Merge tag 'driver-core-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Just a few patches this time around for the 4.6-rc1 merge window.
  Largest is a new firmware driver, but there are some other updates to
  the driver core in here as well, the shortlog has the details.

  All have been in linux-next for a while with no reported issues"

* tag 'driver-core-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Revert "driver-core: platform: probe of-devices only using list of compatibles"
  firmware: qemu config needs I/O ports
  firmware: qemu_fw_cfg.c: fix typo FW_CFG_DATA_OFF
  driver-core: platform: probe of-devices only using list of compatibles
  driver-core: platform: fix typo in documentation for multi-driver helper
  component: remove impossible condition
  drivers: dma-coherent: simplify dma_init_coherent_memory return value
  devicetree: update documentation for fw_cfg ARM bindings
  firmware: create directory hierarchy for sysfs fw_cfg entries
  firmware: introduce sysfs driver for QEMU's fw_cfg device
  kobject: export kset_find_obj() for module use
  driver core: bus: use to_subsys_private and to_device_private_bus
  driver core: bus: use list_for_each_entry*
  debugfs: Add stub function for debugfs_create_automount().
  kernfs: make kernfs_walk_ns() use kernfs_pr_cont_buf[]

1 files changed, 14 insertions, 5 deletions

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 996b7742c90b..118d033bcbbc 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -691,15 +691,22 @@ static struct kernfs_node *kernfs_walk_ns(struct kernfs_node *parent,
 					  const unsigned char *path,
 					  const void *ns)
 {
-	static char path_buf[PATH_MAX];	/* protected by kernfs_mutex */
-	size_t len = strlcpy(path_buf, path, PATH_MAX);
-	char *p = path_buf;
-	char *name;
+	size_t len;
+	char *p, *name;
 
 	lockdep_assert_held(&kernfs_mutex);
 
-	if (len >= PATH_MAX)
+	/* grab kernfs_rename_lock to piggy back on kernfs_pr_cont_buf */
+	spin_lock_irq(&kernfs_rename_lock);
+
+	len = strlcpy(kernfs_pr_cont_buf, path, sizeof(kernfs_pr_cont_buf));
+
+	if (len >= sizeof(kernfs_pr_cont_buf)) {
+		spin_unlock_irq(&kernfs_rename_lock);
 		return NULL;
+	}
+
+	p = kernfs_pr_cont_buf;
 
 	while ((name = strsep(&p, "/")) && parent) {
 		if (*name == '\0')
@@ -707,6 +714,8 @@ static struct kernfs_node *kernfs_walk_ns(struct kernfs_node *parent,
 		parent = kernfs_find_ns(parent, name, ns);
 	}
 
+	spin_unlock_irq(&kernfs_rename_lock);
+
 	return parent;
 }