524 lines
13 KiB
C
524 lines
13 KiB
C
/* Low level interface to ptrace, for GDB when running under Unix.
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Copyright (C) 1986, 1987 Free Software Foundation, Inc.
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GDB is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY. No author or distributor accepts responsibility to anyone
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for the consequences of using it or for whether it serves any
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particular purpose or works at all, unless he says so in writing.
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Refer to the GDB General Public License for full details.
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Everyone is granted permission to copy, modify and redistribute GDB,
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but only under the conditions described in the GDB General Public
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License. A copy of this license is supposed to have been given to you
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along with GDB so you can know your rights and responsibilities. It
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should be in a file named COPYING. Among other things, the copyright
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notice and this notice must be preserved on all copies.
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In other words, go ahead and share GDB, but don't try to stop
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anyone else from sharing it farther. Help stamp out software hoarding!
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*/
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#include "defs.h"
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#include "param.h"
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#include "frame.h"
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#include "inferior.h"
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#ifdef USG
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#include <sys/types.h>
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#endif
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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 <signal.h>
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#include <sys/user.h>
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#include <sys/ioctl.h>
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#include <fcntl.h>
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#include <a.out.h>
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#include <sys/file.h>
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#include <sys/stat.h>
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extern int errno;
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/* This function simply calls ptrace with the given arguments.
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It exists so that all calls to ptrace are isolated in this
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machine-dependent file. */
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int
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call_ptrace (request, pid, arg3, arg4)
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int request, pid, arg3, arg4;
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{
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return ptrace (request, pid, arg3, arg4);
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}
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kill_inferior ()
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{
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if (remote_debugging)
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return;
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if (inferior_pid == 0)
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return;
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/* Convex ptrace needs an extra 0 arg */
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ptrace (8, inferior_pid, 0, 0, 0);
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wait (0);
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inferior_died ();
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}
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/* This is used when GDB is exiting. It gives less chance of error.*/
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kill_inferior_fast ()
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{
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if (remote_debugging)
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return;
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if (inferior_pid == 0)
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return;
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ptrace (8, inferior_pid, 0, 0);
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wait (0);
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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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resume (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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if (remote_debugging)
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remote_resume (step, signal);
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else
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{
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extern char registers[];
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/* Blam the trace bits in the stack's saved psws to match the
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desired step mode. This is required so that single-stepping a
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return doesn't restore a psw with a clear trace bit and fly away,
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and conversely, proceeding through a return in a routine that was
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stepped into doesn't cause a phantom break by restoring a psw
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with the trace bit set. */
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scan_stack (PSW_T_BIT, step);
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/* Write the registers back now */
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ptrace (11, inferior_pid, 0, registers, REGISTER_BYTES);
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if (errno != 0) perror_with_name ("writing registers");
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errno = 0;
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ptrace (step ? 9 : 7, inferior_pid, 1, &signal, sizeof signal);
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if (errno)
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perror_with_name ("ptrace");
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}
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}
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void
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fetch_inferior_registers ()
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{
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extern char registers[];
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ptrace (10, inferior_pid, 0, registers, REGISTER_BYTES);
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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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store_inferior_registers (regno)
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int regno;
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{
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/* do this only once, right before resuming inferior. */
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return;
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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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On failure (cannot read from inferior, usually because address is out
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of bounds) returns the value of errno. */
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int
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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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errno = 0;
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ptrace (1, inferior_pid, memaddr, myaddr, len);
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if (errno)
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bzero (myaddr, len);
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return errno;
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}
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/* Copy LEN bytes of data from debugger memnory at MYADDR
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to inferior's memory at MEMADDR.
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Returns errno on failure (cannot write the inferior) */
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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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errno = 0;
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ptrace (4, inferior_pid, memaddr, myaddr, len);
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return errno;
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}
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/* Work with core dump and executable files, for GDB.
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This code would be in core.c if it weren't machine-dependent. */
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/* Required by convex's SOFF format
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It may be desirable to remove the conditionals for SOFF_FORMAT, if
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Convex is the only machine which will ever make use of them. */
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#ifdef SOFF_FORMAT
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#include <convex/filehdr.h>
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#include <convex/opthdr.h>
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#include <convex/scnhdr.h>
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#include <convex/core.h>
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#endif /* SOFF_FORMAT */
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/* Recognize COFF format systems because a.out.h defines AOUTHDR. */
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#ifdef AOUTHDR
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#define COFF_FORMAT
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#endif
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#ifndef N_TXTADDR
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#define N_TXTADDR(hdr) 0
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#endif /* no N_TXTADDR */
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#ifndef N_DATADDR
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#define N_DATADDR(hdr) hdr.a_text
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#endif /* no N_DATADDR */
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/* Make COFF and non-COFF names for things a little more compatible
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to reduce conditionals later. */
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#ifdef COFF_FORMAT
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#define a_magic magic
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#endif
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#ifndef COFF_FORMAT
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#define AOUTHDR struct exec
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#endif
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extern char *sys_siglist[];
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/* Hook for `exec_file_command' command to call. */
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extern void (*exec_file_display_hook) ();
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/* File names of core file and executable file. */
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extern char *corefile;
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extern char *execfile;
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/* Descriptors on which core file and executable file are open.
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Note that the execchan is closed when an inferior is created
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and reopened if the inferior dies or is killed. */
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extern int corechan;
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extern int execchan;
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/* Last modification time of executable file.
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Also used in source.c to compare against mtime of a source file. */
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extern int exec_mtime;
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/* Virtual addresses of bounds of the two areas of memory in the core file. */
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extern CORE_ADDR data_start;
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extern CORE_ADDR data_end;
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extern CORE_ADDR stack_start;
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extern CORE_ADDR stack_end;
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/* Virtual addresses of bounds of two areas of memory in the exec file.
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Note that the data area in the exec file is used only when there is no core file. */
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extern CORE_ADDR text_start;
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extern CORE_ADDR text_end;
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extern CORE_ADDR exec_data_start;
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extern CORE_ADDR exec_data_end;
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/* Address in executable file of start of text area data. */
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extern int text_offset;
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/* Address in executable file of start of data area data. */
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extern int exec_data_offset;
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/* Address in core file of start of data area data. */
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extern int data_offset;
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/* Address in core file of start of stack area data. */
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extern int stack_offset;
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#ifdef COFF_FORMAT
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/* various coff data structures */
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extern FILHDR file_hdr;
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extern SCNHDR text_hdr;
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extern SCNHDR data_hdr;
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#endif /* not COFF_FORMAT */
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/* a.out header saved in core file. */
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extern AOUTHDR core_aouthdr;
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/* a.out header of exec file. */
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extern AOUTHDR exec_aouthdr;
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extern void validate_files ();
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core_file_command (filename, from_tty)
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char *filename;
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int from_tty;
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{
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int val;
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extern char registers[];
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/* Discard all vestiges of any previous core file
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and mark data and stack spaces as empty. */
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if (corefile)
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free (corefile);
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corefile = 0;
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if (corechan >= 0)
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close (corechan);
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corechan = -1;
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data_start = 0;
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data_end = 0;
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stack_start = STACK_END_ADDR;
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stack_end = STACK_END_ADDR;
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/* Now, if a new core file was specified, open it and digest it. */
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if (filename)
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{
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if (have_inferior_p ())
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error ("To look at a core file, you must kill the inferior with \"kill\".");
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corechan = open (filename, O_RDONLY, 0);
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if (corechan < 0)
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perror_with_name (filename);
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#ifdef SOFF_FORMAT
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{
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extern char *sys_errlist[], *sys_siglist[];
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extern int sys_nerr;
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int stop_signal;
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struct core_hdr corehdr;
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struct user u;
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if (myread (corechan, &corehdr, sizeof corehdr) < 0)
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perror_with_name (filename);
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if (corehdr.c_magic != CH_MAGIC)
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error ("%s: not a core file.", filename);
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lseek (corechan, corehdr.c_user, 0);
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if (myread (corechan, &u, sizeof u) < 0)
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perror_with_name (filename);
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lseek (corechan, corehdr.c_syscall_context, 0);
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if (myread (corechan, registers, REGISTER_BYTES) < 0)
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perror_with_name (filename);
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if (corehdr.c_vecst)
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{
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lseek (corechan, corehdr.c_vecst, 0);
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if (myread (corechan, vecst, sizeof vecst) < 0)
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perror_with_name (filename);
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}
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data_offset = corehdr.c_data;
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data_start = exec_data_start;
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data_end = data_start + ctob (u.u_dsize);
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stack_offset = corehdr.c_stack;
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stack_start = stack_end - ctob (u.u_ssize);
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printf ("Program %s", u.u_comm );
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if (u.u_error >= sys_nerr)
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printf (", last error: %d (undocumented),\n", u.u_error);
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else if (u.u_error != 0)
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printf (", last error: %s,", sys_errlist[u.u_error]);
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stop_signal = u.u_arg[0];
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printf (" received signal %d, %s\n", stop_signal,
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stop_signal < NSIG ? sys_siglist[stop_signal] : "(undocumented)");
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core_aouthdr.a_magic = 0;
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}
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#ifdef SOFF_FORMAT
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if (filename[0] == '/')
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corefile = savestring (filename, strlen (filename));
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else
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{
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corefile = concat (current_directory, "/", filename);
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}
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/* Convex-specific code: remove the frame stored by a
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user-mode trap, if present */
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if (read_register (PC_REGNUM) > STACK_END_ADDR)
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{
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POP_FRAME;
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}
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set_current_frame ( create_new_frame (read_register (FP_REGNUM),
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read_pc ()));
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select_frame (get_current_frame (), 0);
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validate_files ();
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}
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else if (from_tty)
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printf ("No core file now.\n");
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}
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exec_file_command (filename, from_tty)
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char *filename;
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int from_tty;
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{
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int val;
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/* Eliminate all traces of old exec file.
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Mark text segment as empty. */
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if (execfile)
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free (execfile);
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execfile = 0;
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data_start = 0;
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data_end -= exec_data_start;
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text_start = 0;
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text_end = 0;
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exec_data_start = 0;
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exec_data_end = 0;
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if (execchan >= 0)
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close (execchan);
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execchan = -1;
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/* Now open and digest the file the user requested, if any. */
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if (filename)
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{
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execchan = openp (getenv ("PATH"), 1, filename, O_RDONLY, 0,
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&execfile);
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if (execchan < 0)
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perror_with_name (filename);
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#ifdef COFF_FORMAT
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{
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int aout_hdrsize;
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int num_sections;
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if (read_file_hdr (execchan, &file_hdr) < 0)
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error ("\"%s\": not in executable format.", execfile);
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aout_hdrsize = file_hdr.f_opthdr;
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num_sections = file_hdr.f_nscns;
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if (read_aout_hdr (execchan, &exec_aouthdr, aout_hdrsize) < 0)
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error ("\"%s\": can't read optional aouthdr", execfile);
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if (read_section_hdr (execchan, _TEXT, &text_hdr, num_sections) < 0)
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error ("\"%s\": can't read text section header", execfile);
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if (read_section_hdr (execchan, _DATA, &data_hdr, num_sections) < 0)
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error ("\"%s\": can't read data section header", execfile);
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text_start = exec_aouthdr.text_start;
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text_end = text_start + exec_aouthdr.tsize;
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text_offset = text_hdr.s_scnptr;
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exec_data_start = exec_aouthdr.data_start;
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exec_data_end = exec_data_start + exec_aouthdr.dsize;
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exec_data_offset = data_hdr.s_scnptr;
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data_start = exec_data_start;
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data_end += exec_data_start;
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exec_mtime = file_hdr.f_timdat;
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}
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#else /* not COFF_FORMAT */
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{
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struct stat st_exec;
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val = myread (execchan, &exec_aouthdr, sizeof (AOUTHDR));
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if (val < 0)
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perror_with_name (filename);
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/* Convex-specific SOFF-FORMAT */
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#ifdef SOFF_FORMAT
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if (IS_SOFF_MAGIC (exec_aouthdr.a_magic))
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{
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FILEHDR filhdr;
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OPTHDR opthdr;
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SCNHDR scnhdr;
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int n, gotem;
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lseek (execchan, 0L, 0);
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if (myread (execchan, &filhdr, sizeof filhdr) < 0)
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perror_with_name (filename);
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if (myread (execchan, &opthdr, filhdr.h_opthdr) <= 0)
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perror_with_name (filename);
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lseek (execchan, (long) filhdr.h_scnptr, 0);
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n = -1;
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gotem = 0;
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while (++n < filhdr.h_nscns && gotem < 2)
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{
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if (myread (execchan, &scnhdr, SCNHSZ) < 0)
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perror_with_name (filename);
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if ((scnhdr.s_flags & S_TYPMASK) == S_TEXT)
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{
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text_start = scnhdr.s_vaddr;
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text_end = text_start + scnhdr.s_size;
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text_offset = scnhdr.s_scnptr;
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++gotem;
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}
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else if ((scnhdr.s_flags & S_TYPMASK) == S_DATA)
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{
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exec_data_start = scnhdr.s_vaddr;
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exec_data_end = exec_data_start + scnhdr.s_size;
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exec_data_offset = scnhdr.s_scnptr;
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data_start = exec_data_start;
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data_end += exec_data_start;
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++gotem;
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}
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}
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}
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else
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#endif SOFF_FORMAT
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{
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text_start = N_TXTADDR (exec_aouthdr);
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text_end = text_start + exec_aouthdr.a_text;
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text_offset = N_TXTOFF (exec_aouthdr);
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exec_data_start = N_DATADDR (exec_aouthdr);
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exec_data_end = exec_data_start + exec_aouthdr.a_data;
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exec_data_offset = N_TXTOFF (exec_aouthdr) + exec_aouthdr.a_text;
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data_start = exec_data_start;
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data_end += exec_data_start;
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}
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fstat (execchan, &st_exec);
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exec_mtime = st_exec.st_mtime;
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}
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#endif /* not COFF_FORMAT */
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validate_files ();
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}
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else if (from_tty)
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printf ("No exec file now.\n");
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/* Tell display code (if any) about the changed file name. */
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if (exec_file_display_hook)
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(*exec_file_display_hook) (filename);
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}
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