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, 2002
   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 /* Attaching is not supported.  */
  79 int
  80 myattach (int pid)
  81 {
  82   return -1;
  83 }
  84
  85 /* Kill the inferior process.  Make us have no inferior.  */
  86
  87 void
  88 kill_inferior (void)
  89 {
  90   if (inferior_pid == 0)
  91     return;
  92   ptrace (8, inferior_pid, 0, 0);
  93   wait (0);
  94 /*************inferior_died ();****VK**************/
  95 }
  96
  97 /* Return nonzero if the given thread is still alive.  */
  98 int
  99 mythread_alive (int pid)
 100 {
 101   return 1;
 102 }
 103
 104 /* Wait for process, returns status */
 105
 106 unsigned char
 107 mywait (char *status)
 108 {
 109   int pid;
 110   union wait w;
 111
 112   enable_async_io ();
 113   pid = waitpid (inferior_pid, &w, 0);
 114   disable_async_io ();
 115   if (pid != inferior_pid)
 116     perror_with_name ("wait");
 117
 118   if (WIFEXITED (w))
 119     {
 120       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
 121       *status = 'W';
 122       return ((unsigned char) WEXITSTATUS (w));
 123     }
 124   else if (!WIFSTOPPED (w))
 125     {
 126       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
 127       *status = 'X';
 128       return ((unsigned char) WTERMSIG (w));
 129     }
 130
 131   fetch_inferior_registers (0);
 132
 133   *status = 'T';
 134   return ((unsigned char) WSTOPSIG (w));
 135 }
 136
 137 /* Resume execution of the inferior process.
 138    If STEP is nonzero, single-step it.
 139    If SIGNAL is nonzero, give it that signal.  */
 140
 141 void
 142 myresume (int step, int signal)
 143 {
 144   errno = 0;
 145   ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
 146   if (errno)
 147     perror_with_name ("ptrace");
 148 }
 149
 150 /* Fetch one or more registers from the inferior.  REGNO == -1 to get
 151    them all.  We actually fetch more than requested, when convenient,
 152    marking them as valid so we won't fetch them again.  */
 153
 154 void
 155 fetch_inferior_registers (int ignored)
 156 {
 157   struct regs inferior_registers;
 158   struct fp_status inferior_fp_registers;
 159   int i;
 160
 161   /* Global and Out regs are fetched directly, as well as the control
 162      registers.  If we're getting one of the in or local regs,
 163      and the stack pointer has not yet been fetched,
 164      we have to do that first, since they're found in memory relative
 165      to the stack pointer.  */
 166
 167   if (ptrace (PTRACE_GETREGS, inferior_pid,
 168               (PTRACE_ARG3_TYPE) & inferior_registers, 0))
 169     perror ("ptrace_getregs");
 170
 171   registers[REGISTER_BYTE (0)] = 0;
 172   memcpy (&registers[REGISTER_BYTE (1)], &inferior_registers.r_g1,
 173           15 * REGISTER_RAW_SIZE (G0_REGNUM));
 174   *(int *) &registers[REGISTER_BYTE (PS_REGNUM)] = inferior_registers.r_ps;
 175   *(int *) &registers[REGISTER_BYTE (PC_REGNUM)] = inferior_registers.r_pc;
 176   *(int *) &registers[REGISTER_BYTE (NPC_REGNUM)] = inferior_registers.r_npc;
 177   *(int *) &registers[REGISTER_BYTE (Y_REGNUM)] = inferior_registers.r_y;
 178
 179   /* Floating point registers */
 180
 181   if (ptrace (PTRACE_GETFPREGS, inferior_pid,
 182               (PTRACE_ARG3_TYPE) & inferior_fp_registers,
 183               0))
 184     perror ("ptrace_getfpregs");
 185   memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], &inferior_fp_registers,
 186           sizeof inferior_fp_registers.fpu_fr);
 187
 188   /* These regs are saved on the stack by the kernel.  Only read them
 189      all (16 ptrace calls!) if we really need them.  */
 190
 191   read_inferior_memory (*(CORE_ADDR *) & registers[REGISTER_BYTE (SP_REGNUM)],
 192                         &registers[REGISTER_BYTE (L0_REGNUM)],
 193                         16 * REGISTER_RAW_SIZE (L0_REGNUM));
 194 }
 195
 196 /* Store our register values back into the inferior.
 197    If REGNO is -1, do this for all registers.
 198    Otherwise, REGNO specifies which register (so we can save time).  */
 199
 200 void
 201 store_inferior_registers (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 void
 244 read_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 245 {
 246   register int i;
 247   /* Round starting address down to longword boundary.  */
 248   register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (int);
 249   /* Round ending address up; get number of longwords that makes.  */
 250   register int count
 251   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 252   /* Allocate buffer of that many longwords.  */
 253   register int *buffer = (int *) alloca (count * sizeof (int));
 254
 255   /* Read all the longwords */
 256   for (i = 0; i < count; i++, addr += sizeof (int))
 257     {
 258       buffer[i] = ptrace (1, inferior_pid, addr, 0);
 259     }
 260
 261   /* Copy appropriate bytes out of the buffer.  */
 262   memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 263 }
 264
 265 /* Copy LEN bytes of data from debugger memory at MYADDR
 266    to inferior's memory at MEMADDR.
 267    On failure (cannot write the inferior)
 268    returns the value of errno.  */
 269
 270 int
 271 write_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 272 {
 273   register int i;
 274   /* Round starting address down to longword boundary.  */
 275   register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (int);
 276   /* Round ending address up; get number of longwords that makes.  */
 277   register int count
 278   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 279   /* Allocate buffer of that many longwords.  */
 280   register int *buffer = (int *) alloca (count * sizeof (int));
 281   extern int errno;
 282
 283   /* Fill start and end extra bytes of buffer with existing memory data.  */
 284
 285   buffer[0] = ptrace (1, inferior_pid, addr, 0);
 286
 287   if (count > 1)
 288     {
 289       buffer[count - 1]
 290         = ptrace (1, inferior_pid,
 291                   addr + (count - 1) * sizeof (int), 0);
 292     }
 293
 294   /* Copy data to be written over corresponding part of buffer */
 295
 296   bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 297
 298   /* Write the entire buffer.  */
 299
 300   for (i = 0; i < count; i++, addr += sizeof (int))
 301     {
 302       errno = 0;
 303       ptrace (4, inferior_pid, addr, buffer[i]);
 304       if (errno)
 305         return errno;
 306     }
 307
 308   return 0;
 309 }
 310 \f
 311 void
 312 initialize_low (void)
 313 {
 314 }