Add three tests for cgrp local storage support for sleepable progs.
Two tests can load and run properly, one for cgroup_iter, another
for passing current->cgroups->dfl_cgrp to bpf_cgrp_storage_get()
helper. One test has bpf_rcu_read_lock() and failed to load.
Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
.../bpf/prog_tests/cgrp_local_storage.c | 94 +++++++++++++++++++
.../selftests/bpf/progs/cgrp_ls_sleepable.c | 80 ++++++++++++++++
2 files changed, 174 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c
diff --git a/tools/testing/selftests/bpf/prog_tests/cgrp_local_storage.c b/tools/testing/selftests/bpf/prog_tests/cgrp_local_storage.c
index 1c30412ba132..33a2776737e7 100644
--- a/tools/testing/selftests/bpf/prog_tests/cgrp_local_storage.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgrp_local_storage.c
@@ -10,7 +10,9 @@
#include "cgrp_ls_recursion.skel.h"
#include "cgrp_ls_attach_cgroup.skel.h"
#include "cgrp_ls_negative.skel.h"
+#include "cgrp_ls_sleepable.skel.h"
#include "network_helpers.h"
+#include "cgroup_helpers.h"
struct socket_cookie {
__u64 cookie_key;
@@ -150,14 +152,100 @@ static void test_negative(void)
}
}
+static void test_cgroup_iter_sleepable(int cgroup_fd, __u64 cgroup_id)
+{
+ DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);
+ union bpf_iter_link_info linfo;
+ struct cgrp_ls_sleepable *skel;
+ struct bpf_link *link;
+ int err, iter_fd;
+ char buf[16];
+
+ skel = cgrp_ls_sleepable__open();
+ if (!ASSERT_OK_PTR(skel, "skel_open"))
+ return;
+
+ bpf_program__set_autoload(skel->progs.cgroup_iter, true);
+ err = cgrp_ls_sleepable__load(skel);
+ if (!ASSERT_OK(err, "skel_load"))
+ goto out;
+
+ memset(&linfo, 0, sizeof(linfo));
+ linfo.cgroup.cgroup_fd = cgroup_fd;
+ linfo.cgroup.order = BPF_CGROUP_ITER_SELF_ONLY;
+ opts.link_info = &linfo;
+ opts.link_info_len = sizeof(linfo);
+ link = bpf_program__attach_iter(skel->progs.cgroup_iter, &opts);
+ if (!ASSERT_OK_PTR(link, "attach_iter"))
+ goto out;
+
+ iter_fd = bpf_iter_create(bpf_link__fd(link));
+ if (!ASSERT_GE(iter_fd, 0, "iter_create"))
+ goto out;
+
+ /* trigger the program run */
+ (void)read(iter_fd, buf, sizeof(buf));
+
+ ASSERT_EQ(skel->bss->cgroup_id, cgroup_id, "cgroup_id");
+
+ close(iter_fd);
+out:
+ cgrp_ls_sleepable__destroy(skel);
+}
+
+static void test_no_rcu_lock(__u64 cgroup_id)
+{
+ struct cgrp_ls_sleepable *skel;
+ int err;
+
+ skel = cgrp_ls_sleepable__open();
+ if (!ASSERT_OK_PTR(skel, "skel_open"))
+ return;
+
+ skel->bss->target_pid = syscall(SYS_gettid);
+
+ bpf_program__set_autoload(skel->progs.no_rcu_lock, true);
+ err = cgrp_ls_sleepable__load(skel);
+ if (!ASSERT_OK(err, "skel_load"))
+ goto out;
+
+ err = cgrp_ls_sleepable__attach(skel);
+ if (!ASSERT_OK(err, "skel_attach"))
+ goto out;
+
+ syscall(SYS_getpgid);
+
+ ASSERT_EQ(skel->bss->cgroup_id, cgroup_id, "cgroup_id");
+out:
+ cgrp_ls_sleepable__destroy(skel);
+}
+
+static void test_rcu_lock(void)
+{
+ struct cgrp_ls_sleepable *skel;
+ int err;
+
+ skel = cgrp_ls_sleepable__open();
+ if (!ASSERT_OK_PTR(skel, "skel_open"))
+ return;
+
+ bpf_program__set_autoload(skel->progs.yes_rcu_lock, true);
+ err = cgrp_ls_sleepable__load(skel);
+ ASSERT_ERR(err, "skel_load");
+
+ cgrp_ls_sleepable__destroy(skel);
+}
+
void test_cgrp_local_storage(void)
{
+ __u64 cgroup_id;
int cgroup_fd;
cgroup_fd = test__join_cgroup("/cgrp_local_storage");
if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /cgrp_local_storage"))
return;
+ cgroup_id = get_cgroup_id("/cgrp_local_storage");
if (test__start_subtest("tp_btf"))
test_tp_btf(cgroup_fd);
if (test__start_subtest("attach_cgroup"))
@@ -166,6 +254,12 @@ void test_cgrp_local_storage(void)
test_recursion(cgroup_fd);
if (test__start_subtest("negative"))
test_negative();
+ if (test__start_subtest("cgroup_iter_sleepable"))
+ test_cgroup_iter_sleepable(cgroup_fd, cgroup_id);
+ if (test__start_subtest("no_rcu_lock"))
+ test_no_rcu_lock(cgroup_id);
+ if (test__start_subtest("rcu_lock"))
+ test_rcu_lock();
close(cgroup_fd);
}
diff --git a/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c b/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c
new file mode 100644
index 000000000000..2d11ed528b6f
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include "bpf_iter.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include "bpf_misc.h"
+
+char _license[] SEC("license") = "GPL";
+
+struct {
+ __uint(type, BPF_MAP_TYPE_CGRP_STORAGE);
+ __uint(map_flags, BPF_F_NO_PREALLOC);
+ __type(key, int);
+ __type(value, long);
+} map_a SEC(".maps");
+
+__u32 target_pid;
+__u64 cgroup_id;
+
+void bpf_rcu_read_lock(void) __ksym;
+void bpf_rcu_read_unlock(void) __ksym;
+
+SEC("?iter.s/cgroup")
+int cgroup_iter(struct bpf_iter__cgroup *ctx)
+{
+ struct seq_file *seq = ctx->meta->seq;
+ struct cgroup *cgrp = ctx->cgroup;
+ long *ptr;
+
+ if (cgrp == NULL)
+ return 0;
+
+ ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0,
+ BPF_LOCAL_STORAGE_GET_F_CREATE);
+ if (ptr)
+ cgroup_id = cgrp->kn->id;
+ 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;
+
+ /* ptr_to_btf_id semantics. should work. */
+ 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;
+ return 0;
+}
+
+SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
+int yes_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;
+
+ bpf_rcu_read_lock();
+ cgrp = task->cgroups->dfl_cgrp;
+ /* cgrp is untrusted and cannot pass to bpf_cgrp_storage_get() helper. */
+ ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
+ if (ptr)
+ cgroup_id = cgrp->kn->id;
+ bpf_rcu_read_unlock();
+ return 0;
+}
--
2.30.2
