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Commit 16e1904e authored by Chris Wright's avatar Chris Wright Committed by David Woodhouse
Browse files

AUDIT: Add helper functions to allocate and free audit_buffers. 



Signed-off-by: default avatarChris Wright <chrisw@osdl.org>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent c2f0c7c3

kernel/audit.c

+38 −23
Original line number Diff line number Diff line
@@ -620,6 +620,42 @@ static int __init audit_enable(char *str) 


__setup("audit=", audit_enable);



static void audit_buffer_free(struct audit_buffer *ab)

{

	unsigned long flags;



	atomic_dec(&audit_backlog);

	spin_lock_irqsave(&audit_freelist_lock, flags);

	if (++audit_freelist_count > AUDIT_MAXFREE)

		kfree(ab);

	else

		list_add(&ab->list, &audit_freelist);

	spin_unlock_irqrestore(&audit_freelist_lock, flags);

}



static struct audit_buffer * audit_buffer_alloc(int gfp_mask)

{

	unsigned long flags;

	struct audit_buffer *ab = NULL;



	spin_lock_irqsave(&audit_freelist_lock, flags);

	if (!list_empty(&audit_freelist)) {

		ab = list_entry(audit_freelist.next,

				struct audit_buffer, list);

		list_del(&ab->list);

		--audit_freelist_count;

	}

	spin_unlock_irqrestore(&audit_freelist_lock, flags);



	if (!ab) {

		ab = kmalloc(sizeof(*ab), GFP_ATOMIC);

		if (!ab)

			goto out;

	}

	atomic_inc(&audit_backlog);

out:

	return ab;

}



/* Obtain an audit buffer.  This routine does locking to obtain the

 * audit buffer, but then no locking is required for calls to
@@ -630,7 +666,6 @@ __setup("audit=", audit_enable); 
struct audit_buffer *audit_log_start(struct audit_context *ctx)

{

	struct audit_buffer	*ab	= NULL;

	unsigned long		flags;

	struct timespec		t;

	unsigned int		serial;
@@ -649,23 +684,12 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx) 
		return NULL;

	}



	spin_lock_irqsave(&audit_freelist_lock, flags);

	if (!list_empty(&audit_freelist)) {

		ab = list_entry(audit_freelist.next,

				struct audit_buffer, list);

		list_del(&ab->list);

		--audit_freelist_count;

	}

	spin_unlock_irqrestore(&audit_freelist_lock, flags);



	if (!ab)

		ab = kmalloc(sizeof(*ab), GFP_ATOMIC);

	ab = audit_buffer_alloc(GFP_ATOMIC);

	if (!ab) {

		audit_log_lost("out of memory in audit_log_start");

		return NULL;

	}



	atomic_inc(&audit_backlog);

	skb_queue_head_init(&ab->sklist);



	ab->ctx   = ctx;
@@ -824,8 +848,6 @@ static void audit_log_end_irq(struct audit_buffer *ab) 
 * be called in an irq context. */

static void audit_log_end_fast(struct audit_buffer *ab)

{

	unsigned long flags;



	BUG_ON(in_irq());

	if (!ab)

		return;
@@ -836,14 +858,7 @@ static void audit_log_end_fast(struct audit_buffer *ab) 
		if (audit_log_drain(ab))

			return;

	}



	atomic_dec(&audit_backlog);

	spin_lock_irqsave(&audit_freelist_lock, flags);

	if (++audit_freelist_count > AUDIT_MAXFREE)

		kfree(ab);

	else

		list_add(&ab->list, &audit_freelist);

	spin_unlock_irqrestore(&audit_freelist_lock, flags);

	audit_buffer_free(ab);

}



/* Send or queue the message in the audit buffer, depending on the