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Commit 9090589d authored by Shaohua Li's avatar Shaohua Li Committed by Len Brown
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ACPI: convert acpi_device_lock spinlock to mutex 



Convert acpi_device_lock to a mutex to avoid
a potential race upon access to /proc/acpi/wakeup

Delete the lock entirely in wakeup.c
since it is not necessary (and can not sleep)

Found-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent d508afb4

drivers/acpi/proc.c

+4 −9
Original line number Diff line number Diff line
@@ -343,9 +343,6 @@ acpi_system_write_alarm(struct file *file, 
}

#endif				/* HAVE_ACPI_LEGACY_ALARM */



extern struct list_head acpi_wakeup_device_list;

extern spinlock_t acpi_device_lock;



static int

acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)

{
@@ -353,7 +350,7 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) 


	seq_printf(seq, "Device\tS-state\t  Status   Sysfs node\n");



	spin_lock(&acpi_device_lock);

	mutex_lock(&acpi_device_lock);

	list_for_each_safe(node, next, &acpi_wakeup_device_list) {

		struct acpi_device *dev =

		    container_of(node, struct acpi_device, wakeup_list);
@@ -361,7 +358,6 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) 


		if (!dev->wakeup.flags.valid)

			continue;

		spin_unlock(&acpi_device_lock);



		ldev = acpi_get_physical_device(dev->handle);

		seq_printf(seq, "%s\t  S%d\t%c%-8s  ",
@@ -376,9 +372,8 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) 
		seq_printf(seq, "\n");

		put_device(ldev);



		spin_lock(&acpi_device_lock);

	}

	spin_unlock(&acpi_device_lock);

	mutex_unlock(&acpi_device_lock);

	return 0;

}
@@ -409,7 +404,7 @@ acpi_system_write_wakeup_device(struct file *file, 
	strbuf[len] = '\0';

	sscanf(strbuf, "%s", str);



	spin_lock(&acpi_device_lock);

	mutex_lock(&acpi_device_lock);

	list_for_each_safe(node, next, &acpi_wakeup_device_list) {

		struct acpi_device *dev =

		    container_of(node, struct acpi_device, wakeup_list);
@@ -446,7 +441,7 @@ acpi_system_write_wakeup_device(struct file *file, 
			}

		}

	}

	spin_unlock(&acpi_device_lock);

	mutex_unlock(&acpi_device_lock);

	return count;

}

drivers/acpi/scan.c

+7 −7
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ extern struct acpi_device *acpi_root; 


static LIST_HEAD(acpi_device_list);

static LIST_HEAD(acpi_bus_id_list);

DEFINE_SPINLOCK(acpi_device_lock);

DEFINE_MUTEX(acpi_device_lock);

LIST_HEAD(acpi_wakeup_device_list);



struct acpi_device_bus_id{
@@ -500,7 +500,7 @@ static int acpi_device_register(struct acpi_device *device, 
		return -ENOMEM;

	}



	spin_lock(&acpi_device_lock);

	mutex_lock(&acpi_device_lock);

	/*

	 * Find suitable bus_id and instance number in acpi_bus_id_list

	 * If failed, create one and link it into acpi_bus_id_list
@@ -528,7 +528,7 @@ static int acpi_device_register(struct acpi_device *device, 
		list_add_tail(&device->g_list, &acpi_device_list);

	if (device->wakeup.flags.valid)

		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);

	spin_unlock(&acpi_device_lock);

	mutex_unlock(&acpi_device_lock);



	if (device->parent)

		device->dev.parent = &parent->dev;
@@ -549,20 +549,20 @@ static int acpi_device_register(struct acpi_device *device, 
	device->removal_type = ACPI_BUS_REMOVAL_NORMAL;

	return 0;

  end:

	spin_lock(&acpi_device_lock);

	mutex_lock(&acpi_device_lock);

	if (device->parent) {

		list_del(&device->node);

		list_del(&device->g_list);

	} else

		list_del(&device->g_list);

	list_del(&device->wakeup_list);

	spin_unlock(&acpi_device_lock);

	mutex_unlock(&acpi_device_lock);

	return result;

}



static void acpi_device_unregister(struct acpi_device *device, int type)

{

	spin_lock(&acpi_device_lock);

	mutex_lock(&acpi_device_lock);

	if (device->parent) {

		list_del(&device->node);

		list_del(&device->g_list);
@@ -570,7 +570,7 @@ static void acpi_device_unregister(struct acpi_device *device, int type) 
		list_del(&device->g_list);



	list_del(&device->wakeup_list);

	spin_unlock(&acpi_device_lock);

	mutex_unlock(&acpi_device_lock);



	acpi_detach_data(device->handle, acpi_bus_data_handler);

drivers/acpi/sleep.h

+3 −0
Original line number Diff line number Diff line
@@ -5,3 +5,6 @@ extern int acpi_suspend (u32 state); 
extern void acpi_enable_wakeup_device_prep(u8 sleep_state);

extern void acpi_enable_wakeup_device(u8 sleep_state);

extern void acpi_disable_wakeup_device(u8 sleep_state);



extern struct list_head acpi_wakeup_device_list;

extern struct mutex acpi_device_lock;

drivers/acpi/wakeup.c

+7 −23
Original line number Diff line number Diff line
@@ -12,12 +12,14 @@ 
#include "internal.h"

#include "sleep.h"



/*

 * We didn't lock acpi_device_lock in the file, because it invokes oops in

 * suspend/resume and isn't really required as this is called in S-state. At

 * that time, there is no device hotplug

 **/

#define _COMPONENT		ACPI_SYSTEM_COMPONENT

ACPI_MODULE_NAME("wakeup_devices")



extern struct list_head acpi_wakeup_device_list;

extern spinlock_t acpi_device_lock;



/**

 * acpi_enable_wakeup_device_prep - prepare wakeup devices

 *	@sleep_state:	ACPI state
@@ -29,7 +31,6 @@ void acpi_enable_wakeup_device_prep(u8 sleep_state) 
{

	struct list_head *node, *next;



	spin_lock(&acpi_device_lock);

	list_for_each_safe(node, next, &acpi_wakeup_device_list) {

		struct acpi_device *dev = container_of(node,

						       struct acpi_device,
@@ -40,11 +41,8 @@ void acpi_enable_wakeup_device_prep(u8 sleep_state) 
		    (sleep_state > (u32) dev->wakeup.sleep_state))

			continue;



		spin_unlock(&acpi_device_lock);

		acpi_enable_wakeup_device_power(dev, sleep_state);

		spin_lock(&acpi_device_lock);

	}

	spin_unlock(&acpi_device_lock);

}



/**
@@ -60,7 +58,6 @@ void acpi_enable_wakeup_device(u8 sleep_state) 
	 * Caution: this routine must be invoked when interrupt is disabled 

	 * Refer ACPI2.0: P212

	 */

	spin_lock(&acpi_device_lock);

	list_for_each_safe(node, next, &acpi_wakeup_device_list) {

		struct acpi_device *dev =

			container_of(node, struct acpi_device, wakeup_list);
@@ -74,22 +71,17 @@ void acpi_enable_wakeup_device(u8 sleep_state) 
		if ((!dev->wakeup.state.enabled && !dev->wakeup.flags.prepared)

		    || sleep_state > (u32) dev->wakeup.sleep_state) {

			if (dev->wakeup.flags.run_wake) {

				spin_unlock(&acpi_device_lock);

				/* set_gpe_type will disable GPE, leave it like that */

				acpi_set_gpe_type(dev->wakeup.gpe_device,

						  dev->wakeup.gpe_number,

						  ACPI_GPE_TYPE_RUNTIME);

				spin_lock(&acpi_device_lock);

			}

			continue;

		}

		spin_unlock(&acpi_device_lock);

		if (!dev->wakeup.flags.run_wake)

			acpi_enable_gpe(dev->wakeup.gpe_device,

					dev->wakeup.gpe_number);

		spin_lock(&acpi_device_lock);

	}

	spin_unlock(&acpi_device_lock);

}



/**
@@ -101,7 +93,6 @@ void acpi_disable_wakeup_device(u8 sleep_state) 
{

	struct list_head *node, *next;



	spin_lock(&acpi_device_lock);

	list_for_each_safe(node, next, &acpi_wakeup_device_list) {

		struct acpi_device *dev =

			container_of(node, struct acpi_device, wakeup_list);
@@ -112,19 +103,16 @@ void acpi_disable_wakeup_device(u8 sleep_state) 
		if ((!dev->wakeup.state.enabled && !dev->wakeup.flags.prepared)

		    || sleep_state > (u32) dev->wakeup.sleep_state) {

			if (dev->wakeup.flags.run_wake) {

				spin_unlock(&acpi_device_lock);

				acpi_set_gpe_type(dev->wakeup.gpe_device,

						  dev->wakeup.gpe_number,

						  ACPI_GPE_TYPE_WAKE_RUN);

				/* Re-enable it, since set_gpe_type will disable it */

				acpi_enable_gpe(dev->wakeup.gpe_device,

						dev->wakeup.gpe_number);

				spin_lock(&acpi_device_lock);

			}

			continue;

		}



		spin_unlock(&acpi_device_lock);

		acpi_disable_wakeup_device_power(dev);

		/* Never disable run-wake GPE */

		if (!dev->wakeup.flags.run_wake) {
@@ -133,16 +121,14 @@ void acpi_disable_wakeup_device(u8 sleep_state) 
			acpi_clear_gpe(dev->wakeup.gpe_device,

				       dev->wakeup.gpe_number, ACPI_NOT_ISR);

		}

		spin_lock(&acpi_device_lock);

	}

	spin_unlock(&acpi_device_lock);

}



int __init acpi_wakeup_device_init(void)

{

	struct list_head *node, *next;



	spin_lock(&acpi_device_lock);

	mutex_lock(&acpi_device_lock);

	list_for_each_safe(node, next, &acpi_wakeup_device_list) {

		struct acpi_device *dev = container_of(node,

						       struct acpi_device,
@@ -150,15 +136,13 @@ int __init acpi_wakeup_device_init(void) 
		/* In case user doesn't load button driver */

		if (!dev->wakeup.flags.run_wake || dev->wakeup.state.enabled)

			continue;

		spin_unlock(&acpi_device_lock);

		acpi_set_gpe_type(dev->wakeup.gpe_device,

				  dev->wakeup.gpe_number,

				  ACPI_GPE_TYPE_WAKE_RUN);

		acpi_enable_gpe(dev->wakeup.gpe_device,

				dev->wakeup.gpe_number);

		dev->wakeup.state.enabled = 1;

		spin_lock(&acpi_device_lock);

	}

	spin_unlock(&acpi_device_lock);

	mutex_unlock(&acpi_device_lock);

	return 0;

}