Merge "iommu: iommu-debug: Fix race with respect to test buffer allocation" (c231872b) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/iommu/iommu-debug.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -110,6 +110,7 @@ static LIST_HEAD(iommu_debug_devices);
		static struct dentry *debugfs_tests_dir;
		static u32 iters_per_op = 1;
		static void *test_virt_addr;
		static DEFINE_MUTEX(test_virt_addr_lock);

		struct iommu_debug_device {
		struct device *dev;
		@@ -1409,6 +1410,7 @@ static ssize_t iommu_debug_test_virt_addr_read(struct file *file,

		memset(buf, 0, buf_len);

		mutex_lock(&test_virt_addr_lock);
		if (IS_ERR_OR_NULL(test_virt_addr))
		test_virt_addr = kzalloc(SZ_1M, GFP_KERNEL);

		@@ -1417,6 +1419,7 @@ static ssize_t iommu_debug_test_virt_addr_read(struct file *file,
		strlcpy(buf, "FAIL\n", buf_len);
		} else
		snprintf(buf, buf_len, "0x%pK\n", test_virt_addr);
		mutex_unlock(&test_virt_addr_lock);

		return simple_read_from_buffer(ubuf, count, offset, buf, strlen(buf));
		}
		@@ -1745,11 +1748,17 @@ static ssize_t iommu_debug_dma_map_write(struct file *file,
		if (kstrtouint(comma2 + 1, 0, &attr))
		goto invalid_format;

		if (IS_ERR(test_virt_addr))
		mutex_lock(&test_virt_addr_lock);
		if (IS_ERR(test_virt_addr)) {
		mutex_unlock(&test_virt_addr_lock);
		goto allocation_failure;
		}

		if (!test_virt_addr)
		if (!test_virt_addr) {
		mutex_unlock(&test_virt_addr_lock);
		goto missing_allocation;
		}
		mutex_unlock(&test_virt_addr_lock);

		if (v_addr < test_virt_addr \|\| v_addr + size > test_virt_addr + SZ_1M)
		goto invalid_addr;