[PATCH 3.16 074/366] iio:buffer: make length types match kfifo types

Ben Hutchings
2018-10-14T15:25:41Z

From: Martin Kelly <mkelly@xevo.com>

commit c043ec1ca5baae63726aae32abbe003192bc6eec upstream.

Currently, we use int for buffer length and bytes_per_datum. However,
kfifo uses unsigned int for length and size_t for element size. We need
to make sure these matches or we will have bugs related to overflow (in
the range between INT_MAX and UINT_MAX for length, for example).

In addition, set_bytes_per_datum uses size_t while bytes_per_datum is an
int, which would cause bugs for large values of bytes_per_datum.

Change buffer length to use unsigned int and bytes_per_datum to use
size_t.

Signed-off-by: Martin Kelly <mkelly@xevo.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[bwh: Backported to 3.16:
- Drop change in iio_dma_buffer_set_length()
- Adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/drivers/iio/kfifo_buf.c
+++ b/drivers/iio/kfifo_buf.c
@@ -19,7 +19,7 @@ struct iio_kfifo {
#define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)

static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
- int bytes_per_datum, int length)
+ size_t bytes_per_datum, unsigned int length)
{
if ((length == 0) || (bytes_per_datum == 0))
return -EINVAL;
@@ -87,7 +87,7 @@ static int iio_set_bytes_per_datum_kfifo
return 0;
}

-static int iio_set_length_kfifo(struct iio_buffer *r, int length)
+static int iio_set_length_kfifo(struct iio_buffer *r, unsigned int length)
{
/* Avoid an invalid state */
if (length < 2)
--- a/include/linux/iio/buffer.h
+++ b/include/linux/iio/buffer.h
@@ -52,7 +52,7 @@ struct iio_buffer_access_funcs {
int (*get_bytes_per_datum)(struct iio_buffer *buffer);
int (*set_bytes_per_datum)(struct iio_buffer *buffer, size_t bpd);
int (*get_length)(struct iio_buffer *buffer);
- int (*set_length)(struct iio_buffer *buffer, int length);
+ int (*set_length)(struct iio_buffer *buffer, unsigned int length);

void (*release)(struct iio_buffer *buffer);
};
@@ -78,8 +78,8 @@ struct iio_buffer_access_funcs {
* @ref: [INTERN] reference count of the buffer.
*/
struct iio_buffer {
- int length;
- int bytes_per_datum;
+ unsigned int length;
+ size_t bytes_per_datum;
struct attribute_group *scan_el_attrs;
long *scan_mask;
bool scan_timestamp;