diff options
| author | Mandeep Singh Baines <msb@chromium.org> | 2013-02-27 17:03:18 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-27 19:10:11 -0800 |
| commit | 6aa9707099c4b25700940eb3d016f16c4434360d (patch) | |
| tree | 6996f5789a3c0a09eea2fe57d318c1d387c24f3a /include/linux | |
| parent | c2c1b089b44b783bd50fae4bccaa6f367f92e492 (diff) | |
| download | lwn-6aa9707099c4b25700940eb3d016f16c4434360d.tar.gz lwn-6aa9707099c4b25700940eb3d016f16c4434360d.zip | |
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.h | 4 | ||||
| -rw-r--r-- | include/linux/freezer.h | 3 |
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; |