bpf: Simplify ptr_min_max_vals adjustment

An upcoming commit will add another two pointer types that need very
similar behaviour, so generalise this function now.

Signed-off-by: Joe Stringer <joe@wand.net.nz>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 10 insertions, 12 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 9c82d8f58085..abf567200574 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2669,20 +2669,18 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
                 return -EACCES;
         }
 
-        if (ptr_reg->type == PTR_TO_MAP_VALUE_OR_NULL) {
-                verbose(env, "R%d pointer arithmetic on PTR_TO_MAP_VALUE_OR_NULL prohibited, null-check it first\n",
-                        dst);
-                return -EACCES;
-        }
-        if (ptr_reg->type == CONST_PTR_TO_MAP) {
-                verbose(env, "R%d pointer arithmetic on CONST_PTR_TO_MAP prohibited\n",
-                        dst);
+        switch (ptr_reg->type) {
+        case PTR_TO_MAP_VALUE_OR_NULL:
+                verbose(env, "R%d pointer arithmetic on %s prohibited, null-check it first\n",
+                        dst, reg_type_str[ptr_reg->type]);
                 return -EACCES;
-        }
-        if (ptr_reg->type == PTR_TO_PACKET_END) {
-                verbose(env, "R%d pointer arithmetic on PTR_TO_PACKET_END prohibited\n",
-                        dst);
+        case CONST_PTR_TO_MAP:
+        case PTR_TO_PACKET_END:
+                verbose(env, "R%d pointer arithmetic on %s prohibited\n",
+                        dst, reg_type_str[ptr_reg->type]);
                 return -EACCES;
+        default:
+                break;
         }
 
         /* In case of 'scalar += pointer', dst_reg inherits pointer type and id.