bpf: Fix a warning message in mark_ptr_not_null_reg()

The WARN_ON() argument is a condition, not an error message.  So this
code will print a stack trace but will not print the warning message.
Fix that and also change it to only WARN_ONCE().

Fixes: 4ddb74165ae5 ("bpf: Extract nullable reg type conversion into a helper function")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/YCzJlV3hnF%2Ft1Pk4@mwanda

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1dda9d81f12c5e8ef3bbc7327ebe51f305b6e67a..3d34ba492d461f20f9a17afee016e069c9d55d6d 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1120,7 +1120,7 @@ static void mark_ptr_not_null_reg(struct bpf_reg_state *reg)
                reg->type = PTR_TO_RDWR_BUF;
                break;
        default:
-               WARN_ON("unknown nullable register type");
+               WARN_ONCE(1, "unknown nullable register type");
        }
 }