Re: [PATCH v2 2/2] libvchan: replace munmap with correct xc_gntshr_munmap

[Daniel De Graaf <dgdegra@tycho.nsa.gov>]

On 05/04/2013 06:10 PM, Marek Marczykowski wrote:
> On linux it will end up in munmap anyway, but do not assume any
> particular xc_gntshr_munmap implementation details.
>
> Signed-off-by: Marek Marczykowski <marmarek@invisiblethingslab.com>

On a client, this ends up using xc_gntshr_munmap to unmap pages that
were mapped with xc_gnttab_map_* instead of using xc_gnttab_unmam

George: unless there is another OS besides Linux that implements the
xc_gntshr_* interfaces (I found none from a grep of the source), this
is just code clean-up and so could be postponed to 4.4.

> ---
>   tools/libvchan/io.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/tools/libvchan/io.c b/tools/libvchan/io.c
> index 5ec5fb9..3040099 100644
> --- a/tools/libvchan/io.c
> +++ b/tools/libvchan/io.c
> @@ -324,9 +324,11 @@ void libxenvchan_close(struct libxenvchan *ctrl)
>   	if (!ctrl)
>   		return;
>   	if (ctrl->read.order >= PAGE_SHIFT)
> -		munmap(ctrl->read.buffer, 1 << ctrl->read.order);
> +		xc_gntshr_munmap(ctrl->gntshr, ctrl->read.buffer,
> +				1 << (ctrl->read.order - PAGE_SHIFT));
>   	if (ctrl->write.order >= PAGE_SHIFT)
> -		munmap(ctrl->write.buffer, 1 << ctrl->write.order);
> +		xc_gntshr_munmap(ctrl->gntshr, ctrl->write.buffer,
> +				1 << (ctrl->write.order - PAGE_SHIFT));
>   	if (ctrl->ring) {
>   		if (ctrl->is_server) {
>   			ctrl->ring->srv_live = 0;
>
-- 
Daniel De Graaf
National Security Agency