Merge tag 'cgroup-for-7.1-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:

 - cpuset fixes:
     - Partition invalidation could return CPUs still in use by sibling
       partitions, producing overlapping effective_cpus
     - cpuset_can_attach() over-reserved DL bandwidth on moves that
       stayed within the same root domain
     - Pending DL migration state leaked into later attaches when a
       later can_attach() check failed
     - Reorder PF_EXITING and __GFP_HARDWALL checks so dying tasks can
       allocate from any node and exit quickly

 - dmem: propagate -ENOMEM instead of spinning forever when the fallback
   pool allocation also fails

 - selftests/cgroup: percpu test error-path leak, bogus numeric
   comparison of cpuset strings, and a zero-length read() that silently
   passed OOM-kill tests

* tag 'cgroup-for-7.1-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/cpuset: Return only actually allocated CPUs during partition invalidation
  selftests/cgroup: Fix error path leaks in test_percpu_basic
  cgroup/cpuset: Reserve DL bandwidth only for root-domain moves
  cgroup/cpuset: Reset DL migration state on can_attach() failure
  selftests/cgroup: Fix string comparison in write_test
  selftests/cgroup: Fix cg_read_strcmp() empty string comparison
  cgroup/dmem: Return -ENOMEM on failed pool preallocation
  cgroup/cpuset: move PF_EXITING check before __GFP_HARDWALL in cpuset_current_node_allowed()

3 files changed, 11 insertions, 6 deletions

diff --git a/tools/testing/selftests/cgroup/lib/cgroup_util.c b/tools/testing/selftests/cgroup/lib/cgroup_util.c
index 6a7295347e90..42f54936f4bb 100644
--- a/tools/testing/selftests/cgroup/lib/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/lib/cgroup_util.c
@@ -106,8 +106,9 @@ int cg_read_strcmp(const char *cgroup, const char *control,
 	/* Handle the case of comparing against empty string */
 	if (!expected)
 		return -1;
-	else
-		size = strlen(expected) + 1;
+
+	/* needs size > 1, otherwise cg_read() reads 0 bytes */
+	size = (expected[0] == '\0') ? 2 : strlen(expected) + 1;
 
 	buf = malloc(size);
 	if (!buf)
diff --git a/tools/testing/selftests/cgroup/test_cpuset_v1_base.sh b/tools/testing/selftests/cgroup/test_cpuset_v1_base.sh
index 42a6628fb8bc..1c0444729e70 100755
--- a/tools/testing/selftests/cgroup/test_cpuset_v1_base.sh
+++ b/tools/testing/selftests/cgroup/test_cpuset_v1_base.sh
@@ -18,7 +18,7 @@ write_test() {
 	echo "testing $interface $value"
 	echo $value > $dir/$interface
 	new=$(cat $dir/$interface)
-	[[ $value -ne $(cat $dir/$interface) ]] && {
+	[[ "$value" != "$new" ]] && {
 		echo "$interface write $value failed: new:$new"
 		exit 1
 	}
diff --git a/tools/testing/selftests/cgroup/test_kmem.c b/tools/testing/selftests/cgroup/test_kmem.c
index eeabd34bf083..12f59925500b 100644
--- a/tools/testing/selftests/cgroup/test_kmem.c
+++ b/tools/testing/selftests/cgroup/test_kmem.c
@@ -368,11 +368,15 @@ static int test_percpu_basic(const char *root)
 
 	for (i = 0; i < 1000; i++) {
 		child = cg_name_indexed(parent, "child", i);
-		if (!child)
-			return -1;
+		if (!child) {
+			ret = -1;
+			goto cleanup_children;
+		}
 
-		if (cg_create(child))
+		if (cg_create(child)) {
+			free(child);
 			goto cleanup_children;
+		}
 
 		free(child);
 	}