Re: [PATCH bpf-next 1/4] bpf: arm64: Add support for instructions array

[Anton Protopopov <a.s.protopopov@gmail.com>]

On 25/11/17 12:46AM, Puranjay Mohan wrote:
> Add support for the instructions array map type in the arm64 JIT by
> calling bpf_prog_update_insn_ptrs() with the offsets that map
> xlated_offset to the jited_offset in the final image. arm64 JIT already
> has this offset array which was being used for
> bpf_prog_fill_jited_linfo() and can be used directly for
> bpf_prog_update_insn_ptrs.
> 
> Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
> ---
>  arch/arm64/net/bpf_jit_comp.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
> index 0c9a50a1e73e..4a2afc0cefc4 100644
> --- a/arch/arm64/net/bpf_jit_comp.c
> +++ b/arch/arm64/net/bpf_jit_comp.c
> @@ -2231,6 +2231,13 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
>  		for (i = 0; i <= prog->len; i++)
>  			ctx.offset[i] *= AARCH64_INSN_SIZE;
>  		bpf_prog_fill_jited_linfo(prog, ctx.offset + 1);
> +		/*
> +		 * The bpf_prog_update_insn_ptrs function expects offsets to
> +		 * point to the first byte of the jitted instruction (unlike
> +		 * the bpf_prog_fill_jited_linfo above, which, for historical
> +		 * reasons, expects to point to the next instruction)
> +		 */
> +		bpf_prog_update_insn_ptrs(prog, ctx.offset, ctx.ro_image);
>  out_off:
>  		if (!ro_header && priv_stack_ptr) {
>  			free_percpu(priv_stack_ptr);
> -- 
> 2.47.3
> 

Reviewed-by: Anton Protopopov <a.s.protopopov@gmail.com>