rv: Fully convert enabled_monitors to use list_head as iterator

JIRA: https://issues.redhat.com/browse/RHEL-114754

commit 103541e
Author: Nam Cao <namcao@linutronix.de>
Date:   Thu Oct 2 08:22:35 2025 +0000

    rv: Fully convert enabled_monitors to use list_head as iterator

    The callbacks in enabled_monitors_seq_ops are inconsistent. Some treat the
    iterator as struct rv_monitor *, while others treat the iterator as struct
    list_head *.

    This causes a wrong type cast and crashes the system as reported by Nathan.

    Convert everything to use struct list_head * as iterator. This also makes
    enabled_monitors consistent with available_monitors.

    Fixes: de090d1 ("rv: Fix wrong type cast in enabled_monitors_next()")
    Reported-by: Nathan Chancellor <nathan@kernel.org>
    Closes: https://lore.kernel.org/linux-trace-kernel/20250923002004.GA2836051@ax162/
    Signed-off-by: Nam Cao <namcao@linutronix.de>
    Cc: stable@vger.kernel.org
    Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
    Link: https://lore.kernel.org/r/20251002082235.973099-1-namcao@linutronix.de
    Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>

Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>

Author: glemco

kernel/trace/rv/rv.c

@@ -501,31 +501,31 @@ static void *enabled_monitors_next(struct seq_file *m, void *p, loff_t *pos)
 
 	list_for_each_entry_continue(mon, &rv_monitors_list, list) {
 		if (mon->enabled)
-			return mon;
+			return &mon->list;
 	}
 
 	return NULL;
 }
 
 static void *enabled_monitors_start(struct seq_file *m, loff_t *pos)
 {
-	struct rv_monitor *mon;
+	struct list_head *head;
 	loff_t l;
 
 	mutex_lock(&rv_interface_lock);
 
 	if (list_empty(&rv_monitors_list))
 		return NULL;
 
-	mon = list_entry(&rv_monitors_list, struct rv_monitor, list);
+	head = &rv_monitors_list;
 
 	for (l = 0; l <= *pos; ) {
-		mon = enabled_monitors_next(m, mon, &l);
-		if (!mon)
+		head = enabled_monitors_next(m, head, &l);
+		if (!head)
 			break;
 	}
 
-	return mon;
+	return head;
 }
 
 /*