[PATCH v4 1/4] firmware: Move umh locking code into fw_load_from_user_helper()

[Daniel Wagner]

From: Daniel Wagner <daniel.wag...@bmw-carit.de>

When we load the firmware directly we don't need to take the umh
lock. So move this part inside fw_load_from_user_helper which is only
available when CONFIG_FW_LOADER_USER_HELPER is set.

This avoids a dependency on firmware_loading_timeout() even when
!CONFIG_FW_LOADER_UER_HELPER.

The usermodehelper locking code was added by b298d289c792 ("PM / Sleep:
Fix freezer failures due to racy usermodehelper_is_disabled()").

Signed-off-by: Daniel Wagner <daniel.wag...@bmw-carit.de>
Cc: Ming Lei <ming....@canonical.com>
Cc: Luis R. Rodriguez <mcg...@kernel.org>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/base/firmware_class.c | 52 +++++++++++++++++++++++--------------------
 1 file changed, 28 insertions(+), 24 deletions(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 960f8f7..d4fee06 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -981,13 +981,38 @@ static int fw_load_from_user_helper(struct firmware 
*firmware,
                                    unsigned int opt_flags, long timeout)
 {
        struct firmware_priv *fw_priv;
+       int ret;
+
+       timeout = firmware_loading_timeout();
+       if (opt_flags & FW_OPT_NOWAIT) {
+               timeout = usermodehelper_read_lock_wait(timeout);
+               if (!timeout) {
+                       dev_dbg(device, "firmware: %s loading timed out\n",
+                               name);
+                       return -EBUSY;
+               }
+       } else {
+               ret = usermodehelper_read_trylock();
+               if (WARN_ON(ret)) {
+                       dev_err(device, "firmware: %s will not be loaded\n",
+                               name);
+                       return ret;
+               }
+       }
 
        fw_priv = fw_create_instance(firmware, name, device, opt_flags);
-       if (IS_ERR(fw_priv))
-               return PTR_ERR(fw_priv);
+       if (IS_ERR(fw_priv)) {
+               ret = PTR_ERR(fw_priv);
+               goto release_lock;
+       }
 
        fw_priv->buf = firmware->priv;
-       return _request_firmware_load(fw_priv, opt_flags, timeout);
+       ret = _request_firmware_load(fw_priv, opt_flags, timeout);
+
+release_lock:
+       usermodehelper_read_unlock();
+
+       return ret;
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -1150,25 +1175,6 @@ _request_firmware(const struct firmware **firmware_p, 
const char *name,
        if (ret <= 0) /* error or already assigned */
                goto out;
 
-       ret = 0;
-       timeout = firmware_loading_timeout();
-       if (opt_flags & FW_OPT_NOWAIT) {
-               timeout = usermodehelper_read_lock_wait(timeout);
-               if (!timeout) {
-                       dev_dbg(device, "firmware: %s loading timed out\n",
-                               name);
-                       ret = -EBUSY;
-                       goto out;
-               }
-       } else {
-               ret = usermodehelper_read_trylock();
-               if (WARN_ON(ret)) {
-                       dev_err(device, "firmware: %s will not be loaded\n",
-                               name);
-                       goto out;
-               }
-       }
-
        ret = fw_get_filesystem_firmware(device, fw->priv);
        if (ret) {
                if (!(opt_flags & FW_OPT_NO_WARN))
@@ -1185,8 +1191,6 @@ _request_firmware(const struct firmware **firmware_p, 
const char *name,
        if (!ret)
                ret = assign_firmware_buf(fw, device, opt_flags);
 
-       usermodehelper_read_unlock();
-
  out:
        if (ret < 0) {
                release_firmware(fw);
-- 
2.7.4