diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2023-03-17 13:19:20 -0700 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2023-03-17 15:46:02 -0700 |
| commit | 95fdf6e313a981b0729886f86916190cb418b04c (patch) | |
| tree | dd3fb68a821169c52d13421de0ba528db0ce70ba | |
| parent | 5cbd3fe3a91df46ea201cc5d8ab4e390332ec26e (diff) | |
selftests/bpf: Add test for bpf_ksym_exists().
Add load and run time test for bpf_ksym_exists() and check that the verifier
performs dead code elimination for non-existing kfunc.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20230317201920.62030-5-alexei.starovoitov@gmail.com
| -rw-r--r-- | tools/testing/selftests/bpf/progs/task_kfunc_success.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_success.c b/tools/testing/selftests/bpf/progs/task_kfunc_success.c index 4f61596b0242..cfa7f12b84e8 100644 --- a/tools/testing/selftests/bpf/progs/task_kfunc_success.c +++ b/tools/testing/selftests/bpf/progs/task_kfunc_success.c @@ -17,6 +17,10 @@ int err, pid; * TP_PROTO(struct task_struct *p, u64 clone_flags) */ +struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym __weak; +void invalid_kfunc(void) __ksym __weak; +void bpf_testmod_test_mod_kfunc(int i) __ksym __weak; + static bool is_test_kfunc_task(void) { int cur_pid = bpf_get_current_pid_tgid() >> 32; @@ -26,7 +30,21 @@ static bool is_test_kfunc_task(void) static int test_acquire_release(struct task_struct *task) { - struct task_struct *acquired; + struct task_struct *acquired = NULL; + + if (!bpf_ksym_exists(bpf_task_acquire)) { + err = 3; + return 0; + } + if (!bpf_ksym_exists(bpf_testmod_test_mod_kfunc)) { + err = 4; + return 0; + } + if (bpf_ksym_exists(invalid_kfunc)) { + /* the verifier's dead code elimination should remove this */ + err = 5; + asm volatile ("goto -1"); /* for (;;); */ + } acquired = bpf_task_acquire(task); bpf_task_release(acquired); |