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path: root/drivers/base/devtmpfs.c
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Diffstat (limited to 'drivers/base/devtmpfs.c')
-rw-r--r--drivers/base/devtmpfs.c148
1 files changed, 68 insertions, 80 deletions
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 8493536ea55..25798db1455 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -7,9 +7,9 @@
* devtmpfs, a tmpfs-based filesystem is created. Every driver-core
* device which requests a device node, will add a node in this
* filesystem.
- * By default, all devices are named after the the name of the
- * device, owned by root and have a default mode of 0600. Subsystems
- * can overwrite the default setting if needed.
+ * By default, all devices are named after the name of the device,
+ * owned by root and have a default mode of 0600. Subsystems can
+ * overwrite the default setting if needed.
*/
#include <linux/kernel.h>
@@ -24,6 +24,7 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/kthread.h>
+#include "base.h"
static struct task_struct *thread;
@@ -41,6 +42,8 @@ static struct req {
int err;
const char *name;
umode_t mode; /* 0 => delete */
+ kuid_t uid;
+ kgid_t gid;
struct device *dev;
} *requests;
@@ -85,7 +88,9 @@ int devtmpfs_create_node(struct device *dev)
return 0;
req.mode = 0;
- req.name = device_get_devnode(dev, &req.mode, &tmp);
+ req.uid = GLOBAL_ROOT_UID;
+ req.gid = GLOBAL_ROOT_GID;
+ req.name = device_get_devnode(dev, &req.mode, &req.uid, &req.gid, &tmp);
if (!req.name)
return -ENOMEM;
@@ -121,7 +126,7 @@ int devtmpfs_delete_node(struct device *dev)
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;
@@ -148,7 +153,7 @@ static int dev_mkdir(const char *name, umode_t mode)
struct path path;
int err;
- dentry = kern_path_create(AT_FDCWD, name, &path, 1);
+ dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
@@ -156,9 +161,7 @@ static int dev_mkdir(const char *name, umode_t mode)
if (!err)
/* mark as kernel-created inode */
dentry->d_inode->i_private = &thread;
- dput(dentry);
- mutex_unlock(&path.dentry->d_inode->i_mutex);
- path_put(&path);
+ done_path_create(&path, dentry);
return err;
}
@@ -189,7 +192,8 @@ static int create_path(const char *nodepath)
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, kuid_t uid,
+ kgid_t gid, struct device *dev)
{
struct dentry *dentry;
struct path path;
@@ -203,57 +207,45 @@ static int handle_create(const char *nodename, umode_t mode, struct device *dev)
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);
+ notify_change(dentry, &newattrs, NULL);
mutex_unlock(&dentry->d_inode->i_mutex);
/* mark as kernel-created inode */
dentry->d_inode->i_private = &thread;
}
- dput(dentry);
-
- mutex_unlock(&path.dentry->d_inode->i_mutex);
- path_put(&path);
+ done_path_create(&path, dentry);
return err;
}
static int dev_rmdir(const char *name)
{
- struct nameidata nd;
+ struct path parent;
struct dentry *dentry;
int err;
- err = kern_path_parent(name, &nd);
- if (err)
- return err;
-
- mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
- dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
- if (!IS_ERR(dentry)) {
- if (dentry->d_inode) {
- if (dentry->d_inode->i_private == &thread)
- err = vfs_rmdir(nd.path.dentry->d_inode,
- dentry);
- else
- err = -EPERM;
- } else {
- err = -ENOENT;
- }
- dput(dentry);
+ dentry = kern_path_locked(name, &parent);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+ if (dentry->d_inode) {
+ if (dentry->d_inode->i_private == &thread)
+ err = vfs_rmdir(parent.dentry->d_inode, dentry);
+ else
+ err = -EPERM;
} else {
- err = PTR_ERR(dentry);
+ err = -ENOENT;
}
-
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
- path_put(&nd.path);
+ dput(dentry);
+ mutex_unlock(&parent.dentry->d_inode->i_mutex);
+ path_put(&parent);
return err;
}
@@ -305,50 +297,44 @@ static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *sta
static int handle_remove(const char *nodename, struct device *dev)
{
- struct nameidata nd;
+ struct path parent;
struct dentry *dentry;
- struct kstat stat;
- int deleted = 1;
+ int deleted = 0;
int err;
- err = kern_path_parent(nodename, &nd);
- if (err)
- return err;
+ dentry = kern_path_locked(nodename, &parent);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
- mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
- dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
- if (!IS_ERR(dentry)) {
- if (dentry->d_inode) {
- err = vfs_getattr(nd.path.mnt, dentry, &stat);
- if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
- struct iattr newattrs;
- /*
- * before unlinking this node, reset permissions
- * of possible references like hardlinks
- */
- newattrs.ia_uid = 0;
- newattrs.ia_gid = 0;
- newattrs.ia_mode = stat.mode & ~0777;
- newattrs.ia_valid =
- ATTR_UID|ATTR_GID|ATTR_MODE;
- mutex_lock(&dentry->d_inode->i_mutex);
- notify_change(dentry, &newattrs);
- mutex_unlock(&dentry->d_inode->i_mutex);
- err = vfs_unlink(nd.path.dentry->d_inode,
- dentry);
- if (!err || err == -ENOENT)
- deleted = 1;
- }
- } else {
- err = -ENOENT;
+ if (dentry->d_inode) {
+ struct kstat stat;
+ struct path p = {.mnt = parent.mnt, .dentry = dentry};
+ err = vfs_getattr(&p, &stat);
+ if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
+ struct iattr newattrs;
+ /*
+ * before unlinking this node, reset permissions
+ * of possible references like hardlinks
+ */
+ newattrs.ia_uid = GLOBAL_ROOT_UID;
+ newattrs.ia_gid = GLOBAL_ROOT_GID;
+ newattrs.ia_mode = stat.mode & ~0777;
+ newattrs.ia_valid =
+ ATTR_UID|ATTR_GID|ATTR_MODE;
+ mutex_lock(&dentry->d_inode->i_mutex);
+ notify_change(dentry, &newattrs, NULL);
+ mutex_unlock(&dentry->d_inode->i_mutex);
+ err = vfs_unlink(parent.dentry->d_inode, dentry, NULL);
+ if (!err || err == -ENOENT)
+ deleted = 1;
}
- dput(dentry);
} else {
- err = PTR_ERR(dentry);
+ err = -ENOENT;
}
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+ dput(dentry);
+ mutex_unlock(&parent.dentry->d_inode->i_mutex);
- path_put(&nd.path);
+ path_put(&parent);
if (deleted && strchr(nodename, '/'))
delete_path(nodename);
return err;
@@ -378,10 +364,11 @@ int devtmpfs_mount(const char *mntdir)
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, kuid_t uid, kgid_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);
}
@@ -407,7 +394,8 @@ static int devtmpfsd(void *p)
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;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 20:39:44 +0000