[PATCH] staging: comedi: use memdup_user

[Geliang Tang]

Use memdup_user() helper instead of open-coding to simplify the code.

Signed-off-by: Geliang Tang <geliangt...@gmail.com>
---
 drivers/staging/comedi/comedi_fops.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/drivers/staging/comedi/comedi_fops.c 
b/drivers/staging/comedi/comedi_fops.c
index f191c2a..4797c8f 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -1450,22 +1450,14 @@ static int do_insnlist_ioctl(struct comedi_device *dev,
                return -EFAULT;
 
        data = kmalloc_array(MAX_SAMPLES, sizeof(unsigned int), GFP_KERNEL);
-       if (!data) {
-               ret = -ENOMEM;
-               goto error;
-       }
-
-       insns = kcalloc(insnlist.n_insns, sizeof(*insns), GFP_KERNEL);
-       if (!insns) {
-               ret = -ENOMEM;
-               goto error;
-       }
+       if (!data)
+               return -ENOMEM;
 
-       if (copy_from_user(insns, insnlist.insns,
-                          sizeof(*insns) * insnlist.n_insns)) {
-               dev_dbg(dev->class_dev, "copy_from_user failed\n");
-               ret = -EFAULT;
-               goto error;
+       insns = memdup_user(insnlist.insns, sizeof(*insns) * insnlist.n_insns);
+       if (IS_ERR(insns)) {
+               dev_dbg(dev->class_dev, "memdup_user failed\n");
+               kfree(data);
+               return PTR_ERR(insns);
        }
 
        for (i = 0; i < insnlist.n_insns; i++) {
-- 
2.9.3