Re: [PATCH] dmaengine: dmatest: fix container_of member in dmatest_callback

[Yang, Shunyong]

Hi, Vinod,

On Mon, 2018-01-29 at 10:15 +0530, Vinod Koul wrote:
> On Mon, Jan 22, 2018 at 03:28:28PM +0800, Yang Shunyong wrote:
> > 
> > The type of arg passed to dmatest_callback is struct dmatest_done.
> > It refers to test_done in struct dmatest_thread, not done_wait.
> > 
> > Fixes: 6f6a23a213be ("dmaengine: dmatest: move callback wait ...")
> > Signed-off-by: Yang Shunyong <shunyong.yang@xxxxxxxxxxxxxxxx>
> > ---
> >  drivers/dma/dmatest.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
> > index ec5f9d2bc820..906e85d6dedc 100644
> > --- a/drivers/dma/dmatest.c
> > +++ b/drivers/dma/dmatest.c
> > @@ -355,7 +355,7 @@ static void dmatest_callback(void *arg)
> >  {
> >  	struct dmatest_done *done = arg;
> >  	struct dmatest_thread *thread =
> > -		container_of(arg, struct dmatest_thread,
> > done_wait);
> > +		container_of(arg, struct dmatest_thread,
> > test_done);
> This fixes it but one of the reason why compilers didn't catch this
> was the void arg. I just tested and used 'done' as the argument here
> rather than 'arg' and compiler was quick to point out the error.
> 
> So a better fix IMO would be:
> 
> -- >8 --
> 
> diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
> index ec5f9d2bc820..80cc2be6483c 100644
> --- a/drivers/dma/dmatest.c
> +++ b/drivers/dma/dmatest.c
> @@ -355,7 +355,7 @@ static void dmatest_callback(void *arg)
>  {
>         struct dmatest_done *done = arg;
>         struct dmatest_thread *thread =
> -               container_of(arg, struct dmatest_thread, done_wait);
> +               container_of(done, struct dmatest_thread, test_done);
>         if (!thread->done) {
>                 done->done = true;
>                 wake_up_all(done->wait);
> 

Thanks. I will send out v2 patch soon.

Shunyong