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-rw-r--r--kernel/locking/lockdep.c70
1 files changed, 20 insertions, 50 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 0233863..edcac5d 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -561,20 +561,24 @@ static void print_lock(struct held_lock *hlock)
printk(KERN_CONT ", at: %pS\n", (void *)hlock->acquire_ip);
}
-static void lockdep_print_held_locks(struct task_struct *curr)
+static void lockdep_print_held_locks(struct task_struct *p)
{
- int i, depth = curr->lockdep_depth;
+ int i, depth = READ_ONCE(p->lockdep_depth);
- if (!depth) {
- printk("no locks held by %s/%d.\n", curr->comm, task_pid_nr(curr));
+ if (!depth)
+ printk("no locks held by %s/%d.\n", p->comm, task_pid_nr(p));
+ else
+ printk("%d lock%s held by %s/%d:\n", depth,
+ depth > 1 ? "s" : "", p->comm, task_pid_nr(p));
+ /*
+ * It's not reliable to print a task's held locks if it's not sleeping
+ * and it's not the current task.
+ */
+ if (p->state == TASK_RUNNING && p != current)
return;
- }
- printk("%d lock%s held by %s/%d:\n",
- depth, depth > 1 ? "s" : "", curr->comm, task_pid_nr(curr));
-
for (i = 0; i < depth; i++) {
printk(" #%d: ", i);
- print_lock(curr->held_locks + i);
+ print_lock(p->held_locks + i);
}
}
@@ -4451,8 +4455,6 @@ EXPORT_SYMBOL_GPL(debug_check_no_locks_held);
void debug_show_all_locks(void)
{
struct task_struct *g, *p;
- int count = 10;
- int unlock = 1;
if (unlikely(!debug_locks)) {
pr_warn("INFO: lockdep is turned off.\n");
@@ -4460,50 +4462,18 @@ void debug_show_all_locks(void)
}
pr_warn("\nShowing all locks held in the system:\n");
- /*
- * Here we try to get the tasklist_lock as hard as possible,
- * if not successful after 2 seconds we ignore it (but keep
- * trying). This is to enable a debug printout even if a
- * tasklist_lock-holding task deadlocks or crashes.
- */
-retry:
- if (!read_trylock(&tasklist_lock)) {
- if (count == 10)
- pr_warn("hm, tasklist_lock locked, retrying... ");
- if (count) {
- count--;
- pr_cont(" #%d", 10-count);
- mdelay(200);
- goto retry;
- }
- pr_cont(" ignoring it.\n");
- unlock = 0;
- } else {
- if (count != 10)
- pr_cont(" locked it.\n");
- }
-
- do_each_thread(g, p) {
- /*
- * It's not reliable to print a task's held locks
- * if it's not sleeping (or if it's not the current
- * task):
- */
- if (p->state == TASK_RUNNING && p != current)
+ rcu_read_lock();
+ for_each_process_thread(g, p) {
+ if (!p->lockdep_depth)
continue;
- if (p->lockdep_depth)
- lockdep_print_held_locks(p);
- if (!unlock)
- if (read_trylock(&tasklist_lock))
- unlock = 1;
+ lockdep_print_held_locks(p);
touch_nmi_watchdog();
- } while_each_thread(g, p);
+ touch_all_softlockup_watchdogs();
+ }
+ rcu_read_unlock();
pr_warn("\n");
pr_warn("=============================================\n\n");
-
- if (unlock)
- read_unlock(&tasklist_lock);
}
EXPORT_SYMBOL_GPL(debug_show_all_locks);
#endif
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