From 5f536bc5ae7948555af12b105a97aa887fe5da48 Mon Sep 17 00:00:00 2001
From: Justus Winter <4winter@informatik.uni-hamburg.de>
Date: Thu, 15 Aug 2013 09:37:57 +0200
Subject: hurd: add proc_mark_important

This is based on a fragment of Guillem Jovers patch presented here:

http://lists.gnu.org/archive/html/bug-hurd/2006-02/msg00081.html

It has been refreshed, updated and the copyright year is adjusted
properly. It has been complemented with the necessary features to
address the issues the original patch set out to address, namely
that killall5 freezes the proc translator before it tries to walk
over /proc/*/stat to decide which process to kill. Prior to this
patch (and the one marking the procfs server as important
process), killall5 would deadlock trying to walk over the proc
file system.

Ironically it would not have killed any process later on even if
it had the chance, since two values obtained from /proc/*/stat
are currently hardcoded to zero in our procfs. Patches addressing
the problem as a whole are prepared and will be sent as a follow
up.

* hurd/process.defs (proc_mark_important): New routine definitions.
* hurd/process_reply.defs (proc_mark_important_request): Likewise.
* hurd/process_request.defs (proc_mark_important_request): Likewise.
---
 hurd/process.defs         | 11 ++++++++++-
 hurd/process_reply.defs   |  9 ++++++++-
 hurd/process_request.defs | 12 +++++++++++-
 3 files changed, 29 insertions(+), 3 deletions(-)

(limited to 'hurd')

diff --git a/hurd/process.defs b/hurd/process.defs
index c74031a3..b7e1775a 100644
--- a/hurd/process.defs
+++ b/hurd/process.defs
@@ -1,5 +1,5 @@
 /* Definitions for process server interface
-   Copyright (C) 1992,93,94,95,96,97,2001 Free Software Foundation
+   Copyright (C) 1992,93,94,95,96,97,2001,2013 Free Software Foundation
 
 This file is part of the GNU Hurd.
 
@@ -374,3 +374,12 @@ routine proc_getnports (
 /*** Routines related to early server bootstrapping ***/
 
 skip;  /* Reserved for proc_set_init_task */
+
+/* Inform the process server that the process is important.  */
+routine proc_mark_important (
+	process: process_t);
+
+/* Query whether the process is important.  */
+routine proc_is_important (
+	process: process_t;
+	out essential: boolean_t);
diff --git a/hurd/process_reply.defs b/hurd/process_reply.defs
index bea00648..38f2082e 100644
--- a/hurd/process_reply.defs
+++ b/hurd/process_reply.defs
@@ -1,5 +1,5 @@
 /* Reply half of wait
-   Copyright (C) 1991,93,94,96,2001 Free Software Foundation, Inc.
+   Copyright (C) 1991,93,94,96,2001,13 Free Software Foundation, Inc.
 
 This file is part of the GNU Hurd.
 
@@ -178,3 +178,10 @@ simpleroutine proc_getnports (
 /*** Routines related to early server bootstrapping ***/
 
 skip;  /* Reserved for proc_set_init_task */
+skip; /* proc_mark_important */
+
+simpleroutine proc_is_important (
+	reply_port: reply_port_t;
+	RETURN_CODE_ARG;
+	essential: boolean_t);
+
diff --git a/hurd/process_request.defs b/hurd/process_request.defs
index e36b3679..3ef73536 100644
--- a/hurd/process_request.defs
+++ b/hurd/process_request.defs
@@ -1,6 +1,6 @@
 /* Definitions for process server interface (request-only version)
 
-   Copyright (C) 1992, 93, 94, 95, 96, 98 Free Software Foundation, Inc.
+   Copyright (C) 1992, 93, 94, 95, 96, 98, 2013 Free Software Foundation, Inc.
 
 This file is part of the GNU Hurd.
 
@@ -375,3 +375,13 @@ simpleroutine proc_getnports_request (
 /*** Routines related to early server bootstrapping ***/
 
 skip;  /* Reserved for proc_set_init_task */
+
+/* Inform the process server that the process is important.  */
+simpleroutine proc_mark_important_request (
+	process: process_t;
+	ureplyport reply: reply_port_t);
+
+/* Query whether the process is important.  */
+simpleroutine proc_is_important_request (
+	process: process_t;
+	ureplyport reply: reply_port_t);
-- 
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