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>

1 files changed, 169 insertions, 4 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
 }