lockdep: remove task argument from debug_check_no_locks_held

The only existing caller to debug_check_no_locks_held calls it
with 'current' as the task, and the freezer needs to call
debug_check_no_locks_held but doesn't already have a current
task pointer, so remove the argument.  It is already assuming
that the current task is relevant by dumping the current stack
trace as part of the warning.

This was originally part of 6aa9707099c (lockdep: check that
no locks held at freeze time) which was reverted in
dbf520a9d7d4.

Original-author: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 11 insertions, 12 deletions

diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h
index 21ca773f77bf..822c1354f3a6 100644
--- a/include/linux/debug_locks.h
+++ b/include/linux/debug_locks.h
@@ -51,7 +51,7 @@ struct task_struct;
 extern void debug_show_all_locks(void);
 extern void debug_show_held_locks(struct task_struct *task);
 extern void debug_check_no_locks_freed(const void *from, unsigned long len);
-extern void debug_check_no_locks_held(struct task_struct *task);
+extern void debug_check_no_locks_held(void);
 #else
 static inline void debug_show_all_locks(void)
 {
@@ -67,7 +67,7 @@ debug_check_no_locks_freed(const void *from, unsigned long len)
 }
 
 static inline void
-debug_check_no_locks_held(struct task_struct *task)
+debug_check_no_locks_held(void)
 {
 }
 #endif
diff --git a/kernel/exit.c b/kernel/exit.c
index af2eb3cbd499..e59756275000 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -835,7 +835,7 @@ void do_exit(long code)
         /*
          * Make sure we are holding no locks:
          */
-        debug_check_no_locks_held(tsk);
+        debug_check_no_locks_held();
         /*
          * We can do this unlocked here. The futex code uses this flag
          * just to verify whether the pi state cleanup has been done
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 1f3186b37fd5..e16c45b9ee77 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -4090,7 +4090,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
 }
 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;
@@ -4099,22 +4099,21 @@ static void print_held_locks_bug(struct task_struct *curr)
 
         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)
 {