[lm-sensors] [PATCH] applesmc: Expose Operating System Key in AppleSMC

Alexander Graf agraf at suse.de
Mon Oct 6 20:41:17 CEST 2008


The AppleSMC is used for various tasks. It allows control over fans,
the backlight, invokes the acceleration interrupt and stores a key,
that is used to decrypt binaries on Mac OS X.

This key is necessary to receive when virtualizing Mac OS X, but
may not be distributed due to copyright restrictions.

This patch makes reading this key easy by exporting it via sysfs.

Signed-off-by: Alexander Graf <agraf at suse.de>
Cc: Nicolas Boichat <nicolas at boichat.ch>
Cc: Jean Delvare <khali at linux-fr.org>
Cc: René Rebe <rene at exactcode.de>
---
 drivers/hwmon/applesmc.c |   34 ++++++++++++++++++++++++++++++++++
 1 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
index b06b8e0..655e217 100644
--- a/drivers/hwmon/applesmc.c
+++ b/drivers/hwmon/applesmc.c
@@ -61,6 +61,9 @@
 #define LIGHT_SENSOR_RIGHT_KEY	"ALV1" /* r-o {alv (6 bytes) */
 #define BACKLIGHT_KEY		"LKSB" /* w-o {lkb (2 bytes) */
 
+#define OSK0_KEY		"OSK0" /* r-o ascii (32 bytes) */
+#define OSK1_KEY		"OSK1" /* r-o ascii (32 bytes) */
+
 #define CLAMSHELL_KEY		"MSLD" /* r-o ui8 (unused) */
 
 #define MOTION_SENSOR_X_KEY	"MO_X" /* r-o sp78 (2 bytes) */
@@ -548,6 +551,31 @@ out:
 		return snprintf(sysfsbuf, PAGE_SIZE, "(%d,%d)\n", left, right);
 }
 
+static ssize_t applesmc_osk_show(struct device *dev,
+				struct device_attribute *attr, char *sysfsbuf)
+{
+	int ret;
+	u8 osk0[33];
+	u8 osk1[33];
+
+	osk0[32] = '\0';
+	osk1[32] = '\0';
+
+	mutex_lock(&applesmc_lock);
+
+	ret = applesmc_read_key(OSK0_KEY, osk0, 32);
+	if (ret)
+		goto out;
+	ret = applesmc_read_key(OSK1_KEY, osk1, 32);
+
+out:
+	mutex_unlock(&applesmc_lock);
+	if (ret)
+		return ret;
+	else
+		return snprintf(sysfsbuf, PAGE_SIZE, "%s%s\n", osk0, osk1);
+}
+
 /* Displays degree Celsius * 1000 */
 static ssize_t applesmc_show_temperature(struct device *dev,
 			struct device_attribute *devattr, char *sysfsbuf)
@@ -935,6 +963,7 @@ static const struct attribute_group accelerometer_attributes_group =
 	{ .attrs = accelerometer_attributes };
 
 static DEVICE_ATTR(light, 0444, applesmc_light_show, NULL);
+static DEVICE_ATTR(osk, 0444, applesmc_osk_show, NULL);
 
 static DEVICE_ATTR(key_count, 0444, applesmc_key_count_show, NULL);
 static DEVICE_ATTR(key_at_index, 0644,
@@ -1386,6 +1415,10 @@ static int __init applesmc_init(void)
 			goto out_light_wq;
 	}
 
+	ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_osk.attr);
+	if (ret)
+		goto out_osk;
+
 	hwmon_dev = hwmon_device_register(&pdev->dev);
 	if (IS_ERR(hwmon_dev)) {
 		ret = PTR_ERR(hwmon_dev);
@@ -1397,6 +1430,7 @@ static int __init applesmc_init(void)
 	return 0;
 
 out_light_ledclass:
+out_osk:
 	if (applesmc_light)
 		led_classdev_unregister(&applesmc_backlight);
 out_light_wq:
-- 
1.5.6





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