1 /*
2  * This file is part of ltrace.
3  * Copyright (C) 2013 Petr Machata, Red Hat Inc.
4  * Copyright (C) 2004,2008,2009 Juan Cespedes
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 of the
9  * License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19  * 02110-1301 USA
20  */
21 
22 #include "config.h"
23 
24 #include <sys/types.h>
25 #include <sys/ptrace.h>
26 #include <asm/ptrace.h>
27 
28 #include "proc.h"
29 #include "common.h"
30 
31 #if (!defined(PTRACE_PEEKUSER) && defined(PTRACE_PEEKUSR))
32 # define PTRACE_PEEKUSER PTRACE_PEEKUSR
33 #endif
34 
35 #if (!defined(PTRACE_POKEUSER) && defined(PTRACE_POKEUSR))
36 # define PTRACE_POKEUSER PTRACE_POKEUSR
37 #endif
38 
39 void *
get_instruction_pointer(struct process * proc)40 get_instruction_pointer(struct process *proc)
41 {
42 	return (void *)ptrace(PTRACE_PEEKUSER, proc->pid, 64 /* REG_PC */ , 0);
43 }
44 
45 void
set_instruction_pointer(struct process * proc,void * addr)46 set_instruction_pointer(struct process *proc, void *addr)
47 {
48 	ptrace(PTRACE_POKEUSER, proc->pid, 64 /* REG_PC */ , addr);
49 }
50 
51 void *
get_stack_pointer(struct process * proc)52 get_stack_pointer(struct process *proc)
53 {
54 	return (void *)ptrace(PTRACE_PEEKUSER, proc->pid, 30 /* REG_FP */ , 0);
55 }
56 
57 void *
get_return_addr(struct process * proc,void * stack_pointer)58 get_return_addr(struct process *proc, void *stack_pointer)
59 {
60 	return (void *)ptrace(PTRACE_PEEKUSER, proc->pid, 26 /* RA */ , 0);
61 }
62