traps: x86: make traps_32.c and traps_64.c equal

Use CONFIG_X86_64/CONFIG_X86_32 to condtionally compile the
parts needed for x86_64 or i386 only.

Runs a small userspace for a number of minimal configurations
and boots the defconfigs.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 536 insertions, 5 deletions

diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index 076739863d24..ffb131f74f78 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -48,7 +48,6 @@
 
 #include <asm/stacktrace.h>
 #include <asm/processor.h>
-#include <asm/kmemcheck.h>
 #include <asm/debugreg.h>
 #include <asm/atomic.h>
 #include <asm/system.h>
@@ -59,6 +58,11 @@
 
 #include <mach_traps.h>
 
+#ifdef CONFIG_X86_64
+#include <asm/pgalloc.h>
+#include <asm/proto.h>
+#include <asm/pda.h>
+#else
 #include <asm/processor-flags.h>
 #include <asm/arch_hooks.h>
 #include <asm/nmi.h>
@@ -83,6 +87,7 @@ char ignore_fpu_irq;
  */
 gate_desc idt_table[256]
         __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
+#endif
 
 static int ignore_nmis;
 
@@ -106,6 +111,7 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
         dec_preempt_count();
 }
 
+#ifdef CONFIG_X86_32
 static inline void
 die_if_kernel(const char *str, struct pt_regs *regs, long err)
 {
@@ -153,6 +159,7 @@ static int lazy_iobitmap_copy(void)
 
         return 0;
 }
+#endif
 
 static void __kprobes
 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
@@ -160,6 +167,7 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
 {
         struct task_struct *tsk = current;
 
+#ifdef CONFIG_X86_32
         if (regs->flags & X86_VM_MASK) {
                 /*
                  * traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
@@ -169,11 +177,14 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
                         goto vm86_trap;
                 goto trap_signal;
         }
+#endif
 
         if (!user_mode(regs))
                 goto kernel_trap;
 
+#ifdef CONFIG_X86_32
 trap_signal:
+#endif
         /*
          * We want error_code and trap_no set for userspace faults and
          * kernelspace faults which result in die(), but not
@@ -186,6 +197,18 @@ trap_signal:
         tsk->thread.error_code = error_code;
         tsk->thread.trap_no = trapnr;
 
+#ifdef CONFIG_X86_64
+        if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
+            printk_ratelimit()) {
+                printk(KERN_INFO
+                       "%s[%d] trap %s ip:%lx sp:%lx error:%lx",
+                       tsk->comm, tsk->pid, str,
+                       regs->ip, regs->sp, error_code);
+                print_vma_addr(" in ", regs->ip);
+                printk("\n");
+        }
+#endif
+
         if (info)
                 force_sig_info(signr, info, tsk);
         else
@@ -200,11 +223,13 @@ kernel_trap:
         }
         return;
 
+#ifdef CONFIG_X86_32
 vm86_trap:
         if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
                                                 error_code, trapnr))
                 goto trap_signal;
         return;
+#endif
 }
 
 #define DO_ERROR(trapnr, signr, str, name)                              \
@@ -239,9 +264,41 @@ DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip)
 DO_ERROR(9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
+#ifdef CONFIG_X86_32
 DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
+#endif
 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
 
+#ifdef CONFIG_X86_64
+/* Runs on IST stack */
+dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
+{
+        if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
+                        12, SIGBUS) == NOTIFY_STOP)
+                return;
+        preempt_conditional_sti(regs);
+        do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
+        preempt_conditional_cli(regs);
+}
+
+dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
+{
+        static const char str[] = "double fault";
+        struct task_struct *tsk = current;
+
+        /* Return not checked because double check cannot be ignored */
+        notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
+
+        tsk->thread.error_code = error_code;
+        tsk->thread.trap_no = 8;
+
+        /* This is always a kernel trap and never fixable (and thus must
+           never return). */
+        for (;;)
+                die(str, regs, error_code);
+}
+#endif
+
 dotraplinkage void __kprobes
 do_general_protection(struct pt_regs *regs, long error_code)
 {
@@ -249,6 +306,7 @@ do_general_protection(struct pt_regs *regs, long error_code)
 
         conditional_sti(regs);
 
+#ifdef CONFIG_X86_32
         if (lazy_iobitmap_copy()) {
                 /* restart the faulting instruction */
                 return;
@@ -256,6 +314,7 @@ do_general_protection(struct pt_regs *regs, long error_code)
 
         if (regs->flags & X86_VM_MASK)
                 goto gp_in_vm86;
+#endif
 
         tsk = current;
         if (!user_mode(regs))
@@ -277,10 +336,12 @@ do_general_protection(struct pt_regs *regs, long error_code)
         force_sig(SIGSEGV, tsk);
         return;
 
+#ifdef CONFIG_X86_32
 gp_in_vm86:
         local_irq_enable();
         handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
         return;
+#endif
 
 gp_in_kernel:
         if (fixup_exception(regs))
@@ -368,6 +429,7 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
         printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
 }
 
+#ifdef CONFIG_X86_32
 static DEFINE_SPINLOCK(nmi_print_lock);
 
 void notrace __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
@@ -402,6 +464,7 @@ void notrace __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
 
         do_exit(SIGSEGV);
 }
+#endif
 
 static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
 {
@@ -441,11 +504,13 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
                 mem_parity_error(reason, regs);
         if (reason & 0x40)
                 io_check_error(reason, regs);
+#ifdef CONFIG_X86_32
         /*
          * Reassert NMI in case it became active meanwhile
          * as it's edge-triggered:
          */
         reassert_nmi();
+#endif
 }
 
 dotraplinkage notrace __kprobes void
@@ -453,7 +518,11 @@ do_nmi(struct pt_regs *regs, long error_code)
 {
         nmi_enter();
 
+#ifdef CONFIG_X86_32
         { int cpu; cpu = smp_processor_id(); ++nmi_count(cpu); }
+#else
+        add_pda(__nmi_count, 1);
+#endif
 
         if (!ignore_nmis)
                 default_do_nmi(regs);
@@ -491,6 +560,29 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
         preempt_conditional_cli(regs);
 }
 
+#ifdef CONFIG_X86_64
+/* Help handler running on IST stack to switch back to user stack
+   for scheduling or signal handling. The actual stack switch is done in
+   entry.S */
+asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
+{
+        struct pt_regs *regs = eregs;
+        /* Did already sync */
+        if (eregs == (struct pt_regs *)eregs->sp)
+                ;
+        /* Exception from user space */
+        else if (user_mode(eregs))
+                regs = task_pt_regs(current);
+        /* Exception from kernel and interrupts are enabled. Move to
+           kernel process stack. */
+        else if (eregs->flags & X86_EFLAGS_IF)
+                regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
+        if (eregs != regs)
+                *regs = *eregs;
+        return regs;
+}
+#endif
+
 /*
  * Our handling of the processor debug registers is non-trivial.
  * We do not clear them on entry and exit from the kernel. Therefore
@@ -542,8 +634,10 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
                         goto clear_dr7;
         }
 
+#ifdef CONFIG_X86_32
         if (regs->flags & X86_VM_MASK)
                 goto debug_vm86;
+#endif
 
         /* Save debug status register where ptrace can see it */
         tsk->thread.debugreg6 = condition;
@@ -570,10 +664,12 @@ clear_dr7:
         preempt_conditional_cli(regs);
         return;
 
+#ifdef CONFIG_X86_32
 debug_vm86:
         handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
         preempt_conditional_cli(regs);
         return;
+#endif
 
 clear_TF_reenable:
         set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
@@ -582,6 +678,20 @@ clear_TF_reenable:
         return;
 }
 
+#ifdef CONFIG_X86_64
+static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
+{
+        if (fixup_exception(regs))
+                return 1;
+
+        notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
+        /* Illegal floating point operation in the kernel */
+        current->thread.trap_no = trapnr;
+        die(str, regs, 0);
+        return 0;
+}
+#endif
+
 /*
  * Note that we play around with the 'TS' bit in an attempt to get
  * the correct behaviour even in the presence of the asynchronous
@@ -618,7 +728,9 @@ void math_error(void __user *ip)
         swd = get_fpu_swd(task);
         switch (swd & ~cwd & 0x3f) {
         case 0x000: /* No unmasked exception */
+#ifdef CONFIG_X86_32
                 return;
+#endif
         default: /* Multiple exceptions */
                 break;
         case 0x001: /* Invalid Op */
@@ -649,7 +761,15 @@ void math_error(void __user *ip)
 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 {
         conditional_sti(regs);
+
+#ifdef CONFIG_X86_32
         ignore_fpu_irq = 1;
+#else
+        if (!user_mode(regs) &&
+            kernel_math_error(regs, "kernel x87 math error", 16))
+                return;
+#endif
+
         math_error((void __user *)regs->ip);
 }
 
@@ -706,6 +826,7 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 {
         conditional_sti(regs);
 
+#ifdef CONFIG_X86_32
         if (cpu_has_xmm) {
                 /* Handle SIMD FPU exceptions on PIII+ processors. */
                 ignore_fpu_irq = 1;
@@ -724,6 +845,12 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
         current->thread.error_code = error_code;
         die_if_kernel("cache flush denied", regs, error_code);
         force_sig(SIGSEGV, current);
+#else
+        if (!user_mode(regs) &&
+                        kernel_math_error(regs, "kernel simd math error", 19))
+                return;
+        simd_math_error((void __user *)regs->ip);
+#endif
 }
 
 dotraplinkage void
@@ -736,6 +863,7 @@ do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
 #endif
 }
 
+#ifdef CONFIG_X86_32
 unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp)
 {
         struct desc_struct *gdt = get_cpu_gdt_table(smp_processor_id());
@@ -754,6 +882,15 @@ unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp)
 
         return new_kesp;
 }
+#else
+asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
+{
+}
+
+asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
+{
+}
+#endif
 
 /*
  * 'math_state_restore()' saves the current math information in the
@@ -786,14 +923,24 @@ asmlinkage void math_state_restore(void)
         }
 
         clts();                         /* Allow maths ops (or we recurse) */
+#ifdef CONFIG_X86_32
         restore_fpu(tsk);
+#else
+        /*
+         * Paranoid restore. send a SIGSEGV if we fail to restore the state.
+         */
+        if (unlikely(restore_fpu_checking(tsk))) {
+                stts();
+                force_sig(SIGSEGV, tsk);
+                return;
+        }
+#endif
         thread->status |= TS_USEDFPU;   /* So we fnsave on switch_to() */
         tsk->fpu_counter++;
 }
 EXPORT_SYMBOL_GPL(math_state_restore);
 
 #ifndef CONFIG_MATH_EMULATION
-
 asmlinkage void math_emulate(long arg)
 {
         printk(KERN_EMERG
@@ -802,12 +949,12 @@ asmlinkage void math_emulate(long arg)
         force_sig(SIGFPE, current);
         schedule();
 }
-
 #endif /* CONFIG_MATH_EMULATION */
 
 dotraplinkage void __kprobes
 do_device_not_available(struct pt_regs *regs, long error)
 {
+#ifdef CONFIG_X86_32
         if (read_cr0() & X86_CR0_EM) {
                 conditional_sti(regs);
                 math_emulate(0);
@@ -815,8 +962,12 @@ do_device_not_available(struct pt_regs *regs, long error)
                 math_state_restore(); /* interrupts still off */
                 conditional_sti(regs);
         }
+#else
+        math_state_restore();
+#endif
 }
 
+#ifdef CONFIG_X86_32
 #ifdef CONFIG_X86_MCE
 dotraplinkage void __kprobes do_machine_check(struct pt_regs *regs, long error)
 {
@@ -839,10 +990,13 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
                 return;
         do_trap(32, SIGILL, "iret exception", regs, error_code, &info);
 }
+#endif
 
 void __init trap_init(void)
 {
+#ifdef CONFIG_X86_32
         int i;
+#endif
 
 #ifdef CONFIG_EISA
         void __iomem *p = early_ioremap(0x0FFFD9, 4);
@@ -862,7 +1016,11 @@ void __init trap_init(void)
         set_intr_gate(5, &bounds);
         set_intr_gate(6, &invalid_op);
         set_intr_gate(7, &device_not_available);
+#ifdef CONFIG_X86_32
         set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS);
+#else
+        set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK);
+#endif
         set_intr_gate(9, &coprocessor_segment_overrun);
         set_intr_gate(10, &invalid_TSS);
         set_intr_gate(11, &segment_not_present);
@@ -877,6 +1035,11 @@ void __init trap_init(void)
 #endif
         set_intr_gate(19, &simd_coprocessor_error);
 
+#ifdef CONFIG_IA32_EMULATION
+        set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
+#endif
+
+#ifdef CONFIG_X86_32
         if (cpu_has_fxsr) {
                 printk(KERN_INFO "Enabling fast FPU save and restore... ");
                 set_in_cr4(X86_CR4_OSFXSR);
@@ -896,11 +1059,13 @@ void __init trap_init(void)
                 set_bit(i, used_vectors);
 
         set_bit(SYSCALL_VECTOR, used_vectors);
-
+#endif
         /*
          * Should be a barrier for any external CPU state:
          */
         cpu_init();
 
+#ifdef CONFIG_X86_32
         trap_init_hook();
+#endif
 }
diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index 22fe62a24edb..60ecc855ab81 100644
--- a/arch/x86/kernel/traps_64.c
+++ b/arch/x86/kernel/traps_64.c
@@ -33,13 +33,21 @@
 #include <linux/smp.h>
 #include <linux/io.h>
 
+#ifdef CONFIG_EISA
+#include <linux/ioport.h>
+#include <linux/eisa.h>
+#endif
+
+#ifdef CONFIG_MCA
+#include <linux/mca.h>
+#endif
+
 #if defined(CONFIG_EDAC)
 #include <linux/edac.h>
 #endif
 
 #include <asm/stacktrace.h>
 #include <asm/processor.h>
-#include <asm/kmemcheck.h>
 #include <asm/debugreg.h>
 #include <asm/atomic.h>
 #include <asm/system.h>
@@ -50,10 +58,35 @@
 
 #include <mach_traps.h>
 
+#ifdef CONFIG_X86_64
 #include <asm/pgalloc.h>
 #include <asm/proto.h>
 #include <asm/pda.h>
+#else
+#include <asm/processor-flags.h>
+#include <asm/arch_hooks.h>
+#include <asm/nmi.h>
+#include <asm/smp.h>
+#include <asm/io.h>
+
+#include "cpu/mcheck/mce.h"
 
+DECLARE_BITMAP(used_vectors, NR_VECTORS);
+EXPORT_SYMBOL_GPL(used_vectors);
+
+asmlinkage int system_call(void);
+
+/* Do we ignore FPU interrupts ? */
+char ignore_fpu_irq;
+
+/*
+ * The IDT has to be page-aligned to simplify the Pentium
+ * F0 0F bug workaround.. We have a special link segment
+ * for this.
+ */
+gate_desc idt_table[256]
+        __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
+#endif
 
 static int ignore_nmis;
 
@@ -77,15 +110,80 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
         dec_preempt_count();
 }
 
+#ifdef CONFIG_X86_32
+static inline void
+die_if_kernel(const char *str, struct pt_regs *regs, long err)
+{
+        if (!user_mode_vm(regs))
+                die(str, regs, err);
+}
+
+/*
+ * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
+ * invalid offset set (the LAZY one) and the faulting thread has
+ * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS,
+ * we set the offset field correctly and return 1.
+ */
+static int lazy_iobitmap_copy(void)
+{
+        struct thread_struct *thread;
+        struct tss_struct *tss;
+        int cpu;
+
+        cpu = get_cpu();
+        tss = &per_cpu(init_tss, cpu);
+        thread = &current->thread;
+
+        if (tss->x86_tss.io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
+            thread->io_bitmap_ptr) {
+                memcpy(tss->io_bitmap, thread->io_bitmap_ptr,
+                       thread->io_bitmap_max);
+                /*
+                 * If the previously set map was extending to higher ports
+                 * than the current one, pad extra space with 0xff (no access).
+                 */
+                if (thread->io_bitmap_max < tss->io_bitmap_max) {
+                        memset((char *) tss->io_bitmap +
+                                thread->io_bitmap_max, 0xff,
+                                tss->io_bitmap_max - thread->io_bitmap_max);
+                }
+                tss->io_bitmap_max = thread->io_bitmap_max;
+                tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
+                tss->io_bitmap_owner = thread;
+                put_cpu();
+
+                return 1;
+        }
+        put_cpu();
+
+        return 0;
+}
+#endif
+
 static void __kprobes
 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
         long error_code, siginfo_t *info)
 {
         struct task_struct *tsk = current;
 
+#ifdef CONFIG_X86_32
+        if (regs->flags & X86_VM_MASK) {
+                /*
+                 * traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
+                 * On nmi (interrupt 2), do_trap should not be called.
+                 */
+                if (trapnr < 6)
+                        goto vm86_trap;
+                goto trap_signal;
+        }
+#endif
+
         if (!user_mode(regs))
                 goto kernel_trap;
 
+#ifdef CONFIG_X86_32
+trap_signal:
+#endif
         /*
          * We want error_code and trap_no set for userspace faults and
          * kernelspace faults which result in die(), but not
@@ -98,6 +196,7 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
         tsk->thread.error_code = error_code;
         tsk->thread.trap_no = trapnr;
 
+#ifdef CONFIG_X86_64
         if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
             printk_ratelimit()) {
                 printk(KERN_INFO
@@ -107,6 +206,7 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
                 print_vma_addr(" in ", regs->ip);
                 printk("\n");
         }
+#endif
 
         if (info)
                 force_sig_info(signr, info, tsk);
@@ -121,6 +221,14 @@ kernel_trap:
                 die(str, regs, error_code);
         }
         return;
+
+#ifdef CONFIG_X86_32
+vm86_trap:
+        if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
+                                                error_code, trapnr))
+                goto trap_signal;
+        return;
+#endif
 }
 
 #define DO_ERROR(trapnr, signr, str, name)                              \
@@ -155,8 +263,12 @@ DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip)
 DO_ERROR(9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
+#ifdef CONFIG_X86_32
+DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
+#endif
 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
 
+#ifdef CONFIG_X86_64
 /* Runs on IST stack */
 dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
 {
@@ -184,6 +296,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
         for (;;)
                 die(str, regs, error_code);
 }
+#endif
 
 dotraplinkage void __kprobes
 do_general_protection(struct pt_regs *regs, long error_code)
@@ -192,6 +305,16 @@ do_general_protection(struct pt_regs *regs, long error_code)
 
         conditional_sti(regs);
 
+#ifdef CONFIG_X86_32
+        if (lazy_iobitmap_copy()) {
+                /* restart the faulting instruction */
+                return;
+        }
+
+        if (regs->flags & X86_VM_MASK)
+                goto gp_in_vm86;
+#endif
+
         tsk = current;
         if (!user_mode(regs))
                 goto gp_in_kernel;
@@ -212,6 +335,13 @@ do_general_protection(struct pt_regs *regs, long error_code)
         force_sig(SIGSEGV, tsk);
         return;
 
+#ifdef CONFIG_X86_32
+gp_in_vm86:
+        local_irq_enable();
+        handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
+        return;
+#endif
+
 gp_in_kernel:
         if (fixup_exception(regs))
                 return;
@@ -277,6 +407,16 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
         if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) ==
                         NOTIFY_STOP)
                 return;
+#ifdef CONFIG_MCA
+        /*
+         * Might actually be able to figure out what the guilty party
+         * is:
+         */
+        if (MCA_bus) {
+                mca_handle_nmi();
+                return;
+        }
+#endif
         printk(KERN_EMERG
                 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
                         reason, smp_processor_id());
@@ -288,6 +428,43 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
         printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
 }
 
+#ifdef CONFIG_X86_32
+static DEFINE_SPINLOCK(nmi_print_lock);
+
+void notrace __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
+{
+        if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
+                return;
+
+        spin_lock(&nmi_print_lock);
+        /*
+        * We are in trouble anyway, lets at least try
+        * to get a message out:
+        */
+        bust_spinlocks(1);
+        printk(KERN_EMERG "%s", str);
+        printk(" on CPU%d, ip %08lx, registers:\n",
+                smp_processor_id(), regs->ip);
+        show_registers(regs);
+        if (do_panic)
+                panic("Non maskable interrupt");
+        console_silent();
+        spin_unlock(&nmi_print_lock);
+        bust_spinlocks(0);
+
+        /*
+         * If we are in kernel we are probably nested up pretty bad
+         * and might aswell get out now while we still can:
+         */
+        if (!user_mode_vm(regs)) {
+                current->thread.trap_no = 2;
+                crash_kexec(regs);
+        }
+
+        do_exit(SIGSEGV);
+}
+#endif
+
 static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
 {
         unsigned char reason = 0;
@@ -303,6 +480,7 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
                 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
                                                                 == NOTIFY_STOP)
                         return;
+#ifdef CONFIG_X86_LOCAL_APIC
                 /*
                  * Ok, so this is none of the documented NMI sources,
                  * so it must be the NMI watchdog.
@@ -311,6 +489,9 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
                         return;
                 if (!do_nmi_callback(regs, cpu))
                         unknown_nmi_error(reason, regs);
+#else
+                unknown_nmi_error(reason, regs);
+#endif
 
                 return;
         }
@@ -322,6 +503,13 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
                 mem_parity_error(reason, regs);
         if (reason & 0x40)
                 io_check_error(reason, regs);
+#ifdef CONFIG_X86_32
+        /*
+         * Reassert NMI in case it became active meanwhile
+         * as it's edge-triggered:
+         */
+        reassert_nmi();
+#endif
 }
 
 dotraplinkage notrace __kprobes void
@@ -329,7 +517,11 @@ do_nmi(struct pt_regs *regs, long error_code)
 {
         nmi_enter();
 
+#ifdef CONFIG_X86_32
+        { int cpu; cpu = smp_processor_id(); ++nmi_count(cpu); }
+#else
         add_pda(__nmi_count, 1);
+#endif
 
         if (!ignore_nmis)
                 default_do_nmi(regs);
@@ -352,15 +544,22 @@ void restart_nmi(void)
 /* May run on IST stack. */
 dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
 {
+#ifdef CONFIG_KPROBES
         if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
                         == NOTIFY_STOP)
                 return;
+#else
+        if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP)
+                        == NOTIFY_STOP)
+                return;
+#endif
 
         preempt_conditional_sti(regs);
         do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
         preempt_conditional_cli(regs);
 }
 
+#ifdef CONFIG_X86_64
 /* Help handler running on IST stack to switch back to user stack
    for scheduling or signal handling. The actual stack switch is done in
    entry.S */
@@ -381,6 +580,7 @@ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
                 *regs = *eregs;
         return regs;
 }
+#endif
 
 /*
  * Our handling of the processor debug registers is non-trivial.
@@ -433,6 +633,11 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
                         goto clear_dr7;
         }
 
+#ifdef CONFIG_X86_32
+        if (regs->flags & X86_VM_MASK)
+                goto debug_vm86;
+#endif
+
         /* Save debug status register where ptrace can see it */
         tsk->thread.debugreg6 = condition;
 
@@ -458,6 +663,13 @@ clear_dr7:
         preempt_conditional_cli(regs);
         return;
 
+#ifdef CONFIG_X86_32
+debug_vm86:
+        handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
+        preempt_conditional_cli(regs);
+        return;
+#endif
+
 clear_TF_reenable:
         set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
         regs->flags &= ~X86_EFLAGS_TF;
@@ -465,6 +677,7 @@ clear_TF_reenable:
         return;
 }
 
+#ifdef CONFIG_X86_64
 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
 {
         if (fixup_exception(regs))
@@ -476,6 +689,7 @@ static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
         die(str, regs, 0);
         return 0;
 }
+#endif
 
 /*
  * Note that we play around with the 'TS' bit in an attempt to get
@@ -513,6 +727,9 @@ void math_error(void __user *ip)
         swd = get_fpu_swd(task);
         switch (swd & ~cwd & 0x3f) {
         case 0x000: /* No unmasked exception */
+#ifdef CONFIG_X86_32
+                return;
+#endif
         default: /* Multiple exceptions */
                 break;
         case 0x001: /* Invalid Op */
@@ -543,9 +760,15 @@ void math_error(void __user *ip)
 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 {
         conditional_sti(regs);
+
+#ifdef CONFIG_X86_32
+        ignore_fpu_irq = 1;
+#else
         if (!user_mode(regs) &&
             kernel_math_error(regs, "kernel x87 math error", 16))
                 return;
+#endif
+
         math_error((void __user *)regs->ip);
 }
 
@@ -601,17 +824,64 @@ dotraplinkage void
 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 {
         conditional_sti(regs);
+
+#ifdef CONFIG_X86_32
+        if (cpu_has_xmm) {
+                /* Handle SIMD FPU exceptions on PIII+ processors. */
+                ignore_fpu_irq = 1;
+                simd_math_error((void __user *)regs->ip);
+                return;
+        }
+        /*
+         * Handle strange cache flush from user space exception
+         * in all other cases.  This is undocumented behaviour.
+         */
+        if (regs->flags & X86_VM_MASK) {
+                handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
+                return;
+        }
+        current->thread.trap_no = 19;
+        current->thread.error_code = error_code;
+        die_if_kernel("cache flush denied", regs, error_code);
+        force_sig(SIGSEGV, current);
+#else
         if (!user_mode(regs) &&
                         kernel_math_error(regs, "kernel simd math error", 19))
                 return;
         simd_math_error((void __user *)regs->ip);
+#endif
 }
 
 dotraplinkage void
 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
 {
+        conditional_sti(regs);
+#if 0
+        /* No need to warn about this any longer. */
+        printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
+#endif
 }
 
+#ifdef CONFIG_X86_32
+unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp)
+{
+        struct desc_struct *gdt = get_cpu_gdt_table(smp_processor_id());
+        unsigned long base = (kesp - uesp) & -THREAD_SIZE;
+        unsigned long new_kesp = kesp - base;
+        unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT;
+        __u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS];
+
+        /* Set up base for espfix segment */
+        desc &= 0x00f0ff0000000000ULL;
+        desc |= ((((__u64)base) << 16) & 0x000000ffffff0000ULL) |
+                ((((__u64)base) << 32) & 0xff00000000000000ULL) |
+                ((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) |
+                (lim_pages & 0xffff);
+        *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc;
+
+        return new_kesp;
+}
+#else
 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
 {
 }
@@ -619,6 +889,7 @@ asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
 {
 }
+#endif
 
 /*
  * 'math_state_restore()' saves the current math information in the
@@ -626,6 +897,9 @@ asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
  *
  * Careful.. There are problems with IBM-designed IRQ13 behaviour.
  * Don't touch unless you *really* know how it works.
+ *
+ * Must be called with kernel preemption disabled (in this case,
+ * local interrupts are disabled at the call-site in entry.S).
  */
 asmlinkage void math_state_restore(void)
 {
@@ -648,6 +922,9 @@ asmlinkage void math_state_restore(void)
         }
 
         clts();                         /* Allow maths ops (or we recurse) */
+#ifdef CONFIG_X86_32
+        restore_fpu(tsk);
+#else
         /*
          * Paranoid restore. send a SIGSEGV if we fail to restore the state.
          */
@@ -656,19 +933,78 @@ asmlinkage void math_state_restore(void)
                 force_sig(SIGSEGV, tsk);
                 return;
         }
+#endif
         thread->status |= TS_USEDFPU;   /* So we fnsave on switch_to() */
         tsk->fpu_counter++;
 }
 EXPORT_SYMBOL_GPL(math_state_restore);
 
+#ifndef CONFIG_MATH_EMULATION
+asmlinkage void math_emulate(long arg)
+{
+        printk(KERN_EMERG
+                "math-emulation not enabled and no coprocessor found.\n");
+        printk(KERN_EMERG "killing %s.\n", current->comm);
+        force_sig(SIGFPE, current);
+        schedule();
+}
+#endif /* CONFIG_MATH_EMULATION */
+
 dotraplinkage void __kprobes
 do_device_not_available(struct pt_regs *regs, long error)
 {
+#ifdef CONFIG_X86_32
+        if (read_cr0() & X86_CR0_EM) {
+                conditional_sti(regs);
+                math_emulate(0);
+        } else {
+                math_state_restore(); /* interrupts still off */
+                conditional_sti(regs);
+        }
+#else
         math_state_restore();
+#endif
+}
+
+#ifdef CONFIG_X86_32
+#ifdef CONFIG_X86_MCE
+dotraplinkage void __kprobes do_machine_check(struct pt_regs *regs, long error)
+{
+        conditional_sti(regs);
+        machine_check_vector(regs, error);
 }
+#endif
+
+dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
+{
+        siginfo_t info;
+        local_irq_enable();
+
+        info.si_signo = SIGILL;
+        info.si_errno = 0;
+        info.si_code = ILL_BADSTK;
+        info.si_addr = 0;
+        if (notify_die(DIE_TRAP, "iret exception",
+                        regs, error_code, 32, SIGILL) == NOTIFY_STOP)
+                return;
+        do_trap(32, SIGILL, "iret exception", regs, error_code, &info);
+}
+#endif
 
 void __init trap_init(void)
 {
+#ifdef CONFIG_X86_32
+        int i;
+#endif
+
+#ifdef CONFIG_EISA
+        void __iomem *p = early_ioremap(0x0FFFD9, 4);
+
+        if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
+                EISA_bus = 1;
+        early_iounmap(p, 4);
+#endif
+
         set_intr_gate(0, &divide_error);
         set_intr_gate_ist(1, &debug, DEBUG_STACK);
         set_intr_gate_ist(2, &nmi, NMI_STACK);
@@ -679,7 +1015,11 @@ void __init trap_init(void)
         set_intr_gate(5, &bounds);
         set_intr_gate(6, &invalid_op);
         set_intr_gate(7, &device_not_available);
+#ifdef CONFIG_X86_32
+        set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS);
+#else
         set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK);
+#endif
         set_intr_gate(9, &coprocessor_segment_overrun);
         set_intr_gate(10, &invalid_TSS);
         set_intr_gate(11, &segment_not_present);
@@ -697,8 +1037,34 @@ void __init trap_init(void)
 #ifdef CONFIG_IA32_EMULATION
         set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
 #endif
+
+#ifdef CONFIG_X86_32
+        if (cpu_has_fxsr) {
+                printk(KERN_INFO "Enabling fast FPU save and restore... ");
+                set_in_cr4(X86_CR4_OSFXSR);
+                printk("done.\n");
+        }
+        if (cpu_has_xmm) {
+                printk(KERN_INFO
+                        "Enabling unmasked SIMD FPU exception support... ");
+                set_in_cr4(X86_CR4_OSXMMEXCPT);
+                printk("done.\n");
+        }
+
+        set_system_trap_gate(SYSCALL_VECTOR, &system_call);
+
+        /* Reserve all the builtin and the syscall vector: */
+        for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
+                set_bit(i, used_vectors);
+
+        set_bit(SYSCALL_VECTOR, used_vectors);
+#endif
         /*
          * Should be a barrier for any external CPU state:
          */
         cpu_init();
+
+#ifdef CONFIG_X86_32
+        trap_init_hook();
+#endif
 }