[src/trunk]: src/sys/arch/aarch64/aarch64 Byte-swapping instructions for arm ...

[rin <rin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a548981c78d1
branches:  trunk
changeset: 944907:a548981c78d1
user:      rin <rin%NetBSD.org@localhost>
date:      Thu Oct 15 23:15:36 2020 +0000

description:
Byte-swapping instructions for arm and thumb on aarch64eb;
instructions are stored in little-endian byte-order for BE8,
an only valid binary format for ILP32BE executables.

XXX
Apply similar fixes to armv7{,hf}eb.

diffstat:

 sys/arch/aarch64/aarch64/trap.c |  13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

diffs (55 lines):

diff -r 5b5a9ea9e840 -r a548981c78d1 sys/arch/aarch64/aarch64/trap.c
--- a/sys/arch/aarch64/aarch64/trap.c   Thu Oct 15 23:10:06 2020 +0000
+++ b/sys/arch/aarch64/aarch64/trap.c   Thu Oct 15 23:15:36 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: trap.c,v 1.37 2020/09/14 10:53:02 ryo Exp $ */
+/* $NetBSD: trap.c,v 1.38 2020/10/15 23:15:36 rin Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(1, "$NetBSD: trap.c,v 1.37 2020/09/14 10:53:02 ryo Exp $");
+__KERNEL_RCSID(1, "$NetBSD: trap.c,v 1.38 2020/10/15 23:15:36 rin Exp $");
 
 #include "opt_arm_intr_impl.h"
 #include "opt_compat_netbsd32.h"
@@ -532,6 +532,12 @@
 fetch_arm_insn(uint64_t pc, uint64_t spsr, uint32_t *insn)
 {
 
+       /*
+        * Instructions are stored in little endian for BE8,
+        * only a valid binary format for ILP32EB. Therefore,
+        * we need byte-swapping before decoding on aarch64eb.
+        */
+
        /* THUMB? */
        if (spsr & SPSR_A32_T) {
                uint16_t *p = (uint16_t *)(pc & ~1UL); /* XXX */
@@ -539,6 +545,7 @@
 
                if (ufetch_16(p, &hi))
                        return -1;
+               LE16TOH(hi);
 
                if (!THUMB_32BIT(hi)) {
                        /* 16-bit Thumb instruction */
@@ -549,6 +556,7 @@
                /* 32-bit Thumb instruction */
                if (ufetch_16(p + 1, &lo))
                        return -1;
+               LE16TOH(lo);
 
                *insn = ((uint32_t)hi << 16) | lo;
                return 4;
@@ -556,6 +564,7 @@
 
        if (ufetch_32((uint32_t *)pc, insn))
                return -1;
+       LE32TOH(*insn);
 
        return 4;
 }