Re: [PATCH bpf-next v5 3/3] bpf, arm64: use bpf_jit_binary_pack_alloc

[Xu Kuohai <xukuohai@xxxxxxxxxxxxxxx>]

On 9/8/2023 10:43 PM, Puranjay Mohan wrote:

[ ... ]

> +
> +void bpf_jit_free(struct bpf_prog *prog)
> +{
> +	if (prog->jited) {
> +		struct arm64_jit_data *jit_data = prog->aux->jit_data;
> +		struct bpf_binary_header *hdr;
> +
> +		/*
> +		 * If we fail the final pass of JIT (from jit_subprogs),
> +		 * the program may not be finalized yet. Call finalize here
> +		 * before freeing it.
> +		 */
> +		if (jit_data) {
> +			bpf_jit_binary_pack_finalize(prog, jit_data->ro_header,
> +						     jit_data->header);

bpf_jit_binary_pack_finalize copies all instructions on the rw image to
the ro_image, which is unnecessary in a free function.

> +			kfree(jit_data);
> +		}
> +		hdr = bpf_jit_binary_pack_hdr(prog);
> +		bpf_jit_binary_pack_free(hdr, NULL);
> +		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(prog));
> +	}
> +
> +	bpf_prog_unlock_free(prog);
> +}