Commit 8970bfe7 authored by Andrew Morton's avatar Andrew Morton Committed by Len Brown
Browse files

ACPI: SBS: fix initialization, sem2mutex 



cm_sbs_sem is being downed (via acpi_ac_init->acpi_lock_ac_dir) before it is
initialised, with grave results.

- Make it a mutex

- Initialise it

- Make it static

- Clean other stuff up.

Thanks to Paul Drynoff <pauldrynoff@gmail.com> for reporting and testing.

Cc: Rich Townsend <rhdt@bartol.udel.edu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 953969dd

drivers/acpi/cm_sbs.c

+14 −32
Original line number Diff line number Diff line
@@ -39,50 +39,43 @@ ACPI_MODULE_NAME("cm_sbs") 
static struct proc_dir_entry *acpi_ac_dir;

static struct proc_dir_entry *acpi_battery_dir;



static struct semaphore cm_sbs_sem;

static DEFINE_MUTEX(cm_sbs_mutex);



static int lock_ac_dir_cnt = 0;

static int lock_battery_dir_cnt = 0;

static int lock_ac_dir_cnt;

static int lock_battery_dir_cnt;



struct proc_dir_entry *acpi_lock_ac_dir(void)

{



	down(&cm_sbs_sem);

	if (!acpi_ac_dir) {

	mutex_lock(&cm_sbs_mutex);

	if (!acpi_ac_dir)

		acpi_ac_dir = proc_mkdir(ACPI_AC_CLASS, acpi_root_dir);

	}

	if (acpi_ac_dir) {

		lock_ac_dir_cnt++;

	} else {

		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,

				  "Cannot create %s\n", ACPI_AC_CLASS));

	}

	up(&cm_sbs_sem);

	mutex_unlock(&cm_sbs_mutex);

	return acpi_ac_dir;

}



EXPORT_SYMBOL(acpi_lock_ac_dir);



void acpi_unlock_ac_dir(struct proc_dir_entry *acpi_ac_dir_param)

{



	down(&cm_sbs_sem);

	if (acpi_ac_dir_param) {

	mutex_lock(&cm_sbs_mutex);

	if (acpi_ac_dir_param)

		lock_ac_dir_cnt--;

	}

	if (lock_ac_dir_cnt == 0 && acpi_ac_dir_param && acpi_ac_dir) {

		remove_proc_entry(ACPI_AC_CLASS, acpi_root_dir);

		acpi_ac_dir = 0;

	}

	up(&cm_sbs_sem);

	mutex_unlock(&cm_sbs_mutex);

}



EXPORT_SYMBOL(acpi_unlock_ac_dir);



struct proc_dir_entry *acpi_lock_battery_dir(void)

{



	down(&cm_sbs_sem);

	mutex_lock(&cm_sbs_mutex);

	if (!acpi_battery_dir) {

		acpi_battery_dir =

		    proc_mkdir(ACPI_BATTERY_CLASS, acpi_root_dir);
@@ -93,39 +86,28 @@ struct proc_dir_entry *acpi_lock_battery_dir(void) 
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,

				  "Cannot create %s\n", ACPI_BATTERY_CLASS));

	}

	up(&cm_sbs_sem);

	mutex_unlock(&cm_sbs_mutex);

	return acpi_battery_dir;

}



EXPORT_SYMBOL(acpi_lock_battery_dir);



void acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir_param)

{



	down(&cm_sbs_sem);

	if (acpi_battery_dir_param) {

	mutex_lock(&cm_sbs_mutex);

	if (acpi_battery_dir_param)

		lock_battery_dir_cnt--;

	}

	if (lock_battery_dir_cnt == 0 && acpi_battery_dir_param

	    && acpi_battery_dir) {

		remove_proc_entry(ACPI_BATTERY_CLASS, acpi_root_dir);

		acpi_battery_dir = 0;

	}

	up(&cm_sbs_sem);

	mutex_unlock(&cm_sbs_mutex);

	return;

}



EXPORT_SYMBOL(acpi_unlock_battery_dir);



static int __init acpi_cm_sbs_init(void)

{



	if (acpi_disabled)

		return 0;



	init_MUTEX(&cm_sbs_sem);



	return 0;

}



subsys_initcall(acpi_cm_sbs_init);

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