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