driver core: add uid and gid to devtmpfs
Some drivers want to tell userspace what uid and gid should be used for
their device nodes, so allow that information to percolate through the
driver core to userspace in order to make this happen. This means that
some systems (i.e. Android and friends) will not need to even run a
udev-like daemon for their device node manager and can just rely in
devtmpfs fully, reducing their footprint even more.
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 01fc5b0..fda5256 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -41,6 +41,8 @@
int err;
const char *name;
umode_t mode; /* 0 => delete */
+ uid_t uid;
+ gid_t gid;
struct device *dev;
} *requests;
@@ -85,7 +87,9 @@
return 0;
req.mode = 0;
- req.name = device_get_devnode(dev, &req.mode, &tmp);
+ req.uid = 0;
+ req.gid = 0;
+ req.name = device_get_devnode(dev, &req.mode, &req.uid, &req.gid, &tmp);
if (!req.name)
return -ENOMEM;
@@ -121,7 +125,7 @@
if (!thread)
return 0;
- req.name = device_get_devnode(dev, NULL, &tmp);
+ req.name = device_get_devnode(dev, NULL, NULL, NULL, &tmp);
if (!req.name)
return -ENOMEM;
@@ -187,7 +191,8 @@
return err;
}
-static int handle_create(const char *nodename, umode_t mode, struct device *dev)
+static int handle_create(const char *nodename, umode_t mode, uid_t uid,
+ gid_t gid, struct device *dev)
{
struct dentry *dentry;
struct path path;
@@ -201,14 +206,14 @@
if (IS_ERR(dentry))
return PTR_ERR(dentry);
- err = vfs_mknod(path.dentry->d_inode,
- dentry, mode, dev->devt);
+ err = vfs_mknod(path.dentry->d_inode, dentry, mode, dev->devt);
if (!err) {
struct iattr newattrs;
- /* fixup possibly umasked mode */
newattrs.ia_mode = mode;
- newattrs.ia_valid = ATTR_MODE;
+ newattrs.ia_uid = uid;
+ newattrs.ia_gid = gid;
+ newattrs.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID;
mutex_lock(&dentry->d_inode->i_mutex);
notify_change(dentry, &newattrs);
mutex_unlock(&dentry->d_inode->i_mutex);
@@ -358,10 +363,11 @@
static DECLARE_COMPLETION(setup_done);
-static int handle(const char *name, umode_t mode, struct device *dev)
+static int handle(const char *name, umode_t mode, uid_t uid, gid_t gid,
+ struct device *dev)
{
if (mode)
- return handle_create(name, mode, dev);
+ return handle_create(name, mode, uid, gid, dev);
else
return handle_remove(name, dev);
}
@@ -387,7 +393,8 @@
spin_unlock(&req_lock);
while (req) {
struct req *next = req->next;
- req->err = handle(req->name, req->mode, req->dev);
+ req->err = handle(req->name, req->mode,
+ req->uid, req->gid, req->dev);
complete(&req->done);
req = next;
}