[bug report] selftests: cgroup: add memory controller self-tests

From: guro at fb.com (Roman Gushchin)
Subject: [bug report] selftests: cgroup: add memory controller self-tests
Date: Wed, 27 Mar 2019 22:24:37 +0000	[thread overview]
Message-ID: <20190327222429.GA11226@castle> (raw)
In-Reply-To: <20190327073204.GA15448@kadam>

On Wed, Mar 27, 2019 at 10:32:04AM +0300, Dan Carpenter wrote:
> Hello Roman Gushchin,
> 
> The patch 84092dbcf901: "selftests: cgroup: add memory controller
> self-tests" from May 11, 2018, leads to the following static checker
> warning:

Hi Dan!

As I remember, this problem has been reported already, and I've
proposed a fix for it: https://patchwork.kernel.org/patch/10489785/
However, for some reason it hasn't been merged.

Shuakh, can you, please, merge it? Do you want me to respin and resend it?

Thank you!

Roman

> 
> 	./tools/testing/selftests/cgroup/test_memcontrol.c:77 test_memcg_subtree_control()
> 	error: uninitialized symbol 'child2'.
> 
> ./tools/testing/selftests/cgroup/test_memcontrol.c
>     27 static int test_memcg_subtree_control(const char *root)
>     28 {
>     29 	char *parent, *child, *parent2, *child2;
>                                ^^^^^^^^^^^^^^^^
>     30 	int ret = KSFT_FAIL;
>     31 	char buf[PAGE_SIZE];
>     32 
>     33 	/* Create two nested cgroups with the memory controller enabled */
>     34 	parent = cg_name(root, "memcg_test_0");
>     35 	child = cg_name(root, "memcg_test_0/memcg_test_1");
>     36 	if (!parent || !child)
>     37 		goto cleanup;
>                 ^^^^^^^^^^^^
> 
>     38 
>     39 	if (cg_create(parent))
>     40 		goto cleanup;
>     41 
>     42 	if (cg_write(parent, "cgroup.subtree_control", "+memory"))
>     43 		goto cleanup;
>     44 
>     45 	if (cg_create(child))
>     46 		goto cleanup;
>     47 
>     48 	if (cg_read_strstr(child, "cgroup.controllers", "memory"))
>     49 		goto cleanup;
>     50 
>     51 	/* Create two nested cgroups without enabling memory controller */
>     52 	parent2 = cg_name(root, "memcg_test_1");
>     53 	child2 = cg_name(root, "memcg_test_1/memcg_test_1");
>     54 	if (!parent2 || !child2)
>     55 		goto cleanup;
>     56 
>     57 	if (cg_create(parent2))
>     58 		goto cleanup;
>     59 
>     60 	if (cg_create(child2))
>     61 		goto cleanup;
>     62 
>     63 	if (cg_read(child2, "cgroup.controllers", buf, sizeof(buf)))
>     64 		goto cleanup;
>     65 
>     66 	if (!cg_read_strstr(child2, "cgroup.controllers", "memory"))
>     67 		goto cleanup;
>     68 
>     69 	ret = KSFT_PASS;
>     70 
>     71 cleanup:
>     72 	cg_destroy(child);
>     73 	cg_destroy(parent);
>     74 	free(parent);
>     75 	free(child);
>     76 
> --> 77 	cg_destroy(child2);
>         ^^^^^^^^^^^^^^^^^
>     78 	cg_destroy(parent2);
>         ^^^^^^^^^^^^^^^^^^
>     79 	free(parent2);
>     80 	free(child2);
>     81 
>     82 	return ret;
>     83 }
> 
> regards,
> dan carpenter