dynamic_debug: early return if _ddebug table is empty

If _ddebug table is empty (in a CONFIG_DYNAMIC_DEBUG build this
shouldn't happen), then warn (error?) and return early.  This skips
empty table scan and parsing of setup-string, including the pr_info
call noting the parse.  By inspection, copy return-code handling from
1st ddebug_add_module() callsite to 2nd.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 20 insertions, 15 deletions

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 5a7bacc2e901..4be55d8d76b8 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -871,23 +871,28 @@ static int __init dynamic_debug_init(void)
         int ret = 0;
         int n = 0;
 
-        if (__start___verbose != __stop___verbose) {
-                iter = __start___verbose;
-                modname = iter->modname;
-                iter_start = iter;
-                for (; iter < __stop___verbose; iter++) {
-                        if (strcmp(modname, iter->modname)) {
-                                ret = ddebug_add_module(iter_start, n, modname);
-                                if (ret)
-                                        goto out_free;
-                                n = 0;
-                                modname = iter->modname;
-                                iter_start = iter;
-                        }
-                        n++;
+        if (__start___verbose == __stop___verbose) {
+                pr_warn("_ddebug table is empty in a "
+                        "CONFIG_DYNAMIC_DEBUG build");
+                return 1;
+        }
+        iter = __start___verbose;
+        modname = iter->modname;
+        iter_start = iter;
+        for (; iter < __stop___verbose; iter++) {
+                if (strcmp(modname, iter->modname)) {
+                        ret = ddebug_add_module(iter_start, n, modname);
+                        if (ret)
+                                goto out_free;
+                        n = 0;
+                        modname = iter->modname;
+                        iter_start = iter;
                 }
-                ret = ddebug_add_module(iter_start, n, modname);
+                n++;
         }
+        ret = ddebug_add_module(iter_start, n, modname);
+        if (ret)
+                goto out_free;
 
         /* ddebug_query boot param got passed -> set it up */
         if (ddebug_setup_string[0] != '\0') {