Add selftests covering the following cases:
- A static subprog called from within a RCU read section works
- A static subprog taking an RCU read lock which is released in caller works
- A static subprog releasing the caller's RCU read lock works
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/rcu_read_lock.c | 3 +
.../selftests/bpf/progs/rcu_read_lock.c | 64 +++++++++++++++++++
2 files changed, 67 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/rcu_read_lock.c b/tools/testing/selftests/bpf/prog_tests/rcu_read_lock.c
index 3f1f58d3a729..328a25e031d8 100644
--- a/tools/testing/selftests/bpf/prog_tests/rcu_read_lock.c
+++ b/tools/testing/selftests/bpf/prog_tests/rcu_read_lock.c
@@ -29,6 +29,9 @@ static void test_success(void)
bpf_program__set_autoload(skel->progs.non_sleepable_1, true);
bpf_program__set_autoload(skel->progs.non_sleepable_2, true);
bpf_program__set_autoload(skel->progs.task_trusted_non_rcuptr, true);
+ bpf_program__set_autoload(skel->progs.rcu_read_lock_subprog, true);
+ bpf_program__set_autoload(skel->progs.rcu_read_lock_subprog_lock, true);
+ bpf_program__set_autoload(skel->progs.rcu_read_lock_subprog_unlock, true);
err = rcu_read_lock__load(skel);
if (!ASSERT_OK(err, "skel_load"))
goto out;
diff --git a/tools/testing/selftests/bpf/progs/rcu_read_lock.c b/tools/testing/selftests/bpf/progs/rcu_read_lock.c
index 14fb01437fb8..687df026feb0 100644
--- a/tools/testing/selftests/bpf/progs/rcu_read_lock.c
+++ b/tools/testing/selftests/bpf/progs/rcu_read_lock.c
@@ -319,3 +319,67 @@ int cross_rcu_region(void *ctx)
bpf_rcu_read_unlock();
return 0;
}
+
+__noinline
+static int static_subprog(void *ctx)
+{
+ volatile int ret = 0;
+
+ if (bpf_get_prandom_u32())
+ return ret + 42;
+ return ret + bpf_get_prandom_u32();
+}
+
+__noinline
+static int static_subprog_lock(void *ctx)
+{
+ volatile int ret = 0;
+
+ bpf_rcu_read_lock();
+ if (bpf_get_prandom_u32())
+ return ret + 42;
+ return ret + bpf_get_prandom_u32();
+}
+
+__noinline
+static int static_subprog_unlock(void *ctx)
+{
+ volatile int ret = 0;
+
+ bpf_rcu_read_unlock();
+ if (bpf_get_prandom_u32())
+ return ret + 42;
+ return ret + bpf_get_prandom_u32();
+}
+
+SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
+int rcu_read_lock_subprog(void *ctx)
+{
+ volatile int ret = 0;
+
+ bpf_rcu_read_lock();
+ if (bpf_get_prandom_u32())
+ ret += static_subprog(ctx);
+ bpf_rcu_read_unlock();
+ return 0;
+}
+
+SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
+int rcu_read_lock_subprog_lock(void *ctx)
+{
+ volatile int ret = 0;
+
+ ret += static_subprog_lock(ctx);
+ bpf_rcu_read_unlock();
+ return 0;
+}
+
+SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
+int rcu_read_lock_subprog_unlock(void *ctx)
+{
+ volatile int ret = 0;
+
+ bpf_rcu_read_lock();
+ ret += static_subprog_unlock(ctx);
+ return 0;
+}
--
2.40.1
