nfp: bpf: add helper for basic map call checks

Add a verifier helper for performing the basic state checks
before a call to a map helper.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 25 insertions, 15 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
index 45aa11fcdcad..acfc4d798116 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
@@ -139,6 +139,28 @@ nfp_bpf_stack_arg_ok(const char *fname, struct bpf_verifier_env *env,
         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;
+        }
+
+        /* Rest of the checks is only if we re-parse the same insn */
+        if (!meta->func_id)
+                return true;
+
+        if (meta->arg1.map_ptr != reg1->map_ptr) {
+                pr_vlog(env, "%s: called for different map\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)
@@ -163,23 +185,11 @@ nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env,
                 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 (!nfp_bpf_stack_arg_ok("map_lookup", env, reg2,
+                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;
-
-                /* Rest of the checks is only if we re-parse the same insn */
-                if (!meta->func_id)
-                        break;
-
-                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);