On Mon 11 May 09:29 PDT 2020, Srinivas Kandagatla wrote:
> fastrpc_invoke_ctx can have refcount of 2 in error path where
> rpmsg_send() fails to send invoke message. decrement the refcount
> properly in the error path to fix this leak.
>
> This also fixes below static checker warning:
>
> drivers/misc/fastrpc.c:990 fastrpc_internal_invoke()
> warn: 'ctx->refcount.refcount.ref.counter' not decremented on lines: 990.
>
> Fixes: c68cfb718c8f ("misc: fastrpc: Add support for context")
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
> drivers/misc/fastrpc.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> index 9065d3e71ff7..07065728e39f 100644
> --- a/drivers/misc/fastrpc.c
> +++ b/drivers/misc/fastrpc.c
> @@ -949,8 +949,10 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl, u32 kernel,
> dma_wmb();
> /* Send invoke buffer to remote dsp */
> err = fastrpc_invoke_send(fl->sctx, ctx, kernel, handle);
> - if (err)
> + if (err) {
> + fastrpc_context_put(ctx);
So we refcount ctx once for the invoke function and once between send
and callback. And this fastrpc_context_put() would counter the fact that
rpmsg_send() failed, so we will not get the "remote's" put().
I think that if you moved this call inside fastrpc_invoke_send() it's
relationship to the failing rpmsg_send() would be obvious.
Regards,
Bjorn
> goto bail;
> + }
>
> if (kernel) {
> if (!wait_for_completion_timeout(&ctx->work, 10 * HZ))
> --
> 2.21.0
>
