/*
* This program was advertised on unix-wizards. I have had such a large
* response I'm sending it out to the world.
*
* Here is the source. It works fine under 4.1bsd, I see no fundamental
* reason why it shouldn't work on an 11. (Except possibly small format
* changes in exec header or user structure.) No documentation yet.
* Usage is
* undump new-a.out-file [old-a.out-file] [core-file]
* where old-a.out-file and core-file default to "a.out" and "core",
* respectively. Probably should have an option to not require
* old-a.out-file if the core came from a 407 file.
*
* It doesn't preserve open files, and the program is re-entered at main
* when you run it. It's used locally to dump a lisp and restart it.
*
* It requires a local subroutine called scanargs, somewhat similar to
* getopt (I think). You should be able to easily get around this, though.
* =Spencer
*/
/*
* undump.c - Convert a core file to an a.out.
*
* Author: Spencer W. Thomas
* Computer Science Dept.
* University of Utah
* Date: Wed Feb 17 1982
* Copyright (c) 1982 Spencer W. Thomas
*
* Usage:
* undump new-a.out [a.out] [core]
*/
#include <stdio.h>
#include <sys/param.h>
#include <sys/dir.h>
#include <sys/stat.h>
#include <aouthdr.h>
#include <filehdr.h>
#include <scnhdr.h>
#include <linenum.h>
#include <sys/ptrace.h>
#define PSIZE 10240
#define MAXSCNS 8
struct ptrace_user u;
AOUTHDR ahdr, oahdr;
struct filehdr fhdr, ofhdr;
struct scnhdr scns[MAXSCNS];
int nscns;
long cur_pos, sym_top;
main(argc, argv)
char **argv;
{
char *new_name, *a_out_name = "a.out", *core_name = "core";
FILE *new, *a_out, *core;
if (scanargs(argc, argv, "undump new-a.out!s a.out%s core%s",
&new_name, &a_out_name, &core_name)
!= 1)
exit(1);
if ((a_out = fopen(a_out_name, "r")) == NULL)
{
perror(a_out_name);
exit(1);
}
if ((core = fopen(core_name, "r")) == NULL)
{
perror(core_name);
exit(1);
}
if ((new = fopen(new_name, "w")) == NULL)
{
perror(new_name);
exit(1);
}
read_u(core);
make_hdr(new, a_out);
copy_text(new, a_out);
copy_data(new, core);
copy_sym(new, a_out);
fclose(new);
fclose(core);
fclose(a_out);
mark_x(new_name);
}
/*
* read the u structure from the core file.
*/
read_u(core)
FILE *core;
{
if ( fread(&u, sizeof u, 1, core) != 1 )
{
perror("Couldn't read user structure from core file");
exit(1);
}
}
/*
* Make the header in the new a.out from the header in the old one
* modified by the new data size.
*/
make_hdr(new, a_out)
FILE *new, *a_out;
{
int i;
/* sym_top points to the beginning of the line#/sym/str data */
/*
* read file header from a.out
*/
if (fread(&fhdr, sizeof fhdr, 1, a_out) != 1)
{
perror("Couldn't read file header from a.out file");
exit(1);
}
/*
* read system header from a.out COFF format
*/
if (fhdr.f_opthdr > 0)
{
if (fread(&ahdr, sizeof ahdr, 1, a_out) != 1)
{
perror("Couldn't read system file header from a.out file");
exit(1);
}
/*
* read section headers from a.out COFF format
*/
nscns = fhdr.f_nscns;
for(i=0;(i != nscns);i++) {
if (fread(&scns[i], sizeof(struct scnhdr), 1, a_out) != 1) {
perror("Couldn't read section headers from a.out file");
exit(1);
}
}
}
/* if N_BADMAG(hdr)
{
fprintf(stderr, "a.out file doesn't have legal magic number\n");
exit(1);
} */
if (ahdr.magic != u.pt_aouthdr.magic ||
ahdr.tsize != u.pt_aouthdr.tsize ||
ahdr.dsize != u.pt_aouthdr.dsize ||
ahdr.entry != u.pt_aouthdr.entry)
{
fprintf(stderr, "Core file didn't come from this a.out\n");
exit(1);
}
printf("Data segment size was %u", ahdr.dsize);
ahdr.dsize = u.pt_dsize;
ahdr.bsize = 0; /* all data is inited now! */
printf(" now is %u\n", ahdr.dsize);
/*
* point to top of old line#/symbol/string info if there is any so
* we can find it later...
*/
sym_top = 0;
if (scns[0].s_nlnno != 0)
sym_top = scns[0].s_lnnoptr;
else if (fhdr.f_nsyms != 0)
sym_top = fhdr.f_symptr;
scns[1].s_size = u.pt_dsize;
scns[2].s_size = 0;
scns[2].s_vaddr = 0;
scns[2].s_paddr = 0;
cur_pos = scns[1].s_scnptr + scns[1].s_size;
if (scns[0].s_nlnno != 0) {
scns[0].s_lnnoptr = cur_pos;
cur_pos += scns[0].s_nlnno * sizeof(struct lineno);
}
if (fhdr.f_nsyms != 0) {
fhdr.f_symptr = cur_pos;
}
if (fwrite(&fhdr, sizeof fhdr, 1, new) != 1)
{
perror("Couldn't write file header to new a.out file");
exit(1);
}
if (fhdr.f_opthdr > 0)
{
if (fwrite(&ahdr, sizeof ahdr, 1, new) != 1)
{
perror("Couldn't write system file header to new a.out file");
exit(1);
}
for(i=0;(i != nscns);i++) {
if (fwrite(&scns[i], sizeof(struct scnhdr), 1, new) != 1) {
perror("Couldn't write section headers to new a.out file");
exit(1);
}
}
}
}
/*
* Copy the text from the a.out to the new a.out
*/
copy_text(new, a_out)
FILE *new, *a_out;
{
char page[PSIZE];
int txtcnt;
txtcnt = ahdr.tsize;
fseek(new, scns[0].s_scnptr, 0);
fseek(a_out, scns[0].s_scnptr, 0);
/* if (hdr.a_magic == OMAGIC)
{
printf("a.out file is not shared text, getting text from core file\n");
fseek(a_out, hdr.a_text, 1); * skip over text *
return;
} */
while (txtcnt >= PSIZE)
{
if (fread(page, PSIZE, 1, a_out) != 1)
{
perror("Read failure on a.out text");
exit(1);
}
if (fwrite(page, PSIZE, 1, new) != 1)
{
perror("Write failure in text segment");
exit(1);
}
txtcnt -= PSIZE;
}
if (txtcnt)
{
if (fread(page, txtcnt, 1, a_out) != 1)
{
perror("Read failure on a.out text");
exit(1);
}
if (fwrite(page, txtcnt, 1, new) != 1)
{
perror("Write failure in text segment");
exit(1);
}
}
}
/*
* copy the data from the core file to the new a.out
*/
copy_data(new, core)
FILE *new, *core;
{
char page[PSIZE];
int datacnt;
datacnt = u.pt_dsize;
/* if (hdr.a_magic == OMAGIC)
datacnt += u.u_tsize; */
fseek(core,(long) sizeof(struct ptrace_user), 0);
fseek(new, scns[1].s_scnptr, 0);
while (datacnt >= PSIZE)
{
if (fread(page, PSIZE, 1, core) != 1)
{
perror("Read failure on core data");
exit(1);
}
if (fwrite(page, PSIZE, 1, new) != 1)
{
perror("Write failure in data segment");
exit(1);
}
datacnt -= PSIZE;
}
if (datacnt)
{
if (fread(page, datacnt, 1, core) != 1)
{
perror("Read failure on core data");
exit(1);
}
if (fwrite(page, datacnt, 1, new) != 1)
{
perror("Write failure in data segment");
exit(1);
}
}
}
/*
* Copy the relocation information and symbol table from the a.out to the new
*/
copy_sym(new, a_out)
FILE *new, *a_out;
{
char page[PSIZE];
int n;
fseek(a_out, sym_top, 0); /* skip over data segment */
while ((n = fread(page, 1, PSIZE, a_out)) > 0)
{
if (fwrite(page, 1, n, new) != n)
{
perror("Error writing symbol table to new a.out");
fprintf(stderr, "new a.out should be ok otherwise\n");
return;
}
}
if (n < 0)
{
perror("Error reading symbol table from a.out");
fprintf(stderr, "new a.out should be ok otherwise\n");
}
}
/*
* After succesfully building the new a.out, mark it executable
*/
mark_x(name)
char *name;
{
struct stat sbuf;
int um;
um = umask(777);
umask(um);
if (stat(name, &sbuf) == -1)
{
perror ("Can't stat new a.out");
fprintf(stderr, "Setting protection to %o\n", 0777 & ~um);
sbuf.st_mode = 0777;
}
sbuf.st_mode |= 0111 & ~um;
if (chmod(name, sbuf.st_mode) == -1)
perror("Couldn't change mode of new a.out to executable");
}