bpf: let verifier to calculate and record max_pkt_offset
In check_packet_access, update max_pkt_offset after the offset has passed
__check_packet_access.
It should be safe to use u32 for max_pkt_offset as explained in code
comment.
Also, when there is tail call, the max_pkt_offset of the called program is
unknown, so conservatively set max_pkt_offset to MAX_PACKET_OFF for such
case.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 33014ae..b6a296e 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -293,6 +293,7 @@ struct bpf_prog_aux {
atomic_t refcnt;
u32 used_map_cnt;
u32 max_ctx_offset;
+ u32 max_pkt_offset;
u32 stack_depth;
u32 id;
u32 func_cnt;