/*
* Copyright (c) 2010 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Rui Paulo under sponsorship from the
* FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifdef __FBSDID
__FBSDID("$FreeBSD: head/lib/libproc/proc_regs.c 285003 2015-07-01 13:59:26Z br $");
#else
__RCSID("$NetBSD: proc_regs.c,v 1.4 2015/09/25 19:09:38 christos Exp $");
#endif

#include <sys/types.h>
#include <sys/ptrace.h>

#include <err.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/ucontext.h>
#include "_libproc.h"

int
proc_regget(struct proc_handle *phdl, proc_reg_t reg, unsigned long *regvalue)
{
       struct reg regs;

       if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
           phdl->status == PS_IDLE) {
               errno = ENOENT;
               return (-1);
       }
       memset(&regs, 0, sizeof(regs));
       if (ptrace(PT_GETREGS, proc_getpid(phdl), &regs, 0) < 0)
               return (-1);
       switch (reg) {
       case REG_PC:
#ifdef PTRACE_REG_PC
               *regvalue = PTRACE_REG_PC(&regs);
#else
#       error "Add support for your architecture"
#endif
               break;
       case REG_SP:
#ifdef PTRACE_REG_SP
               *regvalue = PTRACE_REG_SP(&regs);
#else
#       error "Add support for your architecture"
#endif
               break;
       default:
               DPRINTFX("ERROR: no support for reg number %d", reg);
               return (-1);
       }

       return (0);
}

int
proc_regset(struct proc_handle *phdl, proc_reg_t reg, unsigned long regvalue)
{
       struct reg regs;

       if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
           phdl->status == PS_IDLE) {
               errno = ENOENT;
               return (-1);
       }
       if (ptrace(PT_GETREGS, proc_getpid(phdl), &regs, 0) < 0)
               return (-1);
       switch (reg) {
       case REG_PC:
#ifdef PTRACE_REG_SET_PC
               PTRACE_REG_SET_PC(&regs, regvalue);
#else
#       error "Add support for your architecture"
#endif
               break;
       case REG_SP:
#ifdef PTRACE_REG_SP
               PTRACE_REG_SP(&regs) = regvalue;
#else
#       error "Add support for your architecture"
#endif
               break;
       default:
               DPRINTFX("ERROR: no support for reg number %d", reg);
               return (-1);
       }
       if (ptrace(PT_SETREGS, proc_getpid(phdl), &regs, 0) < 0)
               return (-1);

       return (0);
}