x86: x86-32 thread_struct.debugreg

This replaces the debugreg[7] member of thread_struct with individual
members debugreg0, etc.  This saves two words for the dummies 4 and 5,
and harmonizes the code between 32 and 64.

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, 24 insertions, 5 deletions

diff --git a/arch/x86/kernel/ptrace_32.c b/arch/x86/kernel/ptrace_32.c
index 26071305de2c..fed83d066135 100644
--- a/arch/x86/kernel/ptrace_32.c
+++ b/arch/x86/kernel/ptrace_32.c
@@ -133,19 +133,39 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno)
  */
 static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
 {
-        return child->thread.debugreg[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 6:         return child->thread.debugreg6;
+        case 7:         return child->thread.debugreg7;
+        }
+        return 0;
 }
 
 static int ptrace_set_debugreg(struct task_struct *child,
                                int n, unsigned long data)
 {
+        int i;
+
         if (unlikely(n == 4 || n == 5))
                 return -EIO;
 
         if (n < 4 && unlikely(data >= TASK_SIZE - 3))
                 return -EIO;
 
-        if (n == 7) {
+        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 6:
+                child->thread.debugreg6 = data;
+                break;
+
+        case 7:
                 /*
                  * Sanity-check data. Take one half-byte at once with
                  * check = (val >> (16 + 4*i)) & 0xf. It contains the
@@ -176,19 +196,18 @@ static int ptrace_set_debugreg(struct task_struct *child,
                  * 64-bit kernel), so the x86_64 mask value is 0x5454.
                  * See the AMD manual no. 24593 (AMD64 System Programming)
                  */
-                int i;
                 data &= ~DR_CONTROL_RESERVED;
                 for (i = 0; i < 4; i++)
                         if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
                                 return -EIO;
+                child->thread.debugreg7 = data;
                 if (data)
                         set_tsk_thread_flag(child, TIF_DEBUG);
                 else
                         clear_tsk_thread_flag(child, TIF_DEBUG);
+                break;
         }
 
-        child->thread.debugreg[n] = data;
-
         return 0;
 }