lockdep: check that no locks held at freeze time
We shouldn't try_to_freeze if locks are held. Holding a lock can cause a
deadlock if the lock is later acquired in the suspend or hibernate path
(e.g. by dpm). Holding a lock can also cause a deadlock in the case of
cgroup_freezer if a lock is held inside a frozen cgroup that is later
acquired by a process outside that group.
[akpm@linux-foundation.org: export debug_check_no_locks_held]
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Ben Chan <benchan@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 8a0efac..259db20 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -4088,7 +4088,7 @@
}
EXPORT_SYMBOL_GPL(debug_check_no_locks_freed);
-static void print_held_locks_bug(struct task_struct *curr)
+static void print_held_locks_bug(void)
{
if (!debug_locks_off())
return;
@@ -4097,22 +4097,21 @@
printk("\n");
printk("=====================================\n");
- printk("[ BUG: lock held at task exit time! ]\n");
+ printk("[ BUG: %s/%d still has locks held! ]\n",
+ current->comm, task_pid_nr(current));
print_kernel_ident();
printk("-------------------------------------\n");
- printk("%s/%d is exiting with locks still held!\n",
- curr->comm, task_pid_nr(curr));
- lockdep_print_held_locks(curr);
-
+ lockdep_print_held_locks(current);
printk("\nstack backtrace:\n");
dump_stack();
}
-void debug_check_no_locks_held(struct task_struct *task)
+void debug_check_no_locks_held(void)
{
- if (unlikely(task->lockdep_depth > 0))
- print_held_locks_bug(task);
+ if (unlikely(current->lockdep_depth > 0))
+ print_held_locks_bug();
}
+EXPORT_SYMBOL_GPL(debug_check_no_locks_held);
void debug_show_all_locks(void)
{