Avoid race in do_release_ts()

The list is concurrently being modified by the waking processes.  This
requires the use of the list_for_each_safe() iterator.

Reported by Glenn Elliott.

1 files changed, 2 insertions, 2 deletions

diff --git a/litmus/sync.c b/litmus/sync.c
index 873b3ffb2e7e..3e79e0a12a5a 100644
--- a/litmus/sync.c
+++ b/litmus/sync.c
@@ -89,7 +89,7 @@ static long do_release_ts(lt_t start)
 {
         long  task_count = 0;
 
-        struct list_head        *pos;
+        struct list_head        *pos, *safe;
         struct ts_release_wait  *wait;
 
         if (mutex_lock_interruptible(&task_release_lock)) {
@@ -101,7 +101,7 @@ static long do_release_ts(lt_t start)
         sched_trace_sys_release(&start);
 
         task_count = 0;
-        list_for_each(pos, &task_release_list) {
+        list_for_each_safe(pos, safe, &task_release_list) {
                 wait = (struct ts_release_wait*)
                         list_entry(pos, struct ts_release_wait, list);