[alsa-devel] [PATCH 01/11] ASoC: SOF: Add Sound Open Firmware driver core

[Takashi Iwai]

On Tue, 24 Jul 2018 17:57:42 +0200,
Pierre-Louis Bossart wrote:
> 
> we seem to have a new 0-day report with randconfig related to the
> page/sgbuffer management. Not sure why it wasn't seen before, I've
> already fixed quite a few exotic configurations for non-Intel targets.
> 
> sound/soc/sof/core.c: In function 'snd_sof_create_page_table':
> sound/soc/sof/core.c:201:10: error: implicit declaration of function
> 'snd_sgbuf_aligned_pages' [-Werror=implicit-function-declaration]
>   pages = snd_sgbuf_aligned_pages(size);
>           ^
> Looking at the code:
> > +static inline unsigned int sof_get_pages(size_t size)
> > +{
> > +	return (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
> > +}
> this inline doesn't seem to be used but duplicates the code from
> 
> static inline unsigned int snd_sgbuf_aligned_pages(size_t size)
> {
>     return (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
> }
> 
> which is used below
> > +int snd_sof_create_page_table(struct snd_sof_dev *sdev,
> > +			      struct snd_dma_buffer *dmab,
> > +			      unsigned char *page_table, size_t size)
> > +{
> > +	int i, pages;
> > +
> > +	pages = snd_sgbuf_aligned_pages(size);
> this code doesn't compile unless CONFIG_SND_DMA_SGBUF is defined (it
> is set for the intel-specific code but not for the SOF core). We can
> fix this in different ways
> 0. require SND_CMD_SGBUF for the core - likely not desirable
> 1. use sof_get_pages()
> 2. change include/sound/memalloc.h to make sure this
> snd_sgbuf_aligned_pages() inline is available whether
> CONFIG_SND_DMA_SGBUF is defined or not - maybe making sure while we
> are at it that the malloc and free functions are empty static inlines?

The latter sounds like a better choice to me.
Just move the function to outside ifdef.


thanks,

Takashi