arch: Remove unnecessary inclusions of asm/semaphore.h

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

diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index 2ef1a5f..92c20fe 100644 (file)
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -140,12 +140,15 @@ static int enable_single_step(struct task_struct *child)
  */
 static void write_debugctlmsr(struct task_struct *child, unsigned long val)
 {
+       if (child->thread.debugctlmsr == val)
+               return;
+
        child->thread.debugctlmsr = val;
 
        if (child != current)
                return;
 
-       wrmsrl(MSR_IA32_DEBUGCTLMSR, val);
+       update_debugctlmsr(val);
 }
 
 /*
@@ -165,11 +168,11 @@ static void enable_step(struct task_struct *child, bool block)
                write_debugctlmsr(child,
                                  child->thread.debugctlmsr | DEBUGCTLMSR_BTF);
        } else {
-           write_debugctlmsr(child,
-                             child->thread.debugctlmsr & ~TIF_DEBUGCTLMSR);
+               write_debugctlmsr(child,
+                                 child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF);
 
-           if (!child->thread.debugctlmsr)
-                   clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
+               if (!child->thread.debugctlmsr)
+                       clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
        }
 }
 
@@ -189,7 +192,7 @@ void user_disable_single_step(struct task_struct *child)
         * Make sure block stepping (BTF) is disabled.
         */
        write_debugctlmsr(child,
-                         child->thread.debugctlmsr & ~TIF_DEBUGCTLMSR);
+                         child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF);
 
        if (!child->thread.debugctlmsr)
                clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);