From bcfdfb7c962d84ef07aa2b400ef1c9d70e1120e5 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Sun, 7 Oct 2018 12:56:50 +0100 Subject: [PATCH] nfp: bpf: ignore helper-related checks for BPF calls in nfp verifier The checks related to eBPF helper calls are performed each time the nfp driver meets a BPF_JUMP | BPF_CALL instruction. However, these checks are not relevant for BPF-to-BPF call (same instruction code, different value in source register), so just skip the checks for such calls. While at it, rename the function that runs those checks to make it clear they apply to _helper_ calls only. Signed-off-by: Quentin Monnet Reviewed-by: Jiong Wang Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- drivers/net/ethernet/netronome/nfp/bpf/main.h | 8 ++++++++ drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 9 +++++---- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h index 7f6e850e42da..853a5346378c 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/main.h +++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h @@ -423,6 +423,14 @@ static inline bool is_mbpf_div(const struct nfp_insn_meta *meta) return is_mbpf_alu(meta) && mbpf_op(meta) == BPF_DIV; } +static inline bool is_mbpf_helper_call(const struct nfp_insn_meta *meta) +{ + struct bpf_insn insn = meta->insn; + + return insn.code == (BPF_JMP | BPF_CALL) && + insn.src_reg != BPF_PSEUDO_CALL; +} + /** * struct nfp_bpf_subprog_info - nfp BPF sub-program (a.k.a. function) info * @stack_depth: maximum stack depth used by this sub-program diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c index 9ef74bc1ec1d..c642c2c07d96 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c @@ -155,8 +155,9 @@ nfp_bpf_map_call_ok(const char *fname, struct bpf_verifier_env *env, } static int -nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env, - struct nfp_insn_meta *meta) +nfp_bpf_check_helper_call(struct nfp_prog *nfp_prog, + struct bpf_verifier_env *env, + struct nfp_insn_meta *meta) { const struct bpf_reg_state *reg1 = cur_regs(env) + BPF_REG_1; const struct bpf_reg_state *reg2 = cur_regs(env) + BPF_REG_2; @@ -620,8 +621,8 @@ nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx) return -EINVAL; } - if (meta->insn.code == (BPF_JMP | BPF_CALL)) - return nfp_bpf_check_call(nfp_prog, env, meta); + if (is_mbpf_helper_call(meta)) + return nfp_bpf_check_helper_call(nfp_prog, env, meta); if (meta->insn.code == (BPF_JMP | BPF_EXIT)) return nfp_bpf_check_exit(nfp_prog, env); -- 2.11.0