efivarfs: 'efivarfs_file_write' function reorganization

This reorganization removes useless 'bytes' prior assignment and uses
'memdup_user' instead 'kmalloc' + 'copy_from_user'.

Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index 8dd524f32284..cdb2971192a5 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -21,7 +21,7 @@ static ssize_t efivarfs_file_write(struct file *file,
         u32 attributes;
         struct inode *inode = file->f_mapping->host;
         unsigned long datasize = count - sizeof(attributes);
-        ssize_t bytes = 0;
+        ssize_t bytes;
         bool set = false;
 
         if (count < sizeof(attributes))
@@ -33,14 +33,9 @@ static ssize_t efivarfs_file_write(struct file *file,
         if (attributes & ~(EFI_VARIABLE_MASK))
                 return -EINVAL;
 
-        data = kmalloc(datasize, GFP_KERNEL);
-        if (!data)
-                return -ENOMEM;
-
-        if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
-                bytes = -EFAULT;
-                goto out;
-        }
+        data = memdup_user(userbuf + sizeof(attributes), datasize);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
         bytes = efivar_entry_set_get_size(var, attributes, &datasize,
                                           data, &set);