Merge tag 'audit-pr-20221212' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit updates from Paul Moore:
 "Two performance oriented patches for the audit subsystem: one
  consolidates similar code to gain some caching advantages, while the
  other stores a value in a stack variable to avoid repeated lookups in
  a loop.

  The commit descriptions have more information, including some
  before/after performance measurements"

* tag 'audit-pr-20221212' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: unify audit_filter_{uring(), inode_name(), syscall()}
  audit: cache ctx->major in audit_filter_syscall()

1 files changed, 39 insertions, 36 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 9f8c05228d6d65..547c88be8a284a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -806,30 +806,53 @@ static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
 }
 
 /**
- * audit_filter_uring - apply filters to an io_uring operation
+ * __audit_filter_op - common filter helper for operations (syscall/uring/etc)
  * @tsk: associated task
  * @ctx: audit context
+ * @list: audit filter list
+ * @name: audit_name (can be NULL)
+ * @op: current syscall/uring_op
+ *
+ * Run the udit filters specified in @list against @tsk using @ctx,
+ * @name, and @op, as necessary; the caller is responsible for ensuring
+ * that the call is made while the RCU read lock is held. The @name
+ * parameter can be NULL, but all others must be specified.
+ * Returns 1/true if the filter finds a match, 0/false if none are found.
  */
-static void audit_filter_uring(struct task_struct *tsk,
-			       struct audit_context *ctx)
+static int __audit_filter_op(struct task_struct *tsk,
+			   struct audit_context *ctx,
+			   struct list_head *list,
+			   struct audit_names *name,
+			   unsigned long op)
 {
 	struct audit_entry *e;
 	enum audit_state state;
 
+	list_for_each_entry_rcu(e, list, list) {
+		if (audit_in_mask(&e->rule, op) &&
+		    audit_filter_rules(tsk, &e->rule, ctx, name,
+				       &state, false)) {
+			ctx->current_state = state;
+			return 1;
+		}
+	}
+	return 0;
+}
+
+/**
+ * audit_filter_uring - apply filters to an io_uring operation
+ * @tsk: associated task
+ * @ctx: audit context
+ */
+static void audit_filter_uring(struct task_struct *tsk,
+			       struct audit_context *ctx)
+{
 	if (auditd_test_task(tsk))
 		return;
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_URING_EXIT],
-				list) {
-		if (audit_in_mask(&e->rule, ctx->uring_op) &&
-		    audit_filter_rules(tsk, &e->rule, ctx, NULL, &state,
-				       false)) {
-			rcu_read_unlock();
-			ctx->current_state = state;
-			return;
-		}
-	}
+	__audit_filter_op(tsk, ctx, &audit_filter_list[AUDIT_FILTER_URING_EXIT],
+			NULL, ctx->uring_op);
 	rcu_read_unlock();
 }
 
@@ -841,24 +864,13 @@ static void audit_filter_uring(struct task_struct *tsk,
 static void audit_filter_syscall(struct task_struct *tsk,
 				 struct audit_context *ctx)
 {
-	struct audit_entry *e;
-	enum audit_state state;
-
 	if (auditd_test_task(tsk))
 		return;
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_EXIT], list) {
-		if (audit_in_mask(&e->rule, ctx->major) &&
-		    audit_filter_rules(tsk, &e->rule, ctx, NULL,
-				       &state, false)) {
-			rcu_read_unlock();
-			ctx->current_state = state;
-			return;
-		}
-	}
+	__audit_filter_op(tsk, ctx, &audit_filter_list[AUDIT_FILTER_EXIT],
+			NULL, ctx->major);
 	rcu_read_unlock();
-	return;
 }
 
 /*
@@ -870,17 +882,8 @@ static int audit_filter_inode_name(struct task_struct *tsk,
 				   struct audit_context *ctx) {
 	int h = audit_hash_ino((u32)n->ino);
 	struct list_head *list = &audit_inode_hash[h];
-	struct audit_entry *e;
-	enum audit_state state;
 
-	list_for_each_entry_rcu(e, list, list) {
-		if (audit_in_mask(&e->rule, ctx->major) &&
-		    audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
-			ctx->current_state = state;
-			return 1;
-		}
-	}
-	return 0;
+	return __audit_filter_op(tsk, ctx, list, n, ctx->major);
 }
 
 /* At syscall exit time, this filter is called if any audit_names have been