From e32e6f02168f2ad7991eb5d160d312d2001520c8 Mon Sep 17 00:00:00 2001 From: Hongfu Li Date: Sat, 9 May 2026 16:03:28 +0800 Subject: selftests/cgroup: Fix cg_read_strcmp() empty string comparison cg_read_strcmp() allocated a buffer sized to strlen(expected) + 1, then passed it to read_text() which calls read(fd, buf, size-1). When comparing against an empty string (""), strlen("") = 0 gives a 1-byte buffer, and read() is asked to read 0 bytes. The file content is never actually read, so strcmp("", buf) always returns 0 regardless of the real content. This caused cg_test_proc_killed() to always report the cgroup as empty immediately, making OOM tests pass without verifying that processes were killed. Signed-off-by: Hongfu Li Signed-off-by: Tejun Heo --- tools/testing/selftests/cgroup/lib/cgroup_util.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'tools/testing') 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) -- cgit v1.2.3 From 2a3d7256faf06d1a15bb5b07e851ac4e1680c26d Mon Sep 17 00:00:00 2001 From: Hongfu Li Date: Mon, 11 May 2026 09:39:57 +0800 Subject: selftests/cgroup: Fix string comparison in write_test Use string comparison (!=) instead of numeric comparison (-ne) for cpuset values like "0-1". For example: $ [[ "0-1" != "2-3" ]] && echo "true" || echo "false" true $ [[ "0-1" -ne "2-3" ]] && echo "true" || echo "false" false Signed-off-by: Hongfu Li Signed-off-by: Tejun Heo --- tools/testing/selftests/cgroup/test_cpuset_v1_base.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/testing') 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 } -- cgit v1.2.3 From 7d8f3158a51cb40fc710d2a781549141a139b796 Mon Sep 17 00:00:00 2001 From: Yu Miao Date: Wed, 13 May 2026 10:39:07 +0800 Subject: selftests/cgroup: Fix error path leaks in test_percpu_basic When cg_name_indexed() returns NULL partway through the child creation loop, the code returned -1 without running cleanup_children and cleanup. That left the `parent` pathname allocation unreleased and did not remove child cgroup directories already created under the parent. Fix by jumping to cleanup_children instead of returning. When cg_create() fails, `child` (the pathname from cg_name_indexed()) was not freed before cleanup_children. Fix by freeing `child` before branching to cleanup_children. Fixes: 90631e1dea55 ("kselftests: cgroup: add perpcu memory accounting test") Signed-off-by: Yu Miao Signed-off-by: Tejun Heo --- tools/testing/selftests/cgroup/test_kmem.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'tools/testing') 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); } -- cgit v1.2.3