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.

        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.

PR:		i386/7591, i386/6219
Submitted by:	Luoqi Chen <luoqi@watermarkgroup.com>

10 files changed, 58 insertions, 18 deletions

diff --git a/sys/i386/i386/genassym.c b/sys/i386/i386/genassym.c
index d545c08..cf931cc 100644
--- a/sys/i386/i386/genassym.c
+++ b/sys/i386/i386/genassym.c
@@ -34,10 +34,11 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)genassym.c	5.11 (Berkeley) 5/10/91
- *	$Id: genassym.c,v 1.58 1998/05/28 09:29:55 phk Exp $
+ *	$Id: genassym.c,v 1.59 1998/07/11 12:17:07 bde Exp $
  */
 
 #include "opt_vm86.h"
+#include "opt_user_ldt.h"
 
 #include <stddef.h>
 
@@ -204,6 +205,9 @@ main()
 	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));
 	printf("#define\tGD_CPU_LOCKID %#x\n", OS(globaldata, cpu_lockid));
diff --git a/sys/i386/i386/globals.s b/sys/i386/i386/globals.s
index a9783a9..a1c2ce5 100644
--- a/sys/i386/i386/globals.s
+++ b/sys/i386/i386/globals.s
@@ -23,10 +23,11 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: globals.s,v 1.5 1998/05/28 09:29:56 phk Exp $
+ * $Id: globals.s,v 1.6 1998/06/21 14:45:00 bde Exp $
  */
 
 #include "opt_vm86.h"
+#include "opt_user_ldt.h"
 
 #ifndef SMP
 #include <machine/asmacros.h>
@@ -84,6 +85,11 @@ globaldata:
 	.set	_my_tr,globaldata + GD_MY_TR
 #endif
 
+#ifdef USER_LDT
+	.globl	_currentldt
+	.set	_currentldt,globaldata + GD_CURRENTLDT
+#endif
+
 #ifdef SMP
 	/*
 	 * The BSP version of these get setup in locore.s and pmap.c, while
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index c991f91..f0db465 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.302 1998/06/30 21:25:58 phk Exp $
+ *	$Id: machdep.c,v 1.303 1998/07/11 07:45:30 bde Exp $
  */
 
 #include "apm.h"
@@ -801,14 +801,15 @@ setregs(p, entry, stack)
 	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 @@ setregs(p, entry, stack)
 	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 @@ SYSCTL_INT(_machdep, CPU_WALLCLOCK, wall_cmos_clock,
  * Initialize segments & interrupt table
  */
 
-int currentldt;
 int _default_ldt;
 #ifdef SMP
 union descriptor gdt[NGDT + NCPU];	/* global descriptor table */
@@ -1248,7 +1256,9 @@ init386(first)
 
 	_default_ldt = GSEL(GLDT_SEL, SEL_KPL);
 	lldt(_default_ldt);
+#ifdef USER_LDT
 	currentldt = _default_ldt;
+#endif
 
 #ifdef DDB
 	kdb_init();
diff --git a/sys/i386/i386/mp_machdep.c b/sys/i386/i386/mp_machdep.c
index 8052740..d36835d 100644
--- a/sys/i386/i386/mp_machdep.c
+++ b/sys/i386/i386/mp_machdep.c
@@ -22,12 +22,13 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: mp_machdep.c,v 1.76 1998/05/17 22:12:08 tegge Exp $
+ *	$Id: mp_machdep.c,v 1.77 1998/08/16 00:41:40 bde Exp $
  */
 
 #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 @@ init_secondary(void)
 	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);
diff --git a/sys/i386/i386/mptable.c b/sys/i386/i386/mptable.c
index 8052740..d36835d 100644
--- a/sys/i386/i386/mptable.c
+++ b/sys/i386/i386/mptable.c
@@ -22,12 +22,13 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: mp_machdep.c,v 1.76 1998/05/17 22:12:08 tegge Exp $
+ *	$Id: mp_machdep.c,v 1.77 1998/08/16 00:41:40 bde Exp $
  */
 
 #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 @@ init_secondary(void)
 	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);
diff --git a/sys/i386/i386/sys_machdep.c b/sys/i386/i386/sys_machdep.c
index bd3dab7..573052e 100644
--- a/sys/i386/i386/sys_machdep.c
+++ b/sys/i386/i386/sys_machdep.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)sys_machdep.c	5.5 (Berkeley) 1/19/91
- *	$Id: sys_machdep.c,v 1.34 1998/03/23 19:52:34 jlemon Exp $
+ *	$Id: sys_machdep.c,v 1.35 1998/07/28 03:29:32 jlemon Exp $
  *
  */
 
@@ -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
diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c
index 9c8b1f5..cf16f53 100644
--- a/sys/i386/i386/vm_machdep.c
+++ b/sys/i386/i386/vm_machdep.c
@@ -38,7 +38,7 @@
  *
  *	from: @(#)vm_machdep.c	7.3 (Berkeley) 5/13/91
  *	Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
- *	$Id: vm_machdep.c,v 1.107 1998/05/17 22:12:11 tegge Exp $
+ *	$Id: vm_machdep.c,v 1.108 1998/05/19 00:00:10 tegge Exp $
  */
 
 #include "npx.h"
@@ -710,8 +710,10 @@ cpu_exit(p)
 #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;
diff --git a/sys/i386/include/globaldata.h b/sys/i386/include/globaldata.h
index c6c5a17..e182d0a 100644
--- a/sys/i386/include/globaldata.h
+++ b/sys/i386/include/globaldata.h
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: globaldata.h,v 1.4 1998/05/17 23:08:02 tegge Exp $
+ * $Id: globaldata.h,v 1.5 1998/05/28 09:30:02 phk Exp $
  */
 
 /*
@@ -49,6 +49,9 @@ struct globaldata {
 	u_int		private_tss;
 	u_int		my_tr;		
 #endif
+#ifdef USER_LDT
+	int		currentldt;
+#endif
 #ifdef SMP
 	u_int		cpuid;
 	u_int		cpu_lockid;
diff --git a/sys/i386/include/mptable.h b/sys/i386/include/mptable.h
index 8052740..d36835d 100644
--- a/sys/i386/include/mptable.h
+++ b/sys/i386/include/mptable.h
@@ -22,12 +22,13 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: mp_machdep.c,v 1.76 1998/05/17 22:12:08 tegge Exp $
+ *	$Id: mp_machdep.c,v 1.77 1998/08/16 00:41:40 bde Exp $
  */
 
 #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 @@ init_secondary(void)
 	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);
diff --git a/sys/i386/include/pcpu.h b/sys/i386/include/pcpu.h
index c6c5a17..e182d0a 100644
--- a/sys/i386/include/pcpu.h
+++ b/sys/i386/include/pcpu.h
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: globaldata.h,v 1.4 1998/05/17 23:08:02 tegge Exp $
+ * $Id: globaldata.h,v 1.5 1998/05/28 09:30:02 phk Exp $
  */
 
 /*
@@ -49,6 +49,9 @@ struct globaldata {
 	u_int		private_tss;
 	u_int		my_tr;		
 #endif
+#ifdef USER_LDT
+	int		currentldt;
+#endif
 #ifdef SMP
 	u_int		cpuid;
 	u_int		cpu_lockid;