AUDIT: Wait for backlog to clear when generating messages.

Add a gfp_mask to audit_log_start() and audit_log(), to reduce the
amount of GFP_ATOMIC allocation -- most of it doesn't need to be 
GFP_ATOMIC. Also if the mask includes __GFP_WAIT, then wait up to
60 seconds for the auditd backlog to clear instead of immediately 
abandoning the message. 

The timeout should probably be made configurable, but for now it'll 
suffice that it only happens if auditd is actually running.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 77adef6..2f56546 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -259,11 +259,11 @@
 #ifdef CONFIG_AUDIT
 /* These are defined in audit.c */
 				/* Public API */
-extern void		    audit_log(struct audit_context *ctx, int type,
-				      const char *fmt, ...)
-			    __attribute__((format(printf,3,4)));
+extern void		    audit_log(struct audit_context *ctx, int gfp_mask,
+				      int type, const char *fmt, ...)
+				      __attribute__((format(printf,4,5)));
 
-extern struct audit_buffer *audit_log_start(struct audit_context *ctx,int type);
+extern struct audit_buffer *audit_log_start(struct audit_context *ctx, int gfp_mask, int type);
 extern void		    audit_log_format(struct audit_buffer *ab,
 					     const char *fmt, ...)
 			    __attribute__((format(printf,2,3)));