On Thu, Apr 28, 2016 at 3:56 AM, Alexei Starovoitov <a...@fb.com> wrote:
> The commit 35578d798400 ("bpf: Implement function bpf_perf_event_read() that
> get the selected hardware PMU conuter")
> introduced clever way to check bpf_helper<->map_type compatibility.
> Later on commit a43eec304259 ("bpf: introduce bpf_perf_event_output()
> helper") adjusted
> the logic and inadvertently broke it.
> Get rid of the clever bool compare and go back to two-way check
> from map and from helper perspective.
>
> Fixes: a43eec304259 ("bpf: introduce bpf_perf_event_output() helper")
> Reported-by: Jann Horn <ja...@google.com>
> Signed-off-by: Alexei Starovoitov <a...@kernel.org>
> Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
> ---
> kernel/bpf/verifier.c | 65
> +++++++++++++++++++++++++++++++--------------------
> 1 file changed, 40 insertions(+), 25 deletions(-)
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 89bcaa0966da..c5c17a62f509 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
[...]
> + case BPF_MAP_TYPE_PROG_ARRAY:
> + if (func_id != BPF_FUNC_tail_call)
> + goto error;
> + break;
> + case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
> + if (func_id != BPF_FUNC_perf_event_read &&
> + func_id != BPF_FUNC_perf_event_output)
> + goto error;
> + break;
> + case BPF_MAP_TYPE_STACK_TRACE:
> + if (func_id != BPF_FUNC_get_stackid)
> + goto error;
> + break;
> + default:
> + break;
> + }
> +
> + /* ... and second from the function itself. */
> + switch (func_id) {
> + case BPF_FUNC_tail_call:
> + if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
> + goto error;
> + break;
> + case BPF_FUNC_perf_event_read:
> + case BPF_FUNC_perf_event_output:
> + if (map->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY)
> + goto error;
> + break;
> + case BPF_FUNC_get_stackid:
> + if (map->map_type != BPF_MAP_TYPE_STACK_TRACE)
> + goto error;
> + break;
> + default:
> + break;
> }
Looks good to me.
