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authorMandeep Singh Baines <msb@chromium.org>2013-02-27 17:03:18 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-27 19:10:11 -0800
commit6aa9707099c4b25700940eb3d016f16c4434360d (patch)
tree6996f5789a3c0a09eea2fe57d318c1d387c24f3a /include/linux
parentc2c1b089b44b783bd50fae4bccaa6f367f92e492 (diff)
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>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/debug_locks.h4
-rw-r--r--include/linux/freezer.h3
2 files changed, 5 insertions, 2 deletions
diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h
index 3bd46f766751..a975de1ff59f 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/include/linux/freezer.h b/include/linux/freezer.h
index e70df40d84f6..043a5cf8b5ba 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -3,6 +3,7 @@
#ifndef FREEZER_H_INCLUDED
#define FREEZER_H_INCLUDED
+#include <linux/debug_locks.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/atomic.h>
@@ -48,6 +49,8 @@ extern void thaw_kernel_threads(void);
static inline bool try_to_freeze(void)
{
+ if (!(current->flags & PF_NOFREEZE))
+ debug_check_no_locks_held();
might_sleep();
if (likely(!freezing(current)))
return false;