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path: root/drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c
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Diffstat (limited to 'drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c')
-rw-r--r--drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c171
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c b/drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c
new file mode 100644
index 000000000000..144cae87f63a
--- /dev/null
+++ b/drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c
@@ -0,0 +1,171 @@
+/*
+ * 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;
+}
+
+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 (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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}