gdb/gdbserver/low-sparc.c

   1 /* Low level interface to ptrace, for the remote server for GDB.
   2    Copyright (C) 1986, 1987, 1993 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU 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., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22 #include <sys/wait.h>
  23 #include "frame.h"
  24 #include "inferior.h"
  25 /***************************
  26 #include "initialize.h"
  27 ****************************/
  28
  29 #include <stdio.h>
  30 #include <sys/param.h>
  31 #include <sys/dir.h>
  32 #include <sys/user.h>
  33 #include <signal.h>
  34 #include <sys/ioctl.h>
  35 #include <sgtty.h>
  36 #include <fcntl.h>
  37
  38 /***************Begin MY defs*********************/
  39 static char my_registers[REGISTER_BYTES];
  40 char *registers = my_registers;
  41 /***************End MY defs*********************/
  42
  43 #include <sys/ptrace.h>
  44 #include <sys/reg.h>
  45
  46 extern int sys_nerr;
  47 extern char **sys_errlist;
  48 extern int errno;
  49 extern int inferior_pid;
  50 void perror_with_name ();
  51
  52 /* Start an inferior process and returns its pid.
  53    ALLARGS is a vector of program-name and args. */
  54
  55 int
  56 create_inferior (char *program, char **allargs)
  57 {
  58   int pid;
  59
  60   pid = fork ();
  61   if (pid < 0)
  62     perror_with_name ("fork");
  63
  64   if (pid == 0)
  65     {
  66       ptrace (PTRACE_TRACEME);
  67
  68       execv (program, allargs);
  69
  70       fprintf (stderr, "Cannot exec %s: %s.\n", program,
  71                errno < sys_nerr ? sys_errlist[errno] : "unknown error");
  72       fflush (stderr);
  73       _exit (0177);
  74     }
  75
  76   return pid;
  77 }
  78
  79 /* Kill the inferior process.  Make us have no inferior.  */
  80
  81 void
  82 kill_inferior (void)
  83 {
  84   if (inferior_pid == 0)
  85     return;
  86   ptrace (8, inferior_pid, 0, 0);
  87   wait (0);
  88 /*************inferior_died ();****VK**************/
  89 }
  90
  91 /* Return nonzero if the given thread is still alive.  */
  92 int
  93 mythread_alive (int pid)
  94 {
  95   return 1;
  96 }
  97
  98 /* Wait for process, returns status */
  99
 100 unsigned char
 101 mywait (char *status)
 102 {
 103   int pid;
 104   union wait w;
 105
 106   pid = wait (&w);
 107   if (pid != inferior_pid)
 108     perror_with_name ("wait");
 109
 110   if (WIFEXITED (w))
 111     {
 112       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
 113       *status = 'W';
 114       return ((unsigned char) WEXITSTATUS (w));
 115     }
 116   else if (!WIFSTOPPED (w))
 117     {
 118       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
 119       *status = 'X';
 120       return ((unsigned char) WTERMSIG (w));
 121     }
 122
 123   fetch_inferior_registers (0);
 124
 125   *status = 'T';
 126   return ((unsigned char) WSTOPSIG (w));
 127 }
 128
 129 /* Resume execution of the inferior process.
 130    If STEP is nonzero, single-step it.
 131    If SIGNAL is nonzero, give it that signal.  */
 132
 133 void
 134 myresume (int step, int signal)
 135 {
 136   errno = 0;
 137   ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
 138   if (errno)
 139     perror_with_name ("ptrace");
 140 }
 141
 142 /* Fetch one or more registers from the inferior.  REGNO == -1 to get
 143    them all.  We actually fetch more than requested, when convenient,
 144    marking them as valid so we won't fetch them again.  */
 145
 146 void
 147 fetch_inferior_registers (int ignored)
 148 {
 149   struct regs inferior_registers;
 150   struct fp_status inferior_fp_registers;
 151   int i;
 152
 153   /* Global and Out regs are fetched directly, as well as the control
 154      registers.  If we're getting one of the in or local regs,
 155      and the stack pointer has not yet been fetched,
 156      we have to do that first, since they're found in memory relative
 157      to the stack pointer.  */
 158
 159   if (ptrace (PTRACE_GETREGS, inferior_pid,
 160               (PTRACE_ARG3_TYPE) & inferior_registers, 0))
 161     perror ("ptrace_getregs");
 162
 163   registers[REGISTER_BYTE (0)] = 0;
 164   memcpy (&registers[REGISTER_BYTE (1)], &inferior_registers.r_g1,
 165           15 * REGISTER_RAW_SIZE (G0_REGNUM));
 166   *(int *) &registers[REGISTER_BYTE (PS_REGNUM)] = inferior_registers.r_ps;
 167   *(int *) &registers[REGISTER_BYTE (PC_REGNUM)] = inferior_registers.r_pc;
 168   *(int *) &registers[REGISTER_BYTE (NPC_REGNUM)] = inferior_registers.r_npc;
 169   *(int *) &registers[REGISTER_BYTE (Y_REGNUM)] = inferior_registers.r_y;
 170
 171   /* Floating point registers */
 172
 173   if (ptrace (PTRACE_GETFPREGS, inferior_pid,
 174               (PTRACE_ARG3_TYPE) & inferior_fp_registers,
 175               0))
 176     perror ("ptrace_getfpregs");
 177   memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], &inferior_fp_registers,
 178           sizeof inferior_fp_registers.fpu_fr);
 179
 180   /* These regs are saved on the stack by the kernel.  Only read them
 181      all (16 ptrace calls!) if we really need them.  */
 182
 183   read_inferior_memory (*(CORE_ADDR *) & registers[REGISTER_BYTE (SP_REGNUM)],
 184                         &registers[REGISTER_BYTE (L0_REGNUM)],
 185                         16 * REGISTER_RAW_SIZE (L0_REGNUM));
 186 }
 187
 188 /* Store our register values back into the inferior.
 189    If REGNO is -1, do this for all registers.
 190    Otherwise, REGNO specifies which register (so we can save time).  */
 191
 192 void
 193 store_inferior_registers (int ignored)
 194 {
 195   struct regs inferior_registers;
 196   struct fp_status inferior_fp_registers;
 197   CORE_ADDR sp = *(CORE_ADDR *) & registers[REGISTER_BYTE (SP_REGNUM)];
 198
 199   write_inferior_memory (sp, &registers[REGISTER_BYTE (L0_REGNUM)],
 200                          16 * REGISTER_RAW_SIZE (L0_REGNUM));
 201
 202   memcpy (&inferior_registers.r_g1, &registers[REGISTER_BYTE (G1_REGNUM)],
 203           15 * REGISTER_RAW_SIZE (G1_REGNUM));
 204
 205   inferior_registers.r_ps =
 206     *(int *) &registers[REGISTER_BYTE (PS_REGNUM)];
 207   inferior_registers.r_pc =
 208     *(int *) &registers[REGISTER_BYTE (PC_REGNUM)];
 209   inferior_registers.r_npc =
 210     *(int *) &registers[REGISTER_BYTE (NPC_REGNUM)];
 211   inferior_registers.r_y =
 212     *(int *) &registers[REGISTER_BYTE (Y_REGNUM)];
 213
 214   if (ptrace (PTRACE_SETREGS, inferior_pid,
 215               (PTRACE_ARG3_TYPE) & inferior_registers, 0))
 216     perror ("ptrace_setregs");
 217
 218   memcpy (&inferior_fp_registers, &registers[REGISTER_BYTE (FP0_REGNUM)],
 219           sizeof inferior_fp_registers.fpu_fr);
 220
 221   if (ptrace (PTRACE_SETFPREGS, inferior_pid,
 222               (PTRACE_ARG3_TYPE) & inferior_fp_registers, 0))
 223     perror ("ptrace_setfpregs");
 224 }
 225
 226 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
 227    in the NEW_SUN_PTRACE case.
 228    It ought to be straightforward.  But it appears that writing did
 229    not write the data that I specified.  I cannot understand where
 230    it got the data that it actually did write.  */
 231
 232 /* Copy LEN bytes from inferior's memory starting at MEMADDR
 233    to debugger memory starting at MYADDR.  */
 234
 235 read_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 236 {
 237   register int i;
 238   /* Round starting address down to longword boundary.  */
 239   register CORE_ADDR addr = memaddr & -sizeof (int);
 240   /* Round ending address up; get number of longwords that makes.  */
 241   register int count
 242   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 243   /* Allocate buffer of that many longwords.  */
 244   register int *buffer = (int *) alloca (count * sizeof (int));
 245
 246   /* Read all the longwords */
 247   for (i = 0; i < count; i++, addr += sizeof (int))
 248     {
 249       buffer[i] = ptrace (1, inferior_pid, addr, 0);
 250     }
 251
 252   /* Copy appropriate bytes out of the buffer.  */
 253   memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 254 }
 255
 256 /* Copy LEN bytes of data from debugger memory at MYADDR
 257    to inferior's memory at MEMADDR.
 258    On failure (cannot write the inferior)
 259    returns the value of errno.  */
 260
 261 int
 262 write_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 263 {
 264   register int i;
 265   /* Round starting address down to longword boundary.  */
 266   register CORE_ADDR addr = memaddr & -sizeof (int);
 267   /* Round ending address up; get number of longwords that makes.  */
 268   register int count
 269   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 270   /* Allocate buffer of that many longwords.  */
 271   register int *buffer = (int *) alloca (count * sizeof (int));
 272   extern int errno;
 273
 274   /* Fill start and end extra bytes of buffer with existing memory data.  */
 275
 276   buffer[0] = ptrace (1, inferior_pid, addr, 0);
 277
 278   if (count > 1)
 279     {
 280       buffer[count - 1]
 281         = ptrace (1, inferior_pid,
 282                   addr + (count - 1) * sizeof (int), 0);
 283     }
 284
 285   /* Copy data to be written over corresponding part of buffer */
 286
 287   bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 288
 289   /* Write the entire buffer.  */
 290
 291   for (i = 0; i < count; i++, addr += sizeof (int))
 292     {
 293       errno = 0;
 294       ptrace (4, inferior_pid, addr, buffer[i]);
 295       if (errno)
 296         return errno;
 297     }
 298
 299   return 0;
 300 }
 301 \f
 302 void
 303 initialize_low (void)
 304 {
 305 }