Re: [PATCH v2] rpmsg: smd: do not use mananged resources for endpoints and channels

From: Bjorn Andersson
Date: Mon Jun 04 2018 - 15:36:06 EST


On Mon 04 Jun 02:39 PDT 2018, Srinivas Kandagatla wrote:

> All the managed resources would be freed by the time release function
> is invoked. Handling such memory in qcom_smd_edge_release() would do
> bad things.
>
> Found this issue while testing Audio usecase where the dsp is started up
> and shutdown in a loop.
>
> This patch fixes this issue by using simple kzalloc for allocating
> channel->name and channel which is then freed in qcom_smd_edge_release().
>
> Without this patch restarting a remoteproc would crash the system.
> Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>

Thanks Srini,
Bjorn

> ---
> drivers/rpmsg/qcom_smd.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/rpmsg/qcom_smd.c b/drivers/rpmsg/qcom_smd.c
> index 5ce9bf7b897d..f63adcd95eb0 100644
> --- a/drivers/rpmsg/qcom_smd.c
> +++ b/drivers/rpmsg/qcom_smd.c
> @@ -1100,12 +1100,12 @@ static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *ed
> void *info;
> int ret;
>
> - channel = devm_kzalloc(&edge->dev, sizeof(*channel), GFP_KERNEL);
> + channel = kzalloc(sizeof(*channel), GFP_KERNEL);
> if (!channel)
> return ERR_PTR(-ENOMEM);
>
> channel->edge = edge;
> - channel->name = devm_kstrdup(&edge->dev, name, GFP_KERNEL);
> + channel->name = kstrdup(name, GFP_KERNEL);
> if (!channel->name)
> return ERR_PTR(-ENOMEM);
>
> @@ -1156,8 +1156,8 @@ static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *ed
> return channel;
>
> free_name_and_channel:
> - devm_kfree(&edge->dev, channel->name);
> - devm_kfree(&edge->dev, channel);
> + kfree(channel->name);
> + kfree(channel);
>
> return ERR_PTR(ret);
> }
> @@ -1378,13 +1378,13 @@ static int qcom_smd_parse_edge(struct device *dev,
> */
> static void qcom_smd_edge_release(struct device *dev)
> {
> - struct qcom_smd_channel *channel;
> + struct qcom_smd_channel *channel, *tmp;
> struct qcom_smd_edge *edge = to_smd_edge(dev);
>
> - list_for_each_entry(channel, &edge->channels, list) {
> - SET_RX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
> - SET_RX_CHANNEL_INFO(channel, head, 0);
> - SET_RX_CHANNEL_INFO(channel, tail, 0);
> + list_for_each_entry_safe(channel, tmp, &edge->channels, list) {
> + list_del(&channel->list);
> + kfree(channel->name);
> + kfree(channel);
> }
>
> kfree(edge);
> --
> 2.16.2
>