[AUDIT] Requeue messages at head of queue, up to audit_backlog

If netlink_unicast() fails, requeue the skb back at the head of the queue
it just came from, instead of the tail. And do so unless we've exceeded
the audit_backlog limit; not according to some other arbitrary limit.

From: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

diff --git a/kernel/audit.c b/kernel/audit.c
index 587d3b2eba7fb1506dbe277ed3967ccffdd24a80..4a697c73faec0b952d4b240e7c3fadef49313148 100644 (file)
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -142,7 +142,6 @@ struct audit_buffer {
        int                  total;
        int                  type;
        int                  pid;
-       int                  count; /* Times requeued */
 };
 
 void audit_set_type(struct audit_buffer *ab, int type)
@@ -526,9 +525,9 @@ static inline int audit_log_drain(struct audit_buffer *ab)
                        retval = netlink_unicast(audit_sock, skb, audit_pid,
                                                 MSG_DONTWAIT);
                }
-               if (retval == -EAGAIN && ab->count < 5) {
-                       ++ab->count;
-                       skb_queue_tail(&ab->sklist, skb);
+               if (retval == -EAGAIN &&
+                   (atomic_read(&audit_backlog)) < audit_backlog_limit) {
+                       skb_queue_head(&ab->sklist, skb);
                        audit_log_end_irq(ab);
                        return 1;
                }
@@ -666,7 +665,6 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx)
        ab->total = 0;
        ab->type  = AUDIT_KERNEL;
        ab->pid   = 0;
-       ab->count = 0;
 
 #ifdef CONFIG_AUDITSYSCALL
        if (ab->ctx)