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-rw-r--r--kernel/kmod.c67
1 files changed, 29 insertions, 38 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 2456d1a0befb..3d3c3ea3a023 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -113,7 +113,7 @@ int request_module(const char *fmt, ...)
113 return ret; 113 return ret;
114} 114}
115EXPORT_SYMBOL(request_module); 115EXPORT_SYMBOL(request_module);
116#endif /* CONFIG_KMOD */ 116#endif /* CONFIG_MODULES */
117 117
118struct subprocess_info { 118struct subprocess_info {
119 struct work_struct work; 119 struct work_struct work;
@@ -265,7 +265,7 @@ static void __call_usermodehelper(struct work_struct *work)
265 } 265 }
266} 266}
267 267
268#ifdef CONFIG_PM 268#ifdef CONFIG_PM_SLEEP
269/* 269/*
270 * If set, call_usermodehelper_exec() will exit immediately returning -EBUSY 270 * If set, call_usermodehelper_exec() will exit immediately returning -EBUSY
271 * (used for preventing user land processes from being created after the user 271 * (used for preventing user land processes from being created after the user
@@ -288,39 +288,37 @@ static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
288 */ 288 */
289#define RUNNING_HELPERS_TIMEOUT (5 * HZ) 289#define RUNNING_HELPERS_TIMEOUT (5 * HZ)
290 290
291static int usermodehelper_pm_callback(struct notifier_block *nfb, 291/**
292 unsigned long action, 292 * usermodehelper_disable - prevent new helpers from being started
293 void *ignored) 293 */
294int usermodehelper_disable(void)
294{ 295{
295 long retval; 296 long retval;
296 297
297 switch (action) { 298 usermodehelper_disabled = 1;
298 case PM_HIBERNATION_PREPARE: 299 smp_mb();
299 case PM_SUSPEND_PREPARE: 300 /*
300 usermodehelper_disabled = 1; 301 * From now on call_usermodehelper_exec() won't start any new
301 smp_mb(); 302 * helpers, so it is sufficient if running_helpers turns out to
302 /* 303 * be zero at one point (it may be increased later, but that
303 * From now on call_usermodehelper_exec() won't start any new 304 * doesn't matter).
304 * helpers, so it is sufficient if running_helpers turns out to 305 */
305 * be zero at one point (it may be increased later, but that 306 retval = wait_event_timeout(running_helpers_waitq,
306 * doesn't matter).
307 */
308 retval = wait_event_timeout(running_helpers_waitq,
309 atomic_read(&running_helpers) == 0, 307 atomic_read(&running_helpers) == 0,
310 RUNNING_HELPERS_TIMEOUT); 308 RUNNING_HELPERS_TIMEOUT);
311 if (retval) { 309 if (retval)
312 return NOTIFY_OK; 310 return 0;
313 } else {
314 usermodehelper_disabled = 0;
315 return NOTIFY_BAD;
316 }
317 case PM_POST_HIBERNATION:
318 case PM_POST_SUSPEND:
319 usermodehelper_disabled = 0;
320 return NOTIFY_OK;
321 }
322 311
323 return NOTIFY_DONE; 312 usermodehelper_disabled = 0;
313 return -EAGAIN;
314}
315
316/**
317 * usermodehelper_enable - allow new helpers to be started again
318 */
319void usermodehelper_enable(void)
320{
321 usermodehelper_disabled = 0;
324} 322}
325 323
326static void helper_lock(void) 324static void helper_lock(void)
@@ -334,18 +332,12 @@ static void helper_unlock(void)
334 if (atomic_dec_and_test(&running_helpers)) 332 if (atomic_dec_and_test(&running_helpers))
335 wake_up(&running_helpers_waitq); 333 wake_up(&running_helpers_waitq);
336} 334}
337 335#else /* CONFIG_PM_SLEEP */
338static void register_pm_notifier_callback(void)
339{
340 pm_notifier(usermodehelper_pm_callback, 0);
341}
342#else /* CONFIG_PM */
343#define usermodehelper_disabled 0 336#define usermodehelper_disabled 0
344 337
345static inline void helper_lock(void) {} 338static inline void helper_lock(void) {}
346static inline void helper_unlock(void) {} 339static inline void helper_unlock(void) {}
347static inline void register_pm_notifier_callback(void) {} 340#endif /* CONFIG_PM_SLEEP */
348#endif /* CONFIG_PM */
349 341
350/** 342/**
351 * call_usermodehelper_setup - prepare to call a usermode helper 343 * call_usermodehelper_setup - prepare to call a usermode helper
@@ -515,5 +507,4 @@ void __init usermodehelper_init(void)
515{ 507{
516 khelper_wq = create_singlethread_workqueue("khelper"); 508 khelper_wq = create_singlethread_workqueue("khelper");
517 BUG_ON(!khelper_wq); 509 BUG_ON(!khelper_wq);
518 register_pm_notifier_callback();
519} 510}