2021-07-22 10:59:17

by Dongliang Mu

[permalink] [raw]
Subject: [PATCH] soundwire: stream: add s_rt into slave_rt_list before sdw_config_stream

The commit 48f17f96a817 ("soundwire: stream: fix memory leak in stream
config error path") fixes the memory leak by implicitly freeing the s_rt
object. However, this fixing style is not very good.

The better fix is to move list_add_tail before sdw_config_stream and
revert the previous commit.

Signed-off-by: Dongliang Mu <[email protected]>
---
drivers/soundwire/stream.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
index 1a18308f4ef4..66a4ce4f923f 100644
--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -1373,19 +1373,11 @@ int sdw_stream_add_slave(struct sdw_slave *slave,
goto stream_error;
}

+ list_add_tail(&s_rt->m_rt_node, &m_rt->slave_rt_list);
+
ret = sdw_config_stream(&slave->dev, stream, stream_config, true);
- if (ret) {
- /*
- * sdw_release_master_stream will release s_rt in slave_rt_list in
- * stream_error case, but s_rt is only added to slave_rt_list
- * when sdw_config_stream is successful, so free s_rt explicitly
- * when sdw_config_stream is failed.
- */
- kfree(s_rt);
+ if (ret)
goto stream_error;
- }
-
- list_add_tail(&s_rt->m_rt_node, &m_rt->slave_rt_list);

ret = sdw_slave_port_config(slave, s_rt, port_config, num_ports);
if (ret)
--
2.25.1


2021-07-22 11:20:29

by Dan Carpenter

[permalink] [raw]
Subject: Re: [PATCH] soundwire: stream: add s_rt into slave_rt_list before sdw_config_stream

On Thu, Jul 22, 2021 at 06:56:11PM +0800, Dongliang Mu wrote:
> The commit 48f17f96a817 ("soundwire: stream: fix memory leak in stream
> config error path") fixes the memory leak by implicitly freeing the s_rt
> object. However, this fixing style is not very good.
>
> The better fix is to move list_add_tail before sdw_config_stream and
> revert the previous commit.
>
> Signed-off-by: Dongliang Mu <[email protected]>
> ---
> drivers/soundwire/stream.c | 14 +++-----------
> 1 file changed, 3 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
> index 1a18308f4ef4..66a4ce4f923f 100644
> --- a/drivers/soundwire/stream.c
> +++ b/drivers/soundwire/stream.c
> @@ -1373,19 +1373,11 @@ int sdw_stream_add_slave(struct sdw_slave *slave,
> goto stream_error;
> }
>
> + list_add_tail(&s_rt->m_rt_node, &m_rt->slave_rt_list);
> +
> ret = sdw_config_stream(&slave->dev, stream, stream_config, true);

There some sanity checks on the stream inside sdw_config_stream() so
that's probably why we didn't add it until later. (I don't know the
code well, but that's what I would suspect from a glance).

regards,
dan carpenter

2021-07-22 11:27:09

by Dongliang Mu

[permalink] [raw]
Subject: Re: [PATCH] soundwire: stream: add s_rt into slave_rt_list before sdw_config_stream

On Thu, Jul 22, 2021 at 7:17 PM Dan Carpenter <[email protected]> wrote:
>
> On Thu, Jul 22, 2021 at 06:56:11PM +0800, Dongliang Mu wrote:
> > The commit 48f17f96a817 ("soundwire: stream: fix memory leak in stream
> > config error path") fixes the memory leak by implicitly freeing the s_rt
> > object. However, this fixing style is not very good.
> >
> > The better fix is to move list_add_tail before sdw_config_stream and
> > revert the previous commit.
> >
> > Signed-off-by: Dongliang Mu <[email protected]>
> > ---
> > drivers/soundwire/stream.c | 14 +++-----------
> > 1 file changed, 3 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
> > index 1a18308f4ef4..66a4ce4f923f 100644
> > --- a/drivers/soundwire/stream.c
> > +++ b/drivers/soundwire/stream.c
> > @@ -1373,19 +1373,11 @@ int sdw_stream_add_slave(struct sdw_slave *slave,
> > goto stream_error;
> > }
> >
> > + list_add_tail(&s_rt->m_rt_node, &m_rt->slave_rt_list);
> > +
> > ret = sdw_config_stream(&slave->dev, stream, stream_config, true);
>
> There some sanity checks on the stream inside sdw_config_stream() so
> that's probably why we didn't add it until later. (I don't know the
> code well, but that's what I would suspect from a glance).

I think those sanity checks are not much related to list_add_tail.

Except that, do you have other concerns?

I think this patch could improve the readability of code, so I submit
this patch to the mailing list. But I am not sure if the community
favors this kind of patch.

>
> regards,
> dan carpenter
>

2021-07-22 11:38:53

by Dan Carpenter

[permalink] [raw]
Subject: Re: [PATCH] soundwire: stream: add s_rt into slave_rt_list before sdw_config_stream

On Thu, Jul 22, 2021 at 07:24:16PM +0800, Dongliang Mu wrote:
> On Thu, Jul 22, 2021 at 7:17 PM Dan Carpenter <[email protected]> wrote:
> >
> > On Thu, Jul 22, 2021 at 06:56:11PM +0800, Dongliang Mu wrote:
> > > The commit 48f17f96a817 ("soundwire: stream: fix memory leak in stream
> > > config error path") fixes the memory leak by implicitly freeing the s_rt
> > > object. However, this fixing style is not very good.
> > >
> > > The better fix is to move list_add_tail before sdw_config_stream and
> > > revert the previous commit.
> > >
> > > Signed-off-by: Dongliang Mu <[email protected]>
> > > ---
> > > drivers/soundwire/stream.c | 14 +++-----------
> > > 1 file changed, 3 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
> > > index 1a18308f4ef4..66a4ce4f923f 100644
> > > --- a/drivers/soundwire/stream.c
> > > +++ b/drivers/soundwire/stream.c
> > > @@ -1373,19 +1373,11 @@ int sdw_stream_add_slave(struct sdw_slave *slave,
> > > goto stream_error;
> > > }
> > >
> > > + list_add_tail(&s_rt->m_rt_node, &m_rt->slave_rt_list);
> > > +
> > > ret = sdw_config_stream(&slave->dev, stream, stream_config, true);
> >
> > There some sanity checks on the stream inside sdw_config_stream() so
> > that's probably why we didn't add it until later. (I don't know the
> > code well, but that's what I would suspect from a glance).
>
> I think those sanity checks are not much related to list_add_tail.

Yeah. I can't point to a bug that it causes, it just feels ugly to add
invalid data to the list.

You didn't add Rander to the CC list and he may have had a good reason
to do it that way.

regards,
dan carpenter