From 198cee939d3e4b4dd99ca5ada89b8b3d4740f3c8 Mon Sep 17 00:00:00 2001
From: deraadt <deraadt@openbsd.org>
Date: Thu, 30 Nov 1995 18:40:21 +0000
Subject: [PATCH] integrate 040 MDP_UNCACHE_WX cache changes by niklas &
 deraadt

---
 sys/arch/mac68k/include/proc.h   |  2 ++
 sys/arch/mac68k/mac68k/machdep.c | 17 +++++++++++++++++
 sys/arch/mac68k/mac68k/pmap.c    |  7 +++++++
 3 files changed, 26 insertions(+)

diff --git a/sys/arch/mac68k/include/proc.h b/sys/arch/mac68k/include/proc.h
index c343f3a496c..7707df4d577 100644
--- a/sys/arch/mac68k/include/proc.h
+++ b/sys/arch/mac68k/include/proc.h
@@ -48,3 +48,5 @@ struct mdproc {
 #define	MDP_STACKADJ	0x0002	/* Frame SP adjusted, might have to
 				   undo when system call returns
 				   ERESTART. */
+#define	MDP_UNCACHE_WX	0x0004	/* The process might modify code, so
+				   don't cache writeable executable pages.  */
diff --git a/sys/arch/mac68k/mac68k/machdep.c b/sys/arch/mac68k/mac68k/machdep.c
index 20f1b8ec68c..d410a95d648 100644
--- a/sys/arch/mac68k/mac68k/machdep.c
+++ b/sys/arch/mac68k/mac68k/machdep.c
@@ -123,6 +123,11 @@
 
 #include <dev/cons.h>
 
+#ifdef COMPAT_SUNOS
+#include <compat/sunos/sunos_syscall.h>
+extern struct emul emul_sunos;
+#endif
+
 #include "via.h"
 #include "macrom.h"
 #include "ether.h"
@@ -478,6 +483,18 @@ setregs(p, pack, sp, retval)
 	if (fpu_type) {
 		m68881_restore(&p->p_addr->u_pcb.pcb_fpregs);
 	}
+
+#ifdef COMPAT_SUNOS
+	/*
+	 * SunOS' ld.so does self-modifying code without knowing
+	 * about the 040's cache purging needs.  So we need to uncache
+	 * writeable executable pages.
+	 */
+	if (p->p_emul == &emul_sunos)
+		p->p_md.md_flags |= MDP_UNCACHE_WX;
+	else
+		p->p_md.md_flags &= ~MDP_UNCACHE_WX;
+#endif
 }
 
 #define SS_RTEFRAME	1
diff --git a/sys/arch/mac68k/mac68k/pmap.c b/sys/arch/mac68k/mac68k/pmap.c
index 8d504e68e82..d9f3b1cc551 100644
--- a/sys/arch/mac68k/mac68k/pmap.c
+++ b/sys/arch/mac68k/mac68k/pmap.c
@@ -1381,6 +1381,13 @@ validate:
 	npte = pa | pte_prot(pmap, prot) | (*pte & (PG_M|PG_U)) | PG_V;
 	if (wired)
 		npte |= PG_W;
+
+	/* Don't cache if process can't take it, like SunOS ones.  */
+	if (mmutype == MMU_68040 && pmap != pmap_kernel() &&
+	    (curproc->p_md.md_flags & MDP_UNCACHE_WX) &&
+	    (prot & VM_PROT_EXECUTE) && (prot & VM_PROT_WRITE))
+		checkpv = cacheable = FALSE;
+
 	if (!checkpv && !cacheable)
 		npte |= PG_CI;
 #if defined(M68040)
-- 
2.20.1