On Wed, Jan 13, 2021 at 7:39 AM <[email protected]> wrote:
> From 82ebcf43481be21ee3e32ec1749b42f651737880 Mon Sep 17 00:00:00 2001
> From: Yang Yang <[email protected]>
> Date: Wed, 13 Jan 2021 20:18:04 +0800
> Subject: [PATCH] [RFC,v1,1/1] speed up syscall rule match while exiting syscall
> If user add any syscall rule, in all syscalls, audit_filter_syscall()
> traverses struct list_head audit_filter_list to find out whether current
> syscall match one rule. This takes o(n), which is not necessary, specially
> for user who add a very few syscall rules. On the other hand, user may not
> much care about rule add/delete speed. So do o(n) calculate at rule changing,
> and ease the burden of audit_filter_syscall().
>
> Define audit_syscall[NR_syscalls], every element stands for one syscall.
> audit_filter_syscall() checks audit_syscall[NR_syscalls].
> audit_syscall[n] == 0 indicates no rule audit syscall n, do a quick exit.
> audit_syscall[n] > 0 indicates at least one rule audit syscall n.
> audit_syscall[n] update when syscall rule changes.
>
> Signed-off-by: Yang Yang <[email protected]>
> ---
> include/linux/audit.h | 2 ++
> kernel/audit.c | 2 ++
> kernel/auditfilter.c | 16 ++++++++++++++++
> kernel/auditsc.c | 9 ++++++++-
> 4 files changed, 28 insertions(+), 1 deletion(-)
Before we go too far into a review of this patch, please provide some
performance measurements using a variety of rule counts, both common
and extreme, so that we can better judge the benefits of this patch.
The measurements should include both the rule add/delete time deltas
as well as the impact on the syscall invocations. If non-obvious,
please also include how you performed the measurements and captured
the data.
These are good things to include in the commit description when
submitting patches focused on improving performance.
--
paul moore
http://www.paul-moore.com