On Wed, Jan 13, 2021 at 7:39 AM <yang.yan...@zte.com.cn> wrote: > From 82ebcf43481be21ee3e32ec1749b42f651737880 Mon Sep 17 00:00:00 2001 > From: Yang Yang <yang.yan...@zte.com.cn> > 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 <yang.yan...@zte.com.cn> > --- > 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 www.paul-moore.com
