[PATCH 2/2] iio: buffer: Move a sanity check at the beginning of 'iio_scan_mask_set()'

From: Christophe JAILLET
Date: Wed Jul 14 2021 - 07:14:57 EST


This is more standard to have sanity checks at the entry of a function,
instead of allocating some memory first and having to free it if a
condition is not met.

Shuffle code a bit to check 'masklength' before calling 'bitmap_alloc()'

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
drivers/iio/industrialio-buffer.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 6d4776a7f002..a95cc2da56be 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -354,13 +354,14 @@ static int iio_scan_mask_set(struct iio_dev *indio_dev,
const unsigned long *mask;
unsigned long *trialmask;

- trialmask = bitmap_alloc(indio_dev->masklength, GFP_KERNEL);
- if (!trialmask)
- return -ENOMEM;
if (!indio_dev->masklength) {
WARN(1, "Trying to set scanmask prior to registering buffer\n");
- goto err_invalid_mask;
+ return -EINVAL;
}
+
+ trialmask = bitmap_alloc(indio_dev->masklength, GFP_KERNEL);
+ if (!trialmask)
+ return -ENOMEM;
bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
set_bit(bit, trialmask);

--
2.30.2