gdb/gdbserver/low-sparc.c

   1 /* Low level interface to ptrace, for the remote server for GDB.
   2    Copyright 1986, 1987, 1993, 1994, 1995, 1997, 1999, 2000, 2001
   3    Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #include "server.h"
  23 #include <sys/wait.h>
  24 #include "frame.h"
  25 #include "inferior.h"
  26 /***************************
  27 #include "initialize.h"
  28 ****************************/
  29
  30 #include <stdio.h>
  31 #include <sys/param.h>
  32 #include <sys/dir.h>
  33 #include <sys/user.h>
  34 #include <signal.h>
  35 #include <sys/ioctl.h>
  36 #include <sgtty.h>
  37 #include <fcntl.h>
  38
  39 /***************Begin MY defs*********************/
  40 static char my_registers[REGISTER_BYTES];
  41 char *registers = my_registers;
  42 /***************End MY defs*********************/
  43
  44 #include <sys/ptrace.h>
  45 #include <sys/reg.h>
  46
  47 extern int sys_nerr;
  48 extern char **sys_errlist;
  49 extern int errno;
  50
  51 /* Start an inferior process and returns its pid.
  52    ALLARGS is a vector of program-name and args. */
  53
  54 int
  55 create_inferior (char *program, char **allargs)
  56 {
  57   int pid;
  58
  59   pid = fork ();
  60   if (pid < 0)
  61     perror_with_name ("fork");
  62
  63   if (pid == 0)
  64     {
  65       ptrace (PTRACE_TRACEME);
  66
  67       execv (program, allargs);
  68
  69       fprintf (stderr, "Cannot exec %s: %s.\n", program,
  70                errno < sys_nerr ? sys_errlist[errno] : "unknown error");
  71       fflush (stderr);
  72       _exit (0177);
  73     }
  74
  75   return pid;
  76 }
  77
  78 /* Kill the inferior process.  Make us have no inferior.  */
  79
  80 void
  81 kill_inferior (void)
  82 {
  83   if (inferior_pid == 0)
  84     return;
  85   ptrace (8, inferior_pid, 0, 0);
  86   wait (0);
  87 /*************inferior_died ();****VK**************/
  88 }
  89
  90 /* Return nonzero if the given thread is still alive.  */
  91 int
  92 mythread_alive (int pid)
  93 {
  94   return 1;
  95 }
  96
  97 /* Wait for process, returns status */
  98
  99 unsigned char
 100 mywait (char *status)
 101 {
 102   int pid;
 103   union wait w;
 104
 105   enable_async_io ();
 106   pid = waitpid (inferior_pid, &w, 0);
 107   disable_async_io ();
 108   if (pid != inferior_pid)
 109     perror_with_name ("wait");
 110
 111   if (WIFEXITED (w))
 112     {
 113       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
 114       *status = 'W';
 115       return ((unsigned char) WEXITSTATUS (w));
 116     }
 117   else if (!WIFSTOPPED (w))
 118     {
 119       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
 120       *status = 'X';
 121       return ((unsigned char) WTERMSIG (w));
 122     }
 123
 124   fetch_inferior_registers (0);
 125
 126   *status = 'T';
 127   return ((unsigned char) WSTOPSIG (w));
 128 }
 129
 130 /* Resume execution of the inferior process.
 131    If STEP is nonzero, single-step it.
 132    If SIGNAL is nonzero, give it that signal.  */
 133
 134 void
 135 myresume (int step, int signal)
 136 {
 137   errno = 0;
 138   ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
 139   if (errno)
 140     perror_with_name ("ptrace");
 141 }
 142
 143 /* Fetch one or more registers from the inferior.  REGNO == -1 to get
 144    them all.  We actually fetch more than requested, when convenient,
 145    marking them as valid so we won't fetch them again.  */
 146
 147 void
 148 fetch_inferior_registers (int ignored)
 149 {
 150   struct regs inferior_registers;
 151   struct fp_status inferior_fp_registers;
 152   int i;
 153
 154   /* Global and Out regs are fetched directly, as well as the control
 155      registers.  If we're getting one of the in or local regs,
 156      and the stack pointer has not yet been fetched,
 157      we have to do that first, since they're found in memory relative
 158      to the stack pointer.  */
 159
 160   if (ptrace (PTRACE_GETREGS, inferior_pid,
 161               (PTRACE_ARG3_TYPE) & inferior_registers, 0))
 162     perror ("ptrace_getregs");
 163
 164   registers[REGISTER_BYTE (0)] = 0;
 165   memcpy (&registers[REGISTER_BYTE (1)], &inferior_registers.r_g1,
 166           15 * REGISTER_RAW_SIZE (G0_REGNUM));
 167   *(int *) &registers[REGISTER_BYTE (PS_REGNUM)] = inferior_registers.r_ps;
 168   *(int *) &registers[REGISTER_BYTE (PC_REGNUM)] = inferior_registers.r_pc;
 169   *(int *) &registers[REGISTER_BYTE (NPC_REGNUM)] = inferior_registers.r_npc;
 170   *(int *) &registers[REGISTER_BYTE (Y_REGNUM)] = inferior_registers.r_y;
 171
 172   /* Floating point registers */
 173
 174   if (ptrace (PTRACE_GETFPREGS, inferior_pid,
 175               (PTRACE_ARG3_TYPE) & inferior_fp_registers,
 176               0))
 177     perror ("ptrace_getfpregs");
 178   memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], &inferior_fp_registers,
 179           sizeof inferior_fp_registers.fpu_fr);
 180
 181   /* These regs are saved on the stack by the kernel.  Only read them
 182      all (16 ptrace calls!) if we really need them.  */
 183
 184   read_inferior_memory (*(CORE_ADDR *) & registers[REGISTER_BYTE (SP_REGNUM)],
 185                         &registers[REGISTER_BYTE (L0_REGNUM)],
 186                         16 * REGISTER_RAW_SIZE (L0_REGNUM));
 187 }
 188
 189 /* Store our register values back into the inferior.
 190    If REGNO is -1, do this for all registers.
 191    Otherwise, REGNO specifies which register (so we can save time).  */
 192
 193 void
 194 store_inferior_registers (int ignored)
 195 {
 196   struct regs inferior_registers;
 197   struct fp_status inferior_fp_registers;
 198   CORE_ADDR sp = *(CORE_ADDR *) & registers[REGISTER_BYTE (SP_REGNUM)];
 199
 200   write_inferior_memory (sp, &registers[REGISTER_BYTE (L0_REGNUM)],
 201                          16 * REGISTER_RAW_SIZE (L0_REGNUM));
 202
 203   memcpy (&inferior_registers.r_g1, &registers[REGISTER_BYTE (G1_REGNUM)],
 204           15 * REGISTER_RAW_SIZE (G1_REGNUM));
 205
 206   inferior_registers.r_ps =
 207     *(int *) &registers[REGISTER_BYTE (PS_REGNUM)];
 208   inferior_registers.r_pc =
 209     *(int *) &registers[REGISTER_BYTE (PC_REGNUM)];
 210   inferior_registers.r_npc =
 211     *(int *) &registers[REGISTER_BYTE (NPC_REGNUM)];
 212   inferior_registers.r_y =
 213     *(int *) &registers[REGISTER_BYTE (Y_REGNUM)];
 214
 215   if (ptrace (PTRACE_SETREGS, inferior_pid,
 216               (PTRACE_ARG3_TYPE) & inferior_registers, 0))
 217     perror ("ptrace_setregs");
 218
 219   memcpy (&inferior_fp_registers, &registers[REGISTER_BYTE (FP0_REGNUM)],
 220           sizeof inferior_fp_registers.fpu_fr);
 221
 222   if (ptrace (PTRACE_SETFPREGS, inferior_pid,
 223               (PTRACE_ARG3_TYPE) & inferior_fp_registers, 0))
 224     perror ("ptrace_setfpregs");
 225 }
 226
 227 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
 228    in the NEW_SUN_PTRACE case.
 229    It ought to be straightforward.  But it appears that writing did
 230    not write the data that I specified.  I cannot understand where
 231    it got the data that it actually did write.  */
 232
 233 /* Copy LEN bytes from inferior's memory starting at MEMADDR
 234    to debugger memory starting at MYADDR.  */
 235
 236 void
 237 read_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 238 {
 239   register int i;
 240   /* Round starting address down to longword boundary.  */
 241   register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (int);
 242   /* Round ending address up; get number of longwords that makes.  */
 243   register int count
 244   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 245   /* Allocate buffer of that many longwords.  */
 246   register int *buffer = (int *) alloca (count * sizeof (int));
 247
 248   /* Read all the longwords */
 249   for (i = 0; i < count; i++, addr += sizeof (int))
 250     {
 251       buffer[i] = ptrace (1, inferior_pid, addr, 0);
 252     }
 253
 254   /* Copy appropriate bytes out of the buffer.  */
 255   memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 256 }
 257
 258 /* Copy LEN bytes of data from debugger memory at MYADDR
 259    to inferior's memory at MEMADDR.
 260    On failure (cannot write the inferior)
 261    returns the value of errno.  */
 262
 263 int
 264 write_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 265 {
 266   register int i;
 267   /* Round starting address down to longword boundary.  */
 268   register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (int);
 269   /* Round ending address up; get number of longwords that makes.  */
 270   register int count
 271   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 272   /* Allocate buffer of that many longwords.  */
 273   register int *buffer = (int *) alloca (count * sizeof (int));
 274   extern int errno;
 275
 276   /* Fill start and end extra bytes of buffer with existing memory data.  */
 277
 278   buffer[0] = ptrace (1, inferior_pid, addr, 0);
 279
 280   if (count > 1)
 281     {
 282       buffer[count - 1]
 283         = ptrace (1, inferior_pid,
 284                   addr + (count - 1) * sizeof (int), 0);
 285     }
 286
 287   /* Copy data to be written over corresponding part of buffer */
 288
 289   bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 290
 291   /* Write the entire buffer.  */
 292
 293   for (i = 0; i < count; i++, addr += sizeof (int))
 294     {
 295       errno = 0;
 296       ptrace (4, inferior_pid, addr, buffer[i]);
 297       if (errno)
 298         return errno;
 299     }
 300
 301   return 0;
 302 }
 303 \f
 304 void
 305 initialize_low (void)
 306 {
 307 }