Hello Frank Rowand,
Commit d1eabd218ede ("of: unittest: treat missing of_root as error
instead of fixing up") from Feb 16, 2024 (linux-next), leads to the
following Smatch static checker warning:
drivers/of/unittest.c:1934 unittest_data_add()
warn: inconsistent returns '&of_overlay_phandle_mutex'.
drivers/of/unittest.c
1857 static int __init unittest_data_add(void)
1858 {
1859 void *unittest_data;
1860 void *unittest_data_align;
1861 struct device_node *unittest_data_node = NULL, *np;
1862 /*
1863 * __dtbo_testcases_begin[] and __dtbo_testcases_end[] are magically
1864 * created by cmd_dt_S_dtbo in scripts/Makefile.lib
1865 */
1866 extern uint8_t __dtbo_testcases_begin[];
1867 extern uint8_t __dtbo_testcases_end[];
1868 const int size = __dtbo_testcases_end - __dtbo_testcases_begin;
1869 int rc;
1870 void *ret;
1871
1872 if (!size) {
1873 pr_warn("%s: testcases is empty\n", __func__);
1874 return -ENODATA;
1875 }
1876
1877 /* creating copy */
1878 unittest_data = kmalloc(size + FDT_ALIGN_SIZE, GFP_KERNEL);
1879 if (!unittest_data)
1880 return -ENOMEM;
1881
1882 unittest_data_align = PTR_ALIGN(unittest_data, FDT_ALIGN_SIZE);
We never save unittest_data anywhere so how is this freed on the success path?
1883 memcpy(unittest_data_align, __dtbo_testcases_begin, size);
1884
1885 ret = of_fdt_unflatten_tree(unittest_data_align, NULL, &unittest_data_node);
1886 if (!ret) {
1887 pr_warn("%s: unflatten testcases tree failed\n", __func__);
1888 kfree(unittest_data);
1889 return -ENODATA;
1890 }
1891 if (!unittest_data_node) {
1892 pr_warn("%s: testcases tree is empty\n", __func__);
1893 kfree(unittest_data);
1894 return -ENODATA;
1895 }
1896
1897 /*
1898 * This lock normally encloses of_resolve_phandles()
1899 */
1900 of_overlay_mutex_lock();
^^^^^^^^^^^^^^^^^^^^^^^^
1901
1902 rc = of_resolve_phandles(unittest_data_node);
1903 if (rc) {
1904 pr_err("%s: Failed to resolve phandles (rc=%i)\n", __func__, rc);
1905 of_overlay_mutex_unlock();
kfree(unittest_data);?
1906 return -EINVAL;
1907 }
1908
1909 /* attach the sub-tree to live tree */
1910 if (!of_root) {
1911 pr_warn("%s: no live tree to attach sub-tree\n", __func__);
1912 kfree(unittest_data);
This used to call of_overlay_mutex_unlock(). I think that was deleted
accidentally.
1913 return -ENODEV;
1914 }
1915
1916 EXPECT_BEGIN(KERN_INFO,
1917 "Duplicate name in testcase-data, renamed to \"duplicate-name#1\"");
1918
1919 np = unittest_data_node->child;
1920 while (np) {
1921 struct device_node *next = np->sibling;
1922
1923 np->parent = of_root;
1924 /* this will clear OF_DETACHED in np and children */
1925 attach_node_and_children(np);
1926 np = next;
1927 }
1928
1929 EXPECT_END(KERN_INFO,
1930 "Duplicate name in testcase-data, renamed to \"duplicate-name#1\"");
1931
1932 of_overlay_mutex_unlock();
1933
--> 1934 return 0;
1935 }
regards,
dan carpenter
