gdb/gdbserver/remote-inflow.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 "frame.h"
  22 #include "inferior.h"
  23 /***************************
  24 #include "initialize.h"
  25 ****************************/
  26
  27 #include <stdio.h>
  28 #include <sys/param.h>
  29 #include <sys/dir.h>
  30 /*#include <sys/user.h>*/
  31 #define LYNXOS
  32 #include <sys/mem.h>
  33 #include <sys/signal.h>
  34 #include <sys/file.h>
  35 #include <sys/kernel.h>
  36 #include <sys/itimer.h>
  37 #include <sys/time.h>
  38 #include <sys/resource.h>
  39 #include <sys/proc.h>
  40 #include <signal.h>
  41 #include <sys/ioctl.h>
  42 #include <sgtty.h>
  43 #include <fcntl.h>
  44 #include "/usr/include/wait.h"
  45
  46 /***************Begin MY defs*********************/
  47 int quit_flag = 0;
  48 char registers[REGISTER_BYTES];
  49
  50 /* Index within `registers' of the first byte of the space for
  51    register N.  */
  52
  53
  54 char buf2[MAX_REGISTER_RAW_SIZE];
  55 /***************End MY defs*********************/
  56
  57 #include <sys/ptrace.h>
  58 /*#include <machine/reg.h>*/
  59
  60 extern char **environ;
  61 extern int errno;
  62 extern int inferior_pid;
  63 void error (), quit (), perror_with_name ();
  64 int query ();
  65
  66 /* Start an inferior process and returns its pid.
  67    ALLARGS is a vector of program-name and args.
  68    ENV is the environment vector to pass.  */
  69
  70 int
  71 create_inferior (program, allargs)
  72      char *program;
  73      char **allargs;
  74 {
  75   int pid;
  76
  77   pid = fork ();
  78   if (pid < 0)
  79     perror_with_name ("fork");
  80
  81   if (pid == 0)
  82     {
  83       ptrace (PTRACE_TRACEME);
  84
  85       execv (program, allargs);
  86
  87       fprintf (stderr, "Cannot exec %s: %s.\n", program,
  88                errno < sys_nerr ? sys_errlist[errno] : "unknown error");
  89       fflush (stderr);
  90       _exit (0177);
  91     }
  92
  93   return pid;
  94 }
  95
  96 /* Kill the inferior process.  Make us have no inferior.  */
  97
  98 void
  99 kill_inferior ()
 100 {
 101   if (inferior_pid == 0)
 102     return;
 103   ptrace (8, inferior_pid, 0, 0);
 104   wait (0);
 105   /*************inferior_died ();****VK**************/
 106 }
 107
 108 /* Wait for process, returns status */
 109
 110 unsigned char
 111 mywait (status)
 112      char *status;
 113 {
 114   int pid;
 115   union wait w;
 116
 117   pid = wait (&w);
 118   if (pid != PIDGET(inferior_pid))
 119     perror_with_name ("wait");
 120
 121   inferior_pid = BUILDPID (inferior_pid, w.w_tid);
 122
 123   if (WIFEXITED (w))
 124     {
 125       fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
 126       *status = 'E';
 127       return ((unsigned char) WEXITSTATUS (w));
 128     }
 129   else if (!WIFSTOPPED (w))
 130     {
 131       fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
 132       *status = 'T';
 133       return ((unsigned char) WTERMSIG (w));
 134     }
 135
 136   fetch_inferior_registers (0);
 137
 138   *status = 'S';
 139   return ((unsigned char) WSTOPSIG (w));
 140 }
 141
 142 /* Resume execution of the inferior process.
 143    If STEP is nonzero, single-step it.
 144    If SIGNAL is nonzero, give it that signal.  */
 145
 146 void
 147 myresume (step, signal)
 148      int step;
 149      int signal;
 150 {
 151   errno = 0;
 152   ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
 153   if (errno)
 154     perror_with_name ("ptrace");
 155 }
 156
 157 #undef offsetof
 158 #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
 159
 160 static struct econtext *
 161 lynx_registers_addr()
 162 {
 163   st_t *stblock;
 164   int ecpoff = offsetof(st_t, ecp);
 165   CORE_ADDR ecp;
 166
 167   errno = 0;
 168   stblock = (st_t *) ptrace (PTRACE_THREADUSER, inferior_pid,
 169                              (PTRACE_ARG3_TYPE)0, 0);
 170   if (errno)
 171     perror_with_name ("PTRACE_THREADUSER");
 172
 173   ecp = (CORE_ADDR) ptrace (PTRACE_PEEKTHREAD, inferior_pid,
 174                             (PTRACE_ARG3_TYPE)ecpoff, 0);
 175   ecp -= (CORE_ADDR)stblock;
 176   if (errno)
 177     perror_with_name ("lynx_registers_addr(PTRACE_PEEKTHREAD)");
 178
 179   return (struct econtext *)ecp;
 180 }
 181
 182 static struct econtext *ecp;
 183
 184 /* Mapping between GDB register #s and offsets into econtext.  Must be
 185    consistent with REGISTER_NAMES macro in tm-i386v.h. */
 186
 187 #define X(ENTRY)(offsetof(struct econtext, ENTRY) / 4)
 188 static int regmap[] = {
 189   X(eax),
 190   X(ecx),
 191   X(edx),
 192   X(ebx),
 193   X(esp),
 194   X(ebp),
 195   X(esi),
 196   X(edi),
 197   X(eip),
 198   X(flags),                     /* ps */
 199   X(cs),
 200   X(ss),
 201   X(ds),
 202   X(es),
 203   X(ecode),                     /* Lynx doesn't give us either fs or gs, so */
 204   X(fault)                      /* we just substitute these two in the hopes
 205                                    that they are useful. */
 206   };
 207
 208 /* Fetch one or more registers from the inferior.  REGNO == -1 to get
 209    them all.  We actually fetch more than requested, when convenient,
 210    marking them as valid so we won't fetch them again.  */
 211
 212 void
 213 fetch_inferior_registers (ignored)
 214      int ignored;
 215 {
 216   int regno;
 217   unsigned long reg;
 218   struct econtext *ecp;
 219
 220   ecp = lynx_registers_addr();
 221
 222   for (regno = 0; regno < NUM_REGS; regno++)
 223     {
 224       errno = 0;
 225       reg = ptrace (PTRACE_PEEKTHREAD, inferior_pid,
 226                     (PTRACE_ARG3_TYPE) (&ecp->fault + regmap[regno]), 0);
 227       if (errno)
 228         perror_with_name ("fetch_inferior_registers(PTRACE_PEEKTHREAD)");
 229
 230       *(unsigned long *)&registers[REGISTER_BYTE (regno)] = reg;
 231     }
 232 }
 233
 234 /* Store our register values back into the inferior.
 235    If REGNO is -1, do this for all registers.
 236    Otherwise, REGNO specifies which register (so we can save time).  */
 237
 238 void
 239 store_inferior_registers (ignored)
 240      int ignored;
 241 {
 242   int regno;
 243   unsigned long reg;
 244   struct econtext *ecp;
 245
 246   ecp = lynx_registers_addr();
 247
 248   for (regno = 0; regno < NUM_REGS; regno++)
 249     {
 250       reg = *(unsigned long *)&registers[REGISTER_BYTE (regno)];
 251
 252       errno = 0;
 253       ptrace (PTRACE_POKEUSER, inferior_pid,
 254               (PTRACE_ARG3_TYPE) (&ecp->fault + regmap[regno]), reg);
 255       if (errno)
 256         perror_with_name ("PTRACE_POKEUSER");
 257     }
 258 }
 259
 260 /* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
 261    in the NEW_SUN_PTRACE case.
 262    It ought to be straightforward.  But it appears that writing did
 263    not write the data that I specified.  I cannot understand where
 264    it got the data that it actually did write.  */
 265
 266 /* Copy LEN bytes from inferior's memory starting at MEMADDR
 267    to debugger memory starting at MYADDR.  */
 268
 269 read_inferior_memory (memaddr, myaddr, len)
 270      CORE_ADDR memaddr;
 271      char *myaddr;
 272      int len;
 273 {
 274   register int i;
 275   /* Round starting address down to longword boundary.  */
 276   register CORE_ADDR addr = memaddr & -sizeof (int);
 277   /* Round ending address up; get number of longwords that makes.  */
 278   register int count
 279   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 280   /* Allocate buffer of that many longwords.  */
 281   register int *buffer = (int *) alloca (count * sizeof (int));
 282
 283   /* Read all the longwords */
 284   for (i = 0; i < count; i++, addr += sizeof (int))
 285     {
 286       buffer[i] = ptrace (1, inferior_pid, addr, 0);
 287     }
 288
 289   /* Copy appropriate bytes out of the buffer.  */
 290   bcopy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len);
 291 }
 292
 293 /* Copy LEN bytes of data from debugger memory at MYADDR
 294    to inferior's memory at MEMADDR.
 295    On failure (cannot write the inferior)
 296    returns the value of errno.  */
 297
 298 int
 299 write_inferior_memory (memaddr, myaddr, len)
 300      CORE_ADDR memaddr;
 301      char *myaddr;
 302      int len;
 303 {
 304   register int i;
 305   /* Round starting address down to longword boundary.  */
 306   register CORE_ADDR addr = memaddr & -sizeof (int);
 307   /* Round ending address up; get number of longwords that makes.  */
 308   register int count
 309   = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
 310   /* Allocate buffer of that many longwords.  */
 311   register int *buffer = (int *) alloca (count * sizeof (int));
 312   extern int errno;
 313
 314   /* Fill start and end extra bytes of buffer with existing memory data.  */
 315
 316   buffer[0] = ptrace (1, inferior_pid, addr, 0);
 317
 318   if (count > 1)
 319     {
 320       buffer[count - 1]
 321         = ptrace (1, inferior_pid,
 322                   addr + (count - 1) * sizeof (int), 0);
 323     }
 324
 325   /* Copy data to be written over corresponding part of buffer */
 326
 327   bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
 328
 329   /* Write the entire buffer.  */
 330
 331   for (i = 0; i < count; i++, addr += sizeof (int))
 332     {
 333       errno = 0;
 334       ptrace (4, inferior_pid, addr, buffer[i]);
 335       if (errno)
 336         return errno;
 337     }
 338
 339   return 0;
 340 }
 341 \f
 342 void
 343 initialize ()
 344 {
 345   inferior_pid = 0;
 346 }
 347
 348 int
 349 have_inferior_p ()
 350 {
 351   return inferior_pid != 0;
 352 }