From 428d6a971cffaba40b0f8ea5f66c3a3e0c853e88 Mon Sep 17 00:00:00 2001
From: Justus Winter <4winter@informatik.uni-hamburg.de>
Date: Tue, 18 Aug 2015 11:32:15 +0200
Subject: ipc: fix locking issues

* ipc/ipc_port.h (struct ipc_port): Document locking exception.
* ipc/ipc_port.c (ipc_port_destroy): Avoid accessing `port's fields
without the lock.
(ipc_port_alloc_special): Lock `port'.
* ipc/mach_msg.c (mach_msg_trap): Avoid using
`ipc_port_flag_protected_payload' on unlocked port.
* ipc/ipc_kmsg.c (ipc_kmsg_copyout_header): Likewise.
---
 ipc/ipc_port.h | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'ipc/ipc_port.h')

diff --git a/ipc/ipc_port.h b/ipc/ipc_port.h
index ade6967..de43b42 100644
--- a/ipc/ipc_port.h
+++ b/ipc/ipc_port.h
@@ -82,6 +82,8 @@ struct ipc_port {
 		ipc_port_timestamp_t timestamp;
 	} data;
 
+	/* Note: For pagers (IKOT_PAGER), this field is protected by
+	   vm_object_cache_lock.  */
 	ipc_kobject_t ip_kobject;
 
 	mach_port_mscount_t ip_mscount;
-- 
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