Merge tag 'driver-core-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg Kroah-Hartman:
 "Here's the merge request for the driver core tree for 3.10-rc1

  It's pretty small, just a number of driver core and sysfs updates and
  fixes, all of which have been in linux-next for a while now.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

Fixed conflict in kernel/rtmutex-tester.c, the locking tree had a better
fix for the same sysfs file mode problem.

* tag 'driver-core-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  PM / Runtime: Idle devices asynchronously after probe|release
  driver core: handle user namespaces properly with the uid/gid devtmpfs change
  driver core: devtmpfs: fix compile failure with CONFIG_UIDGID_STRICT_TYPE_CHECKS
  devtmpfs: add base.h include
  driver core: add uid and gid to devtmpfs
  sysfs: check if one entry has been removed before freeing
  sysfs: fix crash_notes_size build warning
  sysfs: fix use after free in case of concurrent read/write and readdir
  rtmutex-tester: fix mode of sysfs files
  Documentation: Add ABI entry for crash_notes and crash_notes_size
  sysfs: Add crash_notes_size to export percpu note size
  driver core: platform_device.h: fix checkpatch errors and warnings
  driver core: platform.c: fix checkpatch errors and warnings
  driver core: warn that platform_driver_probe can not use deferred probing
  sysfs: use atomic_inc_unless_negative in sysfs_get_active
  base: core: WARN() about bogus permissions on device attributes
  device: separate all subsys mutexes

1 files changed, 21 insertions, 20 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index e14512678c9b..e8e0e71b29d5 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -165,21 +165,8 @@ struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
         if (unlikely(!sd))
                 return NULL;
 
-        while (1) {
-                int v, t;
-
-                v = atomic_read(&sd->s_active);
-                if (unlikely(v < 0))
-                        return NULL;
-
-                t = atomic_cmpxchg(&sd->s_active, v, v + 1);
-                if (likely(t == v))
-                        break;
-                if (t < 0)
-                        return NULL;
-
-                cpu_relax();
-        }
+        if (!atomic_inc_unless_negative(&sd->s_active))
+                return NULL;
 
         if (likely(!ignore_lockdep(sd)))
                 rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
@@ -281,6 +268,10 @@ void release_sysfs_dirent(struct sysfs_dirent * sd)
          */
         parent_sd = sd->s_parent;
 
+        WARN(!(sd->s_flags & SYSFS_FLAG_REMOVED),
+                "sysfs: free using entry: %s/%s\n",
+                parent_sd ? parent_sd->s_name : "", sd->s_name);
+
         if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
                 sysfs_put(sd->s_symlink.target_sd);
         if (sysfs_type(sd) & SYSFS_COPY_NAME)
@@ -399,7 +390,7 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
 
         sd->s_name = name;
         sd->s_mode = mode;
-        sd->s_flags = type;
+        sd->s_flags = type | SYSFS_FLAG_REMOVED;
 
         return sd;
 
@@ -479,6 +470,9 @@ int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
                 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
         }
 
+        /* Mark the entry added into directory tree */
+        sd->s_flags &= ~SYSFS_FLAG_REMOVED;
+
         return 0;
 }
 
@@ -1012,6 +1006,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
         enum kobj_ns_type type;
         const void *ns;
         ino_t ino;
+        loff_t off;
 
         type = sysfs_ns_type(parent_sd);
         ns = sysfs_info(dentry->d_sb)->ns[type];
@@ -1034,6 +1029,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
                         return 0;
         }
         mutex_lock(&sysfs_mutex);
+        off = filp->f_pos;
         for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos);
              pos;
              pos = sysfs_dir_next_pos(ns, parent_sd, filp->f_pos, pos)) {
@@ -1045,19 +1041,24 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
                 len = strlen(name);
                 ino = pos->s_ino;
                 type = dt_type(pos);
-                filp->f_pos = pos->s_hash;
+                off = filp->f_pos = pos->s_hash;
                 filp->private_data = sysfs_get(pos);
 
                 mutex_unlock(&sysfs_mutex);
-                ret = filldir(dirent, name, len, filp->f_pos, ino, type);
+                ret = filldir(dirent, name, len, off, ino, type);
                 mutex_lock(&sysfs_mutex);
                 if (ret < 0)
                         break;
         }
         mutex_unlock(&sysfs_mutex);
-        if ((filp->f_pos > 1) && !pos) { /* EOF */
-                filp->f_pos = INT_MAX;
+
+        /* don't reference last entry if its refcount is dropped */
+        if (!pos) {
                 filp->private_data = NULL;
+
+                /* EOF and not changed as 0 or 1 in read/write path */
+                if (off == filp->f_pos && off > 1)
+                        filp->f_pos = INT_MAX;
         }
         return 0;
 }