Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[safe/jmp/linux-2.6] / arch / x86 / kernel / traps.c

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 2d1f4c7..98c2d05 100644 (file)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -20,7 +20,6 @@
 #include <linux/module.h>
 #include <linux/ptrace.h>
 #include <linux/string.h>
-#include <linux/unwind.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/kexec.h>
@@ -51,7 +50,6 @@
 #include <asm/debugreg.h>
 #include <asm/atomic.h>
 #include <asm/system.h>
-#include <asm/unwind.h>
 #include <asm/traps.h>
 #include <asm/desc.h>
 #include <asm/i387.h>
@@ -65,9 +63,6 @@
 #else
 #include <asm/processor-flags.h>
 #include <asm/arch_hooks.h>
-#include <asm/nmi.h>
-#include <asm/smp.h>
-#include <asm/io.h>
 #include <asm/traps.h>
 
 #include "cpu/mcheck/mce.h"
@@ -292,8 +287,10 @@ 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 +517,11 @@ 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 +531,10 @@ 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 +686,7 @@ 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 +704,11 @@ 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);
 }