Enable the NX bit and use it in the PAE pmap code. PAE is still disabled

while we're chasing at least one remaining bug.

ok mlarkin@, deraadt@

4 files changed, 53 insertions, 7 deletions

diff --git a/sys/arch/i386/i386/locore.s b/sys/arch/i386/i386/locore.s
index 7413d2bc29a..bb8a1d3857d 100644
--- a/sys/arch/i386/i386/locore.s
+++ b/sys/arch/i386/i386/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.154 2015/04/19 06:27:17 sf Exp $	*/
+/*	$OpenBSD: locore.s,v 1.155 2015/04/24 12:52:38 kettenis Exp $	*/
 /*	$NetBSD: locore.s,v 1.145 1996/05/03 19:41:19 christos Exp $	*/
 
 /*-
@@ -1669,7 +1669,7 @@ ENTRY(i686_pagezero)
 ENTRY(cpu_paenable)
 	movl	$-1, %eax
 	testl	$CPUID_PAE, _C_LABEL(cpu_feature)
-	jz	1f
+	jz	2f
 
 	pushl	%esi
 	pushl	%edi
@@ -1682,9 +1682,28 @@ ENTRY(cpu_paenable)
 	cld
 	rep
 	movsl
+
 	movl	%cr4, %eax
 	orl	$CR4_PAE, %eax
 	movl	%eax, %cr4      /* BANG!!! */
+
+	movl	$MSR_EFER,%ecx
+	rdmsr
+	movl	%edx, %edi		# %edx is needed by wrmsr below
+
+	# Check if we need to enable NXE
+	movl	$0x80000001, %eax
+	cpuid
+	andl	$CPUID_NXE, %edx
+	xorl	%eax,%eax
+	testl	%edx, %edx
+	jz	1f
+	orl	$EFER_NXE, %eax
+1:
+	movl	%edi, %edx		# Restore saved %edx
+	movl	$MSR_EFER,%ecx
+	wrmsr
+
 	movl	12(%esp), %eax
 	subl	$KERNBASE, %eax
 	movl	%eax, %cr3      /* reload real PDPT */
@@ -1694,7 +1713,7 @@ ENTRY(cpu_paenable)
 	xorl	%eax, %eax
 	popl	%edi
 	popl	%esi
-1:
+2:
 	ret
 
 /*
diff --git a/sys/arch/i386/i386/mptramp.s b/sys/arch/i386/i386/mptramp.s
index 02efc76dfb9..a6e80b8c9cb 100644
--- a/sys/arch/i386/i386/mptramp.s
+++ b/sys/arch/i386/i386/mptramp.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mptramp.s,v 1.15 2015/04/12 18:37:53 mlarkin Exp $	*/
+/*	$OpenBSD: mptramp.s,v 1.16 2015/04/24 12:52:38 kettenis Exp $	*/
 
 /*-
  * Copyright (c) 2000 The NetBSD Foundation, Inc.
@@ -167,6 +167,24 @@ _TRMP_LABEL(mp_startup)
 	movl	%cr4,%eax
 	orl	$CR4_PAE,%eax
 	movl	%eax, %cr4
+	
+	movl	$MSR_EFER,%ecx
+	rdmsr
+	movl	%edx, %edi		# %edx is needed by wrmsr below
+
+	# Check if we need to enable NXE
+	movl	$0x80000001, %eax
+	cpuid
+	andl	$CPUID_NXE, %edx
+	xorl	%eax,%eax
+	testl	%edx, %edx
+	jz	1f
+	orl	$EFER_NXE, %eax
+1:
+	movl	%edi, %edx		# Restore saved %edx
+	movl	$MSR_EFER,%ecx
+	wrmsr
+
 nopae:
 #endif
 	movl	%cr0,%eax		# get control word
diff --git a/sys/arch/i386/i386/pmapae.c b/sys/arch/i386/i386/pmapae.c
index 98812f7cc86..af1331225dc 100644
--- a/sys/arch/i386/i386/pmapae.c
+++ b/sys/arch/i386/i386/pmapae.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmapae.c,v 1.33 2015/04/22 06:26:23 mlarkin Exp $	*/
+/*	$OpenBSD: pmapae.c,v 1.34 2015/04/24 12:52:38 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2006-2008 Michael Shalayeff
@@ -423,6 +423,7 @@ typedef u_int64_t pt_entry_t;		/* PTE */
 
 extern u_int32_t protection_codes[];	/* maps MI prot to i386 prot code */
 extern boolean_t pmap_initialized;	/* pmap_init done yet? */
+pt_entry_t pg_nx;
 
 /*
  * MULTIPROCESSOR: special VA's/ PTE's are actually allocated inside a
@@ -595,6 +596,8 @@ pmap_bootstrap_pae()
 	}
 
 	cpu_pae = 1;
+	if (ecpu_feature & CPUID_NXE)
+		pg_nx = (1ULL << 63);
 
 	va = (vaddr_t)kpm->pm_pdir;
 	kpm->pm_pdidx[0] = (va + 0*NBPG - KERNBASE) | PG_V;
@@ -1313,7 +1316,7 @@ pmap_write_protect_pae(struct pmap *pmap, vaddr_t sva, vaddr_t eva,
 {
 	pt_entry_t *ptes, *spte, *epte, npte, opte;
 	vaddr_t blockend;
-	u_int32_t md_prot;
+	u_int64_t md_prot;
 	vaddr_t va;
 	int shootall = 0;
 
@@ -1349,6 +1352,8 @@ pmap_write_protect_pae(struct pmap *pmap, vaddr_t sva, vaddr_t eva,
 			continue;
 
 		md_prot = protection_codes[prot];
+		if (!(prot & PROT_EXEC))
+			md_prot |= pg_nx;
 		if (va < VM_MAXUSER_ADDRESS)
 			md_prot |= PG_u;
 		else if (va < VM_MAX_ADDRESS)
@@ -1604,6 +1609,8 @@ enter_now:
 	 */
 
 	npte = pa | protection_codes[prot] | PG_V;
+	if (!(prot & PROT_EXEC))
+		npte |= pg_nx;
 	pmap_exec_account(pmap, va, opte, npte);
 	if (wired)
 		npte |= PG_W;
diff --git a/sys/arch/i386/i386/trap.c b/sys/arch/i386/i386/trap.c
index e277cdf1940..9843a2bac92 100644
--- a/sys/arch/i386/i386/trap.c
+++ b/sys/arch/i386/i386/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.121 2015/04/18 05:14:05 guenther Exp $	*/
+/*	$OpenBSD: trap.c,v 1.122 2015/04/24 12:52:38 kettenis Exp $	*/
 /*	$NetBSD: trap.c,v 1.95 1996/05/05 06:50:02 mycroft Exp $	*/
 
 /*-
@@ -140,6 +140,8 @@ trap(struct trapframe *frame)
 	if (frame->tf_err & PGEX_W) {
 		vftype = PROT_WRITE;
 		ftype = PROT_READ | PROT_WRITE;
+	} else if (frame->tf_err & PGEX_I) {
+		ftype = vftype = PROT_EXEC;
 	} else
 		ftype = vftype = PROT_READ;