Re: [PATCH] iio: add __counted_by_ptr attribute to channels in struct iio_dev

[Gustavo A. R. Silva]

On 9/23/26 13:28, Bill Wendling wrote:

In 'struct iio_dev', the 'channels' pointer refers to an array of IIO
channel specifications ('struct iio_chan_spec const'), and the size of
this array is tracked by the 'num_channels' field within the same
struct.

Applying the '__counted_by_ptr' attribute to 'channels' allows KASAN
and compiler-based bounds checkers to verify that accesses to 'channels'
remain within bounds at runtime.

Cc: codemender-patching+li...@google.com
Assisted-by: LLM
Signed-off-by: Bill Wendling <mo...@google.com>

Reviewed-by: Gustavo A. R. Silva <gustavo...@kernel.org>

Thanks
-Gustavo

---
  include/linux/iio/iio.h | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 711c00f67371..20505139a61b 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -648,7 +648,7 @@ struct iio_dev {
        struct iio_poll_func            *pollfunc;
        struct iio_poll_func            *pollfunc_event;

- struct iio_chan_spec const *channels;

+       struct iio_chan_spec const      *channels 
__counted_by_ptr(num_channels);
        int                             num_channels;

const char *name;