[PATCH] x86_64: Move int 3 handler to debug stack and allow to increase it.

This
- switches the INT3 handler to run on an IST stack (to cope with
  breakpoints set by a kernel debugger on places where the kernel's
  %gs base hasn't been set up, yet); the IST stack used is shared with
  the INT1 handler's
[AK: this also allows setting a kprobe on the interrupt/exception entry
points]
- allows nesting of INT1/INT3 handlers so that one can, with a kernel
  debugger, debug (at least) the user-mode portions of the INT1/INT3
  handling; the nesting isn't actively enabled here since a kernel-
  debugger-free kernel doesn't need it

Signed-Off-By: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 0 insertions, 2 deletions

diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index 4861246548f7..5cb151538cd5 100644
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -273,8 +273,6 @@ struct thread_struct {
 #define DEBUG_STACK 4 
 #define MCE_STACK 5
 #define N_EXCEPTION_STACKS 5  /* hw limit: 7 */
-#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
-#define EXCEPTION_STACK_ORDER 0 
 
 #define start_thread(regs,new_rip,new_rsp) do { \
         asm volatile("movl %0,%%fs; movl %0,%%es; movl %0,%%ds": :"r" (0));      \