x86: debugctlmsr context switch

This adds low-level support for a per-thread value of MSR_IA32_DEBUGCTLMSR.
The per-thread value is switched in when TIF_DEBUGCTLMSR is set.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/asm-x86/processor_32.h b/include/asm-x86/processor_32.h
index 2540bf8d572..3c67eacb316 100644
--- a/include/asm-x86/processor_32.h
+++ b/include/asm-x86/processor_32.h
@@ -368,6 +368,8 @@ struct thread_struct {
         unsigned long   iopl;
 /* max allowed port in the bitmap, in bytes: */
         unsigned long   io_bitmap_max;
+/* MSR_IA32_DEBUGCTLMSR value to switch in if TIF_DEBUGCTLMSR is set.  */
+        unsigned long   debugctlmsr;
 };
 
 #define INIT_THREAD  {                                                  \