From e3b49dc69b320ba93059509ff2b31bde9242a7fa Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Sun, 7 Oct 2018 12:56:51 +0100 Subject: [PATCH] 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: Quentin Monnet Reviewed-by: Jiong Wang Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- drivers/net/ethernet/netronome/nfp/bpf/jit.c | 35 +++++++++++++------ drivers/net/ethernet/netronome/nfp/bpf/main.h | 3 +- 2 files changed, 27 insertions(+), 11 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c index 98a94ca36bfa..ccb80a5ac828 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c @@ -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; - meta->jmp_dst = dst_meta; - dst_meta->flags |= FLAG_INSN_IS_JUMP_DST; - } + 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; + + dst_meta->flags |= FLAG_INSN_IS_JUMP_DST; + meta->jmp_dst = dst_meta; } } diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h index 853a5346378c..20a98ce4b345 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/main.h +++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h @@ -262,7 +262,8 @@ struct nfp_bpf_reg_state { bool var_off; }; -#define FLAG_INSN_IS_JUMP_DST BIT(0) +#define FLAG_INSN_IS_JUMP_DST BIT(0) +#define FLAG_INSN_IS_SUBPROG_START BIT(1) /** * struct nfp_insn_meta - BPF instruction wrapper -- 2.39.5