Re: [PATCH v2 0/3] bpf: switch to new usercopy helpers

Alexei Starovoitov
2019-10-16T02:15:00Z

On Tue, Oct 15, 2019 at 5:41 PM Christian Brauner
<christian.brauner@ubuntu.com> wrote:
>
> Hey everyone,
>
> In v5.4-rc2 we added two new helpers check_zeroed_user() and
> copy_struct_from_user() including selftests (cf. [1]). It is a generic
> interface designed to copy a struct from userspace. The helpers will be
> especially useful for structs versioned by size of which we have quite a
> few.

Was it tested?
Either your conversion is incorrect or that generic helper is broken.
./test_progs -n 2
and
./test_btf
are catching the bug:
BTF prog info raw test[8] (line_info (No subprog. zero tailing
line_info): do_test_info_raw:6205:FAIL prog_fd:-1
expected_prog_load_failure:0 errno:7
nonzero tailing record in line_infoprocessed 0 insns (limit 1000000)
max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0