在 2023/4/7 18:49, Feng Zhou 写道:
在 2023/4/7 17:33, Jiri Olsa 写道:
On Fri, Apr 07, 2023 at 04:46:06PM +0800, Feng zhou wrote:
From: Feng Zhouzhoufeng.zf@bytedance.com
When access traced function arguments with type is u32*, bpf verifier failed. Because u32 have typedef, needs to skip modifier. Add btf_type_is_modifier in is_int_ptr. Add a selftest to check it.
Feng Zhou (2): bpf/btf: Fix is_int_ptr() selftests/bpf: Add test to access u32 ptr argument in tracing program
hi, it breaks several tests in test_progs suite:
#11/36 bpf_iter/link-iter:FAIL #11 bpf_iter:FAIL test_dummy_st_ops_attach:FAIL:dummy_st_ops_load unexpected error: -13 #63/1 dummy_st_ops/dummy_st_ops_attach:FAIL test_dummy_init_ret_value:FAIL:dummy_st_ops_load unexpected error: -13 #63/2 dummy_st_ops/dummy_init_ret_value:FAIL test_dummy_init_ptr_arg:FAIL:dummy_st_ops_load unexpected error: -13 #63/3 dummy_st_ops/dummy_init_ptr_arg:FAIL test_dummy_multiple_args:FAIL:dummy_st_ops_load unexpected error: -13 #63/4 dummy_st_ops/dummy_multiple_args:FAIL test_dummy_sleepable:FAIL:dummy_st_ops_load unexpected error: -13 #63/5 dummy_st_ops/dummy_sleepable:FAIL #63 dummy_st_ops:FAIL test_fentry_fexit:FAIL:fentry_skel_load unexpected error: -13 #69 fentry_fexit:FAIL test_fentry_test:FAIL:fentry_skel_load unexpected error: -13 #70 fentry_test:FAIL
jirka
I tried it, and it did cause the test to fail. Bpfverify reported an error, 'R1 invalid mem access'scalar', let me confirm the reason.
I used btf_type_skip_modifiers，but did not delete the previous "t = btf_type_by_id (btf, t- > type);" resulting in some testcases failing. I will send a v3 nextweek, thank you for your suggestion.
Changelog: v1->v2: Addressed comments from Martin KaFai Lau
- Add a selftest.
- use btf_type_skip_modifiers.
Some details in here: https://lore.kernel.org/all/20221012125815.76120-1-zhouchengming@bytedance.c...
kernel/bpf/btf.c | 5 ++--- net/bpf/test_run.c | 8 +++++++- .../testing/selftests/bpf/verifier/btf_ctx_access.c | 13 +++++++++++++ 3 files changed, 22 insertions(+), 4 deletions(-)
-- 2.20.1