Changed the global `idt' from an array to a pointer so that npx.c

automatically hacks on the active copy of the IDT if f00f_hack()
has changed it.  This also allows simplifications in setidt().
This fixes breakage of FP exception handling by rev.1.55 of
sys/kernel.h.  FP exceptions were sent to npx.c's probe handlers
because npx.c "restored" the old handlers to the wrong copy of the
IDT.  The SYSINIT for f00f_hack() was purposely run quite late to
avoid problems like this, but it is bogusly associated with the
SYSINIT for proc0 so it was moved with the latter.

Problem reported and fix tested by:  Martin Cracauer <cracauer@cons.org>

10 files changed, 36 insertions, 43 deletions

diff --git a/sys/amd64/amd64/locore.S b/sys/amd64/amd64/locore.S
index 4e29fd4..fbede9b 100644
--- a/sys/amd64/amd64/locore.S
+++ b/sys/amd64/amd64/locore.S
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)locore.s	7.3 (Berkeley) 5/13/91
- *	$Id: locore.s,v 1.122 1999/05/09 19:01:49 peter Exp $
+ *	$Id: locore.s,v 1.123 1999/06/01 18:19:39 jlemon Exp $
  *
  *		originally from: locore.s, by William F. Jolitz
  *
@@ -958,7 +958,7 @@ bdb_prepare_paging:
 	movl	%eax,R(bdb_bpt_ljmp+1)
 	movl	24+2(%esi),%eax
 	movw	%ax,R(bdb_bpt_ljmp+5)
-	movl	$R(_idt),%edi
+	movl	R(_idt),%edi
 	movl	%edi,2(%esp)		/* prepare to load kernel idt */
 	movl	$8*4/4,%ecx
 	cld
diff --git a/sys/amd64/amd64/locore.s b/sys/amd64/amd64/locore.s
index 4e29fd4..fbede9b 100644
--- a/sys/amd64/amd64/locore.s
+++ b/sys/amd64/amd64/locore.s
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)locore.s	7.3 (Berkeley) 5/13/91
- *	$Id: locore.s,v 1.122 1999/05/09 19:01:49 peter Exp $
+ *	$Id: locore.s,v 1.123 1999/06/01 18:19:39 jlemon Exp $
  *
  *		originally from: locore.s, by William F. Jolitz
  *
@@ -958,7 +958,7 @@ bdb_prepare_paging:
 	movl	%eax,R(bdb_bpt_ljmp+1)
 	movl	24+2(%esi),%eax
 	movw	%ax,R(bdb_bpt_ljmp+5)
-	movl	$R(_idt),%edi
+	movl	R(_idt),%edi
 	movl	%edi,2(%esp)		/* prepare to load kernel idt */
 	movl	$8*4/4,%ecx
 	cld
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index ae9df8b..7cc1e5f 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.340 1999/06/10 02:48:51 jlemon Exp $
+ *	$Id: machdep.c,v 1.341 1999/06/13 19:20:25 alc Exp $
  */
 
 #include "apm.h"
@@ -887,7 +887,8 @@ union descriptor gdt[NGDT * NCPU];	/* global descriptor table */
 #else
 union descriptor gdt[NGDT];		/* global descriptor table */
 #endif
-struct gate_descriptor idt[NIDT];	/* interrupt descriptor table */
+static struct gate_descriptor idt0[NIDT];
+struct gate_descriptor *idt = &idt0[0];	/* interrupt descriptor table */
 union descriptor ldt[NLDT];		/* local descriptor table */
 #ifdef SMP
 /* table descriptors - used to load tables by microp */
@@ -900,7 +901,6 @@ extern struct segment_descriptor common_tssd, *tss_gdt;
 int private_tss;			/* flag indicating private tss */
 
 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
-struct gate_descriptor *t_idt;
 extern int has_f00f_bug;
 #endif
 
@@ -1090,11 +1090,7 @@ setidt(idx, func, typ, dpl, selec)
 {
 	struct gate_descriptor *ip;
 
-#if defined(I586_CPU) && !defined(NO_F00F_HACK)
-	ip = (t_idt != NULL ? t_idt : idt) + idx;
-#else
 	ip = idt + idx;
-#endif
 	ip->gd_looffset = (int)func;
 	ip->gd_selector = selec;
 	ip->gd_stkcpy = 0;
@@ -1610,7 +1606,7 @@ init386(first)
  	setidt(0x80, &IDTVEC(int0x80_syscall),
 			SDT_SYS386TGT, SEL_UPL, GSEL(GCODE_SEL, SEL_KPL));
 
-	r_idt.rd_limit = sizeof(idt) - 1;
+	r_idt.rd_limit = sizeof(idt0) - 1;
 	r_idt.rd_base = (int) idt;
 	lidt(&r_idt);
 
@@ -1714,6 +1710,7 @@ SYSINIT(f00f_hack, SI_SUB_INTRINSIC, SI_ORDER_FIRST, f00f_hack, NULL);
 
 static void
 f00f_hack(void *unused) {
+	struct gate_descriptor *new_idt;
 #ifndef SMP
 	struct region_descriptor r_idt;
 #endif
@@ -1724,7 +1721,7 @@ f00f_hack(void *unused) {
 
 	printf("Intel Pentium detected, installing workaround for F00F bug\n");
 
-	r_idt.rd_limit = sizeof(idt) - 1;
+	r_idt.rd_limit = sizeof(idt0) - 1;
 
 	tmp = kmem_alloc(kernel_map, PAGE_SIZE * 2);
 	if (tmp == 0)
@@ -1732,10 +1729,11 @@ f00f_hack(void *unused) {
 	if (((unsigned int)tmp & (PAGE_SIZE-1)) != 0)
 		panic("kmem_alloc returned non-page-aligned memory");
 	/* Put the first seven entries in the lower page */
-	t_idt = (struct gate_descriptor*)(tmp + PAGE_SIZE - (7*8));
-	bcopy(idt, t_idt, sizeof(idt));
-	r_idt.rd_base = (int)t_idt;
+	new_idt = (struct gate_descriptor*)(tmp + PAGE_SIZE - (7*8));
+	bcopy(idt, new_idt, sizeof(idt0));
+	r_idt.rd_base = (int)new_idt;
 	lidt(&r_idt);
+	idt = new_idt;
 	if (vm_map_protect(kernel_map, tmp, tmp + PAGE_SIZE,
 			   VM_PROT_READ, FALSE) != KERN_SUCCESS)
 		panic("vm_map_protect failed");
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index df6e295..1d9d216 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.137 1999/05/06 18:12:17 peter Exp $
+ *	$Id: trap.c,v 1.138 1999/06/01 18:19:47 jlemon Exp $
  */
 
 /*
@@ -147,7 +147,6 @@ static __inline void userret __P((struct proc *p, struct trapframe *frame,
 				  u_quad_t oticks));
 
 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
-extern struct gate_descriptor *t_idt;
 extern int has_f00f_bug;
 #endif
 
@@ -727,7 +726,7 @@ trap_pfault(frame, usermode, eva)
 		 * fault.
 		 */
 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
-		if ((eva == (unsigned int)&t_idt[6]) && has_f00f_bug) {
+		if ((eva == (unsigned int)&idt[6]) && has_f00f_bug) {
 			frame->tf_trapno = T_PRIVINFLT;
 			return -2;
 		}
diff --git a/sys/amd64/include/segments.h b/sys/amd64/include/segments.h
index eaecfa3..7028185 100644
--- a/sys/amd64/include/segments.h
+++ b/sys/amd64/include/segments.h
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)segments.h	7.1 (Berkeley) 5/9/91
- *	$Id: segments.h,v 1.18 1999/01/28 11:45:49 newton Exp $
+ *	$Id: segments.h,v 1.19 1999/04/28 01:04:06 luoqi Exp $
  */
 
 #ifndef _MACHINE_SEGMENTS_H_
@@ -246,7 +246,7 @@ extern int	currentldt;
 extern int	_default_ldt;
 extern union descriptor gdt[];
 extern struct soft_segment_descriptor gdt_segs[];
-extern struct gate_descriptor idt[NIDT];
+extern struct gate_descriptor *idt;
 extern union descriptor ldt[NLDT];
 
 void	lgdt		__P((struct region_descriptor *rdp));
diff --git a/sys/i386/i386/locore.s b/sys/i386/i386/locore.s
index 4e29fd4..fbede9b 100644
--- a/sys/i386/i386/locore.s
+++ b/sys/i386/i386/locore.s
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)locore.s	7.3 (Berkeley) 5/13/91
- *	$Id: locore.s,v 1.122 1999/05/09 19:01:49 peter Exp $
+ *	$Id: locore.s,v 1.123 1999/06/01 18:19:39 jlemon Exp $
  *
  *		originally from: locore.s, by William F. Jolitz
  *
@@ -958,7 +958,7 @@ bdb_prepare_paging:
 	movl	%eax,R(bdb_bpt_ljmp+1)
 	movl	24+2(%esi),%eax
 	movw	%ax,R(bdb_bpt_ljmp+5)
-	movl	$R(_idt),%edi
+	movl	R(_idt),%edi
 	movl	%edi,2(%esp)		/* prepare to load kernel idt */
 	movl	$8*4/4,%ecx
 	cld
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index ae9df8b..7cc1e5f 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 1.340 1999/06/10 02:48:51 jlemon Exp $
+ *	$Id: machdep.c,v 1.341 1999/06/13 19:20:25 alc Exp $
  */
 
 #include "apm.h"
@@ -887,7 +887,8 @@ union descriptor gdt[NGDT * NCPU];	/* global descriptor table */
 #else
 union descriptor gdt[NGDT];		/* global descriptor table */
 #endif
-struct gate_descriptor idt[NIDT];	/* interrupt descriptor table */
+static struct gate_descriptor idt0[NIDT];
+struct gate_descriptor *idt = &idt0[0];	/* interrupt descriptor table */
 union descriptor ldt[NLDT];		/* local descriptor table */
 #ifdef SMP
 /* table descriptors - used to load tables by microp */
@@ -900,7 +901,6 @@ extern struct segment_descriptor common_tssd, *tss_gdt;
 int private_tss;			/* flag indicating private tss */
 
 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
-struct gate_descriptor *t_idt;
 extern int has_f00f_bug;
 #endif
 
@@ -1090,11 +1090,7 @@ setidt(idx, func, typ, dpl, selec)
 {
 	struct gate_descriptor *ip;
 
-#if defined(I586_CPU) && !defined(NO_F00F_HACK)
-	ip = (t_idt != NULL ? t_idt : idt) + idx;
-#else
 	ip = idt + idx;
-#endif
 	ip->gd_looffset = (int)func;
 	ip->gd_selector = selec;
 	ip->gd_stkcpy = 0;
@@ -1610,7 +1606,7 @@ init386(first)
  	setidt(0x80, &IDTVEC(int0x80_syscall),
 			SDT_SYS386TGT, SEL_UPL, GSEL(GCODE_SEL, SEL_KPL));
 
-	r_idt.rd_limit = sizeof(idt) - 1;
+	r_idt.rd_limit = sizeof(idt0) - 1;
 	r_idt.rd_base = (int) idt;
 	lidt(&r_idt);
 
@@ -1714,6 +1710,7 @@ SYSINIT(f00f_hack, SI_SUB_INTRINSIC, SI_ORDER_FIRST, f00f_hack, NULL);
 
 static void
 f00f_hack(void *unused) {
+	struct gate_descriptor *new_idt;
 #ifndef SMP
 	struct region_descriptor r_idt;
 #endif
@@ -1724,7 +1721,7 @@ f00f_hack(void *unused) {
 
 	printf("Intel Pentium detected, installing workaround for F00F bug\n");
 
-	r_idt.rd_limit = sizeof(idt) - 1;
+	r_idt.rd_limit = sizeof(idt0) - 1;
 
 	tmp = kmem_alloc(kernel_map, PAGE_SIZE * 2);
 	if (tmp == 0)
@@ -1732,10 +1729,11 @@ f00f_hack(void *unused) {
 	if (((unsigned int)tmp & (PAGE_SIZE-1)) != 0)
 		panic("kmem_alloc returned non-page-aligned memory");
 	/* Put the first seven entries in the lower page */
-	t_idt = (struct gate_descriptor*)(tmp + PAGE_SIZE - (7*8));
-	bcopy(idt, t_idt, sizeof(idt));
-	r_idt.rd_base = (int)t_idt;
+	new_idt = (struct gate_descriptor*)(tmp + PAGE_SIZE - (7*8));
+	bcopy(idt, new_idt, sizeof(idt0));
+	r_idt.rd_base = (int)new_idt;
 	lidt(&r_idt);
+	idt = new_idt;
 	if (vm_map_protect(kernel_map, tmp, tmp + PAGE_SIZE,
 			   VM_PROT_READ, FALSE) != KERN_SUCCESS)
 		panic("vm_map_protect failed");
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index df6e295..1d9d216 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.137 1999/05/06 18:12:17 peter Exp $
+ *	$Id: trap.c,v 1.138 1999/06/01 18:19:47 jlemon Exp $
  */
 
 /*
@@ -147,7 +147,6 @@ static __inline void userret __P((struct proc *p, struct trapframe *frame,
 				  u_quad_t oticks));
 
 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
-extern struct gate_descriptor *t_idt;
 extern int has_f00f_bug;
 #endif
 
@@ -727,7 +726,7 @@ trap_pfault(frame, usermode, eva)
 		 * fault.
 		 */
 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
-		if ((eva == (unsigned int)&t_idt[6]) && has_f00f_bug) {
+		if ((eva == (unsigned int)&idt[6]) && has_f00f_bug) {
 			frame->tf_trapno = T_PRIVINFLT;
 			return -2;
 		}
diff --git a/sys/i386/include/segments.h b/sys/i386/include/segments.h
index eaecfa3..7028185 100644
--- a/sys/i386/include/segments.h
+++ b/sys/i386/include/segments.h
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)segments.h	7.1 (Berkeley) 5/9/91
- *	$Id: segments.h,v 1.18 1999/01/28 11:45:49 newton Exp $
+ *	$Id: segments.h,v 1.19 1999/04/28 01:04:06 luoqi Exp $
  */
 
 #ifndef _MACHINE_SEGMENTS_H_
@@ -246,7 +246,7 @@ extern int	currentldt;
 extern int	_default_ldt;
 extern union descriptor gdt[];
 extern struct soft_segment_descriptor gdt_segs[];
-extern struct gate_descriptor idt[NIDT];
+extern struct gate_descriptor *idt;
 extern union descriptor ldt[NLDT];
 
 void	lgdt		__P((struct region_descriptor *rdp));
diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c
index df6e295..1d9d216 100644
--- a/sys/kern/subr_trap.c
+++ b/sys/kern/subr_trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.137 1999/05/06 18:12:17 peter Exp $
+ *	$Id: trap.c,v 1.138 1999/06/01 18:19:47 jlemon Exp $
  */
 
 /*
@@ -147,7 +147,6 @@ static __inline void userret __P((struct proc *p, struct trapframe *frame,
 				  u_quad_t oticks));
 
 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
-extern struct gate_descriptor *t_idt;
 extern int has_f00f_bug;
 #endif
 
@@ -727,7 +726,7 @@ trap_pfault(frame, usermode, eva)
 		 * fault.
 		 */
 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
-		if ((eva == (unsigned int)&t_idt[6]) && has_f00f_bug) {
+		if ((eva == (unsigned int)&idt[6]) && has_f00f_bug) {
 			frame->tf_trapno = T_PRIVINFLT;
 			return -2;
 		}