arch/um/os-Linux/sys-i386/registers.c

   1 /*
   2  * Copyright (C) 2004 PathScale, Inc
   3  * Licensed under the GPL
   4  */
   5
   6 #include <errno.h>
   7 #include <string.h>
   8 #include "sysdep/ptrace_user.h"
   9 #include "sysdep/ptrace.h"
  10 #include "uml-config.h"
  11 #include "skas_ptregs.h"
  12 #include "registers.h"
  13 #include "longjmp.h"
  14 #include "user.h"
  15
  16 /* These are set once at boot time and not changed thereafter */
  17
  18 static unsigned long exec_regs[HOST_FRAME_SIZE];
  19 static unsigned long exec_fp_regs[HOST_FP_SIZE];
  20 static unsigned long exec_fpx_regs[HOST_XFP_SIZE];
  21 static int have_fpx_regs = 1;
  22
  23 void init_thread_registers(union uml_pt_regs *to)
  24 {
  25         memcpy(to->skas.regs, exec_regs, sizeof(to->skas.regs));
  26         memcpy(to->skas.fp, exec_fp_regs, sizeof(to->skas.fp));
  27         if(have_fpx_regs)
  28                 memcpy(to->skas.xfp, exec_fpx_regs, sizeof(to->skas.xfp));
  29 }
  30
  31 /* XXX These need to use [GS]ETFPXREGS and copy_sc_{to,from}_user_skas needs
  32  * to pass in a sufficiently large buffer
  33  */
  34 int save_fp_registers(int pid, unsigned long *fp_regs)
  35 {
  36         if(ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)
  37                 return(-errno);
  38         return(0);
  39 }
  40
  41 int restore_fp_registers(int pid, unsigned long *fp_regs)
  42 {
  43         if(ptrace(PTRACE_SETFPREGS, pid, 0, fp_regs) < 0)
  44                 return(-errno);
  45         return(0);
  46 }
  47
  48 static int move_registers(int pid, int int_op, union uml_pt_regs *regs,
  49                           int fp_op, unsigned long *fp_regs)
  50 {
  51         if(ptrace(int_op, pid, 0, regs->skas.regs) < 0)
  52                 return(-errno);
  53
  54         if(ptrace(fp_op, pid, 0, fp_regs) < 0)
  55                 return(-errno);
  56
  57         return(0);
  58 }
  59
  60 void save_registers(int pid, union uml_pt_regs *regs)
  61 {
  62         unsigned long *fp_regs;
  63         int err, fp_op;
  64
  65         if(have_fpx_regs){
  66                 fp_op = PTRACE_GETFPXREGS;
  67                 fp_regs = regs->skas.xfp;
  68         }
  69         else {
  70                 fp_op = PTRACE_GETFPREGS;
  71                 fp_regs = regs->skas.fp;
  72         }
  73
  74         err = move_registers(pid, PTRACE_GETREGS, regs, fp_op, fp_regs);
  75         if(err)
  76                 panic("save_registers - saving registers failed, errno = %d\n",
  77                       -err);
  78 }
  79
  80 void restore_registers(int pid, union uml_pt_regs *regs)
  81 {
  82         unsigned long *fp_regs;
  83         int err, fp_op;
  84
  85         if(have_fpx_regs){
  86                 fp_op = PTRACE_SETFPXREGS;
  87                 fp_regs = regs->skas.xfp;
  88         }
  89         else {
  90                 fp_op = PTRACE_SETFPREGS;
  91                 fp_regs = regs->skas.fp;
  92         }
  93
  94         err = move_registers(pid, PTRACE_SETREGS, regs, fp_op, fp_regs);
  95         if(err)
  96                 panic("restore_registers - saving registers failed, "
  97                       "errno = %d\n", -err);
  98 }
  99
 100 void init_registers(int pid)
 101 {
 102         int err;
 103
 104         err = ptrace(PTRACE_GETREGS, pid, 0, exec_regs);
 105         if(err)
 106                 panic("check_ptrace : PTRACE_GETREGS failed, errno = %d",
 107                       errno);
 108
 109         errno = 0;
 110         err = ptrace(PTRACE_GETFPXREGS, pid, 0, exec_fpx_regs);
 111         if(!err)
 112                 return;
 113         if(errno != EIO)
 114                 panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d",
 115                       errno);
 116
 117         have_fpx_regs = 0;
 118
 119         err = ptrace(PTRACE_GETFPREGS, pid, 0, exec_fp_regs);
 120         if(err)
 121                 panic("check_ptrace : PTRACE_GETFPREGS failed, errno = %d",
 122                       errno);
 123 }
 124
 125 void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
 126 {
 127         memcpy(regs, exec_regs, HOST_FRAME_SIZE * sizeof(unsigned long));
 128         if(fp_regs != NULL)
 129                 memcpy(fp_regs, exec_fp_regs,
 130                        HOST_FP_SIZE * sizeof(unsigned long));
 131 }
 132
 133 unsigned long get_thread_reg(int reg, jmp_buf *buf)
 134 {
 135         switch(reg){
 136         case EIP: return buf[0]->__eip;
 137         case UESP: return buf[0]->__esp;
 138         case EBP: return buf[0]->__ebp;
 139         default:
 140                 printk("get_thread_regs - unknown register %d\n", reg);
 141                 return 0;
 142         }
 143 }