X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/6d2010ae8f7a6078e10b361c6962983bab233e0f..008676633c2ad2c325837c2b64915f7ded690a8f:/bsd/security/audit/audit_worker.c

diff --git a/bsd/security/audit/audit_worker.c b/bsd/security/audit/audit_worker.c
index d9ef366a2..85b5c8241 100644
--- a/bsd/security/audit/audit_worker.c
+++ b/bsd/security/audit/audit_worker.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 1999-2010 Apple Inc.
+ * Copyright (c) 1999-2016 Apple Inc.
  * Copyright (c) 2006-2008 Robert N. M. Watson
  * All rights reserved.
  *
@@ -68,10 +68,8 @@
 
 #include <kern/host.h>
 #include <kern/zalloc.h>
-#include <kern/lock.h>
 #include <kern/sched_prim.h>
 #include <kern/task.h>
-#include <kern/wait_queue.h>
 
 #include <net/route.h>
 
@@ -105,10 +103,10 @@ static struct vnode		*audit_vp;
 #define	AUDIT_WORKER_SX_DESTROY()	slck_destroy(&audit_worker_sl)
 
 /*
- * The audit_draining flag is set when audit is disabled and the audit
+ * The audit_q_draining flag is set when audit is disabled and the audit
  * worker queue is being drained.
  */
-static int			audit_draining;
+static int			audit_q_draining;
 
 /*
  * The special kernel audit record, audit_drain_kar, is used to mark the end of
@@ -416,6 +414,7 @@ out:
  * Note: this means that the effect bound on the size of the pending record
  * queue is 2x the length of the global queue.
  */
+__attribute__((noreturn))
 static void
 audit_worker(void)
 {
@@ -460,7 +459,7 @@ audit_worker(void)
 		while ((ar = TAILQ_FIRST(&ar_worklist))) {
 			TAILQ_REMOVE(&ar_worklist, ar, k_q);
 			if (ar->k_ar_commit & AR_DRAIN_QUEUE) {
-				audit_draining = 0;
+				audit_q_draining = 0;
 				cv_broadcast(&audit_drain_cv);
 			} else {
 				audit_worker_process_record(ar);
@@ -485,51 +484,54 @@ audit_rotate_vnode(kauth_cred_t cred, struct vnode *vp)
 {
 	kauth_cred_t old_audit_cred;
 	struct vnode *old_audit_vp;
-	int audit_was_enabled;
 
 	KASSERT((cred != NULL && vp != NULL) || (cred == NULL && vp == NULL),
 	    ("audit_rotate_vnode: cred %p vp %p", cred, vp));
 
-	/*
-	 * Rotate the vnode/cred, and clear the rotate flag so that we will
-	 * send a rotate trigger if the new file fills.
-	 */
-	AUDIT_WORKER_SX_XLOCK();
-	old_audit_cred = audit_ctx.vc_ucred;
-	old_audit_vp = audit_vp;
-	audit_ctx.vc_ucred = cred;
-	audit_file_rotate_wait = 0;
-	audit_was_enabled = audit_enabled;
-	if ((audit_enabled = (NULL != vp)))
-		audit_vp = vp;
-	audit_draining = (audit_was_enabled && !audit_enabled);
-	AUDIT_WORKER_SX_XUNLOCK();
 
-	/*
-	 * If audit (was enabled and) is now disabled then drain the audit
-	 * record queue and wait until it is done.
-	 */
 	mtx_lock(&audit_mtx);
-	if (audit_draining) {
+	if (audit_enabled && (NULL == vp)) {
+		/* Auditing is currently enabled but will be disabled. */
+
 		/*
-		 * Insert the special drain record in the queue.
+		 * Disable auditing now so nothing more is added while the
+		 * audit worker thread is draining the audit record queue.
 		 */
+		audit_enabled = 0;
+
+		/*
+		 * Drain the auditing queue by inserting a drain record at the
+		 * end of the queue and waiting for the audit worker thread
+		 * to find this record and signal that it is done before
+		 * we close the audit trail.
+		 */
+		audit_q_draining = 1;
 		while (audit_q_len >= audit_qctrl.aq_hiwater)
 			cv_wait(&audit_watermark_cv, &audit_mtx);
 		TAILQ_INSERT_TAIL(&audit_q, &audit_drain_kar, k_q);
 		audit_q_len++;
 		cv_signal(&audit_worker_cv);
-
-		/*
-		 * Wait for the audit worker thread to signal it is done.
-		 */
-		while (audit_draining)
-			cv_wait(&audit_drain_cv, &audit_mtx);
-
-		audit_vp = NULL;
 	}
+
+	/* If the audit queue is draining then wait here until it's done. */
+	while (audit_q_draining)
+		cv_wait(&audit_drain_cv, &audit_mtx);
 	mtx_unlock(&audit_mtx);
 
+
+	/*
+	 * Rotate the vnode/cred, and clear the rotate flag so that we will
+	 * send a rotate trigger if the new file fills.
+	 */
+	AUDIT_WORKER_SX_XLOCK();
+	old_audit_cred = audit_ctx.vc_ucred;
+	old_audit_vp = audit_vp;
+	audit_ctx.vc_ucred = cred;
+	audit_vp = vp;
+	audit_file_rotate_wait = 0;
+	audit_enabled = (audit_vp != NULL);
+	AUDIT_WORKER_SX_XUNLOCK();
+
 	/*
 	 * If there was an old vnode/credential, close and free.
 	 */