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 24a905b..2853b40 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;
 }