[Mesa-dev] [Mesa-stable] [PATCH] gallium/winsys/kms: fix leaking gem handle.

[Emil Velikov]

Hi Tao Wu,

Welcome to Mesa!

On 12 November 2017 at 07:00, Tao Wu <lepton at google.com> wrote:
> When handle was got from drmPrimeFDToHandle, it can't be destroyed with
> destroy_dumb. Change to use drm_gem_close to release it. Otherwise video
> ram could get leaked.
>
> Signed-off-by: Tao Wu <lepton at google.com>
> CC: <mesa-stable at lists.freedesktop.org>
> ---
>  src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c b/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
> index 22e1c936ac5..f7cd09b6aa9 100644
> --- a/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
> +++ b/src/gallium/winsys/sw/kms-dri/kms_dri_sw_winsys.c
> @@ -27,6 +27,7 @@
>   *
>   **************************************************************************/
>
> +#include <errno.h>
>  #include <stdio.h>
>  #include <stdlib.h>
>  #include <stddef.h>
> @@ -172,7 +173,25 @@ kms_sw_displaytarget_destroy(struct sw_winsys *ws,
>
>     memset(&destroy_req, 0, sizeof destroy_req);
>     destroy_req.handle = kms_sw_dt->handle;
> -   drmIoctl(kms_sw->fd, DRM_IOCTL_MODE_DESTROY_DUMB, &destroy_req);
> +   int ret = drmIoctl(kms_sw->fd, DRM_IOCTL_MODE_DESTROY_DUMB, &destroy_req);
> +   /* If handle was from drmPrimeFDToHandle, then kms_sw->fd is connected
> +    * as render, we have to use drm_gem_close to release it.
> +    */
> +   if (ret < 0) {
> +      if (errno == EACCES) {
The patch should resolve the leak, although I'm unsure about the
explicit EACCESS check.
AFAICT there is no documentation which that said errno will always
(and only) be returned in this case.

A more robust solution is to have separate bo_list for the
prime/imported buffers. This way will ensure we use the correct ioctl.
What do you think, do you think you can give that a spin?

Thanks
Emil