From: kettenis <kettenis@openbsd.org>
Date: Sat, 7 Jan 2023 10:09:34 +0000 (+0000)
Subject: The PA-RISC architecture supports execute-only mappings by using a
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=2074e18d3250360a5bdd6fe5748f57392a1a3e9f;p=openbsd

The PA-RISC architecture supports execute-only mappings by using a
"remain at privilege level 3" gateway page.  Make use of this.

ok deraadt@, miod@
---

diff --git a/sys/arch/hppa/hppa/pmap.c b/sys/arch/hppa/hppa/pmap.c
index a6d12b5af4c..7301e83a273 100644
--- a/sys/arch/hppa/hppa/pmap.c
+++ b/sys/arch/hppa/hppa/pmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap.c,v 1.179 2022/10/25 18:44:36 miod Exp $	*/
+/*	$OpenBSD: pmap.c,v 1.180 2023/01/07 10:09:34 kettenis Exp $	*/
 
 /*
  * Copyright (c) 1998-2004 Michael Shalayeff
@@ -407,6 +407,7 @@ pmap_check_alias(struct vm_page *pg, vaddr_t va, pt_entry_t pte)
 	for (pve = pg->mdpage.pvh_list; pve; pve = pve->pv_next) {
 		pte |= pmap_vp_find(pve->pv_pmap, pve->pv_va);
 		if ((va & HPPA_PGAOFF) != (pve->pv_va & HPPA_PGAOFF) &&
+		    (pte & PTE_PROT(TLB_GATEWAY)) == 0 &&
 		    (pte & PTE_PROT(TLB_WRITE))) {
 #ifdef PMAPDEBUG
 			printf("pmap_check_alias: "
@@ -494,7 +495,7 @@ pmap_bootstrap(vaddr_t vstart)
 	hppa_prot[PROT_READ]  = TLB_AR_R;
 	hppa_prot[PROT_WRITE] = TLB_AR_RW;
 	hppa_prot[PROT_READ | PROT_WRITE] = TLB_AR_RW;
-	hppa_prot[PROT_EXEC]  = TLB_AR_RX;
+	hppa_prot[PROT_EXEC]  = TLB_AR_X;
 	hppa_prot[PROT_READ | PROT_EXEC] = TLB_AR_RX;
 	hppa_prot[PROT_WRITE | PROT_EXEC] = TLB_AR_RWX;
 	hppa_prot[PROT_READ | PROT_WRITE | PROT_EXEC] = TLB_AR_RWX;
diff --git a/sys/arch/hppa/include/pte.h b/sys/arch/hppa/include/pte.h
index 3883833a3d4..a60a236aceb 100644
--- a/sys/arch/hppa/include/pte.h
+++ b/sys/arch/hppa/include/pte.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pte.h,v 1.13 2013/03/25 20:14:30 deraadt Exp $	*/
+/*	$OpenBSD: pte.h,v 1.14 2023/01/07 10:09:34 kettenis Exp $	*/
 
 /* 
  * Copyright (c) 1990,1993,1994 The University of Utah and
@@ -46,8 +46,11 @@
 #define	TLB_EXECUTE	0x02000000
 #define	TLB_GATEWAY	0x04000000
 #define	TLB_USER	0x00f00000
+/* no execute access at any PL; no GATEWAY promotion */ 
 #define		TLB_AR_NA	0x07300000
 #define		TLB_AR_R	TLB_READ
+/* execute access at designated PL; no GATEWAY promotion */
+#define		TLB_AR_X	0x07000000
 #define		TLB_AR_RW	TLB_READ|TLB_WRITE
 #define		TLB_AR_RX	TLB_READ|TLB_EXECUTE
 #define		TLB_AR_RWX	TLB_READ|TLB_WRITE|TLB_EXECUTE