acpi: use non-racy method for proc entries creation

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 14 deletions

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 6c5da83cdb68..1dfec413588c 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -102,6 +102,7 @@ struct acpi_button {
 };
 
 static const struct file_operations acpi_button_info_fops = {
+        .owner = THIS_MODULE,
         .open = acpi_button_info_open_fs,
         .read = seq_read,
         .llseek = seq_lseek,
@@ -109,6 +110,7 @@ static const struct file_operations acpi_button_info_fops = {
 };
 
 static const struct file_operations acpi_button_state_fops = {
+        .owner = THIS_MODULE,
         .open = acpi_button_state_open_fs,
         .read = seq_read,
         .llseek = seq_lseek,
@@ -207,27 +209,21 @@ static int acpi_button_add_fs(struct acpi_device *device)
         acpi_device_dir(device)->owner = THIS_MODULE;
 
         /* 'info' [R] */
-        entry = create_proc_entry(ACPI_BUTTON_FILE_INFO,
-                                  S_IRUGO, acpi_device_dir(device));
+        entry = proc_create_data(ACPI_BUTTON_FILE_INFO,
+                                 S_IRUGO, acpi_device_dir(device),
+                                 &acpi_button_info_fops,
+                                 acpi_driver_data(device));
         if (!entry)
                 return -ENODEV;
-        else {
-                entry->proc_fops = &acpi_button_info_fops;
-                entry->data = acpi_driver_data(device);
-                entry->owner = THIS_MODULE;
-        }
 
         /* show lid state [R] */
         if (button->type == ACPI_BUTTON_TYPE_LID) {
-                entry = create_proc_entry(ACPI_BUTTON_FILE_STATE,
-                                          S_IRUGO, acpi_device_dir(device));
+                entry = proc_create_data(ACPI_BUTTON_FILE_STATE,
+                                         S_IRUGO, acpi_device_dir(device),
+                                         &acpi_button_state_fops,
+                                         acpi_driver_data(device));
                 if (!entry)
                         return -ENODEV;
-                else {
-                        entry->proc_fops = &acpi_button_state_fops;
-                        entry->data = acpi_driver_data(device);
-                        entry->owner = THIS_MODULE;
-                }
         }
 
         return 0;