On 2021-02-12 1:57 p.m., Emil Velikov wrote:
On Fri, 5 Feb 2021 at 22:01, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote:
Userspace has discovered the functionality offered by SYS_kcmp and has
started to depend upon it. In particular, Mesa uses SYS_kcmp for
os_same_file_description() in order to identify when two fd (e.g. device
or dmabuf)
As you rightfully point out, SYS_kcmp is a bit of a two edged sword.
While you mention the CONFIG issue, there is also a portability aspect
(mesa runs on more than just linux) and as well as sandbox filtering
of the extra syscall.
Last time I looked, the latter was still an issue and mesa was using
SYS_kcmp to compare device node fds.
A far shorter and more portable solution is possible, so let me
prepare a Mesa patch.
Make sure to read my comments on
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6881 first. :)
--
Earthling Michel Dänzer | https://redhat.com
Libre software enthusiast | Mesa and X developer
