419 lines
10 KiB
C
419 lines
10 KiB
C
/* Low level interface to ptrace, for the remote server for GDB.
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Copyright (C) 1995, 1996 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include <sys/wait.h>
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#include "frame.h"
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#include "inferior.h"
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#include <stdio.h>
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#include <sys/param.h>
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#include <sys/dir.h>
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#include <sys/user.h>
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#include <signal.h>
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#include <sys/ioctl.h>
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#if 0
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#include <sgtty.h>
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#endif
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#include <fcntl.h>
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/***************Begin MY defs*********************/
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int quit_flag = 0;
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char registers[REGISTER_BYTES];
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/* Index within `registers' of the first byte of the space for
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register N. */
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char buf2[MAX_REGISTER_RAW_SIZE];
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/***************End MY defs*********************/
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#include <sys/ptrace.h>
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#if 0
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#include <machine/reg.h>
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#endif
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extern char **environ;
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extern int errno;
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extern int inferior_pid;
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void quit (), perror_with_name ();
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int query ();
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/* Start an inferior process and returns its pid.
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ALLARGS is a vector of program-name and args.
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ENV is the environment vector to pass. */
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int
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create_inferior (program, allargs)
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char *program;
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char **allargs;
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{
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int pid;
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pid = fork ();
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if (pid < 0)
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perror_with_name ("fork");
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if (pid == 0)
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{
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ptrace (PTRACE_TRACEME, 0, 0, 0);
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execv (program, allargs);
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fprintf (stderr, "Cannot exec %s: %s.\n", program,
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errno < sys_nerr ? sys_errlist[errno] : "unknown error");
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fflush (stderr);
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_exit (0177);
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}
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return pid;
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}
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/* Kill the inferior process. Make us have no inferior. */
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void
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kill_inferior ()
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{
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if (inferior_pid == 0)
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return;
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ptrace (PTRACE_KILL, inferior_pid, 0, 0);
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wait (0);
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/*************inferior_died ();****VK**************/
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}
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/* Return nonzero if the given thread is still alive. */
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int
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mythread_alive (pid)
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int pid;
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{
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return 1;
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}
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/* Wait for process, returns status */
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unsigned char
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mywait (status)
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char *status;
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{
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int pid;
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union wait w;
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pid = wait (&w);
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if (pid != inferior_pid)
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perror_with_name ("wait");
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if (WIFEXITED (w))
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{
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fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
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*status = 'W';
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return ((unsigned char) WEXITSTATUS (w));
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}
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else if (!WIFSTOPPED (w))
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{
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fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
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*status = 'X';
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return ((unsigned char) WTERMSIG (w));
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}
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fetch_inferior_registers (0);
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*status = 'T';
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return ((unsigned char) WSTOPSIG (w));
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}
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/* Resume execution of the inferior process.
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If STEP is nonzero, single-step it.
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If SIGNAL is nonzero, give it that signal. */
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void
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myresume (step, signal)
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int step;
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int signal;
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{
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errno = 0;
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ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
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if (errno)
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perror_with_name ("ptrace");
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}
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#if !defined (offsetof)
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#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
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#endif
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/* U_REGS_OFFSET is the offset of the registers within the u area. */
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#if !defined (U_REGS_OFFSET)
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#define U_REGS_OFFSET \
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ptrace (PT_READ_U, inferior_pid, \
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(PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \
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- KERNEL_U_ADDR
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#endif
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/* this table must line up with REGISTER_NAMES in tm-i386v.h */
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/* symbols like 'EAX' come from <sys/reg.h> */
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static int regmap[] =
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{
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EAX, ECX, EDX, EBX,
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UESP, EBP, ESI, EDI,
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EIP, EFL, CS, SS,
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DS, ES, FS, GS,
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};
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int
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i386_register_u_addr (blockend, regnum)
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int blockend;
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int regnum;
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{
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#if 0
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/* this will be needed if fp registers are reinstated */
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/* for now, you can look at them with 'info float'
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* sys5 wont let you change them with ptrace anyway
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*/
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if (regnum >= FP0_REGNUM && regnum <= FP7_REGNUM)
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{
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int ubase, fpstate;
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struct user u;
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ubase = blockend + 4 * (SS + 1) - KSTKSZ;
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fpstate = ubase + ((char *)&u.u_fpstate - (char *)&u);
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return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM));
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}
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else
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#endif
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return (blockend + 4 * regmap[regnum]);
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}
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CORE_ADDR
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register_addr (regno, blockend)
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int regno;
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CORE_ADDR blockend;
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{
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CORE_ADDR addr;
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if (regno < 0 || regno >= ARCH_NUM_REGS)
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error ("Invalid register number %d.", regno);
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REGISTER_U_ADDR (addr, blockend, regno);
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return addr;
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}
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/* Fetch one register. */
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static void
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fetch_register (regno)
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int regno;
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{
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register unsigned int regaddr;
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register int i;
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/* Offset of registers within the u area. */
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unsigned int offset;
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offset = U_REGS_OFFSET;
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regaddr = register_addr (regno, offset);
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for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
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{
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errno = 0;
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*(int *) ®isters[ regno * 4 + i] = ptrace (PTRACE_PEEKUSR, inferior_pid,
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(PTRACE_ARG3_TYPE) regaddr, 0);
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regaddr += sizeof (int);
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if (errno != 0)
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{
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/* Warning, not error, in case we are attached; sometimes the
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kernel doesn't let us at the registers. */
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char *err = strerror (errno);
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char *msg = alloca (strlen (err) + 128);
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sprintf (msg, "reading register %d: %s", regno, err);
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error (msg);
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goto error_exit;
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}
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}
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error_exit:;
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}
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/* Fetch all registers, or just one, from the child process. */
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void
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fetch_inferior_registers (regno)
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int regno;
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{
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if (regno == -1 || regno == 0)
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for (regno = 0; regno < NUM_REGS-NUM_FREGS; regno++)
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fetch_register (regno);
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else
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fetch_register (regno);
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}
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/* Store our register values back into the inferior.
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If REGNO is -1, do this for all registers.
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Otherwise, REGNO specifies which register (so we can save time). */
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void
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store_inferior_registers (regno)
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int regno;
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{
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register unsigned int regaddr;
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register int i;
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unsigned int offset = U_REGS_OFFSET;
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if (regno >= 0)
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{
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#if 0
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if (CANNOT_STORE_REGISTER (regno))
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return;
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#endif
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regaddr = register_addr (regno, offset);
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errno = 0;
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#if 0
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if (regno == PCOQ_HEAD_REGNUM || regno == PCOQ_TAIL_REGNUM)
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{
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scratch = *(int *) ®isters[REGISTER_BYTE (regno)] | 0x3;
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ptrace (PT_WUREGS, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
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scratch, 0);
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if (errno != 0)
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{
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/* Error, even if attached. Failing to write these two
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registers is pretty serious. */
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sprintf (buf, "writing register number %d", regno);
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perror_with_name (buf);
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}
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}
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else
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#endif
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for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int))
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{
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errno = 0;
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ptrace (PTRACE_POKEUSR, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
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*(int *) ®isters[REGISTER_BYTE (regno) + i]);
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if (errno != 0)
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{
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/* Warning, not error, in case we are attached; sometimes the
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kernel doesn't let us at the registers. */
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char *err = strerror (errno);
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char *msg = alloca (strlen (err) + 128);
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sprintf (msg, "writing register %d: %s",
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regno, err);
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error (msg);
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return;
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}
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regaddr += sizeof(int);
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}
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}
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else
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for (regno = 0; regno < NUM_REGS-NUM_FREGS; regno++)
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store_inferior_registers (regno);
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}
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/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
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in the NEW_SUN_PTRACE case.
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It ought to be straightforward. But it appears that writing did
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not write the data that I specified. I cannot understand where
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it got the data that it actually did write. */
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/* Copy LEN bytes from inferior's memory starting at MEMADDR
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to debugger memory starting at MYADDR. */
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void
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read_inferior_memory (memaddr, myaddr, len)
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CORE_ADDR memaddr;
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char *myaddr;
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int len;
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{
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register int i;
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/* Round starting address down to longword boundary. */
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register CORE_ADDR addr = memaddr & -sizeof (int);
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/* Round ending address up; get number of longwords that makes. */
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register int count
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= (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
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/* Allocate buffer of that many longwords. */
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register int *buffer = (int *) alloca (count * sizeof (int));
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/* Read all the longwords */
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for (i = 0; i < count; i++, addr += sizeof (int))
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{
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buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, addr, 0);
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}
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/* Copy appropriate bytes out of the buffer. */
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memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
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}
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/* Copy LEN bytes of data from debugger memory at MYADDR
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to inferior's memory at MEMADDR.
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On failure (cannot write the inferior)
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returns the value of errno. */
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int
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write_inferior_memory (memaddr, myaddr, len)
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CORE_ADDR memaddr;
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char *myaddr;
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int len;
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{
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register int i;
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/* Round starting address down to longword boundary. */
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register CORE_ADDR addr = memaddr & -sizeof (int);
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/* Round ending address up; get number of longwords that makes. */
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register int count
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= (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
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/* Allocate buffer of that many longwords. */
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register int *buffer = (int *) alloca (count * sizeof (int));
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extern int errno;
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/* Fill start and end extra bytes of buffer with existing memory data. */
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buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, addr, 0);
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if (count > 1)
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{
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buffer[count - 1]
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= ptrace (PTRACE_PEEKTEXT, inferior_pid,
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addr + (count - 1) * sizeof (int), 0);
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}
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/* Copy data to be written over corresponding part of buffer */
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memcpy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len);
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/* Write the entire buffer. */
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for (i = 0; i < count; i++, addr += sizeof (int))
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{
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errno = 0;
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ptrace (PTRACE_POKETEXT, inferior_pid, addr, buffer[i]);
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if (errno)
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return errno;
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}
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return 0;
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}
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void
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initialize ()
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{
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inferior_pid = 0;
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}
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int
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have_inferior_p ()
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{
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return inferior_pid != 0;
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}
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