[PATCH 1/2] staging: android: ion: Do not BUG on handle client mismatch

Laura Abbott labbott at redhat.com
Mon Aug 22 16:58:40 UTC 2016


On 08/22/2016 03:26 AM, Johanna Abrahamsson wrote:
> The ion_free() and ion_free_nolock() functions should not BUG on a
> handle client mismatch. It is not necessary to explicitly check for that
> mismatch when ion_handle_validate is used.
>

The validate and BUG_ON are checking two slightly different things.
The BUG_ON is trying to catch blatantly wrong kernel users while the
validate is designed to catch races.

I'd like to keep the BUG_ON in ion_free but it's fine to get rid of
it in ion_free_nolock.

Thanks,
Laura

> Signed-off-by: Johanna Abrahamsson <johanna at mjao.org>
> ---
>  drivers/staging/android/ion/ion.c | 4 ----
>  1 file changed, 4 deletions(-)
>
> diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
> index 291d5b8..d209bda 100644
> --- a/drivers/staging/android/ion/ion.c
> +++ b/drivers/staging/android/ion/ion.c
> @@ -550,8 +550,6 @@ static void ion_free_nolock(struct ion_client *client,
>  {
>  	bool valid_handle;
>
> -	BUG_ON(client != handle->client);
> -
>  	valid_handle = ion_handle_validate(client, handle);
>
>  	if (!valid_handle) {
> @@ -563,8 +561,6 @@ static void ion_free_nolock(struct ion_client *client,
>
>  void ion_free(struct ion_client *client, struct ion_handle *handle)
>  {
> -	BUG_ON(client != handle->client);
> -
>  	mutex_lock(&client->lock);
>  	ion_free_nolock(client, handle);
>  	mutex_unlock(&client->lock);
>



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