kprobes: Remove remaining gotos

Remove remaining gotos from kprobes.c to clean up the code.
This does not use cleanup macros, but changes code flow for avoiding
gotos.

Link: https://lore.kernel.org/all/173371212474.480397.5684523564137819115.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 34cbbb2206f49306260bcce74d8d444fe51079f0..0305692106709bcd60d84921f7ee9217c14b6bc1 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1730,29 +1730,31 @@ static int __unregister_kprobe_top(struct kprobe *p)
        if (IS_ERR(ap))
                return PTR_ERR(ap);
 
-       if (ap == p)
-               /*
-                * This probe is an independent(and non-optimized) kprobe
-                * (not an aggrprobe). Remove from the hash list.
-                */
-               goto disarmed;
-
-       /* Following process expects this probe is an aggrprobe */
-       WARN_ON(!kprobe_aggrprobe(ap));
+       WARN_ON(ap != p && !kprobe_aggrprobe(ap));
 
-       if (list_is_singular(&ap->list) && kprobe_disarmed(ap))
+       /*
+        * If the probe is an independent(and non-optimized) kprobe
+        * (not an aggrprobe), the last kprobe on the aggrprobe, or
+        * kprobe is already disarmed, just remove from the hash list.
+        */
+       if (ap == p ||
+               (list_is_singular(&ap->list) && kprobe_disarmed(ap))) {
                /*
                 * !disarmed could be happen if the probe is under delayed
                 * unoptimizing.
                 */
-               goto disarmed;
-       else {
-               /* If disabling probe has special handlers, update aggrprobe */
-               if (p->post_handler && !kprobe_gone(p)) {
-                       list_for_each_entry(list_p, &ap->list, list) {
-                               if ((list_p != p) && (list_p->post_handler))
-                                       goto noclean;
-                       }
+               hlist_del_rcu(&ap->hlist);
+               return 0;
+       }
+
+       /* If disabling probe has special handlers, update aggrprobe */
+       if (p->post_handler && !kprobe_gone(p)) {
+               list_for_each_entry(list_p, &ap->list, list) {
+                       if ((list_p != p) && (list_p->post_handler))
+                               break;
+               }
+               /* No other probe has post_handler */
+               if (list_entry_is_head(list_p, &ap->list, list)) {
                        /*
                         * For the kprobe-on-ftrace case, we keep the
                         * post_handler setting to identify this aggrprobe
@@ -1761,24 +1763,21 @@ static int __unregister_kprobe_top(struct kprobe *p)
                        if (!kprobe_ftrace(ap))
                                ap->post_handler = NULL;
                }
-noclean:
+       }
+
+       /*
+        * Remove from the aggrprobe: this path will do nothing in
+        * __unregister_kprobe_bottom().
+        */
+       list_del_rcu(&p->list);
+       if (!kprobe_disabled(ap) && !kprobes_all_disarmed)
                /*
-                * Remove from the aggrprobe: this path will do nothing in
-                * __unregister_kprobe_bottom().
+                * Try to optimize this probe again, because post
+                * handler may have been changed.
                 */
-               list_del_rcu(&p->list);
-               if (!kprobe_disabled(ap) && !kprobes_all_disarmed)
-                       /*
-                        * Try to optimize this probe again, because post
-                        * handler may have been changed.
-                        */
-                       optimize_kprobe(ap);
-       }
+               optimize_kprobe(ap);
        return 0;
 
-disarmed:
-       hlist_del_rcu(&ap->hlist);
-       return 0;
 }
 
 static void __unregister_kprobe_bottom(struct kprobe *p)