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/*
* Debugger break-points handling
*
* Copyright 1994 Martin von Loewis
* Copyright 1995 Alexandre Julliard
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#ifdef linux
#include <sys/utsname.h>
#endif
#include "windows.h"
#include "debugger.h"
#define INT3 0xcc /* int 3 opcode */
#define STEP_FLAG 0x100 /* single-step flag */
#define MAX_BREAKPOINTS 25
typedef struct
{
unsigned int segment;
unsigned int addr;
BYTE addrlen;
BYTE opcode;
BOOL enabled;
BOOL in_use;
} BREAKPOINT;
static BREAKPOINT breakpoints[MAX_BREAKPOINTS] = { { 0, }, };
static int next_bp = 1; /* breakpoint 0 is reserved for step-over */
/***********************************************************************
* DEBUG_ChangeOpcode
*
* Change the opcode at segment:addr.
*/
static void DEBUG_SetOpcode( unsigned int segment, unsigned int addr, BYTE op )
{
if (segment)
{
*(BYTE *)PTR_SEG_OFF_TO_LIN( segment, addr ) = op;
}
else /* 32-bit code, so we have to change the protection first */
{
/* There are a couple of problems with this. On Linux prior to
1.1.62, this call fails (ENOACCESS) due to a bug in fs/exec.c.
This code is currently not tested at all on BSD.
How do I determine the page size in a more symbolic manner?
And why does mprotect need that start address of the page
in the first place?
Not that portability matters, this code is i386 only anyways...
How do I get the old protection in order to restore it later on?
*/
if (mprotect((caddr_t)(addr & (~4095)), 4096,
PROT_READ|PROT_WRITE|PROT_EXEC) == -1)
{
perror( "Can't set break point" );
return;
}
*(BYTE *)addr = op;
mprotect((caddr_t)(addr & ~4095), 4096, PROT_READ|PROT_EXEC);
}
}
/***********************************************************************
* DEBUG_SetBreakpoints
*
* Set or remove all the breakpoints.
*/
void DEBUG_SetBreakpoints( BOOL set )
{
int i;
for (i = 0; i < MAX_BREAKPOINTS; i++)
{
if (breakpoints[i].in_use && breakpoints[i].enabled)
DEBUG_SetOpcode( breakpoints[i].segment, breakpoints[i].addr,
set ? INT3 : breakpoints[i].opcode );
}
}
/***********************************************************************
* DEBUG_FindBreakpoint
*
* Find the breakpoint for a given address. Return the breakpoint
* number or -1 if none.
*/
int DEBUG_FindBreakpoint( unsigned int segment, unsigned int addr )
{
int i;
for (i = 0; i < MAX_BREAKPOINTS; i++)
{
if (breakpoints[i].in_use && breakpoints[i].enabled &&
breakpoints[i].segment == segment && breakpoints[i].addr == addr)
return i;
}
return -1;
}
/***********************************************************************
* DEBUG_AddBreakpoint
*
* Add a breakpoint.
*/
void DEBUG_AddBreakpoint( unsigned int segment, unsigned int addr )
{
int num;
BYTE *p;
if (segment == 0xffffffff) segment = CS;
if (segment == WINE_CODE_SELECTOR) segment = 0;
if (next_bp < MAX_BREAKPOINTS)
num = next_bp++;
else /* try to find an empty slot */
{
for (num = 1; num < MAX_BREAKPOINTS; num++)
if (!breakpoints[num].in_use) break;
if (num >= MAX_BREAKPOINTS)
{
fprintf( stderr, "Too many breakpoints. Please delete some.\n" );
return;
}
}
p = segment ? (BYTE *)PTR_SEG_OFF_TO_LIN( segment, addr ) : (BYTE *)addr;
breakpoints[num].segment = segment;
breakpoints[num].addr = addr;
breakpoints[num].addrlen = !segment ? 32 :
(GET_SEL_FLAGS(segment) & LDT_FLAGS_32BIT) ? 32 : 16;
breakpoints[num].opcode = *p;
breakpoints[num].enabled = TRUE;
breakpoints[num].in_use = TRUE;
fprintf( stderr, "Breakpoint %d at ", num );
print_address( segment, addr, breakpoints[num].addrlen );
fprintf( stderr, "\n" );
}
/***********************************************************************
* DEBUG_DelBreakpoint
*
* Delete a breakpoint.
*/
void DEBUG_DelBreakpoint( int num )
{
if ((num <= 0) || (num >= next_bp) || !breakpoints[num].in_use)
{
fprintf( stderr, "Invalid breakpoint number %d\n", num );
return;
}
breakpoints[num].enabled = FALSE;
breakpoints[num].in_use = FALSE;
}
/***********************************************************************
* DEBUG_EnableBreakpoint
*
* Enable or disable a break point.
*/
void DEBUG_EnableBreakpoint( int num, BOOL enable )
{
if ((num <= 0) || (num >= next_bp) || !breakpoints[num].in_use)
{
fprintf( stderr, "Invalid breakpoint number %d\n", num );
return;
}
breakpoints[num].enabled = enable;
}
/***********************************************************************
* DEBUG_InfoBreakpoints
*
* Display break points information.
*/
void DEBUG_InfoBreakpoints(void)
{
int i;
fprintf( stderr, "Breakpoints:\n" );
for (i = 1; i < next_bp; i++)
{
if (breakpoints[i].in_use)
{
fprintf( stderr, "%d: %c ", i, breakpoints[i].enabled ? 'y' : 'n');
print_address( breakpoints[i].segment, breakpoints[i].addr,
breakpoints[i].addrlen );
fprintf( stderr, "\n" );
}
}
}
/***********************************************************************
* DEBUG_ShouldContinue
*
* Determine if we should continue execution after a SIGTRAP signal when
* executing in the given mode.
*/
BOOL DEBUG_ShouldContinue( struct sigcontext_struct *context,
enum exec_mode mode )
{
unsigned int segment, addr;
int bpnum;
/* If not single-stepping, back up over the int3 instruction */
if (!(EFL & STEP_FLAG)) EIP--;
segment = (CS == WINE_CODE_SELECTOR) ? 0 : CS;
addr = EIP;
bpnum = DEBUG_FindBreakpoint( segment, addr );
breakpoints[0].enabled = 0; /* disable the step-over breakpoint */
if ((bpnum != 0) && (bpnum != -1))
{
fprintf( stderr, "Stopped on breakpoint %d at ", bpnum );
print_address( breakpoints[bpnum].segment, breakpoints[bpnum].addr,
breakpoints[bpnum].addrlen );
fprintf( stderr, "\n" );
return FALSE;
}
/* no breakpoint, continue if in continuous mode */
return (mode == EXEC_CONT);
}
/***********************************************************************
* DEBUG_RestartExecution
*
* Set the breakpoints to the correct state to restart execution
* in the given mode.
*/
void DEBUG_RestartExecution( struct sigcontext_struct *context,
enum exec_mode mode, int instr_len )
{
unsigned int segment, addr;
segment = (CS == WINE_CODE_SELECTOR) ? 0 : CS;
addr = EIP;
if (DEBUG_FindBreakpoint( segment, addr ) != -1)
mode = EXEC_STEP_INSTR; /* If there's a breakpoint, skip it */
switch(mode)
{
case EXEC_CONT: /* Continuous execution */
EFL &= ~STEP_FLAG;
DEBUG_SetBreakpoints( TRUE );
break;
case EXEC_STEP_OVER: /* Stepping over a call */
EFL &= ~STEP_FLAG;
breakpoints[0].segment = segment;
breakpoints[0].addr = addr + instr_len;
breakpoints[0].enabled = TRUE;
breakpoints[0].in_use = TRUE;
breakpoints[0].opcode = segment ?
*(BYTE *)PTR_SEG_OFF_TO_LIN(segment,addr+instr_len) : *(BYTE *)addr;
DEBUG_SetBreakpoints( TRUE );
break;
case EXEC_STEP_INSTR: /* Single-stepping an instruction */
EFL |= STEP_FLAG;
break;
}
}