From 282e4ae275dc1b9b0b5bba6eb1b145cd1e80fa33 Mon Sep 17 00:00:00 2001
From: Justus Winter <4winter@informatik.uni-hamburg.de>
Date: Fri, 14 Mar 2014 00:29:02 +0100
Subject: mach-defpager: use protected payloads for object lookups

* mach-defpager/default_pager.c (pager_port_list_insert): Set
protected payload.
(pager_port_list_delete): Clear protected payload.
* mach-defpager/mig-decls.h (begin_using_default_pager_payload): New
function.
* mach-defpager/mig-mutate.h: Add mutator.
---
 mach-defpager/default_pager.c | 9 +++++++++
 mach-defpager/mig-decls.h     | 6 ++++++
 mach-defpager/mig-mutate.h    | 3 +++
 3 files changed, 18 insertions(+)

diff --git a/mach-defpager/default_pager.c b/mach-defpager/default_pager.c
index d40a9c92..831ed968 100644
--- a/mach-defpager/default_pager.c
+++ b/mach-defpager/default_pager.c
@@ -1803,6 +1803,12 @@ void pager_port_list_insert(port, ds)
 			(hurd_ihash_key_t) port,
 			(hurd_ihash_value_t) ds);
 	pthread_mutex_unlock(&all_pagers.lock);
+
+	/* Try to set a protected payload.  This is an optimization,
+	   if it fails we degrade gracefully.  */
+	mach_port_set_protected_payload (mach_task_self (),
+					 port,
+					 (unsigned long) ds);
 }
 
 void pager_port_list_delete(ds)
@@ -1812,6 +1818,9 @@ void pager_port_list_delete(ds)
 	hurd_ihash_locp_remove (&all_pagers.htable,
 				ds->htable_locp);
 	pthread_mutex_unlock(&all_pagers.lock);
+
+	mach_port_clear_protected_payload (mach_task_self (),
+					   ds->pager);
 }
 
 /*
diff --git a/mach-defpager/mig-decls.h b/mach-defpager/mig-decls.h
index 8118d61a..3357aa2e 100644
--- a/mach-defpager/mig-decls.h
+++ b/mach-defpager/mig-decls.h
@@ -31,4 +31,10 @@ begin_using_default_pager (mach_port_t port)
                                             (hurd_ihash_key_t) port);
 }
 
+static inline struct dstruct * __attribute__ ((unused))
+begin_using_default_pager_payload (unsigned long payload)
+{
+  return (default_pager_t) payload;
+}
+
 #endif /* __MACH_DEFPAGER_MIG_DECLS_H__ */
diff --git a/mach-defpager/mig-mutate.h b/mach-defpager/mig-mutate.h
index 54aeeba6..31acaa6e 100644
--- a/mach-defpager/mig-mutate.h
+++ b/mach-defpager/mig-mutate.h
@@ -18,5 +18,8 @@
    along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #define MEMORY_OBJECT_INTRAN default_pager_t begin_using_default_pager (mach_port_t)
+#define MEMORY_OBJECT_INTRAN_PAYLOAD			\
+  default_pager_t begin_using_default_pager_payload
+
 #define MEMORY_OBJECT_IMPORTS import "mig-decls.h";
 #define DEFAULT_PAGER_IMPORTS import "mig-decls.h";
-- 
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