From 4666ac50272776168d29d2c4142de771daa30381 Mon Sep 17 00:00:00 2001
From: julian <julian@FreeBSD.org>
Date: Wed, 6 Jan 1999 23:05:42 +0000
Subject: Add (but don't activate) code for a special VM option to make
 downward growing stacks more general. Add (but don't activate) code to use
 the new stack facility when running threads, (specifically the linux threads
 support). This allows people to use both linux compiled linuxthreads, and
 also the native FreeBSD linux-threads port.

The code is conditional on VM_STACK. Not using this will
produce the old heavily tested system.

Submitted by: Richard Seaman <dick@tar.com>
---
 sys/amd64/amd64/trap.c | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

(limited to 'sys/amd64/amd64/trap.c')

diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index e672368..42b0c85 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.131 1998/12/16 15:21:50 bde Exp $
+ *	$Id: trap.c,v 1.132 1998/12/28 23:02:56 msmith Exp $
  */
 
 /*
@@ -665,6 +665,7 @@ trap_pfault(frame, usermode, eva)
 		/*
 		 * Grow the stack if necessary
 		 */
+#ifndef VM_STACK
 		if ((caddr_t)va > vm->vm_maxsaddr && va < USRSTACK) {
 			if (!grow(p, va)) {
 				rv = KERN_FAILURE;
@@ -673,6 +674,20 @@ trap_pfault(frame, usermode, eva)
 			}
 		}
 
+#else
+		/* grow_stack returns false only if va falls into
+		 * a growable stack region and the stack growth
+		 * fails.  It returns true if va was not within
+		 * a growable stack region, or if the stack 
+		 * growth succeeded.
+		 */
+		if (!grow_stack (p, va)) {
+			rv = KERN_FAILURE;
+			--p->p_lock;
+			goto nogo;
+		}
+#endif
+		
 		/* Fault in the user page: */
 		rv = vm_fault(map, va, ftype,
 			(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY : 0);
@@ -775,6 +790,7 @@ trap_pfault(frame, usermode, eva)
 		/*
 		 * Grow the stack if necessary
 		 */
+#ifndef VM_STACK
 		if ((caddr_t)va > vm->vm_maxsaddr && va < USRSTACK) {
 			if (!grow(p, va)) {
 				rv = KERN_FAILURE;
@@ -782,6 +798,19 @@ trap_pfault(frame, usermode, eva)
 				goto nogo;
 			}
 		}
+#else
+		/* grow_stack returns false only if va falls into
+		 * a growable stack region and the stack growth
+		 * fails.  It returns true if va was not within
+		 * a growable stack region, or if the stack 
+		 * growth succeeded.
+		 */
+		if (!grow_stack (p, va)) {
+			rv = KERN_FAILURE;
+			--p->p_lock;
+			goto nogo;
+		}
+#endif
 
 		/* Fault in the user page: */
 		rv = vm_fault(map, va, ftype,
@@ -969,12 +998,19 @@ int trapwrite(addr)
 
 	++p->p_lock;
 
+#ifndef VM_STACK
 	if ((caddr_t)va >= vm->vm_maxsaddr && va < USRSTACK) {
 		if (!grow(p, va)) {
 			--p->p_lock;
 			return (1);
 		}
 	}
+#else
+	if (!grow_stack (p, va)) {
+		--p->p_lock;
+		return (1);
+	}
+#endif
 
 	/*
 	 * fault the data page
-- 
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