Re: [PATCH] apparmor: Fix network performance issue in aa_label_sk_perm

From: John Johansen
Date: Fri Sep 07 2018 - 12:37:42 EST


On 09/06/2018 09:33 PM, Tony Jones wrote:
> The netperf benchmark shows a 5.73% reduction in throughput for
> small (64 byte) transfers by unconfined tasks.
>
> DEFINE_AUDIT_SK() in aa_label_sk_perm() should not be performed
> unconditionally, rather only when the label is confined.
>
> netperf-tcp
> 56974a6fc^ 56974a6fc
> Min 64 563.48 ( 0.00%) 531.17 ( -5.73%)
> Min 128 1056.92 ( 0.00%) 999.44 ( -5.44%)
> Min 256 1945.95 ( 0.00%) 1867.97 ( -4.01%)
> Min 1024 6761.40 ( 0.00%) 6364.23 ( -5.87%)
> Min 2048 11110.53 ( 0.00%) 10606.20 ( -4.54%)
> Min 3312 13692.67 ( 0.00%) 13158.41 ( -3.90%)
> Min 4096 14926.29 ( 0.00%) 14457.46 ( -3.14%)
> Min 8192 18399.34 ( 0.00%) 18091.65 ( -1.67%)
> Min 16384 21384.13 ( 0.00%) 21158.05 ( -1.06%)
> Hmean 64 564.96 ( 0.00%) 534.38 ( -5.41%)
> Hmean 128 1064.42 ( 0.00%) 1010.12 ( -5.10%)
> Hmean 256 1965.85 ( 0.00%) 1879.16 ( -4.41%)
> Hmean 1024 6839.77 ( 0.00%) 6478.70 ( -5.28%)
> Hmean 2048 11154.80 ( 0.00%) 10671.13 ( -4.34%)
> Hmean 3312 13838.12 ( 0.00%) 13249.01 ( -4.26%)
> Hmean 4096 15009.99 ( 0.00%) 14561.36 ( -2.99%)
> Hmean 8192 18975.57 ( 0.00%) 18326.54 ( -3.42%)
> Hmean 16384 21440.44 ( 0.00%) 21324.59 ( -0.54%)
> Stddev 64 1.24 ( 0.00%) 2.85 (-130.64%)
> Stddev 128 4.51 ( 0.00%) 6.53 ( -44.84%)
> Stddev 256 11.67 ( 0.00%) 8.50 ( 27.16%)
> Stddev 1024 48.33 ( 0.00%) 75.07 ( -55.34%)
> Stddev 2048 54.82 ( 0.00%) 65.16 ( -18.86%)
> Stddev 3312 153.57 ( 0.00%) 56.29 ( 63.35%)
> Stddev 4096 100.25 ( 0.00%) 88.50 ( 11.72%)
> Stddev 8192 358.13 ( 0.00%) 169.99 ( 52.54%)
> Stddev 16384 43.99 ( 0.00%) 141.82 (-222.39%)
>
> Signed-off-by: Tony Jones <tonyj@xxxxxxx>
> Fixes: 56974a6fcfef ("apparmor: add base infastructure for socket
> mediation")

hey Tony,

thanks for the patch, I am curious did you're investigation look
into what parts of DEFINE_AUDIT_SK are causing the issue?

regardless, I have pulled it into apparmor next

> ---
> security/apparmor/net.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/security/apparmor/net.c b/security/apparmor/net.c
> index bb24cfa0a164..d5d72dd1ca1f 100644
> --- a/security/apparmor/net.c
> +++ b/security/apparmor/net.c
> @@ -146,17 +146,20 @@ int aa_af_perm(struct aa_label *label, const char *op, u32 request, u16 family,
> static int aa_label_sk_perm(struct aa_label *label, const char *op, u32 request,
> struct sock *sk)
> {
> - struct aa_profile *profile;
> - DEFINE_AUDIT_SK(sa, op, sk);
> + int error = 0;
>
> AA_BUG(!label);
> AA_BUG(!sk);
>
> - if (unconfined(label))
> - return 0;
> + if (!unconfined(label)) {
> + struct aa_profile *profile;
> + DEFINE_AUDIT_SK(sa, op, sk);
>
> - return fn_for_each_confined(label, profile,
> - aa_profile_af_sk_perm(profile, &sa, request, sk));
> + error = fn_for_each_confined(label, profile,
> + aa_profile_af_sk_perm(profile, &sa, request, sk));
> + }
> +
> + return error;
> }
>
> int aa_sk_perm(const char *op, u32 request, struct sock *sk)
>