1 files changed, 26 insertions, 19 deletions

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 141907ab6e22..ce6650eb64e9 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -72,9 +72,6 @@
 
 #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 ? */
@@ -89,6 +86,9 @@ gate_desc idt_table[256]
         __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
 #endif
 
+DECLARE_BITMAP(used_vectors, NR_VECTORS);
+EXPORT_SYMBOL_GPL(used_vectors);
+
 static int ignore_nmis;
 
 static inline void conditional_sti(struct pt_regs *regs)
@@ -292,8 +292,10 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
         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). */
+        /*
+         * This is always a kernel trap and never fixable (and thus must
+         * never return).
+         */
         for (;;)
                 die(str, regs, error_code);
 }
@@ -520,9 +522,11 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
 }
 
 #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 */
+/*
+ * 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;
@@ -532,8 +536,10 @@ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
         /* 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. */
+        /*
+         * 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)
@@ -685,12 +691,7 @@ void math_error(void __user *ip)
         cwd = get_fpu_cwd(task);
         swd = get_fpu_swd(task);
 
-        err = swd & ~cwd & 0x3f;
-
-#ifdef CONFIG_X86_32
-        if (!err)
-                return;
-#endif
+        err = swd & ~cwd;
 
         if (err & 0x001) {      /* Invalid op */
                 /*
@@ -708,7 +709,11 @@ void math_error(void __user *ip)
         } else if (err & 0x020) { /* Precision */
                 info.si_code = FPE_FLTRES;
         } else {
-                info.si_code = __SI_FAULT|SI_KERNEL; /* WTF? */
+                /*
+                 * If we're using IRQ 13, or supposedly even some trap 16
+                 * implementations, it's possible we get a spurious trap...
+                 */
+                return;         /* Spurious trap, no error */
         }
         force_sig_info(SIGFPE, &info, task);
 }
@@ -941,9 +946,7 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
 
 void __init trap_init(void)
 {
-#ifdef CONFIG_X86_32
         int i;
-#endif
 
 #ifdef CONFIG_EISA
         void __iomem *p = early_ioremap(0x0FFFD9, 4);
@@ -1000,11 +1003,15 @@ void __init trap_init(void)
         }
 
         set_system_trap_gate(SYSCALL_VECTOR, &system_call);
+#endif
 
         /* Reserve all the builtin and the syscall vector: */
         for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
                 set_bit(i, used_vectors);
 
+#ifdef CONFIG_X86_64
+        set_bit(IA32_SYSCALL_VECTOR, used_vectors);
+#else
         set_bit(SYSCALL_VECTOR, used_vectors);
 #endif
         /*