On 05/23/2015 12:42 AM, Alexei Starovoitov wrote:
x86 has variable length encoding. x86 JIT compiler is trying to pick the shortest encoding for given bpf instruction. While doing so the jump targets are changing, so JIT is doing multiple passes over the program. Typical program needs 3 passes. Some very short programs converge with 2 passes. Large programs may need 4 or 5. But specially crafted bpf programs may hit the pass limit and if the program converges on the last iteration the JIT compiler will be producing an image full of 'int 3' insns. Fix this corner case by doing final iteration over bpf program.Fixes: 0a14842f5a3c ("net: filter: Just In Time compiler for x86-64") Reported-by: Daniel Borkmann <dan...@iogearbox.net> Signed-off-by: Alexei Starovoitov <a...@plumgrid.com>
LGTM, thanks! Tested-by: Daniel Borkmann <dan...@iogearbox.net> Acked-by: Daniel Borkmann <dan...@iogearbox.net> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
