[PATCH bpf-next 06/14] nfp: bpf: add helper for basic map call checks

[Jakub Kicinski]

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

Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Reviewed-by: Quentin Monnet <quentin.mon...@netronome.com>
Reviewed-by: Jiong Wang <jiong.w...@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 40 ++++++++++++++---------
 1 file 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);
-- 
2.16.2