On Sun, 2024-03-03 at 02:37 +0000, Haojian Zhuang wrote: > When user sends message to bpf prog by a user ring buffer, a callback > in bpf prog should load data from the user ring buffer. > > By default, check_mem_access() doesn't handle the type of > CONST_PTR_TO_DYNPTR. So verifier reports an invalid memory access issue. > > So add the case of CONST_PTR_TO_DYNPTR type. Make bpf prog to handle > content in the user ring buffer. > You are referring to bpf_user_ringbuf_drain() helper function, right? Could you please provide an example of program that fails to verify? (ideally the patch set should extend tools/testing/selftests/bpf/progs/user_ringbuf_success.c to make sure that intended use case is tested).
