gdb/gdbserver/low-hppabsd.c

   1 /* Low level interface to ptrace, for the remote server for GDB.
   2    Copyright (C) 1995 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 <stdio.h>
  27 #include <sys/param.h>
  28 #include <sys/dir.h>
  29 #include <sys/user.h>
  30 #include <signal.h>
  31 #include <sys/ioctl.h>
  32 #include <sgtty.h>
  33 #include <fcntl.h>
  34
  35 /***************Begin MY defs*********************/
  36 static char my_registers[REGISTER_BYTES];
  37 char *registers = my_registers;
  38 /***************End MY defs*********************/
  39
  40 #include <sys/ptrace.h>
  41 #include <machine/reg.h>
  42
  43 extern int errno;
  44 extern int inferior_pid;
  45 void perror_with_name ();
  46
  47 /* Start an inferior process and returns its pid.
  48    ALLARGS is a vector of program-name and args. */
  49
  50 int
  51 create_inferior (char *program, char **allargs)
  52 {
  53   int pid;
  54
  55   pid = fork ();
  56   if (pid < 0)
  57     perror_with_name ("fork");
  58
  59   if (pid == 0)
  60     {
  61       ptrace (PT_TRACE_ME, 0, 0, 0, 0);
  62
  63       execv (program, allargs);
  64
  65       fprintf (stderr, "Cannot exec %s: %s.\n", program,
  66                errno < sys_nerr ? sys_errlist[errno] : "unknown error");
  67       fflush (stderr);
  68       _exit (0177);
  69     }
  70
  71   return pid;
  72 }
  73
  74 /* Kill the inferior process.  Make us have no inferior.  */
  75
  76 void
  77 kill_inferior (void)
  78 {
  79   if (inferior_pid == 0)
  80     return;
  81   ptrace (8, inferior_pid, 0, 0, 0);
  82   wait (0);
  83 /*************inferior_died ();****VK**************/
  84 }
  85
  86 /* Return nonzero if the given thread is still alive.  */
  87 int
  88 mythread_alive (int pid)
  89 {
  90   return 1;
  91 }
  92
  93 /* Wait for process, returns status */
  94
  95 unsigned char
  96 mywait (char *status)
  97 {
  98   int pid;
  99   union wait w;
 100
 101   pid = wait (&w);
 102   if (pid != inferior_pid)
 103     perror_with_name ("wait");
 104
 105   if (WIFEXITED (w))
 106     {
 107       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
 108       *status = 'W';
 109       return ((unsigned char) WEXITSTATUS (w));
 110     }
 111   else if (!WIFSTOPPED (w))
 112     {
 113       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
 114       *status = 'X';
 115       return ((unsigned char) WTERMSIG (w));
 116     }
 117
 118   fetch_inferior_registers (0);
 119
 120   *status = 'T';
 121   return ((unsigned char) WSTOPSIG (w));
 122 }
 123
 124 /* Resume execution of the inferior process.
 125    If STEP is nonzero, single-step it.
 126    If SIGNAL is nonzero, give it that signal.  */
 127
 128 void
 129 myresume (int step, int signal)
 130 {
 131   errno = 0;
 132   ptrace (step ? PT_STEP : PT_CONTINUE, inferior_pid, 1, signal, 0);
 133   if (errno)
 134     perror_with_name ("ptrace");
 135 }
 136
 137
 138 #if !defined (offsetof)
 139 #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
 140 #endif
 141
 142 /* U_REGS_OFFSET is the offset of the registers within the u area.  */
 143 #if !defined (U_REGS_OFFSET)
 144 #define U_REGS_OFFSET \
 145   ptrace (PT_READ_U, inferior_pid, \
 146           (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \
 147     - KERNEL_U_ADDR
 148 #endif
 149
 150 CORE_ADDR
 151 register_addr (int regno, CORE_ADDR blockend)
 152 {
 153   CORE_ADDR addr;
 154
 155   if (regno < 0 || regno >= ARCH_NUM_REGS)
 156     error ("Invalid register number %d.", regno);
 157
 158   REGISTER_U_ADDR (addr, blockend, regno);
 159
 160   return addr;
 161 }
 162
 163 /* Fetch one register.  */
 164
 165 static void
 166 fetch_register (int regno)
 167 {
 168   register unsigned int regaddr;
 169   char buf[MAX_REGISTER_RAW_SIZE];
 170   register int i;
 171
 172   /* Offset of registers within the u area.  */
 173   unsigned int offset;
 174
 175   offset = U_REGS_OFFSET;
 176
 177   regaddr = register_addr (regno, offset);
 178   for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
 179     {
 180       errno = 0;
 181       *(int *) &registers[regno * 4 + i] = ptrace (PT_RUREGS, inferior_pid,
 182                                           (PTRACE_ARG3_TYPE) regaddr, 0, 0);
 183       regaddr += sizeof (int);
 184       if (errno != 0)
 185         {
 186           /* Warning, not error, in case we are attached; sometimes the
 187              kernel doesn't let us at the registers.  */
 188           char *err = strerror (errno);
 189           char *msg = alloca (strlen (err) + 128);
 190           sprintf (msg, "reading register %d: %s", regno, err);
 191           error (msg);
 192           goto error_exit;
 193         }
 194     }
 195 error_exit:;
 196 }
 197
 198 /* Fetch all registers, or just one, from the child process.  */
 199
 200 void
 201 fetch_inferior_registers (int regno)
 202 {
 203   if (regno == -1 || regno == 0)
 204     for (regno = 0; regno < NUM_REGS; regno++)
 205       fetch_register (regno);
 206   else
 207     fetch_register (regno);
 208 }
 209
 210 /* Store our register values back into the inferior.
 211    If REGNO is -1, do this for all registers.
 212    Otherwise, REGNO specifies which register (so we can save time).  */
 213
 214 void
 215 store_inferior_registers (int regno)
 216 {
 217   register unsigned int regaddr;
 218   char buf[80];
 219   extern char registers[];
 220   register int i;
 221   unsigned int offset = U_REGS_OFFSET;
 222   int scratch;
 223
 224   if (regno >= 0)
 225     {
 226       if (CANNOT_STORE_REGISTER (regno))
 227         return;
 228       regaddr = register_addr (regno, offset);
 229       errno = 0;
 230       if (regno == PCOQ_HEAD_REGNUM || regno == PCOQ_TAIL_REGNUM)
 231         {
 232           scratch = *(int *) &registers[REGISTER_BYTE (regno)] | 0x3;
 233           ptrace (PT_WUREGS, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
 234                   scratch, 0);
 235           if (errno != 0)
 236             {
 237               /* Error, even if attached.  Failing to write these two
 238                  registers is pretty serious.  */
 239               sprintf (buf, "writing register number %d", regno);
 240               perror_with_name (buf);
 241             }
 242         }
 243       else
 244         for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
 245           {
 246             errno = 0;
 247             ptrace (PT_WUREGS, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
 248                     *(int *) &registers[REGISTER_BYTE (regno) + i], 0);
 249             if (errno != 0)
 250               {
 251                 /* Warning, not error, in case we are attached; sometimes the
 252                    kernel doesn't let us at the registers.  */
 253                 char *err = strerror (errno);
 254                 char *msg = alloca (strlen (err) + 128);
 255                 sprintf (msg, "writing register %d: %s",
 256                          regno, err);
 257                 error (msg);
 258                 return;
 259               }
 260             regaddr += sizeof (int);
 261           }
 262     }
 263   else
 264     for (regno = 0; regno < NUM_REGS; regno++)
 265       store_inferior_registers (regno);
 266 }
 267
 268 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
 269    in the NEW_SUN_PTRACE case.
 270    It ought to be straightforward.  But it appears that writing did
 271    not write the data that I specified.  I cannot understand where
 272    it got the data that it actually did write.  */
 273
 274 /* Copy LEN bytes from inferior's memory starting at MEMADDR
 275    to debugger memory starting at MYADDR.  */
 276
 277 read_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 278 {
 279   register int i;
 280   /* Round starting address down to longword boundary.  */
 281   register CORE_ADDR addr = memaddr & -sizeof (int);
 282   /* Round ending address up; get number of longwords that makes.  */
 283   register int count
 284   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 285   /* Allocate buffer of that many longwords.  */
 286   register int *buffer = (int *) alloca (count * sizeof (int));
 287
 288   /* Read all the longwords */
 289   for (i = 0; i < count; i++, addr += sizeof (int))
 290     {
 291       buffer[i] = ptrace (1, inferior_pid, addr, 0, 0);
 292     }
 293
 294   /* Copy appropriate bytes out of the buffer.  */
 295   memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 296 }
 297
 298 /* Copy LEN bytes of data from debugger memory at MYADDR
 299    to inferior's memory at MEMADDR.
 300    On failure (cannot write the inferior)
 301    returns the value of errno.  */
 302
 303 int
 304 write_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
 305 {
 306   register int i;
 307   /* Round starting address down to longword boundary.  */
 308   register CORE_ADDR addr = memaddr & -sizeof (int);
 309   /* Round ending address up; get number of longwords that makes.  */
 310   register int count
 311   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 312   /* Allocate buffer of that many longwords.  */
 313   register int *buffer = (int *) alloca (count * sizeof (int));
 314   extern int errno;
 315
 316   /* Fill start and end extra bytes of buffer with existing memory data.  */
 317
 318   buffer[0] = ptrace (1, inferior_pid, addr, 0, 0);
 319
 320   if (count > 1)
 321     {
 322       buffer[count - 1]
 323         = ptrace (1, inferior_pid,
 324                   addr + (count - 1) * sizeof (int), 0, 0);
 325     }
 326
 327   /* Copy data to be written over corresponding part of buffer */
 328
 329   memcpy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len);
 330
 331   /* Write the entire buffer.  */
 332
 333   for (i = 0; i < count; i++, addr += sizeof (int))
 334     {
 335       errno = 0;
 336       ptrace (4, inferior_pid, addr, buffer[i], 0);
 337       if (errno)
 338         return errno;
 339     }
 340
 341   return 0;
 342 }
 343 \f
 344 void
 345 initialize_low (void)
 346 {
 347 }