apps/utils/pice/module/trace.c

   1 /*++
   2
   3 Copyright (c) 1998-2001 Klaus P. Gerlicher
   4
   5 Module Name:
   6
   7     trace.c
   8
   9 Abstract:
  10
  11 Environment:
  12
  13     Kernel mode only
  14
  15 Author:
  16
  17     Klaus P. Gerlicher
  18
  19 Revision History:
  20
  21     19-Aug-1998:        created
  22
  23 Copyright notice:
  24
  25   This file may be distributed under the terms of the GNU Public License.
  26
  27 --*/
  28
  29 ////////////////////////////////////////////////////
  30 // INCLUDES
  31 ////
  32 #include "remods.h"
  33
  34 #include "precomp.h"
  35
  36 extern void NewInt31Handler(void);
  37
  38 void DeInstallTraceHook(void);
  39
  40 volatile ULONG OldInt1Handler=0;
  41
  42 BOOLEAN InstallTraceHook(void)
  43 {
  44         ULONG LocalInt1Handler;
  45
  46     DPRINT((0,"InstallTraceHook(OldInt1Handler=%0.8x)...\n",OldInt1Handler));
  47
  48         MaskIrqs();
  49         if(!OldInt1Handler)
  50         {
  51                 __asm__("mov $NewInt1Handler,%0"
  52                         :"=r" (LocalInt1Handler)
  53                         :
  54                         :"eax");
  55                 OldInt1Handler=SetGlobalInt(0x01,(ULONG)LocalInt1Handler);
  56         }
  57         UnmaskIrqs();
  58         return TRUE;
  59 }
  60
  61 //this asm function must be at least second in the file. otherwise gcc does not
  62 //generate correct code.
  63 __asm__("\n\t \
  64 NewInt1Handler:\n\t \
  65        pushl %eax\n\t \
  66                 movl %dr6,%eax\n\t \
  67                 testl $(1<<14),%eax\n\t \
  68                 jz exceptionnotsinglestep\n\t \
  69 \n\t \
  70         popl %eax\n\t \
  71         pushl $" STR(REASON_SINGLESTEP) "\n\t \
  72         jmp NewInt31Handler\n\t \
  73 \n\t \
  74 exceptionnotsinglestep:\n\t \
  75         popl %eax\n\t \
  76         pushl $" STR(REASON_HARDWARE_BP) "\n\t \
  77         jmp NewInt31Handler\n\t \
  78 ");
  79
  80 void DeInstallTraceHook(void)
  81 {
  82         DPRINT((0,"DeInstallTraceHook(OldInt1Handler=%0.8x)...\n",OldInt1Handler));
  83
  84         MaskIrqs();
  85         if(OldInt1Handler)
  86         {
  87                 SetGlobalInt(0x01,(ULONG)OldInt1Handler);
  88         OldInt1Handler = 0;
  89         }
  90         UnmaskIrqs();
  91 }