Driver-Core: extend devnode callbacks to provide permissions

This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 12 insertions, 7 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 390e664ec1c7..6bee6af8d8e1 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -166,13 +166,16 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
         if (MAJOR(dev->devt)) {
                 const char *tmp;
                 const char *name;
+                mode_t mode = 0;
 
                 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
                 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
-                name = device_get_nodename(dev, &tmp);
+                name = device_get_devnode(dev, &mode, &tmp);
                 if (name) {
                         add_uevent_var(env, "DEVNAME=%s", name);
                         kfree(tmp);
+                        if (mode)
+                                add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
                 }
         }
 
@@ -1148,8 +1151,9 @@ static struct device *next_device(struct klist_iter *i)
 }
 
 /**
- * device_get_nodename - path of device node file
+ * device_get_devnode - path of device node file
  * @dev: device
+ * @mode: returned file access mode
  * @tmp: possibly allocated string
  *
  * Return the relative path of a possible device node.
@@ -1157,21 +1161,22 @@ static struct device *next_device(struct klist_iter *i)
  * a name. This memory is returned in tmp and needs to be
  * freed by the caller.
  */
-const char *device_get_nodename(struct device *dev, const char **tmp)
+const char *device_get_devnode(struct device *dev,
+                               mode_t *mode, const char **tmp)
 {
         char *s;
 
         *tmp = NULL;
 
         /* the device type may provide a specific name */
-        if (dev->type && dev->type->nodename)
-                *tmp = dev->type->nodename(dev);
+        if (dev->type && dev->type->devnode)
+                *tmp = dev->type->devnode(dev, mode);
         if (*tmp)
                 return *tmp;
 
         /* the class may provide a specific name */
-        if (dev->class && dev->class->nodename)
-                *tmp = dev->class->nodename(dev);
+        if (dev->class && dev->class->devnode)
+                *tmp = dev->class->devnode(dev, mode);
         if (*tmp)
                 return *tmp;