Commit e3b49dc6 authored by Quentin Monnet's avatar Quentin Monnet Committed by Daniel Borkmann
Browse files

nfp: bpf: account for BPF-to-BPF calls when preparing nfp JIT 



Similarly to "exit" or "helper call" instructions, BPF-to-BPF calls will
require additional processing before translation starts, in order to
record and mark jump destinations.

We also mark the instructions where each subprogram begins. This will be
used in a following commit to determine where to add prologues for
subprograms.

Signed-off-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: default avatarJiong Wang <jiong.wang@netronome.com>
Reviewed-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent bcfdfb7c

drivers/net/ethernet/netronome/nfp/bpf/jit.c

+25 −10
Original line number Diff line number Diff line
@@ -4018,20 +4018,35 @@ void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, unsigned int cnt) 


	/* Another pass to record jump information. */

	list_for_each_entry(meta, &nfp_prog->insns, l) {

		struct nfp_insn_meta *dst_meta;

		u64 code = meta->insn.code;

		unsigned int dst_idx;

		bool pseudo_call;



		if (BPF_CLASS(code) == BPF_JMP && BPF_OP(code) != BPF_EXIT &&

		    BPF_OP(code) != BPF_CALL) {

			struct nfp_insn_meta *dst_meta;

			unsigned short dst_indx;

		if (BPF_CLASS(code) != BPF_JMP)

			continue;

		if (BPF_OP(code) == BPF_EXIT)

			continue;

		if (is_mbpf_helper_call(meta))

			continue;



			dst_indx = meta->n + 1 + meta->insn.off;

			dst_meta = nfp_bpf_goto_meta(nfp_prog, meta, dst_indx,

						     cnt);

		/* If opcode is BPF_CALL at this point, this can only be a

		 * BPF-to-BPF call (a.k.a pseudo call).

		 */

		pseudo_call = BPF_OP(code) == BPF_CALL;



		if (pseudo_call)

			dst_idx = meta->n + 1 + meta->insn.imm;

		else

			dst_idx = meta->n + 1 + meta->insn.off;



		dst_meta = nfp_bpf_goto_meta(nfp_prog, meta, dst_idx, cnt);



		if (pseudo_call)

			dst_meta->flags |= FLAG_INSN_IS_SUBPROG_START;



			meta->jmp_dst = dst_meta;

		dst_meta->flags |= FLAG_INSN_IS_JUMP_DST;

		}

		meta->jmp_dst = dst_meta;

	}

}

drivers/net/ethernet/netronome/nfp/bpf/main.h

+2 −1
Original line number Diff line number Diff line
@@ -263,6 +263,7 @@ struct nfp_bpf_reg_state { 
};



#define FLAG_INSN_IS_JUMP_DST			BIT(0)

#define FLAG_INSN_IS_SUBPROG_START		BIT(1)



/**

 * struct nfp_insn_meta - BPF instruction wrapper

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