From: kettenis <kettenis@openbsd.org>
Date: Sun, 16 Apr 2023 11:14:26 +0000 (+0000)
Subject: Make enabling the BTI feature a per-pmap thing by storing the ATTR_GP bit
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=2c3273c1dc7912446870ac9ec7a9086cfe0bb5ba;p=openbsd

Make enabling the BTI feature a per-pmap thing by storing the ATTR_GP bit
in a new pm_guarded member of struct pmap and using this member to add
the bits to the PTEs

ok deraadt@
---

diff --git a/sys/arch/arm64/arm64/pmap.c b/sys/arch/arm64/arm64/pmap.c
index 23bb1d2e436..038adcfca31 100644
--- a/sys/arch/arm64/arm64/pmap.c
+++ b/sys/arch/arm64/arm64/pmap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: pmap.c,v 1.95 2023/04/13 15:23:22 miod Exp $ */
+/* $OpenBSD: pmap.c,v 1.96 2023/04/16 11:14:26 kettenis Exp $ */
 /*
  * Copyright (c) 2008-2009,2014-2016 Dale Rahn <drahn@dalerahn.com>
  *
@@ -1220,10 +1220,12 @@ pmap_bootstrap(long kvo, paddr_t lpt1, long kernelstart, long kernelend,
 	vp1 = (struct pmapvp1 *)pt1pa;
 	pmap_kernel()->pm_vp.l1 = (struct pmapvp1 *)va;
 	pmap_kernel()->pm_privileged = 1;
+	pmap_kernel()->pm_guarded = ATTR_GP;
 	pmap_kernel()->pm_asid = 0;
 
 	pmap_tramp.pm_vp.l1 = (struct pmapvp1 *)va + 1;
 	pmap_tramp.pm_privileged = 1;
+	pmap_tramp.pm_guarded = ATTR_GP;
 	pmap_tramp.pm_asid = 0;
 
 	/* Mark ASID 0 as in-use. */
@@ -1689,8 +1691,7 @@ pmap_pte_update(struct pte_desc *pted, uint64_t *pl3)
 		access_bits = ap_bits_user[pted->pted_pte & PROT_MASK];
 
 #ifndef SMALL_KERNEL
-	if (pm == pmap_kernel())
-		access_bits |= ATTR_GP;
+	access_bits |= pm->pm_guarded;
 #endif
 
 	pte = (pted->pted_pte & PTE_RPGN) | attr | access_bits | L3_P;
diff --git a/sys/arch/arm64/include/pmap.h b/sys/arch/arm64/include/pmap.h
index 89fa7cdd5e3..d61d9936c66 100644
--- a/sys/arch/arm64/include/pmap.h
+++ b/sys/arch/arm64/include/pmap.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: pmap.h,v 1.22 2023/02/16 20:32:39 miod Exp $ */
+/* $OpenBSD: pmap.h,v 1.23 2023/04/16 11:14:26 kettenis Exp $ */
 /*
  * Copyright (c) 2008,2009,2014 Dale Rahn <drahn@dalerahn.com>
  *
@@ -66,6 +66,7 @@ struct pmap {
 	} pm_vp;
 	uint64_t pm_pt0pa;
 	uint64_t pm_asid;
+	uint64_t pm_guarded;
 	int have_4_level_pt;
 	int pm_privileged;
 	int pm_refs;				/* ref count */