regs.c revision c897cb796dc4a7d256cbfbf0137ef7cdff9e8ece 
1#include "config.h"
2
3#include <sys/types.h>
4#include <sys/ptrace.h>
5#include <asm/ptrace.h>
6
7#include "proc.h"
8#include "common.h"
9
10#if (!defined(PTRACE_PEEKUSER) && defined(PTRACE_PEEKUSR))
11# define PTRACE_PEEKUSER PTRACE_PEEKUSR
12#endif
13
14#if (!defined(PTRACE_POKEUSER) && defined(PTRACE_POKEUSR))
15# define PTRACE_POKEUSER PTRACE_POKEUSR
16#endif
17
18#define off_pc ((void *)60)
19#define off_lr ((void *)56)
20#define off_sp ((void *)52)
21
22void *
23get_instruction_pointer(Process *proc) {
24	return (void *)ptrace(PTRACE_PEEKUSER, proc->pid, off_pc, 0);
25}
26
27void
28set_instruction_pointer(Process *proc, void *addr) {
29	ptrace(PTRACE_POKEUSER, proc->pid, off_pc, addr);
30}
31
32void *
33get_stack_pointer(Process *proc) {
34	return (void *)ptrace(PTRACE_PEEKUSER, proc->pid, off_sp, 0);
35}
36
37/* really, this is given the *stack_pointer expecting
38 * a CISC architecture; in our case, we don't need that */
39void *
40get_return_addr(Process *proc, void *stack_pointer) {
41	long addr = ptrace(PTRACE_PEEKUSER, proc->pid, off_lr, 0);
42
43	/* Remember & unset the thumb mode bit.  XXX This is really a
44	 * bit of a hack, as we assume that the following
45	 * insert_breakpoint call will be related to this address.
46	 * This interface should really be get_return_breakpoint, or
47	 * maybe install_return_breakpoint.  */
48	proc->thumb_mode = addr & 1;
49	if (proc->thumb_mode)
50		addr &= ~1;
51
52	return (void *)addr;
53}
54
55void
56set_return_addr(Process *proc, void *addr) {
57	long iaddr = (int)addr | proc->thumb_mode;
58	ptrace(PTRACE_POKEUSER, proc->pid, off_lr, (void *)iaddr);
59}
60