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authorLinus Torvalds <torvalds@linux-foundation.org>2013-04-29 11:31:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-29 11:31:50 -0700
commit2794b5d408c625e104de813d3de7ac0ec34d46d9 (patch)
treea99e067475ed4e1de27c86a544347be97e7458fb /fs
parent4f567cbc957a7cffd1a428a000d93bd903f42349 (diff)
parent0d1d392f011b284bb4af0411b2d36e5d04e0f058 (diff)
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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
Diffstat (limited to 'fs')
-rw-r--r--fs/sysfs/dir.c41
1 files changed, 21 insertions, 20 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index e14512678c9..e8e0e71b29d 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;
}