selftests/bpf: Add selftests for cgroup1 local storage

Expanding the test coverage from cgroup2 to include cgroup1. The result
as follows,

Already existing test cases for cgroup2:
  #48/1    cgrp_local_storage/tp_btf:OK
  #48/2    cgrp_local_storage/attach_cgroup:OK
  #48/3    cgrp_local_storage/recursion:OK
  #48/4    cgrp_local_storage/negative:OK
  #48/5    cgrp_local_storage/cgroup_iter_sleepable:OK
  #48/6    cgrp_local_storage/yes_rcu_lock:OK
  #48/7    cgrp_local_storage/no_rcu_lock:OK

Expanded test cases for cgroup1:
  #48/8    cgrp_local_storage/cgrp1_tp_btf:OK
  #48/9    cgrp_local_storage/cgrp1_recursion:OK
  #48/10   cgrp_local_storage/cgrp1_negative:OK
  #48/11   cgrp_local_storage/cgrp1_iter_sleepable:OK
  #48/12   cgrp_local_storage/cgrp1_yes_rcu_lock:OK
  #48/13   cgrp_local_storage/cgrp1_no_rcu_lock:OK

Summary:
  #48      cgrp_local_storage:OK
  Summary: 1/13 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231206115326.4295-4-laoar.shao@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

tools/testing/selftests/bpf/prog_tests/cgrp_local_storage.c

@@ -19,6 +19,21 @@ struct socket_cookie {
 	__u64 cookie_value;
 };
 
+static bool is_cgroup1;
+static int target_hid;
+
+#define CGROUP_MODE_SET(skel)			\
+{						\
+	skel->bss->is_cgroup1 = is_cgroup1;	\
+	skel->bss->target_hid = target_hid;	\
+}
+
+static void cgroup_mode_value_init(bool cgroup, int hid)
+{
+	is_cgroup1 = cgroup;
+	target_hid = hid;
+}
+
 static void test_tp_btf(int cgroup_fd)
 {
 	struct cgrp_ls_tp_btf *skel;
@@ -29,6 +44,8 @@ static void test_tp_btf(int cgroup_fd)
 	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
 		return;
 
+	CGROUP_MODE_SET(skel);
+
 	/* populate a value in map_b */
 	err = bpf_map_update_elem(bpf_map__fd(skel->maps.map_b), &cgroup_fd, &val1, BPF_ANY);
 	if (!ASSERT_OK(err, "map_update_elem"))
@@ -130,6 +147,8 @@ static void test_recursion(int cgroup_fd)
 	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
 		return;
 
+	CGROUP_MODE_SET(skel);
+
 	err = cgrp_ls_recursion__attach(skel);
 	if (!ASSERT_OK(err, "skel_attach"))
 		goto out;
@@ -165,6 +184,8 @@ static void test_cgroup_iter_sleepable(int cgroup_fd, __u64 cgroup_id)
 	if (!ASSERT_OK_PTR(skel, "skel_open"))
 		return;
 
+	CGROUP_MODE_SET(skel);
+
 	bpf_program__set_autoload(skel->progs.cgroup_iter, true);
 	err = cgrp_ls_sleepable__load(skel);
 	if (!ASSERT_OK(err, "skel_load"))
@@ -202,6 +223,7 @@ static void test_yes_rcu_lock(__u64 cgroup_id)
 	if (!ASSERT_OK_PTR(skel, "skel_open"))
 		return;
 
+	CGROUP_MODE_SET(skel);
 	skel->bss->target_pid = syscall(SYS_gettid);
 
 	bpf_program__set_autoload(skel->progs.yes_rcu_lock, true);
@@ -229,6 +251,8 @@ static void test_no_rcu_lock(void)
 	if (!ASSERT_OK_PTR(skel, "skel_open"))
 		return;
 
+	CGROUP_MODE_SET(skel);
+
 	bpf_program__set_autoload(skel->progs.no_rcu_lock, true);
 	err = cgrp_ls_sleepable__load(skel);
 	ASSERT_ERR(err, "skel_load");
@@ -236,7 +260,25 @@ static void test_no_rcu_lock(void)
 	cgrp_ls_sleepable__destroy(skel);
 }
 
-void test_cgrp_local_storage(void)
+static void test_cgrp1_no_rcu_lock(void)
+{
+	struct cgrp_ls_sleepable *skel;
+	int err;
+
+	skel = cgrp_ls_sleepable__open();
+	if (!ASSERT_OK_PTR(skel, "skel_open"))
+		return;
+
+	CGROUP_MODE_SET(skel);
+
+	bpf_program__set_autoload(skel->progs.cgrp1_no_rcu_lock, true);
+	err = cgrp_ls_sleepable__load(skel);
+	ASSERT_OK(err, "skel_load");
+
+	cgrp_ls_sleepable__destroy(skel);
+}
+
+static void cgrp2_local_storage(void)
 {
 	__u64 cgroup_id;
 	int cgroup_fd;
@@ -245,6 +287,8 @@ void test_cgrp_local_storage(void)
 	if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /cgrp_local_storage"))
 		return;
 
+	cgroup_mode_value_init(0, -1);
+
 	cgroup_id = get_cgroup_id("/cgrp_local_storage");
 	if (test__start_subtest("tp_btf"))
 		test_tp_btf(cgroup_fd);
@@ -263,3 +307,55 @@ void test_cgrp_local_storage(void)
 
 	close(cgroup_fd);
 }
+
+static void cgrp1_local_storage(void)
+{
+	int cgrp1_fd, cgrp1_hid, cgrp1_id, err;
+
+	/* Setup cgroup1 hierarchy */
+	err = setup_classid_environment();
+	if (!ASSERT_OK(err, "setup_classid_environment"))
+		return;
+
+	err = join_classid();
+	if (!ASSERT_OK(err, "join_cgroup1"))
+		goto cleanup;
+
+	cgrp1_fd = open_classid();
+	if (!ASSERT_GE(cgrp1_fd, 0, "cgroup1 fd"))
+		goto cleanup;
+
+	cgrp1_id = get_classid_cgroup_id();
+	if (!ASSERT_GE(cgrp1_id, 0, "cgroup1 id"))
+		goto close_fd;
+
+	cgrp1_hid = get_cgroup1_hierarchy_id("net_cls");
+	if (!ASSERT_GE(cgrp1_hid, 0, "cgroup1 hid"))
+		goto close_fd;
+
+	cgroup_mode_value_init(1, cgrp1_hid);
+
+	if (test__start_subtest("cgrp1_tp_btf"))
+		test_tp_btf(cgrp1_fd);
+	if (test__start_subtest("cgrp1_recursion"))
+		test_recursion(cgrp1_fd);
+	if (test__start_subtest("cgrp1_negative"))
+		test_negative();
+	if (test__start_subtest("cgrp1_iter_sleepable"))
+		test_cgroup_iter_sleepable(cgrp1_fd, cgrp1_id);
+	if (test__start_subtest("cgrp1_yes_rcu_lock"))
+		test_yes_rcu_lock(cgrp1_id);
+	if (test__start_subtest("cgrp1_no_rcu_lock"))
+		test_cgrp1_no_rcu_lock();
+
+close_fd:
+	close(cgrp1_fd);
+cleanup:
+	cleanup_classid_environment();
+}
+
+void test_cgrp_local_storage(void)
+{
+	cgrp2_local_storage();
+	cgrp1_local_storage();
+}

tools/testing/selftests/bpf/progs/cgrp_ls_recursion.c

@@ -21,50 +21,100 @@ struct {
 	__type(value, long);
 } map_b SEC(".maps");
 
+int target_hid = 0;
+bool is_cgroup1 = 0;
+
+struct cgroup *bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id) __ksym;
+void bpf_cgroup_release(struct cgroup *cgrp) __ksym;
+
+static void __on_lookup(struct cgroup *cgrp)
+{
+	bpf_cgrp_storage_delete(&map_a, cgrp);
+	bpf_cgrp_storage_delete(&map_b, cgrp);
+}
+
 SEC("fentry/bpf_local_storage_lookup")
 int BPF_PROG(on_lookup)
 {
 	struct task_struct *task = bpf_get_current_task_btf();
+	struct cgroup *cgrp;
 
-	bpf_cgrp_storage_delete(&map_a, task->cgroups->dfl_cgrp);
-	bpf_cgrp_storage_delete(&map_b, task->cgroups->dfl_cgrp);
+	if (is_cgroup1) {
+		cgrp = bpf_task_get_cgroup1(task, target_hid);
+		if (!cgrp)
+			return 0;
+
+		__on_lookup(cgrp);
+		bpf_cgroup_release(cgrp);
+		return 0;
+	}
+
+	__on_lookup(task->cgroups->dfl_cgrp);
 	return 0;
 }
 
+static void __on_update(struct cgroup *cgrp)
+{
+	long *ptr;
+
+	ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
+	if (ptr)
+		*ptr += 1;
+
+	ptr = bpf_cgrp_storage_get(&map_b, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
+	if (ptr)
+		*ptr += 1;
+}
+
 SEC("fentry/bpf_local_storage_update")
 int BPF_PROG(on_update)
 {
 	struct task_struct *task = bpf_get_current_task_btf();
+	struct cgroup *cgrp;
+
+	if (is_cgroup1) {
+		cgrp = bpf_task_get_cgroup1(task, target_hid);
+		if (!cgrp)
+			return 0;
+
+		__on_update(cgrp);
+		bpf_cgroup_release(cgrp);
+		return 0;
+	}
+
+	__on_update(task->cgroups->dfl_cgrp);
+	return 0;
+}
+
+static void __on_enter(struct pt_regs *regs, long id, struct cgroup *cgrp)
+{
 	long *ptr;
 
-	ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
-				   BPF_LOCAL_STORAGE_GET_F_CREATE);
+	ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
 	if (ptr)
-		*ptr += 1;
+		*ptr = 200;
 
-	ptr = bpf_cgrp_storage_get(&map_b, task->cgroups->dfl_cgrp, 0,
-				   BPF_LOCAL_STORAGE_GET_F_CREATE);
+	ptr = bpf_cgrp_storage_get(&map_b, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
 	if (ptr)
-		*ptr += 1;
-
-	return 0;
+		*ptr = 100;
 }
 
 SEC("tp_btf/sys_enter")
 int BPF_PROG(on_enter, struct pt_regs *regs, long id)
 {
-	struct task_struct *task;
-	long *ptr;
+	struct task_struct *task = bpf_get_current_task_btf();
+	struct cgroup *cgrp;
 
-	task = bpf_get_current_task_btf();
-	ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
-				   BPF_LOCAL_STORAGE_GET_F_CREATE);
-	if (ptr)
-		*ptr = 200;
+	if (is_cgroup1) {
+		cgrp = bpf_task_get_cgroup1(task, target_hid);
+		if (!cgrp)
+			return 0;
 
-	ptr = bpf_cgrp_storage_get(&map_b, task->cgroups->dfl_cgrp, 0,
-				   BPF_LOCAL_STORAGE_GET_F_CREATE);
-	if (ptr)
-		*ptr = 100;
+		__on_enter(regs, id, cgrp);
+		bpf_cgroup_release(cgrp);
+		return 0;
+	}
+
+	__on_enter(regs, id, task->cgroups->dfl_cgrp);
 	return 0;
 }

tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c

@@ -17,7 +17,11 @@ struct {
 
 __u32 target_pid;
 __u64 cgroup_id;
+int target_hid;
+bool is_cgroup1;
 
+struct cgroup *bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id) __ksym;
+void bpf_cgroup_release(struct cgroup *cgrp) __ksym;
 void bpf_rcu_read_lock(void) __ksym;
 void bpf_rcu_read_unlock(void) __ksym;
 
@@ -37,23 +41,50 @@ int cgroup_iter(struct bpf_iter__cgroup *ctx)
 	return 0;
 }
 
+static void __no_rcu_lock(struct cgroup *cgrp)
+{
+	long *ptr;
+
+	/* Note that trace rcu is held in sleepable prog, so we can use
+	 * bpf_cgrp_storage_get() in sleepable prog.
+	 */
+	ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0,
+				   BPF_LOCAL_STORAGE_GET_F_CREATE);
+	if (ptr)
+		cgroup_id = cgrp->kn->id;
+}
+
+SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
+int cgrp1_no_rcu_lock(void *ctx)
+{
+	struct task_struct *task;
+	struct cgroup *cgrp;
+
+	task = bpf_get_current_task_btf();
+	if (task->pid != target_pid)
+		return 0;
+
+	/* bpf_task_get_cgroup1 can work in sleepable prog */
+	cgrp = bpf_task_get_cgroup1(task, target_hid);
+	if (!cgrp)
+		return 0;
+
+	__no_rcu_lock(cgrp);
+	bpf_cgroup_release(cgrp);
+	return 0;
+}
+
 SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
 int no_rcu_lock(void *ctx)
 {
 	struct task_struct *task;
-	struct cgroup *cgrp;
-	long *ptr;
 
 	task = bpf_get_current_task_btf();
 	if (task->pid != target_pid)
 		return 0;
 
 	/* task->cgroups is untrusted in sleepable prog outside of RCU CS */
-	cgrp = task->cgroups->dfl_cgrp;
-	ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0,
-				   BPF_LOCAL_STORAGE_GET_F_CREATE);
-	if (ptr)
-		cgroup_id = cgrp->kn->id;
+	__no_rcu_lock(task->cgroups->dfl_cgrp);
 	return 0;
 }
 
@@ -68,6 +99,22 @@ int yes_rcu_lock(void *ctx)
 	if (task->pid != target_pid)
 		return 0;
 
+	if (is_cgroup1) {
+		bpf_rcu_read_lock();
+		cgrp = bpf_task_get_cgroup1(task, target_hid);
+		if (!cgrp) {
+			bpf_rcu_read_unlock();
+			return 0;
+		}
+
+		ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
+		if (ptr)
+			cgroup_id = cgrp->kn->id;
+		bpf_cgroup_release(cgrp);
+		bpf_rcu_read_unlock();
+		return 0;
+	}
+
 	bpf_rcu_read_lock();
 	cgrp = task->cgroups->dfl_cgrp;
 	/* cgrp is trusted under RCU CS */

tools/testing/selftests/bpf/progs/cgrp_ls_tp_btf.c

@@ -27,62 +27,100 @@ pid_t target_pid = 0;
 int mismatch_cnt = 0;
 int enter_cnt = 0;
 int exit_cnt = 0;
+int target_hid = 0;
+bool is_cgroup1 = 0;
+
+struct cgroup *bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id) __ksym;
+void bpf_cgroup_release(struct cgroup *cgrp) __ksym;
+
+static void __on_enter(struct pt_regs *regs, long id, struct cgroup *cgrp)
+{
+	long *ptr;
+	int err;
+
+	/* populate value 0 */
+	ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0,
+				   BPF_LOCAL_STORAGE_GET_F_CREATE);
+	if (!ptr)
+		return;
+
+	/* delete value 0 */
+	err = bpf_cgrp_storage_delete(&map_a, cgrp);
+	if (err)
+		return;
+
+	/* value is not available */
+	ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, 0);
+	if (ptr)
+		return;
+
+	/* re-populate the value */
+	ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0,
+				   BPF_LOCAL_STORAGE_GET_F_CREATE);
+	if (!ptr)
+		return;
+	__sync_fetch_and_add(&enter_cnt, 1);
+	*ptr = MAGIC_VALUE + enter_cnt;
+}
 
 SEC("tp_btf/sys_enter")
 int BPF_PROG(on_enter, struct pt_regs *regs, long id)
 {
 	struct task_struct *task;
-	long *ptr;
-	int err;
+	struct cgroup *cgrp;
 
 	task = bpf_get_current_task_btf();
 	if (task->pid != target_pid)
 		return 0;
 
-	/* populate value 0 */
-	ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
-				   BPF_LOCAL_STORAGE_GET_F_CREATE);
-	if (!ptr)
-		return 0;
+	if (is_cgroup1) {
+		cgrp = bpf_task_get_cgroup1(task, target_hid);
+		if (!cgrp)
+			return 0;
 
-	/* delete value 0 */
-	err = bpf_cgrp_storage_delete(&map_a, task->cgroups->dfl_cgrp);
-	if (err)
+		__on_enter(regs, id, cgrp);
+		bpf_cgroup_release(cgrp);
 		return 0;
+	}
 
-	/* value is not available */
-	ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0, 0);
-	if (ptr)
-		return 0;
-
-	/* re-populate the value */
-	ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
-				   BPF_LOCAL_STORAGE_GET_F_CREATE);
-	if (!ptr)
-		return 0;
-	__sync_fetch_and_add(&enter_cnt, 1);
-	*ptr = MAGIC_VALUE + enter_cnt;
-
+	__on_enter(regs, id, task->cgroups->dfl_cgrp);
 	return 0;
 }
 
+static void __on_exit(struct pt_regs *regs, long id, struct cgroup *cgrp)
+{
+	long *ptr;
+
+	ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0,
+				   BPF_LOCAL_STORAGE_GET_F_CREATE);
+	if (!ptr)
+		return;
+
+	__sync_fetch_and_add(&exit_cnt, 1);
+	if (*ptr != MAGIC_VALUE + exit_cnt)
+		__sync_fetch_and_add(&mismatch_cnt, 1);
+}
+
 SEC("tp_btf/sys_exit")
 int BPF_PROG(on_exit, struct pt_regs *regs, long id)
 {
 	struct task_struct *task;
-	long *ptr;
+	struct cgroup *cgrp;
 
 	task = bpf_get_current_task_btf();
 	if (task->pid != target_pid)
 		return 0;
 
-	ptr = bpf_cgrp_storage_get(&map_a, task->cgroups->dfl_cgrp, 0,
-				   BPF_LOCAL_STORAGE_GET_F_CREATE);
-	if (!ptr)
-		return 0;
+	if (is_cgroup1) {
+		cgrp = bpf_task_get_cgroup1(task, target_hid);
+		if (!cgrp)
+			return 0;
 
-	__sync_fetch_and_add(&exit_cnt, 1);
-	if (*ptr != MAGIC_VALUE + exit_cnt)
-		__sync_fetch_and_add(&mismatch_cnt, 1);
+		__on_exit(regs, id, cgrp);
+		bpf_cgroup_release(cgrp);
+		return 0;
+	}
+
+	__on_exit(regs, id, task->cgroups->dfl_cgrp);
 	return 0;
 }