# This patch makes tt mode use filehandles for the pipes it uses for context
# switching.  This protects process creation against failing when there are
# no free file descriptors.
Index: um/arch/um/include/user_util.h
===================================================================
--- um.orig/arch/um/include/user_util.h	2004-08-05 20:38:09.000000000 -0400
+++ um/arch/um/include/user_util.h	2004-08-05 22:54:05.000000000 -0400
@@ -73,7 +73,6 @@
 extern void tracer_panic(char *msg, ...);
 extern char *get_umid(int only_if_set);
 extern void do_longjmp(void *p, int val);
-extern void suspend_new_thread(int fd);
 extern int detach(int pid, int sig);
 extern int attach(int pid);
 extern void kill_child_dead(int pid);
Index: um/arch/um/kernel/process.c
===================================================================
--- um.orig/arch/um/kernel/process.c	2004-08-05 20:38:09.000000000 -0400
+++ um/arch/um/kernel/process.c	2004-08-05 22:54:30.000000000 -0400
@@ -134,16 +134,6 @@
 	return(arg.pid);
 }
 
-void suspend_new_thread(int fd)
-{
-	char c;
-
-	os_stop_process(os_getpid());
-
-	if(os_read_file(fd, &c, sizeof(c)) != sizeof(c))
-		panic("read failed in suspend_new_thread");
-}
-
 static int ptrace_child(void *arg)
 {
 	int pid = os_getpid();
Index: um/arch/um/kernel/skas/process.c
===================================================================
--- um.orig/arch/um/kernel/skas/process.c	2004-08-05 21:24:26.000000000 -0400
+++ um/arch/um/kernel/skas/process.c	2004-08-05 22:54:30.000000000 -0400
@@ -356,28 +356,6 @@
 	siglongjmp(initial_jmpbuf, 4);
 }
 
-int new_mm(int from)
-{
-	struct proc_mm_op copy;
-	int n, fd = os_open_file("/proc/mm", 
-				 of_cloexec(of_write(OPENFLAGS())), 0);
-
-	if(fd < 0)
-		return(fd);
-
-	if(from != -1){
-		copy = ((struct proc_mm_op) { .op 	= MM_COPY_SEGMENTS,
-					      .u 	= 
-					      { .copy_segments	= from } } );
-		n = os_write_file(fd, &copy, sizeof(copy));
-		if(n != sizeof(copy)) 
-			printk("new_mm : /proc/mm copy_segments failed, "
-			       "err = %d\n", -n);
-	}
-
-	return(fd);
-}
-
 void switch_mm_skas(int mm_fd)
 {
 	int err;
Index: um/arch/um/kernel/skas/process_kern.c
===================================================================
--- um.orig/arch/um/kernel/skas/process_kern.c	2004-08-05 22:40:59.000000000 -0400
+++ um/arch/um/kernel/skas/process_kern.c	2004-08-05 22:54:40.000000000 -0400
@@ -16,6 +16,8 @@
 #include "frame.h"
 #include "kern.h"
 #include "mode.h"
+#include "filehandle.h"
+#include "proc_mm.h"
 
 int singlestepping_skas(void)
 {
@@ -136,6 +138,28 @@
 	return(0);
 }
 
+int new_mm(int from)
+{
+	struct proc_mm_op copy;
+	int n, fd;
+
+	fd = open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
+	if(fd < 0)
+		return(fd);
+
+	if(from != -1){
+		copy = ((struct proc_mm_op) { .op 	= MM_COPY_SEGMENTS,
+					      .u 	= 
+					      { .copy_segments	= from } } );
+		n = os_write_file(fd, &copy, sizeof(copy));
+		if(n != sizeof(copy)) 
+			printk("new_mm : /proc/mm copy_segments failed, "
+			       "err = %d\n", -n);
+	}
+
+	return(fd);
+}
+
 void init_idle_skas(void)
 {
 	cpu_tasks[current_thread->cpu].pid = os_getpid();
Index: um/arch/um/kernel/smp.c
===================================================================
--- um.orig/arch/um/kernel/smp.c	2004-08-05 20:38:09.000000000 -0400
+++ um/arch/um/kernel/smp.c	2004-08-05 22:02:40.000000000 -0400
@@ -116,8 +116,7 @@
 			    .task = 	new_task } );
 	idle_threads[cpu] = new_task;
 	CHOOSE_MODE(os_write_file(new_task->thread.mode.tt.switch_pipe[1], &c, 
-			  sizeof(c)),
-		    ({ panic("skas mode doesn't support SMP"); }));
+				  sizeof(c)),
 	wake_up_forked_process(new_task);
 	return(new_task);
 }
Index: um/arch/um/kernel/tt/process_kern.c
===================================================================
--- um.orig/arch/um/kernel/tt/process_kern.c	2004-08-05 20:38:09.000000000 -0400
+++ um/arch/um/kernel/tt/process_kern.c	2004-08-05 22:54:05.000000000 -0400
@@ -116,6 +116,17 @@
 	os_close_file(current->thread.mode.tt.switch_pipe[1]);
 }
 
+void suspend_new_thread(int fd)
+{
+	int err;
+	char c;
+
+	os_stop_process(os_getpid());
+	err = os_read_file(fd, &c, sizeof(c));
+	if(err != sizeof(c))
+		panic("read failed in suspend_new_thread, err = %d", -err);
+}
+
 void schedule_tail(task_t *prev);
 
 static void new_thread_handler(int sig)
@@ -236,7 +247,7 @@
 	err = os_pipe(p->thread.mode.tt.switch_pipe, 1, 1);
 	if(err < 0){
 		printk("copy_thread : pipe failed, err = %d\n", -err);
-		return(err);
+		goto out;
 	}
 
 	stack = alloc_stack(0, 0);
@@ -267,7 +278,9 @@
 	current->thread.request.op = OP_FORK;
 	current->thread.request.u.fork.pid = new_pid;
 	os_usr1_process(os_getpid());
-	return(0);
+	err = 0;
+ out:
+	return(err);
 }
 
 void reboot_tt(void)
@@ -475,7 +488,7 @@
 
 	init_task.thread.mode.tt.extern_pid = pid;
 	err = os_pipe(init_task.thread.mode.tt.switch_pipe, 1, 1);
-	if(err)	
+	if(err)
 		panic("Can't create switch pipe for init_task, errno = %d", 
 		      -err);
 }
Index: um/include/asm-um/processor-generic.h
===================================================================
--- um.orig/include/asm-um/processor-generic.h	2004-08-05 20:38:09.000000000 -0400
+++ um/include/asm-um/processor-generic.h	2004-08-05 22:09:42.000000000 -0400
@@ -1,5 +1,5 @@
 /* 
- * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2000 - 2004 Jeff Dike (jdike@addtoit.com)
  * Licensed under the GPL
  */