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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include "defs.h"
  21 #include <sys/wait.h>
  22 #include "frame.h"
  23 #include "inferior.h"
  24 /***************************
  25 #include "initialize.h"
  26 ****************************/
  27
  28 #include <stdio.h>
  29 #include <sys/param.h>
  30 #include <sys/dir.h>
  31 #include <sys/user.h>
  32 #include <signal.h>
  33 #include <sys/ioctl.h>
  34 #include <sgtty.h>
  35 #include <fcntl.h>
  36
  37 /***************Begin MY defs*********************/
  38 int quit_flag = 0;
  39 char registers[REGISTER_BYTES];
  40
  41 /* Index within `registers' of the first byte of the space for
  42    register N.  */
  43
  44
  45 char buf2[MAX_REGISTER_RAW_SIZE];
  46 /***************End MY defs*********************/
  47
  48 #include <sys/ptrace.h>
  49 #include <machine/reg.h>
  50
  51 extern int sys_nerr;
  52 extern char **sys_errlist;
  53 extern char **environ;
  54 extern int errno;
  55 extern int inferior_pid;
  56 void error (), quit (), perror_with_name ();
  57 int query ();
  58
  59 /* Start an inferior process and returns its pid.
  60    ALLARGS is a vector of program-name and args.
  61    ENV is the environment vector to pass.  */
  62
  63 int
  64 create_inferior (program, allargs)
  65      char *program;
  66      char **allargs;
  67 {
  68   int pid;
  69
  70   pid = fork ();
  71   if (pid < 0)
  72     perror_with_name ("fork");
  73
  74   if (pid == 0)
  75     {
  76       ptrace (PTRACE_TRACEME);
  77
  78       execv (program, allargs);
  79
  80       fprintf (stderr, "Cannot exec %s: %s.\n", program,
  81                errno < sys_nerr ? sys_errlist[errno] : "unknown error");
  82       fflush (stderr);
  83       _exit (0177);
  84     }
  85
  86   return pid;
  87 }
  88
  89 /* Kill the inferior process.  Make us have no inferior.  */
  90
  91 void
  92 kill_inferior ()
  93 {
  94   if (inferior_pid == 0)
  95     return;
  96   ptrace (8, inferior_pid, 0, 0);
  97   wait (0);
  98   /*************inferior_died ();****VK**************/
  99 }
 100
 101 /* Wait for process, returns status */
 102
 103 unsigned char
 104 mywait (status)
 105      char *status;
 106 {
 107   int pid;
 108   union wait w;
 109
 110   pid = wait (&w);
 111   if (pid != inferior_pid)
 112     perror_with_name ("wait");
 113
 114   if (WIFEXITED (w))
 115     {
 116       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
 117       *status = 'E';
 118       return ((unsigned char) WEXITSTATUS (w));
 119     }
 120   else if (!WIFSTOPPED (w))
 121     {
 122       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
 123       *status = 'T';
 124       return ((unsigned char) WTERMSIG (w));
 125     }
 126
 127   fetch_inferior_registers (0);
 128
 129   *status = 'S';
 130   return ((unsigned char) WSTOPSIG (w));
 131 }
 132
 133 /* Resume execution of the inferior process.
 134    If STEP is nonzero, single-step it.
 135    If SIGNAL is nonzero, give it that signal.  */
 136
 137 void
 138 myresume (step, signal)
 139      int step;
 140      int signal;
 141 {
 142   errno = 0;
 143   ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
 144   if (errno)
 145     perror_with_name ("ptrace");
 146 }
 147
 148 /* Fetch one or more registers from the inferior.  REGNO == -1 to get
 149    them all.  We actually fetch more than requested, when convenient,
 150    marking them as valid so we won't fetch them again.  */
 151
 152 void
 153 fetch_inferior_registers (ignored)
 154      int ignored;
 155 {
 156   struct regs inferior_registers;
 157   struct fp_status inferior_fp_registers;
 158   int i;
 159
 160   /* Global and Out regs are fetched directly, as well as the control
 161      registers.  If we're getting one of the in or local regs,
 162      and the stack pointer has not yet been fetched,
 163      we have to do that first, since they're found in memory relative
 164      to the stack pointer.  */
 165
 166   if (ptrace (PTRACE_GETREGS, inferior_pid,
 167               (PTRACE_ARG3_TYPE) &inferior_registers, 0))
 168     perror("ptrace_getregs");
 169
 170   registers[REGISTER_BYTE (0)] = 0;
 171   memcpy (&registers[REGISTER_BYTE (1)], &inferior_registers.r_g1,
 172           15 * REGISTER_RAW_SIZE (G0_REGNUM));
 173   *(int *)&registers[REGISTER_BYTE (PS_REGNUM)] = inferior_registers.r_ps;
 174   *(int *)&registers[REGISTER_BYTE (PC_REGNUM)] = inferior_registers.r_pc;
 175   *(int *)&registers[REGISTER_BYTE (NPC_REGNUM)] = inferior_registers.r_npc;
 176   *(int *)&registers[REGISTER_BYTE (Y_REGNUM)] = inferior_registers.r_y;
 177
 178   /* Floating point registers */
 179
 180   if (ptrace (PTRACE_GETFPREGS, inferior_pid,
 181               (PTRACE_ARG3_TYPE) &inferior_fp_registers,
 182               0))
 183     perror("ptrace_getfpregs");
 184   memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], &inferior_fp_registers,
 185           sizeof inferior_fp_registers.fpu_fr);
 186
 187   /* These regs are saved on the stack by the kernel.  Only read them
 188      all (16 ptrace calls!) if we really need them.  */
 189
 190   read_inferior_memory (*(CORE_ADDR*)&registers[REGISTER_BYTE (SP_REGNUM)],
 191                         &registers[REGISTER_BYTE (L0_REGNUM)],
 192                         16*REGISTER_RAW_SIZE (L0_REGNUM));
 193 }
 194
 195 /* Store our register values back into the inferior.
 196    If REGNO is -1, do this for all registers.
 197    Otherwise, REGNO specifies which register (so we can save time).  */
 198
 199 void
 200 store_inferior_registers (ignored)
 201      int ignored;
 202 {
 203   struct regs inferior_registers;
 204   struct fp_status inferior_fp_registers;
 205   CORE_ADDR sp = *(CORE_ADDR *)&registers[REGISTER_BYTE (SP_REGNUM)];
 206
 207   write_inferior_memory (sp, &registers[REGISTER_BYTE (L0_REGNUM)],
 208                          16*REGISTER_RAW_SIZE (L0_REGNUM));
 209
 210   memcpy (&inferior_registers.r_g1, &registers[REGISTER_BYTE (G1_REGNUM)],
 211           15 * REGISTER_RAW_SIZE (G1_REGNUM));
 212
 213   inferior_registers.r_ps =
 214     *(int *)&registers[REGISTER_BYTE (PS_REGNUM)];
 215   inferior_registers.r_pc =
 216     *(int *)&registers[REGISTER_BYTE (PC_REGNUM)];
 217   inferior_registers.r_npc =
 218     *(int *)&registers[REGISTER_BYTE (NPC_REGNUM)];
 219   inferior_registers.r_y =
 220     *(int *)&registers[REGISTER_BYTE (Y_REGNUM)];
 221
 222   if (ptrace (PTRACE_SETREGS, inferior_pid,
 223               (PTRACE_ARG3_TYPE) &inferior_registers, 0))
 224     perror("ptrace_setregs");
 225
 226   memcpy (&inferior_fp_registers, &registers[REGISTER_BYTE (FP0_REGNUM)],
 227           sizeof inferior_fp_registers.fpu_fr);
 228
 229   if (ptrace (PTRACE_SETFPREGS, inferior_pid,
 230               (PTRACE_ARG3_TYPE) &inferior_fp_registers, 0))
 231     perror("ptrace_setfpregs");
 232 }
 233
 234 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
 235    in the NEW_SUN_PTRACE case.
 236    It ought to be straightforward.  But it appears that writing did
 237    not write the data that I specified.  I cannot understand where
 238    it got the data that it actually did write.  */
 239
 240 /* Copy LEN bytes from inferior's memory starting at MEMADDR
 241    to debugger memory starting at MYADDR.  */
 242
 243 read_inferior_memory (memaddr, myaddr, len)
 244      CORE_ADDR memaddr;
 245      char *myaddr;
 246      int len;
 247 {
 248   register int i;
 249   /* Round starting address down to longword boundary.  */
 250   register CORE_ADDR addr = memaddr & -sizeof (int);
 251   /* Round ending address up; get number of longwords that makes.  */
 252   register int count
 253   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 254   /* Allocate buffer of that many longwords.  */
 255   register int *buffer = (int *) alloca (count * sizeof (int));
 256
 257   /* Read all the longwords */
 258   for (i = 0; i < count; i++, addr += sizeof (int))
 259     {
 260       buffer[i] = ptrace (1, inferior_pid, addr, 0);
 261     }
 262
 263   /* Copy appropriate bytes out of the buffer.  */
 264   memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 265 }
 266
 267 /* Copy LEN bytes of data from debugger memory at MYADDR
 268    to inferior's memory at MEMADDR.
 269    On failure (cannot write the inferior)
 270    returns the value of errno.  */
 271
 272 int
 273 write_inferior_memory (memaddr, myaddr, len)
 274      CORE_ADDR memaddr;
 275      char *myaddr;
 276      int len;
 277 {
 278   register int i;
 279   /* Round starting address down to longword boundary.  */
 280   register CORE_ADDR addr = memaddr & -sizeof (int);
 281   /* Round ending address up; get number of longwords that makes.  */
 282   register int count
 283   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 284   /* Allocate buffer of that many longwords.  */
 285   register int *buffer = (int *) alloca (count * sizeof (int));
 286   extern int errno;
 287
 288   /* Fill start and end extra bytes of buffer with existing memory data.  */
 289
 290   buffer[0] = ptrace (1, inferior_pid, addr, 0);
 291
 292   if (count > 1)
 293     {
 294       buffer[count - 1]
 295         = ptrace (1, inferior_pid,
 296                   addr + (count - 1) * sizeof (int), 0);
 297     }
 298
 299   /* Copy data to be written over corresponding part of buffer */
 300
 301   bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 302
 303   /* Write the entire buffer.  */
 304
 305   for (i = 0; i < count; i++, addr += sizeof (int))
 306     {
 307       errno = 0;
 308       ptrace (4, inferior_pid, addr, buffer[i]);
 309       if (errno)
 310         return errno;
 311     }
 312
 313   return 0;
 314 }
 315 \f
 316 void
 317 initialize ()
 318 {
 319   inferior_pid = 0;
 320 }
 321
 322 int
 323 have_inferior_p ()
 324 {
 325   return inferior_pid != 0;
 326 }