Date: Wed, 12 Aug 1998 13:31:42 -0400 (EDT) From: Luoqi Chen <luoqi@chen.ml.org> To: FreeBSD-gnats-submit@FreeBSD.ORG Subject: i386/7591: Move `currentldt' to per-cpu area (for wine to work on SMP) Message-ID: <199808121731.NAA02965@sabrina.chen.ml.org>
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>Number: 7591
>Category: i386
>Synopsis: `currentldt' should be in per-cpu area on SMP
>Confidential: no
>Severity: serious
>Priority: high
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Wed Aug 12 11:00:00 PDT 1998
>Last-Modified:
>Originator: Luoqi Chen
>Organization:
>Release: FreeBSD 3.0-CURRENT i386
>Environment:
3.0-CURRENT SMP kernel with USER_LDT option.
>Description:
Presently there is only one `currentldt' variable for all cpus
in a SMP system. Unexpected things could happen if each cpu
has a different ldt setting and one cpu tries to use value
of currentldt set by another cpu.
>How-To-Repeat:
Run wine on a SMP machine with SMP kernel.
>Fix:
The fix is to move currentldt to the per-cpu area. It includes
patches I filed in PR i386/6219 which are also user ldt related.
Index: sys/i386/i386/genassym.c
===================================================================
RCS file: /fun/cvs/src/sys/i386/i386/genassym.c,v
retrieving revision 1.59
diff -u -r1.59 genassym.c
--- genassym.c 1998/07/11 12:17:07 1.59
+++ genassym.c 1998/08/11 22:26:13
@@ -38,6 +38,7 @@
*/
#include "opt_vm86.h"
+#include "opt_user_ldt.h"
#include <stddef.h>
@@ -203,6 +204,9 @@
printf("#define\tGD_COMMON_TSSD %#x\n", OS(globaldata, common_tssd));
printf("#define\tGD_PRIVATE_TSS %#x\n", OS(globaldata, private_tss));
printf("#define\tGD_MY_TR %#x\n", OS(globaldata, my_tr));
+#endif
+#ifdef USER_LDT
+ printf("#define\tGD_CURRENTLDT %#x\n", OS(globaldata, currentldt));
#endif
#ifdef SMP
printf("#define\tGD_CPUID %#x\n", OS(globaldata, cpuid));
Index: sys/i386/i386/globals.s
===================================================================
RCS file: /fun/cvs/src/sys/i386/i386/globals.s,v
retrieving revision 1.6
diff -u -r1.6 globals.s
--- globals.s 1998/06/21 14:45:00 1.6
+++ globals.s 1998/08/11 22:26:42
@@ -27,6 +27,7 @@
*/
#include "opt_vm86.h"
+#include "opt_user_ldt.h"
#ifndef SMP
#include <machine/asmacros.h>
@@ -82,6 +83,11 @@
.set _common_tssd,globaldata + GD_COMMON_TSSD
.set _private_tss,globaldata + GD_PRIVATE_TSS
.set _my_tr,globaldata + GD_MY_TR
+#endif
+
+#ifdef USER_LDT
+ .globl _currentldt
+ .set _currentldt,globaldata + GD_CURRENTLDT
#endif
#ifdef SMP
Index: sys/i386/i386/machdep.c
===================================================================
RCS file: /fun/cvs/src/sys/i386/i386/machdep.c,v
retrieving revision 1.303
diff -u -r1.303 machdep.c
--- machdep.c 1998/07/11 07:45:30 1.303
+++ machdep.c 1998/08/11 22:35:23
@@ -801,14 +801,15 @@
u_long stack;
{
struct trapframe *regs = p->p_md.md_regs;
-
-#ifdef USER_LDT
struct pcb *pcb = &p->p_addr->u_pcb;
+#ifdef USER_LDT
/* was i386_user_cleanup() in NetBSD */
if (pcb->pcb_ldt) {
- if (pcb == curpcb)
- lldt(GSEL(GUSERLDT_SEL, SEL_KPL));
+ if (pcb == curpcb) {
+ lldt(_default_ldt);
+ currentldt = _default_ldt;
+ }
kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ldt,
pcb->pcb_ldt_len * sizeof(union descriptor));
pcb->pcb_ldt_len = (int)pcb->pcb_ldt = 0;
@@ -824,6 +825,14 @@
regs->tf_es = _udatasel;
regs->tf_cs = _ucodesel;
+ /* reset %fs and %gs as well */
+ pcb->pcb_fs = _udatasel;
+ pcb->pcb_gs = _udatasel;
+ if (pcb == curpcb) {
+ __asm("mov %0,%%fs" : : "r" (_udatasel));
+ __asm("mov %0,%%gs" : : "r" (_udatasel));
+ }
+
/*
* Initialize the math emulator (if any) for the current process.
* Actually, just clear the bit that says that the emulator has
@@ -881,7 +890,6 @@
* Initialize segments & interrupt table
*/
-int currentldt;
int _default_ldt;
#ifdef SMP
union descriptor gdt[NGDT + NCPU]; /* global descriptor table */
@@ -1248,7 +1256,9 @@
_default_ldt = GSEL(GLDT_SEL, SEL_KPL);
lldt(_default_ldt);
+#ifdef USER_LDT
currentldt = _default_ldt;
+#endif
#ifdef DDB
kdb_init();
Index: sys/i386/i386/mp_machdep.c
===================================================================
RCS file: /fun/cvs/src/sys/i386/i386/mp_machdep.c,v
retrieving revision 1.76
diff -u -r1.76 mp_machdep.c
--- mp_machdep.c 1998/05/17 22:12:08 1.76
+++ mp_machdep.c 1998/08/11 22:25:26
@@ -28,6 +28,7 @@
#include "opt_smp.h"
#include "opt_vm86.h"
#include "opt_cpu.h"
+#include "opt_user_ldt.h"
#ifdef SMP
#include <machine/smptests.h>
@@ -466,6 +467,9 @@
lgdt(&r_gdt); /* does magic intra-segment return */
lidt(&r_idt);
lldt(_default_ldt);
+#ifdef USER_LDT
+ currentldt = _default_ldt;
+#endif
my_tr = NGDT + cpuid;
gsel_tss = GSEL(my_tr, SEL_KPL);
Index: sys/i386/i386/sys_machdep.c
===================================================================
RCS file: /fun/cvs/src/sys/i386/i386/sys_machdep.c,v
retrieving revision 1.35
diff -u -r1.35 sys_machdep.c
--- sys_machdep.c 1998/07/28 03:29:32 1.35
+++ sys_machdep.c 1998/08/11 22:32:03
@@ -64,8 +64,8 @@
-void set_user_ldt __P((struct pcb *pcb));
#ifdef USER_LDT
+void set_user_ldt __P((struct pcb *pcb));
static int i386_get_ldt __P((struct proc *, char *));
static int i386_set_ldt __P((struct proc *, char *));
#endif
Index: sys/i386/i386/vm_machdep.c
===================================================================
RCS file: /fun/cvs/src/sys/i386/i386/vm_machdep.c,v
retrieving revision 1.108
diff -u -r1.108 vm_machdep.c
--- vm_machdep.c 1998/05/19 00:00:10 1.108
+++ vm_machdep.c 1998/07/04 03:05:13
@@ -710,8 +710,10 @@
#endif
#ifdef USER_LDT
if (pcb->pcb_ldt != 0) {
- if (pcb == curpcb)
- lldt(GSEL(GUSERLDT_SEL, SEL_KPL));
+ if (pcb == curpcb) {
+ lldt(_default_ldt);
+ currentldt = _default_ldt;
+ }
kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ldt,
pcb->pcb_ldt_len * sizeof(union descriptor));
pcb->pcb_ldt_len = (int)pcb->pcb_ldt = 0;
Index: sys/i386/include/globaldata.h
===================================================================
RCS file: /fun/cvs/src/sys/i386/include/globaldata.h,v
retrieving revision 1.5
diff -u -r1.5 globaldata.h
--- globaldata.h 1998/05/28 09:30:02 1.5
+++ globaldata.h 1998/08/11 22:15:54
@@ -49,6 +49,9 @@
u_int private_tss;
u_int my_tr;
#endif
+#ifdef USER_LDT
+ int currentldt;
+#endif
#ifdef SMP
u_int cpuid;
u_int cpu_lockid;
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