hw-breakpoints: prepare the code for Hardware Breakpoint interfaces

The generic hardware breakpoint interface provides an abstraction of
hardware breakpoints in front of specific arch implementations for both kernel
and user side breakpoints.
This includes execution breakpoints and read/write breakpoints, also known as
"watchpoints".

This patch introduces header files containing constants, structure definitions
and declaration of functions used by the hardware breakpoint core and x86
specific code.
It also introduces an array based storage for the debug-register values in
'struct thread_struct', while modifying all users of debugreg<n> member in the
structure.

[ Impact: add headers for new hardware breakpoint interface ]

Original-patch-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 09ecbde91c13..313be40be55a 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -471,10 +471,10 @@ static int genregs_set(struct task_struct *target,
 static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
 {
         switch (n) {
-        case 0:         return child->thread.debugreg0;
-        case 1:         return child->thread.debugreg1;
-        case 2:         return child->thread.debugreg2;
-        case 3:         return child->thread.debugreg3;
+        case 0:         return child->thread.debugreg[0];
+        case 1:         return child->thread.debugreg[1];
+        case 2:         return child->thread.debugreg[2];
+        case 3:         return child->thread.debugreg[3];
         case 6:         return child->thread.debugreg6;
         case 7:         return child->thread.debugreg7;
         }
@@ -493,10 +493,10 @@ static int ptrace_set_debugreg(struct task_struct *child,
                 return -EIO;
 
         switch (n) {
-        case 0:         child->thread.debugreg0 = data; break;
-        case 1:         child->thread.debugreg1 = data; break;
-        case 2:         child->thread.debugreg2 = data; break;
-        case 3:         child->thread.debugreg3 = data; break;
+        case 0:         child->thread.debugreg[0] = data; break;
+        case 1:         child->thread.debugreg[1] = data; break;
+        case 2:         child->thread.debugreg[2] = data; break;
+        case 3:         child->thread.debugreg[3] = data; break;
 
         case 6:
                 if ((data & ~0xffffffffUL) != 0)