Module Name: src
Committed By: maxv
Date: Sat Oct 21 08:08:26 UTC 2017
Modified Files:
src/sys/arch/amd64/amd64: locore.S trap.c
Log Message:
Use labels instead of disassembling *(%rip). intrfastexit is now the
only place where the segregs can fault.
To generate a diff of this commit:
cvs rdiff -u -r1.137 -r1.138 src/sys/arch/amd64/amd64/locore.S
cvs rdiff -u -r1.103 -r1.104 src/sys/arch/amd64/amd64/trap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/amd64/amd64/locore.S
diff -u src/sys/arch/amd64/amd64/locore.S:1.137 src/sys/arch/amd64/amd64/locore.S:1.138
--- src/sys/arch/amd64/amd64/locore.S:1.137 Sat Oct 21 06:55:54 2017
+++ src/sys/arch/amd64/amd64/locore.S Sat Oct 21 08:08:26 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: locore.S,v 1.137 2017/10/21 06:55:54 maxv Exp $ */
+/* $NetBSD: locore.S,v 1.138 2017/10/21 08:08:26 maxv Exp $ */
/*
* Copyright-o-rama!
@@ -330,6 +330,10 @@
.globl _C_LABEL(biosextmem)
.globl _C_LABEL(lwp0uarea)
.globl do_sysret
+ .globl do_mov_es
+ .globl do_mov_ds
+ .globl do_mov_fs
+ .globl do_mov_gs
.globl do_iret
.type _C_LABEL(tablesize), @object
@@ -1196,7 +1200,7 @@ lwp_32bit:
movq PCB_GS(%r14),%rax
movq %rax,(GUGS_SEL*8)(%rcx)
- /* Set default 32bit values in %ds, %es, %fs and %gs. */
+ /* Set default 32bit values in %ds, %es and %fs. %gs is special. */
movq L_MD_REGS(%r12),%rbx
movq $GSEL(GUDATA32_SEL, SEL_UPL),%rax
movw %ax,%ds
@@ -1482,11 +1486,15 @@ ENTRY(intrfastexit)
.Luexit32:
NOT_XEN(cli;)
+do_mov_es:
movw TF_ES(%rsp),%es
+do_mov_ds:
movw TF_DS(%rsp),%ds
+do_mov_fs:
movw TF_FS(%rsp),%fs
SWAPGS
#ifndef XEN
+do_mov_gs:
movw TF_GS(%rsp),%gs
#endif
jmp .Lkexit
Index: src/sys/arch/amd64/amd64/trap.c
diff -u src/sys/arch/amd64/amd64/trap.c:1.103 src/sys/arch/amd64/amd64/trap.c:1.104
--- src/sys/arch/amd64/amd64/trap.c:1.103 Sat Oct 21 07:23:22 2017
+++ src/sys/arch/amd64/amd64/trap.c Sat Oct 21 08:08:26 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: trap.c,v 1.103 2017/10/21 07:23:22 maxv Exp $ */
+/* $NetBSD: trap.c,v 1.104 2017/10/21 08:08:26 maxv Exp $ */
/*
* Copyright (c) 1998, 2000, 2017 The NetBSD Foundation, Inc.
@@ -64,7 +64,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.103 2017/10/21 07:23:22 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.104 2017/10/21 08:08:26 maxv Exp $");
#include "opt_ddb.h"
#include "opt_kgdb.h"
@@ -236,6 +236,8 @@ static void trap_user_kernelmode(struct
static void
trap_user_kernelmode(struct trapframe *frame, int type, lwp_t *l, proc_t *p)
{
+ extern uint64_t do_mov_es, do_mov_ds, do_mov_fs, do_mov_gs;
+ extern uint64_t do_iret;
struct trapframe *vframe;
ksiginfo_t ksi;
@@ -260,8 +262,7 @@ trap_user_kernelmode(struct trapframe *f
*/
vframe = (void *)frame->tf_rsp;
- switch (*(uint16_t *)frame->tf_rip) {
- case 0xcf48: /* iretq */
+ if (frame->tf_rip == (uint64_t)&do_iret) {
/*
* The 'iretq' instruction faulted, so we have the
* 'user' registers saved after the kernel
@@ -277,12 +278,10 @@ trap_user_kernelmode(struct trapframe *f
memmove(vframe, frame, offsetof(struct trapframe, tf_rip));
/* Set the faulting address to the user %rip */
ksi.ksi_addr = (void *)vframe->tf_rip;
- break;
-
- case 0x848e: /* mov 0xa8(%rsp),%es (8e 84 24 a8 00 00 00) */
- case 0x9c8e: /* mov 0xb0(%rsp),%ds (8e 9c 24 b0 00 00 00) */
- case 0xa48e: /* mov 0xa0(%rsp),%fs (8e a4 24 a0 00 00 00) */
- case 0xac8e: /* mov 0x98(%rsp),%gs (8e ac 24 98 00 00 00) */
+ } else if (frame->tf_rip == (uint64_t)&do_mov_es ||
+ frame->tf_rip == (uint64_t)&do_mov_ds ||
+ frame->tf_rip == (uint64_t)&do_mov_fs ||
+ frame->tf_rip == (uint64_t)&do_mov_gs) {
/*
* We faulted loading one of the user segment registers.
* The stack frame containing the user registers is
@@ -291,9 +290,7 @@ trap_user_kernelmode(struct trapframe *f
if (KERNELMODE(vframe->tf_cs))
return;
/* There is no valid address for the fault */
- break;
-
- default:
+ } else {
return;
}
