* [PATCH 2/3] selftests: cgroup: Minor code reorganizations
2023-06-29 9:11 [PATCH 0/3] cpuset: Allow setscheduler regardless of manipulated task Michal Koutný
2023-06-29 9:11 ` [PATCH 1/3] " Michal Koutný
@ 2023-06-29 9:11 ` Michal Koutný
2023-06-29 9:11 ` [PATCH 3/3] selftests: cgroup: Add cpuset migrations testcase Michal Koutný
2 siblings, 0 replies; 8+ messages in thread
From: Michal Koutný @ 2023-06-29 9:11 UTC (permalink / raw)
To: linux-kernel, cgroups, linux-kselftest
Cc: Waiman Long, Zefan Li, Tejun Heo, Johannes Weiner, Shuah Khan
No functional change intended, these small changes are merged into one
commit and they serve as a preparation for an upcoming new testcase.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
---
MAINTAINERS | 1 +
tools/testing/selftests/cgroup/cgroup_util.c | 2 ++
tools/testing/selftests/cgroup/cgroup_util.h | 2 ++
tools/testing/selftests/cgroup/test_core.c | 2 +-
tools/testing/selftests/cgroup/test_cpuset_prs.sh | 2 +-
5 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/MAINTAINERS b/MAINTAINERS
index 35e19594640d..50e7056b4383 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5259,6 +5259,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git
F: Documentation/admin-guide/cgroup-v1/cpusets.rst
F: include/linux/cpuset.h
F: kernel/cgroup/cpuset.c
+F: tools/testing/selftests/cgroup/test_cpuset_prs.sh
CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)
M: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c
index e8bbbdb77e0d..0340d4ca8f51 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/cgroup_util.c
@@ -286,6 +286,8 @@ int cg_destroy(const char *cgroup)
{
int ret;
+ if (!cgroup)
+ return 0;
retry:
ret = rmdir(cgroup);
if (ret && errno == EBUSY) {
diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/cgroup_util.h
index c92df4e5d395..1df7f202214a 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.h
+++ b/tools/testing/selftests/cgroup/cgroup_util.h
@@ -11,6 +11,8 @@
#define USEC_PER_SEC 1000000L
#define NSEC_PER_SEC 1000000000L
+#define TEST_UID 65534 /* usually nobody, any !root is fine */
+
/*
* Checks if two given values differ by less than err% of their sum.
*/
diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c
index 600123503063..80aa6b2373b9 100644
--- a/tools/testing/selftests/cgroup/test_core.c
+++ b/tools/testing/selftests/cgroup/test_core.c
@@ -683,7 +683,7 @@ static int test_cgcore_thread_migration(const char *root)
*/
static int test_cgcore_lesser_euid_open(const char *root)
{
- const uid_t test_euid = 65534; /* usually nobody, any !root is fine */
+ const uid_t test_euid = TEST_UID;
int ret = KSFT_FAIL;
char *cg_test_a = NULL, *cg_test_b = NULL;
char *cg_test_a_procs = NULL, *cg_test_b_procs = NULL;
diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh b/tools/testing/selftests/cgroup/test_cpuset_prs.sh
index 2b5215cc599f..4afb132e4e4f 100755
--- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh
+++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh
@@ -10,7 +10,7 @@
skip_test() {
echo "$1"
echo "Test SKIPPED"
- exit 0
+ exit 4 # ksft_skip
}
[[ $(id -u) -eq 0 ]] || skip_test "Test must be run as root!"
--
2.41.0
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH 3/3] selftests: cgroup: Add cpuset migrations testcase
2023-06-29 9:11 [PATCH 0/3] cpuset: Allow setscheduler regardless of manipulated task Michal Koutný
2023-06-29 9:11 ` [PATCH 1/3] " Michal Koutný
2023-06-29 9:11 ` [PATCH 2/3] selftests: cgroup: Minor code reorganizations Michal Koutný
@ 2023-06-29 9:11 ` Michal Koutný
2 siblings, 0 replies; 8+ messages in thread
From: Michal Koutný @ 2023-06-29 9:11 UTC (permalink / raw)
To: linux-kernel, cgroups, linux-kselftest
Cc: Waiman Long, Zefan Li, Tejun Heo, Johannes Weiner, Shuah Khan
Add a separate testfile to verify treating permissions when tasks are
migrated on cgroup v2 hierarchy between cpuset cgroups.
In accordance with v2 design, migration should be allowed based on
delegation boundaries (i.e. cgroup.procs permissions) and does not
depend on the migrated object (i.e. unprivileged process can migrate
another process (even privileged) as long as it remains in the original
dedicated scope).
Signed-off-by: Michal Koutný <mkoutny@suse.com>
---
MAINTAINERS | 1 +
tools/testing/selftests/cgroup/.gitignore | 1 +
tools/testing/selftests/cgroup/Makefile | 2 +
tools/testing/selftests/cgroup/test_cpuset.c | 272 +++++++++++++++++++
4 files changed, 276 insertions(+)
create mode 100644 tools/testing/selftests/cgroup/test_cpuset.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 50e7056b4383..51a31aab077f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5259,6 +5259,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git
F: Documentation/admin-guide/cgroup-v1/cpusets.rst
F: include/linux/cpuset.h
F: kernel/cgroup/cpuset.c
+F: tools/testing/selftests/cgroup/test_cpuset.c
F: tools/testing/selftests/cgroup/test_cpuset_prs.sh
CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)
diff --git a/tools/testing/selftests/cgroup/.gitignore b/tools/testing/selftests/cgroup/.gitignore
index c4a57e69f749..8443a8d46a1c 100644
--- a/tools/testing/selftests/cgroup/.gitignore
+++ b/tools/testing/selftests/cgroup/.gitignore
@@ -5,4 +5,5 @@ test_freezer
test_kmem
test_kill
test_cpu
+test_cpuset
wait_inotify
diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile
index 3d263747d2ad..dee0f013c7f4 100644
--- a/tools/testing/selftests/cgroup/Makefile
+++ b/tools/testing/selftests/cgroup/Makefile
@@ -12,6 +12,7 @@ TEST_GEN_PROGS += test_core
TEST_GEN_PROGS += test_freezer
TEST_GEN_PROGS += test_kill
TEST_GEN_PROGS += test_cpu
+TEST_GEN_PROGS += test_cpuset
LOCAL_HDRS += $(selfdir)/clone3/clone3_selftests.h $(selfdir)/pidfd/pidfd.h
@@ -23,3 +24,4 @@ $(OUTPUT)/test_core: cgroup_util.c
$(OUTPUT)/test_freezer: cgroup_util.c
$(OUTPUT)/test_kill: cgroup_util.c
$(OUTPUT)/test_cpu: cgroup_util.c
+$(OUTPUT)/test_cpuset: cgroup_util.c
diff --git a/tools/testing/selftests/cgroup/test_cpuset.c b/tools/testing/selftests/cgroup/test_cpuset.c
new file mode 100644
index 000000000000..976ec6f014d8
--- /dev/null
+++ b/tools/testing/selftests/cgroup/test_cpuset.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/limits.h>
+#include <signal.h>
+
+#include "../kselftest.h"
+#include "cgroup_util.h"
+
+static int idle_process_fn(const char *cgroup, void *arg)
+{
+ (void)pause();
+ return 0;
+}
+
+static int do_migration_fn(const char *cgroup, void *arg)
+{
+ int object_pid = (int)(size_t)arg;
+
+ if (setuid(TEST_UID))
+ return EXIT_FAILURE;
+
+ // XXX checking /proc/$pid/cgroup would be quicker than wait
+ if (cg_enter(cgroup, object_pid) ||
+ cg_wait_for_proc_count(cgroup, 1))
+ return EXIT_FAILURE;
+
+ return EXIT_SUCCESS;
+}
+
+static int do_controller_fn(const char *cgroup, void *arg)
+{
+ const char *child = cgroup;
+ const char *parent = arg;
+
+ if (setuid(TEST_UID))
+ return EXIT_FAILURE;
+
+ if (!cg_read_strstr(child, "cgroup.controllers", "cpuset"))
+ return EXIT_FAILURE;
+
+ if (cg_write(parent, "cgroup.subtree_control", "+cpuset"))
+ return EXIT_FAILURE;
+
+ if (cg_read_strstr(child, "cgroup.controllers", "cpuset"))
+ return EXIT_FAILURE;
+
+ if (cg_write(parent, "cgroup.subtree_control", "-cpuset"))
+ return EXIT_FAILURE;
+
+ if (!cg_read_strstr(child, "cgroup.controllers", "cpuset"))
+ return EXIT_FAILURE;
+
+ return EXIT_SUCCESS;
+}
+
+/*
+ * Migrate a process between two sibling cgroups.
+ * The success should only depend on the parent cgroup permissions and not the
+ * migrated process itself (cpuset controller is in place because it uses
+ * security_task_setscheduler() in cgroup v1).
+ */
+static int test_cpuset_perms_object(const char *root, bool allow)
+{
+ char *parent = NULL, *child_src = NULL, *child_dst = NULL;
+ char *parent_procs = NULL, *child_src_procs = NULL, *child_dst_procs = NULL;
+ const uid_t test_euid = TEST_UID;
+ int object_pid = 0;
+ int ret = KSFT_FAIL;
+
+ parent = cg_name(root, "cpuset_test_0");
+ if (!parent)
+ goto cleanup;
+ parent_procs = cg_name(parent, "cgroup.procs");
+ if (!parent_procs)
+ goto cleanup;
+ if (cg_create(parent))
+ goto cleanup;
+
+ child_src = cg_name(parent, "cpuset_test_1");
+ if (!child_src)
+ goto cleanup;
+ child_src_procs = cg_name(child_src, "cgroup.procs");
+ if (!child_src_procs)
+ goto cleanup;
+ if (cg_create(child_src))
+ goto cleanup;
+
+ child_dst = cg_name(parent, "cpuset_test_2");
+ if (!child_dst)
+ goto cleanup;
+ child_dst_procs = cg_name(child_dst, "cgroup.procs");
+ if (!child_dst_procs)
+ goto cleanup;
+ if (cg_create(child_dst))
+ goto cleanup;
+
+ if (cg_write(parent, "cgroup.subtree_control", "+cpuset"))
+ goto cleanup;
+
+ if (cg_read_strstr(child_src, "cgroup.controllers", "cpuset") ||
+ cg_read_strstr(child_dst, "cgroup.controllers", "cpuset"))
+ goto cleanup;
+
+ /* Enable permissions along src->dst tree path */
+ if (chown(child_src_procs, test_euid, -1) ||
+ chown(child_dst_procs, test_euid, -1))
+ goto cleanup;
+
+ if (allow && chown(parent_procs, test_euid, -1))
+ goto cleanup;
+
+ /* Fork a privileged child as a test object */
+ object_pid = cg_run_nowait(child_src, idle_process_fn, NULL);
+ if (object_pid < 0)
+ goto cleanup;
+
+ /* Carry out migration in a child process that can drop all privileges
+ * (including capabilities), the main process must remain privileged for
+ * cleanup.
+ * Child process's cgroup is irrelevant but we place it into child_dst
+ * as hacky way to pass information about migration target to the child.
+ */
+ if (allow ^ (cg_run(child_dst, do_migration_fn, (void *)(size_t)object_pid) == EXIT_SUCCESS))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (object_pid > 0) {
+ (void)kill(object_pid, SIGTERM);
+ (void)clone_reap(object_pid, WEXITED);
+ }
+
+ cg_destroy(child_dst);
+ free(child_dst_procs);
+ free(child_dst);
+
+ cg_destroy(child_src);
+ free(child_src_procs);
+ free(child_src);
+
+ cg_destroy(parent);
+ free(parent_procs);
+ free(parent);
+
+ return ret;
+}
+
+static int test_cpuset_perms_object_allow(const char *root)
+{
+ return test_cpuset_perms_object(root, true);
+}
+
+static int test_cpuset_perms_object_deny(const char *root)
+{
+ return test_cpuset_perms_object(root, false);
+}
+
+/*
+ * Migrate a process between parent and child implicitely
+ * Implicit migration happens when a controller is enabled/disabled.
+ *
+ */
+static int test_cpuset_perms_subtree(const char *root)
+{
+ char *parent = NULL, *child = NULL;
+ char *parent_procs = NULL, *parent_subctl = NULL, *child_procs = NULL;
+ const uid_t test_euid = TEST_UID;
+ int object_pid = 0;
+ int ret = KSFT_FAIL;
+
+ parent = cg_name(root, "cpuset_test_0");
+ if (!parent)
+ goto cleanup;
+ parent_procs = cg_name(parent, "cgroup.procs");
+ if (!parent_procs)
+ goto cleanup;
+ parent_subctl = cg_name(parent, "cgroup.subtree_control");
+ if (!parent_subctl)
+ goto cleanup;
+ if (cg_create(parent))
+ goto cleanup;
+
+ child = cg_name(parent, "cpuset_test_1");
+ if (!child)
+ goto cleanup;
+ child_procs = cg_name(child, "cgroup.procs");
+ if (!child_procs)
+ goto cleanup;
+ if (cg_create(child))
+ goto cleanup;
+
+ /* Enable permissions as in a delegated subtree */
+ if (chown(parent_procs, test_euid, -1) ||
+ chown(parent_subctl, test_euid, -1) ||
+ chown(child_procs, test_euid, -1))
+ goto cleanup;
+
+ /* Put a privileged child in the subtree and modify controller state
+ * from an unprivileged process, the main process remains privileged
+ * for cleanup.
+ * The unprivileged child runs in subtree too to avoid parent and
+ * internal-node constraing violation.
+ */
+ object_pid = cg_run_nowait(child, idle_process_fn, NULL);
+ if (object_pid < 0)
+ goto cleanup;
+
+ if (cg_run(child, do_controller_fn, parent) != EXIT_SUCCESS)
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (object_pid > 0) {
+ (void)kill(object_pid, SIGTERM);
+ (void)clone_reap(object_pid, WEXITED);
+ }
+
+ cg_destroy(child);
+ free(child_procs);
+ free(child);
+
+ cg_destroy(parent);
+ free(parent_subctl);
+ free(parent_procs);
+ free(parent);
+
+ return ret;
+}
+
+
+#define T(x) { x, #x }
+struct cpuset_test {
+ int (*fn)(const char *root);
+ const char *name;
+} tests[] = {
+ T(test_cpuset_perms_object_allow),
+ T(test_cpuset_perms_object_deny),
+ T(test_cpuset_perms_subtree),
+};
+#undef T
+
+int main(int argc, char *argv[])
+{
+ char root[PATH_MAX];
+ int i, ret = EXIT_SUCCESS;
+
+ if (cg_find_unified_root(root, sizeof(root)))
+ ksft_exit_skip("cgroup v2 isn't mounted\n");
+
+ if (cg_read_strstr(root, "cgroup.subtree_control", "cpuset"))
+ if (cg_write(root, "cgroup.subtree_control", "+cpuset"))
+ ksft_exit_skip("Failed to set cpuset controller\n");
+
+ for (i = 0; i < ARRAY_SIZE(tests); i++) {
+ switch (tests[i].fn(root)) {
+ case KSFT_PASS:
+ ksft_test_result_pass("%s\n", tests[i].name);
+ break;
+ case KSFT_SKIP:
+ ksft_test_result_skip("%s\n", tests[i].name);
+ break;
+ default:
+ ret = EXIT_FAILURE;
+ ksft_test_result_fail("%s\n", tests[i].name);
+ break;
+ }
+ }
+
+ return ret;
+}
--
2.41.0
^ permalink raw reply related [flat|nested] 8+ messages in thread