mbox series

[v2,0/2] Fix failure to access u32* argument of tracked function

Message ID 20230407084608.62296-1-zhoufeng.zf@bytedance.com
Headers show
Series Fix failure to access u32* argument of tracked function | expand

Message

Feng Zhou April 7, 2023, 8:46 a.m. UTC 
From: Feng Zhou <zhoufeng.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

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.com/

 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(-)