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Diffstat (limited to 'drivers/net/ethernet/netronome/nfp/bpf/verifier.c')
-rw-r--r--drivers/net/ethernet/netronome/nfp/bpf/verifier.c693
1 files changed, 693 insertions, 0 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
new file mode 100644
index 000000000..db7e186da
--- /dev/null
+++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
@@ -0,0 +1,693 @@
+/*
+ * Copyright (C) 2016-2018 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.
+ */
+
+#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
+#include <linux/kernel.h>
+#include <linux/pkt_cls.h>
+
+#include "../nfp_app.h"
+#include "../nfp_main.h"
+#include "fw.h"
+#include "main.h"
+
+#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)
+{
+ 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 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.reg.var_off.value != imm)
+ goto exit_set_location;
+ }
+
+ location = meta->n;
+exit_set_location:
+ nfp_prog->adjust_head_location = location;
+}
+
+static bool nfp_bpf_map_update_value_ok(struct bpf_verifier_env *env)
+{
+ const struct bpf_reg_state *reg1 = cur_regs(env) + BPF_REG_1;
+ const struct bpf_reg_state *reg3 = cur_regs(env) + BPF_REG_3;
+ struct bpf_offloaded_map *offmap;
+ struct bpf_func_state *state;
+ struct nfp_bpf_map *nfp_map;
+ int off, i;
+
+ state = env->cur_state->frame[reg3->frameno];
+
+ /* We need to record each time update happens with non-zero words,
+ * in case such word is used in atomic operations.
+ * Implicitly depend on nfp_bpf_stack_arg_ok(reg3) being run before.
+ */
+
+ offmap = map_to_offmap(reg1->map_ptr);
+ nfp_map = offmap->dev_priv;
+ off = reg3->off + reg3->var_off.value;
+
+ for (i = 0; i < offmap->map.value_size; i++) {
+ struct bpf_stack_state *stack_entry;
+ unsigned int soff;
+
+ soff = -(off + i) - 1;
+ stack_entry = &state->stack[soff / BPF_REG_SIZE];
+ if (stack_entry->slot_type[soff % BPF_REG_SIZE] == STACK_ZERO)
+ continue;
+
+ if (nfp_map->use_map[i / 4].type == NFP_MAP_USE_ATOMIC_CNT) {
+ pr_vlog(env, "value at offset %d/%d may be non-zero, bpf_map_update_elem() is required to initialize atomic counters to zero to avoid offload endian issues\n",
+ i, soff);
+ return false;
+ }
+ nfp_map->use_map[i / 4].non_zero_update = 1;
+ }
+
+ return true;
+}
+
+static int
+nfp_bpf_stack_arg_ok(const char *fname, struct bpf_verifier_env *env,
+ const struct bpf_reg_state *reg,
+ struct nfp_bpf_reg_state *old_arg)
+{
+ s64 off, old_off;
+
+ if (reg->type != PTR_TO_STACK) {
+ pr_vlog(env, "%s: unsupported ptr type %d\n",
+ fname, reg->type);
+ return false;
+ }
+ if (!tnum_is_const(reg->var_off)) {
+ pr_vlog(env, "%s: variable pointer\n", fname);
+ return false;
+ }
+
+ off = reg->var_off.value + reg->off;
+ if (-off % 4) {
+ pr_vlog(env, "%s: unaligned stack pointer %lld\n", fname, -off);
+ return false;
+ }
+
+ /* Rest of the checks is only if we re-parse the same insn */
+ if (!old_arg)
+ return true;
+
+ old_off = old_arg->reg.var_off.value + old_arg->reg.off;
+ old_arg->var_off |= off != old_off;
+
+ return true;
+}
+
+static bool
+nfp_bpf_map_call_ok(const char *fname, struct bpf_verifier_env *env,
+ struct nfp_insn_meta *meta,
+ u32 helper_tgt, const struct bpf_reg_state *reg1)
+{
+ if (!helper_tgt) {
+ pr_vlog(env, "%s: not supported by FW\n", fname);
+ return false;
+ }
+
+ return true;
+}
+
+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;
+ const struct bpf_reg_state *reg3 = cur_regs(env) + BPF_REG_3;
+ struct nfp_app_bpf *bpf = nfp_prog->bpf;
+ u32 func_id = meta->insn.imm;
+
+ 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_xdp_adjust_tail:
+ if (!bpf->adjust_tail) {
+ pr_vlog(env, "adjust_tail not supported by FW\n");
+ return -EOPNOTSUPP;
+ }
+ break;
+
+ case BPF_FUNC_map_lookup_elem:
+ if (!nfp_bpf_map_call_ok("map_lookup", env, meta,
+ bpf->helpers.map_lookup, reg1) ||
+ !nfp_bpf_stack_arg_ok("map_lookup", env, reg2,
+ meta->func_id ? &meta->arg2 : NULL))
+ return -EOPNOTSUPP;
+ break;
+
+ case BPF_FUNC_map_update_elem:
+ if (!nfp_bpf_map_call_ok("map_update", env, meta,
+ bpf->helpers.map_update, reg1) ||
+ !nfp_bpf_stack_arg_ok("map_update", env, reg2,
+ meta->func_id ? &meta->arg2 : NULL) ||
+ !nfp_bpf_stack_arg_ok("map_update", env, reg3, NULL) ||
+ !nfp_bpf_map_update_value_ok(env))
+ return -EOPNOTSUPP;
+ break;
+
+ case BPF_FUNC_map_delete_elem:
+ if (!nfp_bpf_map_call_ok("map_delete", env, meta,
+ bpf->helpers.map_delete, reg1) ||
+ !nfp_bpf_stack_arg_ok("map_delete", env, reg2,
+ meta->func_id ? &meta->arg2 : NULL))
+ return -EOPNOTSUPP;
+ break;
+
+ case BPF_FUNC_get_prandom_u32:
+ if (bpf->pseudo_random)
+ break;
+ pr_vlog(env, "bpf_get_prandom_u32(): FW doesn't support random number generation\n");
+ return -EOPNOTSUPP;
+
+ case BPF_FUNC_perf_event_output:
+ BUILD_BUG_ON(NFP_BPF_SCALAR_VALUE != SCALAR_VALUE ||
+ NFP_BPF_MAP_VALUE != PTR_TO_MAP_VALUE ||
+ NFP_BPF_STACK != PTR_TO_STACK ||
+ NFP_BPF_PACKET_DATA != PTR_TO_PACKET);
+
+ if (!bpf->helpers.perf_event_output) {
+ pr_vlog(env, "event_output: not supported by FW\n");
+ return -EOPNOTSUPP;
+ }
+
+ /* Force current CPU to make sure we can report the event
+ * wherever we get the control message from FW.
+ */
+ if (reg3->var_off.mask & BPF_F_INDEX_MASK ||
+ (reg3->var_off.value & BPF_F_INDEX_MASK) !=
+ BPF_F_CURRENT_CPU) {
+ char tn_buf[48];
+
+ tnum_strn(tn_buf, sizeof(tn_buf), reg3->var_off);
+ pr_vlog(env, "event_output: must use BPF_F_CURRENT_CPU, var_off: %s\n",
+ tn_buf);
+ return -EOPNOTSUPP;
+ }
+
+ /* Save space in meta, we don't care about arguments other
+ * than 4th meta, shove it into arg1.
+ */
+ reg1 = cur_regs(env) + BPF_REG_4;
+
+ if (reg1->type != SCALAR_VALUE /* NULL ptr */ &&
+ reg1->type != PTR_TO_STACK &&
+ reg1->type != PTR_TO_MAP_VALUE &&
+ reg1->type != PTR_TO_PACKET) {
+ pr_vlog(env, "event_output: unsupported ptr type: %d\n",
+ reg1->type);
+ return -EOPNOTSUPP;
+ }
+
+ if (reg1->type == PTR_TO_STACK &&
+ !nfp_bpf_stack_arg_ok("event_output", env, reg1, NULL))
+ return -EOPNOTSUPP;
+
+ /* Warn user that on offload NFP may return success even if map
+ * is not going to accept the event, since the event output is
+ * fully async and device won't know the state of the map.
+ * There is also FW limitation on the event length.
+ *
+ * Lost events will not show up on the perf ring, driver
+ * won't see them at all. Events may also get reordered.
+ */
+ dev_warn_once(&nfp_prog->bpf->app->pf->pdev->dev,
+ "bpf: note: return codes and behavior of bpf_event_output() helper differs for offloaded programs!\n");
+ pr_vlog(env, "warning: return codes and behavior of event_output helper differ for offload!\n");
+
+ if (!meta->func_id)
+ break;
+
+ if (reg1->type != meta->arg1.type) {
+ pr_vlog(env, "event_output: ptr type changed: %d %d\n",
+ meta->arg1.type, reg1->type);
+ return -EINVAL;
+ }
+ break;
+
+ default:
+ pr_vlog(env, "unsupported function id: %d\n", func_id);
+ return -EOPNOTSUPP;
+ }
+
+ meta->func_id = func_id;
+ meta->arg1 = *reg1;
+ meta->arg2.reg = *reg2;
+
+ return 0;
+}
+
+static int
+nfp_bpf_check_exit(struct nfp_prog *nfp_prog,
+ struct bpf_verifier_env *env)
+{
+ const struct bpf_reg_state *reg0 = cur_regs(env) + BPF_REG_0;
+ u64 imm;
+
+ if (nfp_prog->type == BPF_PROG_TYPE_XDP)
+ return 0;
+
+ if (!(reg0->type == SCALAR_VALUE && tnum_is_const(reg0->var_off))) {
+ char tn_buf[48];
+
+ tnum_strn(tn_buf, sizeof(tn_buf), reg0->var_off);
+ pr_vlog(env, "unsupported exit state: %d, var_off: %s\n",
+ reg0->type, tn_buf);
+ return -EINVAL;
+ }
+
+ imm = reg0->var_off.value;
+ if (nfp_prog->type == BPF_PROG_TYPE_SCHED_CLS &&
+ imm <= TC_ACT_REDIRECT &&
+ imm != TC_ACT_SHOT && imm != TC_ACT_STOLEN &&
+ imm != TC_ACT_QUEUED) {
+ pr_vlog(env, "unsupported exit state: %d, imm: %llx\n",
+ reg0->type, imm);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int
+nfp_bpf_check_stack_access(struct nfp_prog *nfp_prog,
+ struct nfp_insn_meta *meta,
+ const struct bpf_reg_state *reg,
+ struct bpf_verifier_env *env)
+{
+ s32 old_off, new_off;
+
+ if (!tnum_is_const(reg->var_off)) {
+ pr_vlog(env, "variable ptr stack access\n");
+ return -EINVAL;
+ }
+
+ if (meta->ptr.type == NOT_INIT)
+ return 0;
+
+ old_off = meta->ptr.off + meta->ptr.var_off.value;
+ new_off = reg->off + reg->var_off.value;
+
+ meta->ptr_not_const |= old_off != new_off;
+
+ if (!meta->ptr_not_const)
+ return 0;
+
+ if (old_off % 4 == new_off % 4)
+ return 0;
+
+ pr_vlog(env, "stack access changed location was:%d is:%d\n",
+ old_off, new_off);
+ return -EINVAL;
+}
+
+static const char *nfp_bpf_map_use_name(enum nfp_bpf_map_use use)
+{
+ static const char * const names[] = {
+ [NFP_MAP_UNUSED] = "unused",
+ [NFP_MAP_USE_READ] = "read",
+ [NFP_MAP_USE_WRITE] = "write",
+ [NFP_MAP_USE_ATOMIC_CNT] = "atomic",
+ };
+
+ if (use >= ARRAY_SIZE(names) || !names[use])
+ return "unknown";
+ return names[use];
+}
+
+static int
+nfp_bpf_map_mark_used_one(struct bpf_verifier_env *env,
+ struct nfp_bpf_map *nfp_map,
+ unsigned int off, enum nfp_bpf_map_use use)
+{
+ if (nfp_map->use_map[off / 4].type != NFP_MAP_UNUSED &&
+ nfp_map->use_map[off / 4].type != use) {
+ pr_vlog(env, "map value use type conflict %s vs %s off: %u\n",
+ nfp_bpf_map_use_name(nfp_map->use_map[off / 4].type),
+ nfp_bpf_map_use_name(use), off);
+ return -EOPNOTSUPP;
+ }
+
+ if (nfp_map->use_map[off / 4].non_zero_update &&
+ use == NFP_MAP_USE_ATOMIC_CNT) {
+ pr_vlog(env, "atomic counter in map value may already be initialized to non-zero value off: %u\n",
+ off);
+ return -EOPNOTSUPP;
+ }
+
+ nfp_map->use_map[off / 4].type = use;
+
+ return 0;
+}
+
+static int
+nfp_bpf_map_mark_used(struct bpf_verifier_env *env, struct nfp_insn_meta *meta,
+ const struct bpf_reg_state *reg,
+ enum nfp_bpf_map_use use)
+{
+ struct bpf_offloaded_map *offmap;
+ struct nfp_bpf_map *nfp_map;
+ unsigned int size, off;
+ int i, err;
+
+ if (!tnum_is_const(reg->var_off)) {
+ pr_vlog(env, "map value offset is variable\n");
+ return -EOPNOTSUPP;
+ }
+
+ off = reg->var_off.value + meta->insn.off + reg->off;
+ size = BPF_LDST_BYTES(&meta->insn);
+ offmap = map_to_offmap(reg->map_ptr);
+ nfp_map = offmap->dev_priv;
+
+ if (off + size > offmap->map.value_size) {
+ pr_vlog(env, "map value access out-of-bounds\n");
+ return -EINVAL;
+ }
+
+ for (i = 0; i < size; i += 4 - (off + i) % 4) {
+ err = nfp_bpf_map_mark_used_one(env, nfp_map, off + i, use);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int
+nfp_bpf_check_ptr(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
+ struct bpf_verifier_env *env, u8 reg_no)
+{
+ const struct bpf_reg_state *reg = cur_regs(env) + reg_no;
+ int err;
+
+ if (reg->type != PTR_TO_CTX &&
+ reg->type != PTR_TO_STACK &&
+ reg->type != PTR_TO_MAP_VALUE &&
+ reg->type != PTR_TO_PACKET) {
+ 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, env);
+ if (err)
+ return err;
+ }
+
+ if (reg->type == PTR_TO_MAP_VALUE) {
+ if (is_mbpf_load(meta)) {
+ err = nfp_bpf_map_mark_used(env, meta, reg,
+ NFP_MAP_USE_READ);
+ if (err)
+ return err;
+ }
+ if (is_mbpf_store(meta)) {
+ pr_vlog(env, "map writes not supported\n");
+ return -EOPNOTSUPP;
+ }
+ if (is_mbpf_xadd(meta)) {
+ err = nfp_bpf_map_mark_used(env, meta, reg,
+ NFP_MAP_USE_ATOMIC_CNT);
+ if (err)
+ return err;
+ }
+ }
+
+ if (meta->ptr.type != NOT_INIT && meta->ptr.type != reg->type) {
+ pr_vlog(env, "ptr type changed for instruction %d -> %d\n",
+ meta->ptr.type, reg->type);
+ return -EINVAL;
+ }
+
+ meta->ptr = *reg;
+
+ return 0;
+}
+
+static int
+nfp_bpf_check_store(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
+ struct bpf_verifier_env *env)
+{
+ const struct bpf_reg_state *reg = cur_regs(env) + meta->insn.dst_reg;
+
+ if (reg->type == PTR_TO_CTX) {
+ if (nfp_prog->type == BPF_PROG_TYPE_XDP) {
+ /* XDP ctx accesses must be 4B in size */
+ switch (meta->insn.off) {
+ case offsetof(struct xdp_md, rx_queue_index):
+ if (nfp_prog->bpf->queue_select)
+ goto exit_check_ptr;
+ pr_vlog(env, "queue selection not supported by FW\n");
+ return -EOPNOTSUPP;
+ }
+ }
+ pr_vlog(env, "unsupported store to context field\n");
+ return -EOPNOTSUPP;
+ }
+exit_check_ptr:
+ return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.dst_reg);
+}
+
+static int
+nfp_bpf_check_xadd(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
+ struct bpf_verifier_env *env)
+{
+ const struct bpf_reg_state *sreg = cur_regs(env) + meta->insn.src_reg;
+ const struct bpf_reg_state *dreg = cur_regs(env) + meta->insn.dst_reg;
+
+ if (dreg->type != PTR_TO_MAP_VALUE) {
+ pr_vlog(env, "atomic add not to a map value pointer: %d\n",
+ dreg->type);
+ return -EOPNOTSUPP;
+ }
+ if (sreg->type != SCALAR_VALUE) {
+ pr_vlog(env, "atomic add not of a scalar: %d\n", sreg->type);
+ return -EOPNOTSUPP;
+ }
+
+ meta->xadd_over_16bit |=
+ sreg->var_off.value > 0xffff || sreg->var_off.mask > 0xffff;
+ meta->xadd_maybe_16bit |=
+ (sreg->var_off.value & ~sreg->var_off.mask) <= 0xffff;
+
+ return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.dst_reg);
+}
+
+static int
+nfp_bpf_check_alu(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
+ struct bpf_verifier_env *env)
+{
+ const struct bpf_reg_state *sreg =
+ cur_regs(env) + meta->insn.src_reg;
+ const struct bpf_reg_state *dreg =
+ cur_regs(env) + meta->insn.dst_reg;
+
+ meta->umin_src = min(meta->umin_src, sreg->umin_value);
+ meta->umax_src = max(meta->umax_src, sreg->umax_value);
+ meta->umin_dst = min(meta->umin_dst, dreg->umin_value);
+ meta->umax_dst = max(meta->umax_dst, dreg->umax_value);
+
+ /* NFP supports u16 and u32 multiplication.
+ *
+ * For ALU64, if either operand is beyond u32's value range, we reject
+ * it. One thing to note, if the source operand is BPF_K, then we need
+ * to check "imm" field directly, and we'd reject it if it is negative.
+ * Because for ALU64, "imm" (with s32 type) is expected to be sign
+ * extended to s64 which NFP mul doesn't support.
+ *
+ * For ALU32, it is fine for "imm" be negative though, because the
+ * result is 32-bits and there is no difference on the low halve of
+ * the result for signed/unsigned mul, so we will get correct result.
+ */
+ if (is_mbpf_mul(meta)) {
+ if (meta->umax_dst > U32_MAX) {
+ pr_vlog(env, "multiplier is not within u32 value range\n");
+ return -EINVAL;
+ }
+ if (mbpf_src(meta) == BPF_X && meta->umax_src > U32_MAX) {
+ pr_vlog(env, "multiplicand is not within u32 value range\n");
+ return -EINVAL;
+ }
+ if (mbpf_class(meta) == BPF_ALU64 &&
+ mbpf_src(meta) == BPF_K && meta->insn.imm < 0) {
+ pr_vlog(env, "sign extended multiplicand won't be within u32 value range\n");
+ return -EINVAL;
+ }
+ }
+
+ /* NFP doesn't have divide instructions, we support divide by constant
+ * through reciprocal multiplication. Given NFP support multiplication
+ * no bigger than u32, we'd require divisor and dividend no bigger than
+ * that as well.
+ *
+ * Also eBPF doesn't support signed divide and has enforced this on C
+ * language level by failing compilation. However LLVM assembler hasn't
+ * enforced this, so it is possible for negative constant to leak in as
+ * a BPF_K operand through assembly code, we reject such cases as well.
+ */
+ if (is_mbpf_div(meta)) {
+ if (meta->umax_dst > U32_MAX) {
+ pr_vlog(env, "dividend is not within u32 value range\n");
+ return -EINVAL;
+ }
+ if (mbpf_src(meta) == BPF_X) {
+ if (meta->umin_src != meta->umax_src) {
+ pr_vlog(env, "divisor is not constant\n");
+ return -EINVAL;
+ }
+ if (meta->umax_src > U32_MAX) {
+ pr_vlog(env, "divisor is not within u32 value range\n");
+ return -EINVAL;
+ }
+ }
+ if (mbpf_src(meta) == BPF_K && meta->insn.imm < 0) {
+ pr_vlog(env, "divide by negative constant is not supported\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static int
+nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx)
+{
+ struct nfp_prog *nfp_prog = env->prog->aux->offload->dev_priv;
+ struct nfp_insn_meta *meta = nfp_prog->verifier_meta;
+
+ 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_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 (is_mbpf_load(meta))
+ return nfp_bpf_check_ptr(nfp_prog, meta, env,
+ meta->insn.src_reg);
+ if (is_mbpf_store(meta))
+ return nfp_bpf_check_store(nfp_prog, meta, env);
+
+ if (is_mbpf_xadd(meta))
+ return nfp_bpf_check_xadd(nfp_prog, meta, env);
+
+ if (is_mbpf_alu(meta))
+ return nfp_bpf_check_alu(nfp_prog, meta, env);
+
+ return 0;
+}
+
+const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops = {
+ .insn_hook = nfp_verify_insn,
+};