From b351d164e860d1ffffdc501c32f55dd1446c385b Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 11 Oct 2007 22:11:12 +0200 Subject: [PATCH] lockdep: syscall exit check Provide a check to validate that we do not hold any locks when switching back to user-space. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- include/linux/lockdep.h | 2 ++ kernel/lockdep.c | 16 ++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 0e843bf6587..9dc46db2985 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -238,6 +238,7 @@ extern void lockdep_info(void); extern void lockdep_reset(void); extern void lockdep_reset_lock(struct lockdep_map *lock); extern void lockdep_free_key_range(void *start, unsigned long size); +extern void lockdep_sys_exit(void); extern void lockdep_off(void); extern void lockdep_on(void); @@ -317,6 +318,7 @@ static inline void lockdep_on(void) # define INIT_LOCKDEP # define lockdep_reset() do { debug_locks = 1; } while (0) # define lockdep_free_key_range(start, size) do { } while (0) +# define lockdep_sys_exit() do { } while (0) /* * The class key takes no space if lockdep is disabled: */ diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 42ae4a5ab4d..a6f1ee9c92d 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3199,3 +3199,19 @@ void debug_show_held_locks(struct task_struct *task) } EXPORT_SYMBOL_GPL(debug_show_held_locks); + +void lockdep_sys_exit(void) +{ + struct task_struct *curr = current; + + if (unlikely(curr->lockdep_depth)) { + if (!debug_locks_off()) + return; + printk("\n================================================\n"); + printk( "[ BUG: lock held when returning to user space! ]\n"); + printk( "------------------------------------------------\n"); + printk("%s/%d is leaving the kernel with locks still held!\n", + curr->comm, curr->pid); + lockdep_print_held_locks(curr); + } +}