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, 4 insertions, 9 deletions

diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index b477a4be8a69..d80b2d1441af 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -411,6 +411,7 @@ EXPORT_SYMBOL(acpi_processor_notify_smm);
 
 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
 static struct file_operations acpi_processor_perf_fops = {
+        .owner = THIS_MODULE,
         .open = acpi_processor_perf_open_fs,
         .read = seq_read,
         .llseek = seq_lseek,
@@ -456,7 +457,6 @@ static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
 
 static void acpi_cpufreq_add_file(struct acpi_processor *pr)
 {
-        struct proc_dir_entry *entry = NULL;
         struct acpi_device *device = NULL;
 
 
@@ -464,14 +464,9 @@ static void acpi_cpufreq_add_file(struct acpi_processor *pr)
                 return;
 
         /* add file 'performance' [R/W] */
-        entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
-                                  S_IFREG | S_IRUGO,
-                                  acpi_device_dir(device));
-        if (entry){
-                entry->proc_fops = &acpi_processor_perf_fops;
-                entry->data = acpi_driver_data(device);
-                entry->owner = THIS_MODULE;
-        }
+        proc_create_data(ACPI_PROCESSOR_FILE_PERFORMANCE, S_IFREG | S_IRUGO,
+                         acpi_device_dir(device),
+                         &acpi_processor_perf_fops, acpi_driver_data(device));
         return;
 }