags format\n");

		mutex_unlock(&ddev->debug_dev_lock);

		return -EFAULT;

	}



	iommu_trigger_fault(ddev->domain, flags);

	mutex_unlock(&ddev->debug_dev_lock);



	return count;

}
@@ -2243,6 +2294,7 @@ static int snarf_iommu_devices(struct device *dev, void *ignored) 
		return -ENODEV;



	mutex_init(&ddev->clk_lock);

	mutex_init(&ddev->debug_dev_lock);

	ddev->dev = dev;

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

	if (!dir) {