On Fri, 12 Feb 2021 at 14:01, Michel Dänzer michel@daenzer.net wrote:
On 2021-02-12 1:57 p.m., Emil Velikov wrote:
On Fri, 5 Feb 2021 at 22:01, Chris Wilson chris@chris-wilson.co.uk 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. :)
Much appreciated. I might have been "slightly" off - pardon for the noise o/
-Emil