net: bpf_jit: fix BPF_S_LDX_B_MSH compilation

net: bpf_jit: fix BPF_S_LDX_B_MSH compilation

Matt Evans spotted that x86 bpf_jit was incorrectly handling negative
constant offsets in BPF_S_LDX_B_MSH instruction.

We need to abort JIT compilation like we do in common_load so that
filter uses the interpreter code and can call __load_pointer()

Reference: http://lists.openwall.net/netdev/2011/07/19/11

Thanks to Indan Zupancic to bring back this issue.

Reported-by: Matt Evans <[email protected]>
Reported-by: Indan Zupancic <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>