Re: [PATCH 1/2] bpf, riscv: fix bugs in JIT for 32-bit ALU operations

Song Liu writes:

On Thu, May 30, 2019 at 3:34 PM Luke Nelson [off-list ref] wrote:

quoted

On Thu, May 30, 2019 at 1:53 PM Song Liu [off-list ref] wrote:

quoted

This is a little messy. How about we introduce some helper function
like:

/* please find a better name... */
emit_32_or_64(bool is64, const u32 insn_32, const u32 inst_64, struct
rv_jit_context *ctx)
{
       if (is64)
            emit(insn_64, ctx);
       else {
            emit(insn_32, ctx);
           rd = xxxx;
           emit_zext_32(rd, ctx);
       }
}

This same check is used throughout the file, maybe clean it up in a
separate patch?

We also need to enable the recent 32-bit opt (on bpf-next) on these missing
insns, like what has been done at:

  https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=66d0d5a854a6625974e7de4b874e7934988b0ef8

Perhaps the best way is to wait this patch merged back to bpf-next, then we
do two patches, the first one to enable the opt, the second one then do the
re-factor. I guess this could avoid some code conflict.

Regards,
Jiong

Yes, let's do follow up patch.

Thanks,
Song