convert a bunch of open-coded instances of memdup_user_nul()

A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 6 insertions, 19 deletions

diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 24a905b076fd..2853b4095344 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -230,14 +230,9 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
         if (size <= 1 || size >= PAGE_SIZE)
                 return -EINVAL;
 
-        kbuf = kmalloc(size + 1, GFP_KERNEL);
-        if (!kbuf)
-                return -ENOMEM;
-
-        ret = -EFAULT;
-        if (copy_from_user(kbuf, buf, size) != 0)
-                goto done;
-        kbuf[size] = 0;
+        kbuf = memdup_user_nul(buf, size);
+        if (IS_ERR(kbuf))
+                return PTR_ERR(kbuf);
 
         /* trim to first NL */
         name = memchr(kbuf, '\n', size);
@@ -315,15 +310,9 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
         if (size <= 1 || size >= PAGE_SIZE)
                 return -EINVAL;
 
-        ret = -ENOMEM;
-        kbuf = kmalloc(size + 1, GFP_KERNEL);
-        if (!kbuf)
-                goto nomem;
-
-        ret = -EFAULT;
-        if (copy_from_user(kbuf, buf, size) != 0)
-                goto infault;
-        kbuf[size] = 0;
+        kbuf = memdup_user_nul(buf, size);
+        if (IS_ERR(kbuf))
+                return PTR_ERR(kbuf);
 
         /* trim to first NL */
         s = memchr(kbuf, '\n', size);
@@ -337,9 +326,7 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
         if (ret >= 0)
                 ret = size;     /* consume everything, always */
 
-infault:
         kfree(kbuf);
-nomem:
         _leave(" = %d", ret);
         return ret;
 }