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>

diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index 8dd524f322847b346e119c6d5c5b3693de6fb8bc..cdb2971192a53fbfe2e340feb9819b7454f8ffa2 100644 (file)
--- 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);