Re: [PATCH v2 1/4] staging: android: Replace BUG_ON with WARN_ON

[Greg Kroah-Hartman]

On Sun, Aug 16, 2020 at 10:23:25PM +0300, Tomer Samara wrote:
> BUG_ON() is replaced with WARN_ON at ion_page_pool.c

Why?

> Fixes the following issue:
> Avoid crashing the kernel - try using WARN_ON & recovery code ratherthan BUG() or BUG_ON().

Ideally you can get rid of WARN_ON() too, right?

Many systems run in panic-on-warn mode, so this really does not change
anything.  Try fixing this up properly to not crash at all.

> 
> Signed-off-by: Tomer Samara <tomersamara98@xxxxxxxxx>
> ---
>  drivers/staging/android/ion/ion_page_pool.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/android/ion/ion_page_pool.c b/drivers/staging/android/ion/ion_page_pool.c
> index 0198b886d906..c1b9eda35c96 100644
> --- a/drivers/staging/android/ion/ion_page_pool.c
> +++ b/drivers/staging/android/ion/ion_page_pool.c
> @@ -46,11 +46,13 @@ static struct page *ion_page_pool_remove(struct ion_page_pool *pool, bool high)
>  	struct page *page;
>  
>  	if (high) {
> -		BUG_ON(!pool->high_count);
> +		if (WARN_ON(!pool->high_count))
> +			return NULL;

And can you test this that it works properly?

thanks,

greg k-h