kernel_optimize_test/init
Chris Wilson 1ea3602095 kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE
commit bfe3911a91047557eb0e620f95a370aee6a248c7 upstream.

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) point to the same struct file. Since they depend on it for
core functionality, lift SYS_kcmp out of the non-default
CONFIG_CHECKPOINT_RESTORE into the selectable syscall category.

Rasmus Villemoes also pointed out that systemd uses SYS_kcmp to
deduplicate the per-service file descriptor store.

Note that some distributions such as Ubuntu are already enabling
CHECKPOINT_RESTORE in their configs and so, by extension, SYS_kcmp.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/3046
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: stable@vger.kernel.org
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> # DRM depends on kcmp
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> # systemd uses kcmp
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210205220012.1983-1-chris@chris-wilson.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:41 +01:00
..
calibrate.c
do_mounts_initrd.c Merge branch 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 09:40:34 -07:00
do_mounts_rd.c init: add an init_unlink helper 2020-07-31 08:17:52 +02:00
do_mounts.c init: add an init_chroot helper 2020-07-31 08:17:52 +02:00
do_mounts.h init: add an init_mknod helper 2020-07-31 08:17:54 +02:00
init_task.c fgraph: Initialize tracing_graph_pause at task creation 2021-02-10 09:29:16 +01:00
initramfs.c initramfs: fix clang build failure 2020-12-11 14:02:14 -08:00
Kconfig kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE 2021-03-04 11:38:41 +01:00
main.c rcu-tasks: Move RCU-tasks initialization to before early_initcall() 2021-01-19 18:27:28 +01:00
Makefile md: move the early init autodetect code to drivers/md/ 2020-07-16 15:34:47 +02:00
noinitramfs.c init: add an init_mknod helper 2020-07-31 08:17:54 +02:00
version.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00