bpf: support 8-byte metafield access
authorAlexei Starovoitov <ast@fb.com>
Fri, 2 Sep 2016 01:37:21 +0000 (18:37 -0700)
committerDavid S. Miller <davem@davemloft.net>
Fri, 2 Sep 2016 17:46:44 +0000 (10:46 -0700)
commitea2e7ce5d0fc878463ba39deb46cf2ab20398fd2
tree7b67c9e451afca1b570835bbd75d9be7aebc931e
parent569e937e0100c8841619bd2150d15682141a6b0b
bpf: support 8-byte metafield access

The verifier supported only 4-byte metafields in
struct __sk_buff and struct xdp_md. The metafields in upcoming
struct bpf_perf_event are 8-byte to match register width in struct pt_regs.
Teach verifier to recognize 8-byte metafield access.
The patch doesn't affect safety of sockets and xdp programs.
They check for 4-byte only ctx access before these conditions are hit.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
kernel/bpf/verifier.c