bitkeeper revision 1.1185 (420cf3c8-bMMcsnH1kMVRwy5AQ-ecg)

Various mini-os and Xen fixes. The M2P table is now definitely
accessible (read-only) from guest context.
Signed-off-by: keir.fraser@cl.cam.ac.uk

9 files changed, 316 insertions, 101 deletions

diff --git a/extras/mini-os/h/lib.h b/extras/mini-os/h/lib.h
index d9996a2f85..0b405ee006 100644
--- a/extras/mini-os/h/lib.h
+++ b/extras/mini-os/h/lib.h
@@ -55,22 +55,7 @@
 #ifndef _LIB_H_
 #define _LIB_H_
 
-
-/* variadic function support */
-typedef char *va_list;
-#define __va_size(type) \
-        (((sizeof(type) + sizeof(int) - 1) / sizeof(int)) * sizeof(int))
-#ifdef __GNUC__
-#define va_start(ap, last) \
-        ((ap) = (va_list)__builtin_next_arg(last))
-#else
-#define va_start(ap, last) \
-        ((ap) = (va_list)&(last) + __va_size(last))
-#endif
-#define va_arg(ap, type) \
-        (*(type *)((ap) += __va_size(type), (ap) - __va_size(type)))
-#define va_end(ap)
-
+#include <stdarg.h>
 
 /* printing */
 #define printk  printf
diff --git a/extras/mini-os/h/mm.h b/extras/mini-os/h/mm.h
index 5c6224db28..c5f6ad4788 100644
--- a/extras/mini-os/h/mm.h
+++ b/extras/mini-os/h/mm.h
@@ -1,20 +1,8 @@
 /* -*-  Mode:C; c-basic-offset:4; tab-width:4 -*-
- ****************************************************************************
- * (C) 2003 - Rolf Neugebauer - Intel Research Cambridge
- ****************************************************************************
  *
- *        File: mm.h
- *      Author: Rolf Neugebauer (neugebar@dcs.gla.ac.uk)
- *     Changes: 
- *              
- *        Date: Aug 2003
- * 
- * Environment: 
- * Description: 
+ * (C) 2003 - Rolf Neugebauer - Intel Research Cambridge
+ * Copyright (c) 2005, Keir A Fraser
  *
- ****************************************************************************
- * $Id: h-insert.h,v 1.4 2002/11/08 16:03:55 rn Exp $
- ****************************************************************************
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to
  * deal in the Software without restriction, including without limitation the
@@ -37,6 +25,48 @@
 #ifndef _MM_H_
 #define _MM_H_
 
+#ifdef __x86_64__
+
+#define L1_PAGETABLE_SHIFT      12
+#define L2_PAGETABLE_SHIFT      21
+#define L3_PAGETABLE_SHIFT      30
+#define L4_PAGETABLE_SHIFT      39
+
+#define L1_PAGETABLE_ENTRIES    512
+#define L2_PAGETABLE_ENTRIES    512
+#define L3_PAGETABLE_ENTRIES    512
+#define L4_PAGETABLE_ENTRIES    512
+
+/* These are page-table limitations. Current CPUs support only 40-bit phys. */
+#define PADDR_BITS              52
+#define VADDR_BITS              48
+#define PADDR_MASK              ((1UL << PADDR_BITS)-1)
+#define VADDR_MASK              ((1UL << VADDR_BITS)-1)
+
+#define pte_to_mfn(_pte) (((_pte) & (PADDR_MASK&PAGE_MASK)) >> PAGE_SHIFT)
+
+/* Given a virtual address, get an entry offset into a page table. */
+#define l1_table_offset(_a) \
+  (((_a) >> L1_PAGETABLE_SHIFT) & (L1_PAGETABLE_ENTRIES - 1))
+#define l2_table_offset(_a) \
+  (((_a) >> L2_PAGETABLE_SHIFT) & (L2_PAGETABLE_ENTRIES - 1))
+#define l3_table_offset(_a) \
+  (((_a) >> L3_PAGETABLE_SHIFT) & (L3_PAGETABLE_ENTRIES - 1))
+#define l4_table_offset(_a) \
+  (((_a) >> L4_PAGETABLE_SHIFT) & (L4_PAGETABLE_ENTRIES - 1))
+#endif
+
+#define _PAGE_PRESENT  0x001UL
+#define _PAGE_RW       0x002UL
+#define _PAGE_USER     0x004UL
+#define _PAGE_PWT      0x008UL
+#define _PAGE_PCD      0x010UL
+#define _PAGE_ACCESSED 0x020UL
+#define _PAGE_DIRTY    0x040UL
+#define _PAGE_PAT      0x080UL
+#define _PAGE_PSE      0x080UL
+#define _PAGE_GLOBAL   0x100UL
+
 #define PAGE_SHIFT      12
 #define PAGE_SIZE       (1UL << PAGE_SHIFT)
 #define PAGE_MASK       (~(PAGE_SIZE-1))
@@ -72,6 +102,8 @@ static __inline__ unsigned long machine_to_phys(unsigned long machine)
 
 #define to_phys(x)                 ((unsigned long)(x)-VIRT_START)
 #define to_virt(x)                 ((void *)((unsigned long)(x)+VIRT_START))
+#define __va to_virt
+#define __pa to_phys
 
 void init_mm(void);
 unsigned long alloc_pages(int order);
diff --git a/extras/mini-os/h/os.h b/extras/mini-os/h/os.h
index 6a0447ca39..434dd992f6 100644
--- a/extras/mini-os/h/os.h
+++ b/extras/mini-os/h/os.h
@@ -29,6 +29,28 @@
 #define __KERNEL_DS  FLAT_KERNEL_DS
 #define __KERNEL_SS  FLAT_KERNEL_SS
 
+#define TRAP_divide_error      0
+#define TRAP_debug             1
+#define TRAP_nmi               2
+#define TRAP_int3              3
+#define TRAP_overflow          4
+#define TRAP_bounds            5
+#define TRAP_invalid_op        6
+#define TRAP_no_device         7
+#define TRAP_double_fault      8
+#define TRAP_copro_seg         9
+#define TRAP_invalid_tss      10
+#define TRAP_no_segment       11
+#define TRAP_stack_error      12
+#define TRAP_gp_fault         13
+#define TRAP_page_fault       14
+#define TRAP_spurious_int     15
+#define TRAP_copro_error      16
+#define TRAP_alignment_check  17
+#define TRAP_machine_check    18
+#define TRAP_simd_error       19
+#define TRAP_deferred_nmi     31
+
 /* Everything below this point is not included by assembler (.S) files. */
 #ifndef __ASSEMBLY__
 
diff --git a/extras/mini-os/h/types.h b/extras/mini-os/h/types.h
index 85ede91c13..7bf103ab9c 100644
--- a/extras/mini-os/h/types.h
+++ b/extras/mini-os/h/types.h
@@ -26,8 +26,13 @@ typedef signed short        s16;
 typedef unsigned short      u16;
 typedef signed int          s32;
 typedef unsigned int        u32;
+#ifdef __i386__
 typedef signed long long    s64;
 typedef unsigned long long  u64;
+#elif defined(__x86_64__)
+typedef signed long         s64;
+typedef unsigned long       u64;
+#endif
 
 typedef unsigned int        size_t;
 
@@ -35,7 +40,13 @@ typedef unsigned int        size_t;
 typedef unsigned char       u_char;
 typedef unsigned int        u_int;
 typedef unsigned long       u_long;
+#ifdef __i386__
 typedef long long           quad_t;
 typedef unsigned long long  u_quad_t;
 typedef unsigned int        uintptr_t;
+#elif defined(__x86_64__)
+typedef long                quad_t;
+typedef unsigned long       u_quad_t;
+typedef unsigned long       uintptr_t;
+#endif
 #endif /* _TYPES_H_ */
diff --git a/extras/mini-os/kernel.c b/extras/mini-os/kernel.c
index a794145e68..b6f89b8bbb 100644
--- a/extras/mini-os/kernel.c
+++ b/extras/mini-os/kernel.c
@@ -65,7 +65,7 @@ extern char shared_info[PAGE_SIZE];
 static shared_info_t *map_shared_info(unsigned long pa)
 {
     if ( HYPERVISOR_update_va_mapping(
-        (unsigned long)shared_info, pa | 3, UVMF_INVLPG) )
+        (unsigned long)shared_info, pa | 7, UVMF_INVLPG) )
     {
         printk("Failed to map shared_info!!\n");
         *(int*)0=0;
diff --git a/extras/mini-os/lib/printf.c b/extras/mini-os/lib/printf.c
index f6232c4044..a08bb20e6c 100644
--- a/extras/mini-os/lib/printf.c
+++ b/extras/mini-os/lib/printf.c
@@ -341,7 +341,9 @@ reswitch:	switch (ch = (u_char)*fmt++) {
 		case 'p':
 			ul = (uintptr_t)va_arg(ap, void *);
 			base = 16;
-			sharpflag = (width == 0);
+			sharpflag = 0;
+            padc  = '0';
+            width = sizeof(uintptr_t)*2;
 			goto nosign;
 		case 'q':
 			qflag = 1;
diff --git a/extras/mini-os/mm.c b/extras/mini-os/mm.c
index 2bc87a5165..40a80e2ccb 100644
--- a/extras/mini-os/mm.c
+++ b/extras/mini-os/mm.c
@@ -84,6 +84,7 @@ void init_mm(void)
      */
 
     max_free_pfn = PFN_DOWN(to_phys(pgd));
+#ifdef __i386__
     {
         unsigned long *pgd = (unsigned long *)start_info.pt_base;
         unsigned long  pte;
@@ -110,6 +111,7 @@ void init_mm(void)
            (u_long)to_virt(PFN_PHYS(start_pfn)), PFN_PHYS(start_pfn), 
            (u_long)to_virt(PFN_PHYS(max_free_pfn)), PFN_PHYS(max_free_pfn));
     init_page_allocator(PFN_PHYS(start_pfn), PFN_PHYS(max_free_pfn));   
+#endif
 
 
     /* Now initialise the physical->machine mapping table. */
diff --git a/extras/mini-os/traps.c b/extras/mini-os/traps.c
index 858c54d3f2..7000128230 100644
--- a/extras/mini-os/traps.c
+++ b/extras/mini-os/traps.c
@@ -15,7 +15,6 @@ void overflow(void);
 void bounds(void);
 void invalid_op(void);
 void device_not_available(void);
-void double_fault(void);
 void coprocessor_segment_overrun(void);
 void invalid_TSS(void);
 void segment_not_present(void);
@@ -33,111 +32,134 @@ extern void do_exit(void);
 
 void dump_regs(struct pt_regs *regs)
 {
-    int in_kernel = 1;
     unsigned long esp;
     unsigned short ss;
 
+#ifdef __x86_64__
+    esp = regs->rsp;
+    ss  = regs->ss;
+#else
     esp = (unsigned long) (&regs->esp);
     ss = __KERNEL_DS;
     if (regs->cs & 2) {
-        in_kernel = 0;
         esp = regs->esp;
         ss = regs->ss & 0xffff;
     }
-    printf("EIP:    %04x:[<%p>]\n",
-           0xffff & regs->cs , regs->eip);
+#endif
+    printf("EIP:    %04x:[<%p>] %08x\n",
+           0xffff & regs->cs , regs->eip, regs->error_code);
     printf("EFLAGS: %p\n",regs->eflags);
     printf("eax: %p   ebx: %p   ecx: %p   edx: %p\n",
            regs->eax, regs->ebx, regs->ecx, regs->edx);
     printf("esi: %p   edi: %p   ebp: %p   esp: %p\n",
            regs->esi, regs->edi, regs->ebp, esp);
+#ifdef __x86_64__
+    printf("r8 : %p   r9 : %p   r10: %p   r11: %p\n",
+           regs->r8,  regs->r9,  regs->r10, regs->r11);
+    printf("r12: %p   r13: %p   r14: %p   r15: %p\n",
+           regs->r12, regs->r13, regs->r14, regs->r15);
+#endif
     printf("ds: %04x   es: %04x   ss: %04x\n",
            regs->ds & 0xffff, regs->es & 0xffff, ss);
-    printf("\n");
 }	
 
 
 static __inline__ void dump_code(unsigned long eip)
 {
-    unsigned *ptr = (unsigned *)eip;
+    unsigned char *ptr = (unsigned char *)eip;
     int x;
     
-    printk("Bytes at eip:\n");
-    for (x = -4; x < 5; x++)
-        printf("%p", ptr[x]);
+    printk("Bytes at eip: ");
+    for ( x = -4; x < 5; x++ )
+        printf("%02x ", ptr[x]);
+    printk("\n");
 }
 
-
-/*
- * C handlers here have their parameter-list constructed by the
- * assembler stubs above. Each one gets a pointer to a list
- * of register values (to be restored at end of exception).
- * Some will also receive an error code -- this is the code that
- * was generated by the processor for the underlying real exception. 
- * 
- * Note that the page-fault exception is special. It also receives
- * the faulting linear address. Normally this would be found in
- * register CR2, but that is not accessible in a virtualised OS.
- */
-
 static void __inline__ do_trap(int trapnr, char *str,
-                               struct pt_regs * regs, long error_code)
+                               struct pt_regs * regs)
 {
-    printk("FATAL:  Unhandled Trap (see mini-os:traps.c)");
-    printf("%d %s", trapnr, str);
+    printk("FATAL:  Unhandled Trap %d (%s)\n", trapnr, str);
     dump_regs(regs);
     dump_code(regs->eip);
-
     do_exit();
 }
 
 #define DO_ERROR(trapnr, str, name) \
-void do_##name(struct pt_regs * regs, long error_code) \
+void do_##name(struct pt_regs * regs) \
 { \
-	do_trap(trapnr, str, regs, error_code); \
+	do_trap(trapnr, str, regs); \
 }
 
 #define DO_ERROR_INFO(trapnr, str, name, sicode, siaddr) \
-void do_##name(struct pt_regs * regs, long error_code) \
+void do_##name(struct pt_regs * regs) \
 { \
-	do_trap(trapnr, str, regs, error_code); \
+	do_trap(trapnr, str, regs); \
 }
 
 DO_ERROR_INFO( 0, "divide error", divide_error, FPE_INTDIV, regs->eip)
-    DO_ERROR( 3, "int3", int3)
-    DO_ERROR( 4, "overflow", overflow)
-    DO_ERROR( 5, "bounds", bounds)
-    DO_ERROR_INFO( 6, "invalid operand", invalid_op, ILL_ILLOPN, regs->eip)
-    DO_ERROR( 7, "device not available", device_not_available)
-    DO_ERROR( 8, "double fault", double_fault)
-    DO_ERROR( 9, "coprocessor segment overrun", coprocessor_segment_overrun)
-    DO_ERROR(10, "invalid TSS", invalid_TSS)
-    DO_ERROR(11, "segment not present", segment_not_present)
-    DO_ERROR(12, "stack segment", stack_segment)
-    DO_ERROR_INFO(17, "alignment check", alignment_check, BUS_ADRALN, 0)
-    DO_ERROR(18, "machine check", machine_check)
-
-    void do_page_fault(struct pt_regs *regs, long error_code,
-                       unsigned long address)
+DO_ERROR( 3, "int3", int3)
+DO_ERROR( 4, "overflow", overflow)
+DO_ERROR( 5, "bounds", bounds)
+DO_ERROR_INFO( 6, "invalid operand", invalid_op, ILL_ILLOPN, regs->eip)
+DO_ERROR( 7, "device not available", device_not_available)
+DO_ERROR( 9, "coprocessor segment overrun", coprocessor_segment_overrun)
+DO_ERROR(10, "invalid TSS", invalid_TSS)
+DO_ERROR(11, "segment not present", segment_not_present)
+DO_ERROR(12, "stack segment", stack_segment)
+DO_ERROR_INFO(17, "alignment check", alignment_check, BUS_ADRALN, 0)
+DO_ERROR(18, "machine check", machine_check)
+
+extern unsigned long virt_cr2;
+void do_page_fault(struct pt_regs *regs)
 {
-    printk("Page fault\n");
-    printk("Address: 0x%p", address);
-    printk("Error Code: 0x%p", error_code);
-    printk("eip: \t 0x%p", regs->eip);
+    unsigned long addr = virt_cr2;
+    printk("Page fault at linear address %p\n", addr);
+    dump_regs(regs);
+    dump_code(regs->eip);
+#ifdef __x86_64__
+    {
+        unsigned long *tab = (unsigned long *)start_info.pt_base;
+        unsigned long page;
+    
+        printk("Pagetable walk from %p:\n", tab);
+        
+        page = tab[l4_table_offset(addr)];
+        tab = __va(mfn_to_pfn(pte_to_mfn(page)) << PAGE_SHIFT);
+        printk(" L4 = %p (%p)\n", page, tab);
+        if ( !(page & _PAGE_PRESENT) )
+            goto out;
+
+        page = tab[l3_table_offset(addr)];
+        tab = __va(mfn_to_pfn(pte_to_mfn(page)) << PAGE_SHIFT);
+        printk("  L3 = %p (%p)\n", page, tab);
+        if ( !(page & _PAGE_PRESENT) )
+            goto out;
+        
+        page = tab[l2_table_offset(addr)];
+        tab = __va(mfn_to_pfn(pte_to_mfn(page)) << PAGE_SHIFT);
+        printk("   L2 = %p (%p) %s\n", page, tab,
+               (page & _PAGE_PSE) ? "(2MB)" : "");
+        if ( !(page & _PAGE_PRESENT) || (page & _PAGE_PSE) )
+            goto out;
+        
+        page = tab[l1_table_offset(addr)];
+        printk("    L1 = %p\n", page);
+    }
+#endif
+ out:
     do_exit();
 }
 
-void do_general_protection(struct pt_regs * regs, long error_code)
+void do_general_protection(struct pt_regs *regs)
 {
     printk("GPF\n");
-    printk("Error Code: 0x%p", error_code);
     dump_regs(regs);
     dump_code(regs->eip);
     do_exit();
 }
 
 
-void do_debug(struct pt_regs * regs, long error_code)
+void do_debug(struct pt_regs * regs)
 {
     printk("Debug exception\n");
 #define TF_MASK 0x100
@@ -146,9 +168,7 @@ void do_debug(struct pt_regs * regs, long error_code)
     do_exit();
 }
 
-
-
-void do_coprocessor_error(struct pt_regs * regs, long error_code)
+void do_coprocessor_error(struct pt_regs * regs)
 {
     printk("Copro error\n");
     dump_regs(regs);
@@ -161,14 +181,12 @@ void simd_math_error(void *eip)
     printk("SIMD error\n");
 }
 
-void do_simd_coprocessor_error(struct pt_regs * regs,
-                               long error_code)
+void do_simd_coprocessor_error(struct pt_regs * regs)
 {
     printk("SIMD copro error\n");
 }
 
-void do_spurious_interrupt_bug(struct pt_regs * regs,
-                               long error_code)
+void do_spurious_interrupt_bug(struct pt_regs * regs)
 {
 }
 
@@ -189,7 +207,6 @@ static trap_info_t trap_table[] = {
     {  5, 3, __KERNEL_CS, _P (unsigned long)bounds                      },
     {  6, 0, __KERNEL_CS, _P (unsigned long)invalid_op                  },
     {  7, 0, __KERNEL_CS, _P (unsigned long)device_not_available        },
-    {  8, 0, __KERNEL_CS, _P (unsigned long)double_fault                },
     {  9, 0, __KERNEL_CS, _P (unsigned long)coprocessor_segment_overrun },
     { 10, 0, __KERNEL_CS, _P (unsigned long)invalid_TSS                 },
     { 11, 0, __KERNEL_CS, _P (unsigned long)segment_not_present         },
diff --git a/extras/mini-os/x86_64.S b/extras/mini-os/x86_64.S
index 4a4708ddd5..0f37d596f7 100644
--- a/extras/mini-os/x86_64.S
+++ b/extras/mini-os/x86_64.S
@@ -6,7 +6,42 @@
 
 #define ENTRY(X) .globl X ; X :
 .globl _start, shared_info
-                        
+
+#define SAVE_ALL \
+        cld; \
+        pushq %rdi; \
+        pushq %rsi; \
+        pushq %rdx; \
+        pushq %rcx; \
+        pushq %rax; \
+        pushq %r8; \
+        pushq %r9; \
+        pushq %r10; \
+        pushq %r11; \
+        pushq %rbx; \
+        pushq %rbp; \
+        pushq %r12; \
+        pushq %r13; \
+        pushq %r14; \
+        pushq %r15;
+
+#define RESTORE_ALL \
+        popq  %r15; \
+        popq  %r14; \
+        popq  %r13; \
+        popq  %r12; \
+        popq  %rbp; \
+        popq  %rbx; \
+        popq  %r11; \
+        popq  %r10; \
+        popq  %r9; \
+        popq  %r8; \
+        popq  %rax; \
+        popq  %rcx; \
+        popq  %rdx; \
+        popq  %rsi; \
+        popq  %rdi
+
 _start:
         cld
         movq stack_start(%rip),%rsp
@@ -23,56 +58,165 @@ shared_info:
         .org 0x2000
 
 ENTRY(hypervisor_callback)
+        popq  %rcx
+        popq  %r11
+        iretq
 
 ENTRY(failsafe_callback)
-      iret
-                
+        popq  %rcx
+        popq  %r11
+        iretq
+
+error_code:
+        SAVE_ALL
+        movq  %rsp,%rdi
+        movl  15*8+4(%rsp),%eax
+        leaq  exception_table(%rip),%rdx
+        callq *(%rdx,%rax,8)
+        RESTORE_ALL
+        addq  $8,%rsp
+        iretq
+                        
 ENTRY(divide_error)
+        popq  %rcx
+        popq  %r11
 	pushq $0
-
+        movl  $TRAP_divide_error,4(%rsp)
+        jmp   error_code
+        
 ENTRY(coprocessor_error)
+        popq  %rcx
+        popq  %r11
 	pushq $0
+        movl  $TRAP_copro_error,4(%rsp)
+        jmp   error_code
 
 ENTRY(simd_coprocessor_error)
+        popq  %rcx
+        popq  %r11
 	pushq $0
+        movl  $TRAP_simd_error,4(%rsp)
+        jmp   error_code
 
 ENTRY(device_not_available)
-        iret
+        popq  %rcx
+        popq  %r11
+        movl  $TRAP_no_device,4(%rsp)
+        jmp   error_code
 
 ENTRY(debug)
+        popq  %rcx
+        popq  %r11
 	pushq $0
+        movl  $TRAP_debug,4(%rsp)
+        jmp   error_code
 
 ENTRY(int3)
+        popq  %rcx
+        popq  %r11
 	pushq $0
+        movl  $TRAP_int3,4(%rsp)
+        jmp   error_code
 
 ENTRY(overflow)
+        popq  %rcx
+        popq  %r11
 	pushq $0
+        movl  $TRAP_overflow,4(%rsp)
+        jmp   error_code
 
 ENTRY(bounds)
+        popq  %rcx
+        popq  %r11
 	pushq $0
+        movl  $TRAP_bounds,4(%rsp)
+        jmp   error_code
 
 ENTRY(invalid_op)
+        popq  %rcx
+        popq  %r11
 	pushq $0
+        movl  $TRAP_invalid_op,4(%rsp)
+        jmp   error_code
 
 ENTRY(coprocessor_segment_overrun)
+        popq  %rcx
+        popq  %r11
 	pushq $0
-
-ENTRY(double_fault)
+        movl  $TRAP_copro_seg,4(%rsp)
+        jmp   error_code
 
 ENTRY(invalid_TSS)
+        popq  %rcx
+        popq  %r11
+        movl  $TRAP_invalid_tss,4(%rsp)
+        jmp   error_code
 
 ENTRY(segment_not_present)
+        popq  %rcx
+        popq  %r11
+        movl  $TRAP_no_segment,4(%rsp)
+        jmp   error_code
 
 ENTRY(stack_segment)
+        popq  %rcx
+        popq  %r11
+        movl  $TRAP_stack_error,4(%rsp)
+        jmp   error_code
 
 ENTRY(general_protection)
+        popq  %rcx
+        popq  %r11
+        movl  $TRAP_gp_fault,4(%rsp)
+        jmp   error_code
 
 ENTRY(alignment_check)
+        popq  %rcx
+        popq  %r11
+        movl  $TRAP_alignment_check,4(%rsp)
+        jmp   error_code
 
+ENTRY(virt_cr2)
+        .quad 0
 ENTRY(page_fault)
-
+        popq  %rcx
+        popq  %r11
+        popq  virt_cr2(%rip)
+        movl  $TRAP_page_fault,4(%rsp)
+        jmp   error_code
+        
 ENTRY(machine_check)
+        popq  %rcx
+        popq  %r11
 	pushq $0
+        movl  $TRAP_machine_check,4(%rsp)
+        jmp   error_code
 
 ENTRY(spurious_interrupt_bug)
+        popq  %rcx
+        popq  %r11
 	pushq $0
+        movl  $TRAP_spurious_int,4(%rsp)
+        jmp   error_code
+
+ENTRY(exception_table)
+        .quad do_divide_error
+        .quad do_debug
+        .quad 0 # nmi
+        .quad do_int3
+        .quad do_overflow
+        .quad do_bounds
+        .quad do_invalid_op
+        .quad 0
+        .quad 0
+        .quad do_coprocessor_segment_overrun
+        .quad do_invalid_TSS
+        .quad do_segment_not_present
+        .quad do_stack_segment
+        .quad do_general_protection
+        .quad do_page_fault
+        .quad do_spurious_interrupt_bug
+        .quad do_coprocessor_error
+        .quad do_alignment_check
+        .quad do_machine_check
+        .quad do_simd_coprocessor_error