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Release 4.11 drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c

/*
 * Copyright (C) 2016 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
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * 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 "nfp_bpf.h"

/* Analyzer/verifier definitions */

struct nfp_bpf_analyzer_priv {
	
struct nfp_prog *prog;
	
struct nfp_insn_meta *meta;
};


static 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) { unsigned int forward, backward, i; backward = meta->n - insn_idx; forward = insn_idx - meta->n; if (min(forward, backward) > n_insns - insn_idx - 1) { backward = n_insns - insn_idx - 1; meta = nfp_prog_last_meta(nfp_prog); } if (min(forward, backward) > insn_idx && backward > insn_idx) { forward = insn_idx; meta = nfp_prog_first_meta(nfp_prog); } if (forward < backward) for (i = 0; i < forward; i++) meta = nfp_meta_next(meta); else for (i = 0; i < backward; i++) meta = nfp_meta_prev(meta); return meta; }

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Jakub Kiciński160100.00%1100.00%
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static int nfp_bpf_check_exit(struct nfp_prog *nfp_prog, const struct bpf_verifier_env *env) { const struct bpf_reg_state *reg0 = &env->cur_state.regs[0]; if (nfp_prog->act == NN_ACT_XDP) return 0; if (reg0->type != CONST_IMM) { pr_info("unsupported exit state: %d, imm: %llx\n", reg0->type, reg0->imm); return -EINVAL; } if (nfp_prog->act != NN_ACT_DIRECT && reg0->imm != 0 && (reg0->imm & ~0U) != ~0U) { pr_info("unsupported exit state: %d, imm: %llx\n", reg0->type, reg0->imm); return -EINVAL; } if (nfp_prog->act == NN_ACT_DIRECT && reg0->imm <= TC_ACT_REDIRECT && reg0->imm != TC_ACT_SHOT && reg0->imm != TC_ACT_STOLEN && reg0->imm != TC_ACT_QUEUED) { pr_info("unsupported exit state: %d, imm: %llx\n", reg0->type, reg0->imm); return -EINVAL; } return 0; }

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Jakub Kiciński170100.00%3100.00%
Total170100.00%3100.00%


static int nfp_bpf_check_ctx_ptr(struct nfp_prog *nfp_prog, const struct bpf_verifier_env *env, u8 reg) { if (env->cur_state.regs[reg].type != PTR_TO_CTX) return -EINVAL; return 0; }

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Jakub Kiciński42100.00%1100.00%
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static int nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx) { struct nfp_bpf_analyzer_priv *priv = env->analyzer_priv; struct nfp_insn_meta *meta = priv->meta; meta = nfp_bpf_goto_meta(priv->prog, meta, insn_idx, env->prog->len); priv->meta = meta; if (meta->insn.src_reg == BPF_REG_10 || meta->insn.dst_reg == BPF_REG_10) { pr_err("stack not yet supported\n"); 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"); return -EINVAL; } if (meta->insn.code == (BPF_JMP | BPF_EXIT)) return nfp_bpf_check_exit(priv->prog, env); if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM)) return nfp_bpf_check_ctx_ptr(priv->prog, env, meta->insn.src_reg); if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM)) return nfp_bpf_check_ctx_ptr(priv->prog, env, meta->insn.dst_reg); return 0; }

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Jakub Kiciński215100.00%1100.00%
Total215100.00%1100.00%

static const struct bpf_ext_analyzer_ops nfp_bpf_analyzer_ops = { .insn_hook = nfp_verify_insn, };
int nfp_prog_verify(struct nfp_prog *nfp_prog, struct bpf_prog *prog) { struct nfp_bpf_analyzer_priv *priv; int ret; priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->prog = nfp_prog; priv->meta = nfp_prog_first_meta(nfp_prog); ret = bpf_analyzer(prog, &nfp_bpf_analyzer_ops, priv); kfree(priv); return ret; }

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Jakub Kiciński80100.00%1100.00%
Total80100.00%1100.00%


Overall Contributors

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Jakub Kiciński719100.00%3100.00%
Total719100.00%3100.00%
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