Messages in this thread | | | From | Andrei Vagin <> | Subject | [PATCH 0/4] seccomp: add the synchronous mode for seccomp_unotify | Date | Mon, 29 Aug 2022 18:43:52 -0700 |
| |
seccomp_unotify allows more privileged processes does actions on behalf of less privileged processes.
In many cases, the workflow is fully synchronous. It means a target process triggers a system call and passes controls to a supervisor process that handles the system call and returns controls to the target process. In this context, "synchronous" means that only one process is running and another one is waiting.
The new WF_CURRENT_CPU flag advises the scheduler to move the wakee to the current CPU. For such synchronous workflows, it makes context switches a few times faster.
Right now, each interaction takes 12µs. With this patch, it takes about 3µs.
Cc: Andy Lutomirski <luto@amacapital.net> Cc: Christian Brauner <brauner@kernel.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Peter Oskolkov <posk@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tycho Andersen <tycho@tycho.pizza> Cc: Will Drewry <wad@chromium.org> Cc: Vincent Guittot <vincent.guittot@linaro.org>
Andrei Vagin (3): seccomp: don't use semaphore and wait_queue together sched: add a few helpers to wake up tasks on the current cpu seccomp: add the synchronous mode for seccomp_unotify
Peter Oskolkov (1): sched/umcg: add WF_CURRENT_CPU and externise ttwu
include/linux/completion.h | 1 + include/linux/swait.h | 1 + include/linux/wait.h | 3 ++ include/uapi/linux/seccomp.h | 4 ++ kernel/sched/completion.c | 12 ++++++ kernel/sched/core.c | 5 +-- kernel/sched/fair.c | 4 ++ kernel/sched/sched.h | 13 ++++--- kernel/sched/swait.c | 11 ++++++ kernel/sched/wait.c | 5 +++ kernel/seccomp.c | 73 +++++++++++++++++++++++++++++------- 11 files changed, 110 insertions(+), 22 deletions(-)
-- 2.37.2
| |