[Sound-open-firmware] [PATCH] ASoC: sof: Fix oops due to trace_sleep use before init

[Pierre-Louis Bossart]

Thanks Daniel for the patch.
I'd need Liam and Yan to chime in since the error handling would be a 
bit different from what it is today, see below.

On 3/19/18 3:47 PM, Daniel Baluta wrote:
> Access happens on the following path:
> 
> 1) sof_ipc_tx_message
>    => tx_wait_done
>      => snd_sof_trace_notify_for_error
>       => wake_up(&sdev->trace_sleep)
> 
> where sdev->trace_sleep is not yet initialized.
> 
> While at it also move initialization of sdev->host_offset
> before starting working with sdev struct.
> 
> Signed-off-by: Daniel Baluta <daniel.baluta at gmail.com>
> ---
>   sound/soc/sof/trace.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/soc/sof/trace.c b/sound/soc/sof/trace.c
> index 744d75b..2772cbee 100644
> --- a/sound/soc/sof/trace.c
> +++ b/sound/soc/sof/trace.c
> @@ -245,6 +245,9 @@ int snd_sof_init_trace(struct snd_sof_dev *sdev)
>   	params.buffer.offset = 0;
>   	params.buffer.pages = sdev->dma_trace_pages;
>   
> +	init_waitqueue_head(&sdev->trace_sleep);
> +	sdev->host_offset = 0;
> +
>   	/* send IPC to the DSP */
>   	ret = sof_ipc_tx_message(sdev->ipc,
>   		params.hdr.cmd, &params, sizeof(params),
> @@ -255,8 +258,6 @@ int snd_sof_init_trace(struct snd_sof_dev *sdev)
>   		goto table_err;

if for some reason this IPC fails, then we end-end with the trace_sleep 
and host_offset initialized. Is this ok?

>   	}
>   
> -	init_waitqueue_head(&sdev->trace_sleep);
> -	sdev->host_offset = 0;
>   	return 0;
>   
>   table_err:
>