From: kay.sievers@vrfy.org <kay.sievers@vrfy.org>
Date: Thu, 16 Dec 2004 15:05:01 +0000 (+0100)
Subject: [PATCH] update libsysfs to CVS version and fix segfaulting attribute reading
X-Git-Tag: 050~2
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=83c35223ed164b95f53633b97846d0963c7bcea9

[PATCH] update libsysfs to CVS version and fix segfaulting attribute reading
---

diff --git a/libsysfs/sysfs_class.c b/libsysfs/sysfs_class.c
index db59aef90..a132bb64c 100644
--- a/libsysfs/sysfs_class.c
+++ b/libsysfs/sysfs_class.c
@@ -640,6 +640,9 @@ struct sysfs_attribute *sysfs_get_classdev_attr
 			return cur;
 	}
 
+	if (clsdev->directory == NULL)
+		return NULL;
+
 	if (clsdev->directory->subdirs == NULL) 
 		if ((sysfs_read_dir_subdirs(clsdev->directory)) != 0 ||
 		    clsdev->directory->subdirs == NULL) 
diff --git a/libsysfs/sysfs_device.c b/libsysfs/sysfs_device.c
index f2f8d2d61..83c3adc08 100644
--- a/libsysfs/sysfs_device.c
+++ b/libsysfs/sysfs_device.c
@@ -24,7 +24,9 @@
 #include "sysfs.h"
 
 /**
- * get_dev_driver: fills in the dev->driver_name field 
+ * get_dev_driver: fills in the dev->driver_name field, but searches by
+ *	opening subsystem. Only to be used if no driver link exists in
+ *	device directory.
  *
  * Returns 0 on SUCCESS and 1 on error
  */
@@ -73,6 +75,32 @@ static int get_dev_driver(struct sysfs_device *dev)
 	}
 	return 1;
 }
+
+/*
+ * get_device_driver_name: gets device's driver name, searches for driver
+ *	link first before going the brute force route.
+ * @dev: device to retrieve driver
+ * returns 0 with success and 1 with error
+ */
+static int get_device_driver_name(struct sysfs_device *dev)
+{
+	char devpath[SYSFS_PATH_MAX], drvpath[SYSFS_PATH_MAX];
+
+	if (dev == NULL) {
+		errno = EINVAL;
+		return 1;
+	}
+	memset(devpath, 0, SYSFS_PATH_MAX);
+	memset(drvpath, 0, SYSFS_PATH_MAX);
+	safestrcpy(devpath, dev->path);
+	safestrcat(devpath, "/driver");
+
+	if ((sysfs_get_link(devpath, drvpath, SYSFS_PATH_MAX)) != 0) 
+		return(get_dev_driver(dev));
+
+	return (sysfs_get_name_from_path(drvpath, dev->driver_name, 
+		SYSFS_NAME_LEN));
+}
 	
 /**
  * sysfs_get_device_bus: retrieves the bus name the device is on, checks path 
@@ -262,7 +290,7 @@ struct sysfs_device *sysfs_open_device_path(const char *path)
 	if (sysfs_get_device_bus(dev) != 0)
 		dprintf("Could not get device bus\n");
 	
-	if (get_dev_driver(dev) != 0) {
+	if (get_device_driver_name(dev) != 0) {
 		dprintf("Could not get device %s's driver\n", dev->bus_id);
 		safestrcpy(dev->driver_name, SYSFS_UNKNOWN);
 	}