diff options
Diffstat (limited to 'drivers/net/ethernet/netronome/nfp/bpf/verifier.c')
-rw-r--r-- | drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 159 |
1 files changed, 143 insertions, 16 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c index 8d43491ddd6b..479f602887e9 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2016 Netronome Systems, Inc. + * Copyright (C) 2016-2017 Netronome Systems, Inc. * * This software is dual licensed under the GNU General License Version 2, * June 1991 as shown in the file COPYING in the top-level directory of this @@ -31,16 +31,18 @@ * SOFTWARE. */ -#define pr_fmt(fmt) "NFP net bpf: " fmt - #include <linux/bpf.h> #include <linux/bpf_verifier.h> #include <linux/kernel.h> #include <linux/pkt_cls.h> +#include "fw.h" #include "main.h" -static struct nfp_insn_meta * +#define pr_vlog(env, fmt, ...) \ + bpf_verifier_log_write(env, "[nfp] " fmt, ##__VA_ARGS__) + +struct nfp_insn_meta * nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, unsigned int insn_idx, unsigned int n_insns) { @@ -68,6 +70,114 @@ nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, return meta; } +static void +nfp_record_adjust_head(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog, + struct nfp_insn_meta *meta, + const struct bpf_reg_state *reg2) +{ + unsigned int location = UINT_MAX; + int imm; + + /* Datapath usually can give us guarantees on how much adjust head + * can be done without the need for any checks. Optimize the simple + * case where there is only one adjust head by a constant. + */ + if (reg2->type != SCALAR_VALUE || !tnum_is_const(reg2->var_off)) + goto exit_set_location; + imm = reg2->var_off.value; + /* Translator will skip all checks, we need to guarantee min pkt len */ + if (imm > ETH_ZLEN - ETH_HLEN) + goto exit_set_location; + if (imm > (int)bpf->adjust_head.guaranteed_add || + imm < -bpf->adjust_head.guaranteed_sub) + goto exit_set_location; + + if (nfp_prog->adjust_head_location) { + /* Only one call per program allowed */ + if (nfp_prog->adjust_head_location != meta->n) + goto exit_set_location; + + if (meta->arg2.var_off.value != imm) + goto exit_set_location; + } + + location = meta->n; +exit_set_location: + nfp_prog->adjust_head_location = location; +} + +static int +nfp_bpf_check_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; + struct nfp_app_bpf *bpf = nfp_prog->bpf; + u32 func_id = meta->insn.imm; + s64 off, old_off; + + switch (func_id) { + case BPF_FUNC_xdp_adjust_head: + if (!bpf->adjust_head.off_max) { + pr_vlog(env, "adjust_head not supported by FW\n"); + return -EOPNOTSUPP; + } + if (!(bpf->adjust_head.flags & NFP_BPF_ADJUST_HEAD_NO_META)) { + pr_vlog(env, "adjust_head: FW requires shifting metadata, not supported by the driver\n"); + return -EOPNOTSUPP; + } + + nfp_record_adjust_head(bpf, nfp_prog, meta, reg2); + break; + + case BPF_FUNC_map_lookup_elem: + if (!bpf->helpers.map_lookup) { + pr_vlog(env, "map_lookup: not supported by FW\n"); + return -EOPNOTSUPP; + } + if (reg2->type != PTR_TO_STACK) { + pr_vlog(env, + "map_lookup: unsupported key ptr type %d\n", + reg2->type); + return -EOPNOTSUPP; + } + if (!tnum_is_const(reg2->var_off)) { + pr_vlog(env, "map_lookup: variable key pointer\n"); + return -EOPNOTSUPP; + } + + off = reg2->var_off.value + reg2->off; + if (-off % 4) { + pr_vlog(env, + "map_lookup: unaligned stack pointer %lld\n", + -off); + return -EOPNOTSUPP; + } + + /* Rest of the checks is only if we re-parse the same insn */ + if (!meta->func_id) + break; + + old_off = meta->arg2.var_off.value + meta->arg2.off; + meta->arg2_var_off |= off != old_off; + + if (meta->arg1.map_ptr != reg1->map_ptr) { + pr_vlog(env, "map_lookup: called for different map\n"); + return -EOPNOTSUPP; + } + break; + default: + pr_vlog(env, "unsupported function id: %d\n", func_id); + return -EOPNOTSUPP; + } + + meta->func_id = func_id; + meta->arg1 = *reg1; + meta->arg2 = *reg2; + + return 0; +} + static int nfp_bpf_check_exit(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env) @@ -82,7 +192,7 @@ nfp_bpf_check_exit(struct nfp_prog *nfp_prog, char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg0->var_off); - pr_info("unsupported exit state: %d, var_off: %s\n", + pr_vlog(env, "unsupported exit state: %d, var_off: %s\n", reg0->type, tn_buf); return -EINVAL; } @@ -92,7 +202,7 @@ nfp_bpf_check_exit(struct nfp_prog *nfp_prog, imm <= TC_ACT_REDIRECT && imm != TC_ACT_SHOT && imm != TC_ACT_STOLEN && imm != TC_ACT_QUEUED) { - pr_info("unsupported exit state: %d, imm: %llx\n", + pr_vlog(env, "unsupported exit state: %d, imm: %llx\n", reg0->type, imm); return -EINVAL; } @@ -103,12 +213,13 @@ nfp_bpf_check_exit(struct nfp_prog *nfp_prog, static int nfp_bpf_check_stack_access(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, - const struct bpf_reg_state *reg) + const struct bpf_reg_state *reg, + struct bpf_verifier_env *env) { s32 old_off, new_off; if (!tnum_is_const(reg->var_off)) { - pr_info("variable ptr stack access\n"); + pr_vlog(env, "variable ptr stack access\n"); return -EINVAL; } @@ -126,7 +237,7 @@ nfp_bpf_check_stack_access(struct nfp_prog *nfp_prog, if (old_off % 4 == new_off % 4) return 0; - pr_info("stack access changed location was:%d is:%d\n", + pr_vlog(env, "stack access changed location was:%d is:%d\n", old_off, new_off); return -EINVAL; } @@ -140,19 +251,27 @@ nfp_bpf_check_ptr(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, if (reg->type != PTR_TO_CTX && reg->type != PTR_TO_STACK && + reg->type != PTR_TO_MAP_VALUE && reg->type != PTR_TO_PACKET) { - pr_info("unsupported ptr type: %d\n", reg->type); + pr_vlog(env, "unsupported ptr type: %d\n", reg->type); return -EINVAL; } if (reg->type == PTR_TO_STACK) { - err = nfp_bpf_check_stack_access(nfp_prog, meta, reg); + err = nfp_bpf_check_stack_access(nfp_prog, meta, reg, env); if (err) return err; } + if (reg->type == PTR_TO_MAP_VALUE) { + if (is_mbpf_store(meta)) { + pr_vlog(env, "map writes not supported\n"); + return -EOPNOTSUPP; + } + } + if (meta->ptr.type != NOT_INIT && meta->ptr.type != reg->type) { - pr_info("ptr type changed for instruction %d -> %d\n", + pr_vlog(env, "ptr type changed for instruction %d -> %d\n", meta->ptr.type, reg->type); return -EINVAL; } @@ -171,25 +290,33 @@ nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx) meta = nfp_bpf_goto_meta(nfp_prog, meta, insn_idx, env->prog->len); nfp_prog->verifier_meta = meta; + if (!nfp_bpf_supported_opcode(meta->insn.code)) { + pr_vlog(env, "instruction %#02x not supported\n", + meta->insn.code); + return -EINVAL; + } + if (meta->insn.src_reg >= MAX_BPF_REG || meta->insn.dst_reg >= MAX_BPF_REG) { - pr_err("program uses extended registers - jit hardening?\n"); + pr_vlog(env, "program uses extended registers - jit hardening?\n"); return -EINVAL; } + if (meta->insn.code == (BPF_JMP | BPF_CALL)) + return nfp_bpf_check_call(nfp_prog, env, meta); if (meta->insn.code == (BPF_JMP | BPF_EXIT)) return nfp_bpf_check_exit(nfp_prog, env); - if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM)) + if (is_mbpf_load(meta)) return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.src_reg); - if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM)) + if (is_mbpf_store(meta)) return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.dst_reg); return 0; } -const struct bpf_ext_analyzer_ops nfp_bpf_analyzer_ops = { +const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops = { .insn_hook = nfp_verify_insn, }; |