{PATCH] Audit Filter Performance

[Steve Grubb]

On Monday 10 April 2006 19:46, Amy Griffis wrote:
> > While testing the watch performance, I noticed that selinux_task_ctxid()
> > was creeping into the results more than it should. Investigation showed
> > that the function call was being called whether it was needed or not. The
> > below patch fixes this.
>
> You've moved selinux_task_ctxid() inside a for loop.  Now it will be
> called for each selinux field in a rule.  I don't think that's what
> you want.  
>
> A better solution would be to set a rule flag in
> audit_data_to_entry(), then check that flag outside the for loop.

Yes, you are right - Thanks!  New patch below.

Signed-off-by: Steve Grubb <sgrubb at redhat.com>


diff -urp linux-2.6.16.x86_64.orig/kernel/auditsc.c linux-2.6.16.x86_64/kernel/auditsc.c
--- linux-2.6.16.x86_64.orig/kernel/auditsc.c	2006-04-11 08:44:02.000000000 -0400
+++ linux-2.6.16.x86_64/kernel/auditsc.c	2006-04-11 08:43:17.000000000 -0400
@@ -189,11 +189,9 @@ static int audit_filter_rules(struct tas
 			      struct audit_context *ctx,
 			      enum audit_state *state)
 {
-	int i, j;
+	int i, j, need_sid = 1;
 	u32 sid;
 
-	selinux_task_ctxid(tsk, &sid);
-
 	for (i = 0; i < rule->field_count; i++) {
 		struct audit_field *f = &rule->fields[i];
 		int result = 0;
@@ -295,11 +293,16 @@ static int audit_filter_rules(struct tas
 			   match for now to avoid losing information that
 			   may be wanted.   An error message will also be
 			   logged upon error */
-			if (f->se_rule)
+			if (f->se_rule) {
+				if (need_sid) {
+					selinux_task_ctxid(tsk, &sid);
+					need_sid = 0;
+				}
 				result = selinux_audit_rule_match(sid, f->type,
 				                                  f->op,
 				                                  f->se_rule,
 				                                  ctx);
+			}
 			break;
 		case AUDIT_ARG0:
 		case AUDIT_ARG1: