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, 9 insertions, 17 deletions

diff --git a/drivers/acpi/sleep/proc.c b/drivers/acpi/sleep/proc.c
index f8df5217d477..8a5fe8710513 100644
--- a/drivers/acpi/sleep/proc.c
+++ b/drivers/acpi/sleep/proc.c
@@ -440,6 +440,7 @@ acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
 }
 
 static const struct file_operations acpi_system_wakeup_device_fops = {
+        .owner = THIS_MODULE,
         .open = acpi_system_wakeup_device_open_fs,
         .read = seq_read,
         .write = acpi_system_write_wakeup_device,
@@ -449,6 +450,7 @@ static const struct file_operations acpi_system_wakeup_device_fops = {
 
 #ifdef  CONFIG_ACPI_PROCFS
 static const struct file_operations acpi_system_sleep_fops = {
+        .owner = THIS_MODULE,
         .open = acpi_system_sleep_open_fs,
         .read = seq_read,
         .write = acpi_system_write_sleep,
@@ -459,6 +461,7 @@ static const struct file_operations acpi_system_sleep_fops = {
 
 #ifdef  HAVE_ACPI_LEGACY_ALARM
 static const struct file_operations acpi_system_alarm_fops = {
+        .owner = THIS_MODULE,
         .open = acpi_system_alarm_open_fs,
         .read = seq_read,
         .write = acpi_system_write_alarm,
@@ -477,37 +480,26 @@ static u32 rtc_handler(void *context)
 
 static int __init acpi_sleep_proc_init(void)
 {
-        struct proc_dir_entry *entry = NULL;
-
         if (acpi_disabled)
                 return 0;
 
 #ifdef  CONFIG_ACPI_PROCFS
         /* 'sleep' [R/W] */
-        entry =
-            create_proc_entry("sleep", S_IFREG | S_IRUGO | S_IWUSR,
-                              acpi_root_dir);
-        if (entry)
-                entry->proc_fops = &acpi_system_sleep_fops;
+        proc_create("sleep", S_IFREG | S_IRUGO | S_IWUSR,
+                    acpi_root_dir, &acpi_system_sleep_fops);
 #endif                          /* CONFIG_ACPI_PROCFS */
 
 #ifdef  HAVE_ACPI_LEGACY_ALARM
         /* 'alarm' [R/W] */
-        entry =
-            create_proc_entry("alarm", S_IFREG | S_IRUGO | S_IWUSR,
-                              acpi_root_dir);
-        if (entry)
-                entry->proc_fops = &acpi_system_alarm_fops;
+        proc_create("alarm", S_IFREG | S_IRUGO | S_IWUSR,
+                    acpi_root_dir, &acpi_system_alarm_fops);
 
         acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
 #endif                          /* HAVE_ACPI_LEGACY_ALARM */
 
         /* 'wakeup device' [R/W] */
-        entry =
-            create_proc_entry("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
-                              acpi_root_dir);
-        if (entry)
-                entry->proc_fops = &acpi_system_wakeup_device_fops;
+        proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
+                    acpi_root_dir, &acpi_system_wakeup_device_fops);
 
         return 0;
 }