gecko-dev/ef/Debugger/LinuxBreakPoint.cpp

64 строки
1.8 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#include <stdio.h>
#include <signal.h>
#include <asm/sigcontext.h>
int old_instruction;
int
SetBreakPoint(void *pc)
{
old_instruction = *((unsigned char *) pc);
*((unsigned char *) pc) = 0xcc; /* break point opcode */
#ifdef DEBUG
fprintf(stderr, "breakpoint at: %x\n", (unsigned int) pc);
#endif
/* Need to flush icache here */
return old_instruction;
}
extern "C" void
sigtrap_handler(int sig, struct sigcontext_struct context)
{
#ifdef DEBUG
fprintf(stderr, "Handler: Restoring old instruction\n");
fprintf(stderr, "ip: %x\n", (unsigned int) context.eip);
#endif
/* Learnt this the hard way. eip points to the next instruction */
(*((unsigned char *) (context.eip -1))) = old_instruction;
context.eip = context.eip - 1;
/* Send a debugger event and do all kinds of things */
return;
}
void
SetupBreakPointHandler()
{
struct sigaction sigtrap_action;
sigemptyset(&sigtrap_action.sa_mask);
sigtrap_action.sa_flags = 0;
sigtrap_action.sa_handler = (__sighandler_t) sigtrap_handler;
sigaction(SIGTRAP, &sigtrap_action, NULL);
}