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 int quit_flag = 0;
  40 static char my_registers[REGISTER_BYTES];
  41 char *registers = my_registers;
  42
  43 /* Index within `registers' of the first byte of the space for
  44    register N.  */
  45
  46
  47 char buf2[MAX_REGISTER_RAW_SIZE];
  48 /***************End MY defs*********************/
  49
  50 #include <sys/ptrace.h>
  51 #include <sys/reg.h>
  52
  53 extern int sys_nerr;
  54 extern char **sys_errlist;
  55 extern char **environ;
  56 extern int errno;
  57 extern int inferior_pid;
  58 void quit (), perror_with_name ();
  59 int query ();
  60
  61 /* Start an inferior process and returns its pid.
  62    ALLARGS is a vector of program-name and args.
  63    ENV is the environment vector to pass.  */
  64
  65 int
  66 create_inferior (program, allargs)
  67      char *program;
  68      char **allargs;
  69 {
  70   int pid;
  71
  72   pid = fork ();
  73   if (pid < 0)
  74     perror_with_name ("fork");
  75
  76   if (pid == 0)
  77     {
  78       ptrace (PTRACE_TRACEME);
  79
  80       execv (program, allargs);
  81
  82       fprintf (stderr, "Cannot exec %s: %s.\n", program,
  83                errno < sys_nerr ? sys_errlist[errno] : "unknown error");
  84       fflush (stderr);
  85       _exit (0177);
  86     }
  87
  88   return pid;
  89 }
  90
  91 /* Kill the inferior process.  Make us have no inferior.  */
  92
  93 void
  94 kill_inferior ()
  95 {
  96   if (inferior_pid == 0)
  97     return;
  98   ptrace (8, inferior_pid, 0, 0);
  99   wait (0);
 100 /*************inferior_died ();****VK**************/
 101 }
 102
 103 /* Return nonzero if the given thread is still alive.  */
 104 int
 105 mythread_alive (pid)
 106      int pid;
 107 {
 108   return 1;
 109 }
 110
 111 /* Wait for process, returns status */
 112
 113 unsigned char
 114 mywait (status)
 115      char *status;
 116 {
 117   int pid;
 118   union wait w;
 119
 120   pid = wait (&w);
 121   if (pid != inferior_pid)
 122     perror_with_name ("wait");
 123
 124   if (WIFEXITED (w))
 125     {
 126       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
 127       *status = 'W';
 128       return ((unsigned char) WEXITSTATUS (w));
 129     }
 130   else if (!WIFSTOPPED (w))
 131     {
 132       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
 133       *status = 'X';
 134       return ((unsigned char) WTERMSIG (w));
 135     }
 136
 137   fetch_inferior_registers (0);
 138
 139   *status = 'T';
 140   return ((unsigned char) WSTOPSIG (w));
 141 }
 142
 143 /* Resume execution of the inferior process.
 144    If STEP is nonzero, single-step it.
 145    If SIGNAL is nonzero, give it that signal.  */
 146
 147 void
 148 myresume (step, signal)
 149      int step;
 150      int signal;
 151 {
 152   errno = 0;
 153   ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
 154   if (errno)
 155     perror_with_name ("ptrace");
 156 }
 157
 158 /* Fetch one or more registers from the inferior.  REGNO == -1 to get
 159    them all.  We actually fetch more than requested, when convenient,
 160    marking them as valid so we won't fetch them again.  */
 161
 162 void
 163 fetch_inferior_registers (ignored)
 164      int ignored;
 165 {
 166   struct regs inferior_registers;
 167   struct fp_status inferior_fp_registers;
 168   int i;
 169
 170   /* Global and Out regs are fetched directly, as well as the control
 171      registers.  If we're getting one of the in or local regs,
 172      and the stack pointer has not yet been fetched,
 173      we have to do that first, since they're found in memory relative
 174      to the stack pointer.  */
 175
 176   if (ptrace (PTRACE_GETREGS, inferior_pid,
 177               (PTRACE_ARG3_TYPE) & inferior_registers, 0))
 178     perror ("ptrace_getregs");
 179
 180   registers[REGISTER_BYTE (0)] = 0;
 181   memcpy (&registers[REGISTER_BYTE (1)], &inferior_registers.r_g1,
 182           15 * REGISTER_RAW_SIZE (G0_REGNUM));
 183   *(int *) &registers[REGISTER_BYTE (PS_REGNUM)] = inferior_registers.r_ps;
 184   *(int *) &registers[REGISTER_BYTE (PC_REGNUM)] = inferior_registers.r_pc;
 185   *(int *) &registers[REGISTER_BYTE (NPC_REGNUM)] = inferior_registers.r_npc;
 186   *(int *) &registers[REGISTER_BYTE (Y_REGNUM)] = inferior_registers.r_y;
 187
 188   /* Floating point registers */
 189
 190   if (ptrace (PTRACE_GETFPREGS, inferior_pid,
 191               (PTRACE_ARG3_TYPE) & inferior_fp_registers,
 192               0))
 193     perror ("ptrace_getfpregs");
 194   memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], &inferior_fp_registers,
 195           sizeof inferior_fp_registers.fpu_fr);
 196
 197   /* These regs are saved on the stack by the kernel.  Only read them
 198      all (16 ptrace calls!) if we really need them.  */
 199
 200   read_inferior_memory (*(CORE_ADDR *) & registers[REGISTER_BYTE (SP_REGNUM)],
 201                         &registers[REGISTER_BYTE (L0_REGNUM)],
 202                         16 * REGISTER_RAW_SIZE (L0_REGNUM));
 203 }
 204
 205 /* Store our register values back into the inferior.
 206    If REGNO is -1, do this for all registers.
 207    Otherwise, REGNO specifies which register (so we can save time).  */
 208
 209 void
 210 store_inferior_registers (ignored)
 211      int ignored;
 212 {
 213   struct regs inferior_registers;
 214   struct fp_status inferior_fp_registers;
 215   CORE_ADDR sp = *(CORE_ADDR *) & registers[REGISTER_BYTE (SP_REGNUM)];
 216
 217   write_inferior_memory (sp, &registers[REGISTER_BYTE (L0_REGNUM)],
 218                          16 * REGISTER_RAW_SIZE (L0_REGNUM));
 219
 220   memcpy (&inferior_registers.r_g1, &registers[REGISTER_BYTE (G1_REGNUM)],
 221           15 * REGISTER_RAW_SIZE (G1_REGNUM));
 222
 223   inferior_registers.r_ps =
 224     *(int *) &registers[REGISTER_BYTE (PS_REGNUM)];
 225   inferior_registers.r_pc =
 226     *(int *) &registers[REGISTER_BYTE (PC_REGNUM)];
 227   inferior_registers.r_npc =
 228     *(int *) &registers[REGISTER_BYTE (NPC_REGNUM)];
 229   inferior_registers.r_y =
 230     *(int *) &registers[REGISTER_BYTE (Y_REGNUM)];
 231
 232   if (ptrace (PTRACE_SETREGS, inferior_pid,
 233               (PTRACE_ARG3_TYPE) & inferior_registers, 0))
 234     perror ("ptrace_setregs");
 235
 236   memcpy (&inferior_fp_registers, &registers[REGISTER_BYTE (FP0_REGNUM)],
 237           sizeof inferior_fp_registers.fpu_fr);
 238
 239   if (ptrace (PTRACE_SETFPREGS, inferior_pid,
 240               (PTRACE_ARG3_TYPE) & inferior_fp_registers, 0))
 241     perror ("ptrace_setfpregs");
 242 }
 243
 244 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
 245    in the NEW_SUN_PTRACE case.
 246    It ought to be straightforward.  But it appears that writing did
 247    not write the data that I specified.  I cannot understand where
 248    it got the data that it actually did write.  */
 249
 250 /* Copy LEN bytes from inferior's memory starting at MEMADDR
 251    to debugger memory starting at MYADDR.  */
 252
 253 read_inferior_memory (memaddr, myaddr, len)
 254      CORE_ADDR memaddr;
 255      char *myaddr;
 256      int len;
 257 {
 258   register int i;
 259   /* Round starting address down to longword boundary.  */
 260   register CORE_ADDR addr = memaddr & -sizeof (int);
 261   /* Round ending address up; get number of longwords that makes.  */
 262   register int count
 263   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 264   /* Allocate buffer of that many longwords.  */
 265   register int *buffer = (int *) alloca (count * sizeof (int));
 266
 267   /* Read all the longwords */
 268   for (i = 0; i < count; i++, addr += sizeof (int))
 269     {
 270       buffer[i] = ptrace (1, inferior_pid, addr, 0);
 271     }
 272
 273   /* Copy appropriate bytes out of the buffer.  */
 274   memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 275 }
 276
 277 /* Copy LEN bytes of data from debugger memory at MYADDR
 278    to inferior's memory at MEMADDR.
 279    On failure (cannot write the inferior)
 280    returns the value of errno.  */
 281
 282 int
 283 write_inferior_memory (memaddr, myaddr, len)
 284      CORE_ADDR memaddr;
 285      char *myaddr;
 286      int len;
 287 {
 288   register int i;
 289   /* Round starting address down to longword boundary.  */
 290   register CORE_ADDR addr = memaddr & -sizeof (int);
 291   /* Round ending address up; get number of longwords that makes.  */
 292   register int count
 293   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 294   /* Allocate buffer of that many longwords.  */
 295   register int *buffer = (int *) alloca (count * sizeof (int));
 296   extern int errno;
 297
 298   /* Fill start and end extra bytes of buffer with existing memory data.  */
 299
 300   buffer[0] = ptrace (1, inferior_pid, addr, 0);
 301
 302   if (count > 1)
 303     {
 304       buffer[count - 1]
 305         = ptrace (1, inferior_pid,
 306                   addr + (count - 1) * sizeof (int), 0);
 307     }
 308
 309   /* Copy data to be written over corresponding part of buffer */
 310
 311   bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 312
 313   /* Write the entire buffer.  */
 314
 315   for (i = 0; i < count; i++, addr += sizeof (int))
 316     {
 317       errno = 0;
 318       ptrace (4, inferior_pid, addr, buffer[i]);
 319       if (errno)
 320         return errno;
 321     }
 322
 323   return 0;
 324 }
 325 \f
 326 void
 327 initialize_low ()
 328 {
 329 }