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, 11 insertions, 16 deletions

diff --git a/drivers/acpi/system.c b/drivers/acpi/system.c
index 4749f379a91..769f24855eb 100644
--- a/drivers/acpi/system.c
+++ b/drivers/acpi/system.c
@@ -396,6 +396,7 @@ static int acpi_system_info_open_fs(struct inode *inode, struct file *file)
 }
 
 static const struct file_operations acpi_system_info_ops = {
+        .owner = THIS_MODULE,
         .open = acpi_system_info_open_fs,
         .read = seq_read,
         .llseek = seq_lseek,
@@ -406,6 +407,7 @@ static ssize_t acpi_system_read_dsdt(struct file *, char __user *, size_t,
                                      loff_t *);
 
 static const struct file_operations acpi_system_dsdt_ops = {
+        .owner = THIS_MODULE,
         .read = acpi_system_read_dsdt,
 };
 
@@ -430,6 +432,7 @@ static ssize_t acpi_system_read_fadt(struct file *, char __user *, size_t,
                                      loff_t *);
 
 static const struct file_operations acpi_system_fadt_ops = {
+        .owner = THIS_MODULE,
         .read = acpi_system_read_fadt,
 };
 
@@ -454,31 +457,23 @@ static int acpi_system_procfs_init(void)
 {
         struct proc_dir_entry *entry;
         int error = 0;
-        char *name;
 
         /* 'info' [R] */
-        name = ACPI_SYSTEM_FILE_INFO;
-        entry = create_proc_entry(name, S_IRUGO, acpi_root_dir);
+        entry = proc_create(ACPI_SYSTEM_FILE_INFO, S_IRUGO, acpi_root_dir,
+                            &acpi_system_info_ops);
         if (!entry)
                 goto Error;
-        else {
-                entry->proc_fops = &acpi_system_info_ops;
-        }
 
         /* 'dsdt' [R] */
-        name = ACPI_SYSTEM_FILE_DSDT;
-        entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
-        if (entry)
-                entry->proc_fops = &acpi_system_dsdt_ops;
-        else
+        entry = proc_create(ACPI_SYSTEM_FILE_DSDT, S_IRUSR, acpi_root_dir,
+                            &acpi_system_dsdt_ops);
+        if (!entry)
                 goto Error;
 
         /* 'fadt' [R] */
-        name = ACPI_SYSTEM_FILE_FADT;
-        entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
-        if (entry)
-                entry->proc_fops = &acpi_system_fadt_ops;
-        else
+        entry = proc_create(ACPI_SYSTEM_FILE_FADT, S_IRUSR, acpi_root_dir,
+                            &acpi_system_fadt_ops);
+        if (!entry)
                 goto Error;
 
       Done: