diff options
Diffstat (limited to 'kernel/power/process.c')
| -rw-r--r-- | kernel/power/process.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/power/process.c b/kernel/power/process.c index f606d8210..1febd6b4f 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -142,6 +142,8 @@ done: /** * freeze_processes - Signal user space processes to enter the refrigerator. + * The current thread will not be frozen. The same process that calls + * freeze_processes must later call thaw_processes. * * On success, returns 0. On failure, -errno and system is fully thawed. */ @@ -154,6 +156,9 @@ int freeze_processes(void) if (error) return error; + /* Make sure this task doesn't get frozen */ + current->flags |= PF_SUSPEND_TASK; + if (!pm_freezing) atomic_inc(&system_freezing_cnt); @@ -219,6 +224,7 @@ EXPORT_SYMBOL_GPL(freeze_kernel_threads); void thaw_processes(void) { struct task_struct *g, *p; + struct task_struct *curr = current; if (pm_freezing) atomic_dec(&system_freezing_cnt); @@ -236,11 +242,16 @@ void thaw_processes(void) read_lock(&tasklist_lock); for_each_process_thread(g, p) { + /* No other threads should have PF_SUSPEND_TASK set */ + WARN_ON((p != curr) && (p->flags & PF_SUSPEND_TASK)); BUG_ON(!virt_addr_valid(next_task(g))); __thaw_task(p); } read_unlock(&tasklist_lock); + WARN_ON(!(curr->flags & PF_SUSPEND_TASK)); + curr->flags &= ~PF_SUSPEND_TASK; + usermodehelper_enable(); schedule(); |