Commit fc589a3c authored by Henrique de Moraes Holschuh's avatar Henrique de Moraes Holschuh Committed by Len Brown
Browse files

ACPI: thinkpad-acpi: allow for syscall restart in sysfs handlers 



Map an mutex_lock_interruptible() error return into ERESTARTSYS, as the
only possible error from mutex_lock_interruptible is EINTR, and that will
only happen if signal_pending() causes the mutex lock attempt to abort.

This still allows signals to be delivered ASAP, which is much nicer than
just doing mutex_lock, and still shadows userspace from EINTR when
SA_RESTART is active.

Problem reported by Peter Jordan.

Signed-off-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Peter Jordan <usernetwork@gmx.info>
Cc: Richard Neill <rn214@hermes.cam.ac.uk>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent b856f5b8

drivers/misc/thinkpad_acpi.c

+16 −24
Original line number Diff line number Diff line
@@ -1342,9 +1342,8 @@ static int hotkey_read(char *p) 
		return len;

	}



	res = mutex_lock_interruptible(&hotkey_mutex);

	if (res < 0)

		return res;

	if (mutex_lock_interruptible(&hotkey_mutex))

		return -ERESTARTSYS;

	res = hotkey_get(&status, &mask);

	mutex_unlock(&hotkey_mutex);

	if (res)
@@ -1373,9 +1372,8 @@ static int hotkey_write(char *buf) 
	if (!tp_features.hotkey)

		return -ENODEV;



	res = mutex_lock_interruptible(&hotkey_mutex);

	if (res < 0)

		return res;

	if (mutex_lock_interruptible(&hotkey_mutex))

		return -ERESTARTSYS;



	res = hotkey_get(&status, &mask);

	if (res)
@@ -3768,9 +3766,8 @@ static ssize_t fan_pwm1_store(struct device *dev, 
	/* scale down from 0-255 to 0-7 */

	newlevel = (s >> 5) & 0x07;



	rc = mutex_lock_interruptible(&fan_mutex);

	if (rc < 0)

		return rc;

	if (mutex_lock_interruptible(&fan_mutex))

		return -ERESTARTSYS;



	rc = fan_get_status(&status);

	if (!rc && (status &
@@ -4020,9 +4017,8 @@ static int fan_get_status_safe(u8 *status) 
	int rc;

	u8 s;



	rc = mutex_lock_interruptible(&fan_mutex);

	if (rc < 0)

		return rc;

	if (mutex_lock_interruptible(&fan_mutex))

		return -ERESTARTSYS;

	rc = fan_get_status(&s);

	if (!rc)

		fan_update_desired_level(s);
@@ -4156,9 +4152,8 @@ static int fan_set_level_safe(int level) 
	if (!fan_control_allowed)

		return -EPERM;



	rc = mutex_lock_interruptible(&fan_mutex);

	if (rc < 0)

		return rc;

	if (mutex_lock_interruptible(&fan_mutex))

		return -ERESTARTSYS;



	if (level == TPACPI_FAN_LAST_LEVEL)

		level = fan_control_desired_level;
@@ -4179,9 +4174,8 @@ static int fan_set_enable(void) 
	if (!fan_control_allowed)

		return -EPERM;



	rc = mutex_lock_interruptible(&fan_mutex);

	if (rc < 0)

		return rc;

	if (mutex_lock_interruptible(&fan_mutex))

		return -ERESTARTSYS;



	switch (fan_control_access_mode) {

	case TPACPI_FAN_WR_ACPI_FANS:
@@ -4235,9 +4229,8 @@ static int fan_set_disable(void) 
	if (!fan_control_allowed)

		return -EPERM;



	rc = mutex_lock_interruptible(&fan_mutex);

	if (rc < 0)

		return rc;

	if (mutex_lock_interruptible(&fan_mutex))

		return -ERESTARTSYS;



	rc = 0;

	switch (fan_control_access_mode) {
@@ -4274,9 +4267,8 @@ static int fan_set_speed(int speed) 
	if (!fan_control_allowed)

		return -EPERM;



	rc = mutex_lock_interruptible(&fan_mutex);

	if (rc < 0)

		return rc;

	if (mutex_lock_interruptible(&fan_mutex))

		return -ERESTARTSYS;



	rc = 0;

	switch (fan_control_access_mode) {

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