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 23bb1d2..038adcf 100644 (file)
--- 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 89fa7cd..d61d993 100644 (file)
--- 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 */