Make EFI runtime calls more robust on arm64 as well. While I have not seen

any broken implementations yet, Linux developers claim that arm64 machines
intended to run Windows are not much better than x86 machines.  And I
totally believe that.

ok patrick@

4 files changed, 38 insertions, 12 deletions

diff --git a/sys/arch/arm64/arm64/support.S b/sys/arch/arm64/arm64/support.S
index a08d11d64c4..5eebc4dbcad 100644
--- a/sys/arch/arm64/arm64/support.S
+++ b/sys/arch/arm64/arm64/support.S
@@ -1,4 +1,4 @@
-/* $OpenBSD: support.S,v 1.9 2019/03/15 05:42:38 kevlo Exp $ */
+/* $OpenBSD: support.S,v 1.10 2022/11/06 11:44:30 kettenis Exp $ */
 /*-
  * Copyright (c) 2014 Andrew Turner
  * Copyright (c) 2014-2015 The FreeBSD Foundation
@@ -36,8 +36,9 @@
 #include <machine/vmparam.h>
 
 #include "assym.h"
+#include "efi.h"
 
-#ifdef DDB
+#if defined(DDB) || NEFI > 0
 ENTRY(setjmp)
 	RETGUARD_SETUP(setjmp, x15)
 	/* Store the stack pointer */
diff --git a/sys/arch/arm64/arm64/trap.c b/sys/arch/arm64/arm64/trap.c
index d30e40eb27d..1932e3850d6 100644
--- a/sys/arch/arm64/arm64/trap.c
+++ b/sys/arch/arm64/arm64/trap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: trap.c,v 1.40 2022/08/15 13:33:22 jsg Exp $ */
+/* $OpenBSD: trap.c,v 1.41 2022/11/06 11:44:30 kettenis Exp $ */
 /*-
  * Copyright (c) 2014 Andrew Turner
  * All rights reserved.
@@ -158,11 +158,14 @@ kdata_abort(struct trapframe *frame, uint64_t esr, uint64_t far, int exe)
 		 * Only allow user-space access using
 		 * unprivileged load/store instructions.
 		 */
-		if (!is_unpriv_ldst(frame->tf_elr)) {
+		if (is_unpriv_ldst(frame->tf_elr))
+			map = &p->p_vmspace->vm_map;
+		else if (pcb->pcb_onfault != NULL)
+			map = kernel_map;
+		else {
 			panic("attempt to access user address"
 			      " 0x%llx from EL1", far);
 		}
-		map = &p->p_vmspace->vm_map;
 	}
 
 	/* Handle referenced/modified emulation */
@@ -175,7 +178,7 @@ kdata_abort(struct trapframe *frame, uint64_t esr, uint64_t far, int exe)
 
 	if (error != 0) {
 		if (curcpu()->ci_idepth == 0 &&
-		    pcb->pcb_onfault != 0) {
+		    pcb->pcb_onfault != NULL) {
 			frame->tf_elr = (register_t)pcb->pcb_onfault;
 			return;
 		}
@@ -215,6 +218,9 @@ do_el1h_sync(struct trapframe *frame)
 	case EXCP_FP_SIMD:
 	case EXCP_TRAP_FP:
 		panic("FP exception in the kernel");
+	case EXCP_INSN_ABORT:
+		kdata_abort(frame, esr, far, 1);
+		break;
 	case EXCP_DATA_ABORT:
 		kdata_abort(frame, esr, far, 0);
 		break;
diff --git a/sys/arch/arm64/conf/files.arm64 b/sys/arch/arm64/conf/files.arm64
index 2a7bdba0c21..e8087bcadd9 100644
--- a/sys/arch/arm64/conf/files.arm64
+++ b/sys/arch/arm64/conf/files.arm64
@@ -1,4 +1,4 @@
-# $OpenBSD: files.arm64,v 1.61 2022/10/03 19:32:22 kettenis Exp $
+# $OpenBSD: files.arm64,v 1.62 2022/11/06 11:44:30 kettenis Exp $
 
 maxpartitions	16
 maxusers	2 8 128
@@ -65,7 +65,7 @@ file	arch/arm64/dev/simplebus.c		simplebus
 
 device	efi {}
 attach	efi at fdt
-file	arch/arm64/dev/efi_machdep.c		efi
+file	arch/arm64/dev/efi_machdep.c		efi needs-flag
 
 device	smbios
 attach	smbios at efi
diff --git a/sys/arch/arm64/dev/efi_machdep.c b/sys/arch/arm64/dev/efi_machdep.c
index 1dd2c4eb71b..3779f9feba1 100644
--- a/sys/arch/arm64/dev/efi_machdep.c
+++ b/sys/arch/arm64/dev/efi_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: efi_machdep.c,v 1.4 2022/10/29 20:35:50 kettenis Exp $	*/
+/*	$OpenBSD: efi_machdep.c,v 1.5 2022/11/06 11:44:30 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2017 Mark Kettenis <kettenis@openbsd.org>
@@ -26,6 +26,7 @@
 #include <machine/bus.h>
 #include <machine/fdt.h>
 #include <machine/fpu.h>
+#include <machine/pcb.h>
 
 #include <dev/ofw/openfirm.h>
 #include <dev/ofw/fdt.h>
@@ -75,6 +76,11 @@ void	efi_leave(struct efi_softc *);
 int	efi_gettime(struct todr_chip_handle *, struct timeval *);
 int	efi_settime(struct todr_chip_handle *, struct timeval *);
 
+label_t efi_jmpbuf;
+
+#define efi_enter_check(sc) (setjmp(&efi_jmpbuf) ? \
+    (efi_leave(sc), EFAULT) : (efi_enter(sc), 0))
+
 int
 efi_match(struct device *parent, void *match, void *aux)
 {
@@ -161,7 +167,8 @@ efi_attach(struct device *parent, struct device *self, void *aux)
 		config_found(self, &fa, NULL);
 	}
 	
-	efi_enter(sc);
+	if (efi_enter_check(sc))
+		return;
 	status = sc->sc_rs->GetTime(&time, NULL);
 	efi_leave(sc);
 	if (status != EFI_SUCCESS)
@@ -253,6 +260,12 @@ efi_map_runtime(struct efi_softc *sc)
 }
 
 void
+efi_fault(void)
+{
+	longjmp(&efi_jmpbuf);
+}
+
+void
 efi_enter(struct efi_softc *sc)
 {
 	struct pmap *pm = sc->sc_pm;
@@ -268,6 +281,8 @@ efi_enter(struct efi_softc *sc)
 	cpu_setttb(pm->pm_asid, pm->pm_pt0pa);
 
 	fpu_kernel_enter();
+
+	curcpu()->ci_curpcb->pcb_onfault = (void *)efi_fault;
 }
 
 void
@@ -276,6 +291,8 @@ efi_leave(struct efi_softc *sc)
 	struct pmap *pm = curcpu()->ci_curpm;
 	uint64_t tcr;
 
+	curcpu()->ci_curpcb->pcb_onfault = NULL;
+
 	fpu_kernel_exit();
 
 	WRITE_SPECIALREG(ttbr0_el1, pmap_kernel()->pm_pt0pa);
@@ -296,7 +313,8 @@ efi_gettime(struct todr_chip_handle *handle, struct timeval *tv)
 	EFI_TIME time;
 	EFI_STATUS status;
 
-	efi_enter(sc);
+	if (efi_enter_check(sc))
+		return EFAULT;
 	status = sc->sc_rs->GetTime(&time, NULL);
 	efi_leave(sc);
 	if (status != EFI_SUCCESS)
@@ -340,7 +358,8 @@ efi_settime(struct todr_chip_handle *handle, struct timeval *tv)
 	time.TimeZone = 0;
 	time.Daylight = 0;
 
-	efi_enter(sc);
+	if (efi_enter_check(sc))
+		return EFAULT;
 	status = sc->sc_rs->SetTime(&time);
 	efi_leave(sc);
 	if (status != EFI_SUCCESS)