[PATCH 2/2] arm64: bpf: add extra pass to handle faulty codegen

[Alexei Starovoitov]

On Wed, Jan 13, 2016 at 11:33:22PM -0800, Zi Shen Lim wrote:
> Code generation functions in arch/arm64/kernel/insn.c previously
> BUG_ON invalid parameters. Following change of that behavior, now we
> need to handle the error case where AARCH64_BREAK_FAULT is returned.
> 
> Instead of error-handling on every emit() in JIT, we add a new
> validation pass at the end of JIT compilation. There's no point in
> running JITed code at run-time only to trap due to AARCH64_BREAK_FAULT.
> Instead, we drop this failed JIT compilation and allow the system to
> gracefully fallback on the BPF interpreter.
> 
> Signed-off-by: Zi Shen Lim <zlim.lnx at gmail.com>
> Suggested-by: Alexei Starovoitov <ast at kernel.org>

Looks good to me.
Acked-by: Alexei Starovoitov <ast at kernel.org>
technically it's a bug fix, though the shift problem is already mitigated.
Will, any comments?