[PATCH v1 bpf-next 4/7] bpf: Reenable bpf_refcount_acquire

Dave Marchevsky
2023-08-01T20:36:40Z

Now that all reported issues are fixed, bpf_refcount_acquire can be
turned back on. Also reenable all bpf_refcount-related tests which were
disabled.

This a revert of:
* commit f3514a5d6740 ("selftests/bpf: Disable newly-added 'owner' field test until refcount re-enabled")
* commit 7deca5eae833 ("bpf: Disable bpf_refcount_acquire kfunc calls until race conditions are fixed")

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
---
kernel/bpf/verifier.c | 5 +---
.../bpf/prog_tests/refcounted_kptr.c | 26 +++++++++++++++++++
2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index ec37e84a11c6..9014b469dd9d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -11222,10 +11222,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_
verbose(env, "arg#%d doesn't point to a type with bpf_refcount field\n", i);
return -EINVAL;
}
- if (rec->refcount_off >= 0) {
- verbose(env, "bpf_refcount_acquire calls are disabled for now\n");
- return -EINVAL;
- }
+
meta->arg_btf = reg->btf;
meta->arg_btf_id = reg->btf_id;
break;
diff --git a/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c b/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c
index 7423983472c7..d6bd5e16e637 100644
--- a/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c
+++ b/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c
@@ -9,12 +9,38 @@

void test_refcounted_kptr(void)
{
+ RUN_TESTS(refcounted_kptr);
}

void test_refcounted_kptr_fail(void)
{
+ RUN_TESTS(refcounted_kptr_fail);
}

void test_refcounted_kptr_wrong_owner(void)
{
+ LIBBPF_OPTS(bpf_test_run_opts, opts,
+ .data_in = &pkt_v4,
+ .data_size_in = sizeof(pkt_v4),
+ .repeat = 1,
+ );
+ struct refcounted_kptr *skel;
+ int ret;
+
+ skel = refcounted_kptr__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "refcounted_kptr__open_and_load"))
+ return;
+
+ ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.rbtree_wrong_owner_remove_fail_a1), &opts);
+ ASSERT_OK(ret, "rbtree_wrong_owner_remove_fail_a1");
+ ASSERT_OK(opts.retval, "rbtree_wrong_owner_remove_fail_a1 retval");
+
+ ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.rbtree_wrong_owner_remove_fail_b), &opts);
+ ASSERT_OK(ret, "rbtree_wrong_owner_remove_fail_b");
+ ASSERT_OK(opts.retval, "rbtree_wrong_owner_remove_fail_b retval");
+
+ ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.rbtree_wrong_owner_remove_fail_a2), &opts);
+ ASSERT_OK(ret, "rbtree_wrong_owner_remove_fail_a2");
+ ASSERT_OK(opts.retval, "rbtree_wrong_owner_remove_fail_a2 retval");
+ refcounted_kptr__destroy(skel);
}
--
2.34.1