+/* Unexec for Sunos 4 using shared libraries.
+ Copyright (C) 1990, 1994, 1999, 2002, 2003, 2004,
+ 2005, 2006 Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+GNU Emacs is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Emacs is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Emacs; see the file COPYING. If not, write to
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA. */
+
/* Contributed by Viktor Dukhovni. */
/*
* Unexec for Berkeley a.out format + SUNOS shared libraries
* is somewhat abused here) is loaded first!
*
*/
+
#ifdef emacs
#include <config.h>
#endif
#include <stdio.h>
#include <a.out.h>
+#if defined (SUNOS4) || defined (__FreeBSD__) || defined (__NetBSD__)
+#define UNDO_RELOCATION
+#endif
+
+#ifdef UNDO_RELOCATION
+#include <link.h>
+#endif
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
/* NetBSD needs this bit, but SunOS does not have it. */
#ifndef MAP_FILE
#define MAP_FILE 0
#endif
extern char *getenv ();
-static unsigned Brk;
+static unsigned brk_value;
static struct exec nhdr;
static int rd_only_len;
static long cookie;
-unexec (new_name, a_name, bndry, bss_start, entry)
+unexec (new_name, a_name, bndry, bss_start, entry)
char *new_name, *a_name;
unsigned bndry, bss_start, entry;
{
struct exec ohdr; /* Allocate on the stack, not needed in the next life */
struct stat stat;
-#ifdef emacs
- fprintf (stderr, "Used %d bytes of Pure Storage\n", pureptr);
-#endif
-
if ((fd = open (a_name, O_RDONLY)) < 0)
{
fprintf (stderr, "%s: open: ", a_name);
*/
cookie = time (0);
- Brk = sbrk (0); /* Save the break, it is reset to &_end (by ld.so?) */
+ /* Save the break, it is reset to &_end (by ld.so?). */
+ brk_value = (unsigned) sbrk (0);
/*
* Round up data start to a page boundary (Lose if not a 2 power!)
/* Have to do this some time before dumping the data */
initialized = 1;
#endif
-
- /*
- * Handle new data and bss sizes and optional new entry point.
- * No one actually uses bss_start and entry, but tradition compels
- * one to support them.
- * Could complain if bss_start > Brk, but the caller is *supposed* to know
- * what she is doing.
- */
- nhdr.a_data = (bss_start ? bss_start : Brk) - N_DATADDR (nhdr);
- nhdr.a_bss = bss_start ? Brk - bss_start : 0;
- if (entry)
+
+ /* Handle new data and bss sizes and optional new entry point.
+ No one actually uses bss_start and entry, but tradition compels
+ one to support them.
+ Could complain if bss_start > brk_value,
+ but the caller is *supposed* to know what she is doing. */
+ nhdr.a_data = (bss_start ? bss_start : brk_value) - N_DATADDR (nhdr);
+ nhdr.a_bss = bss_start ? brk_value - bss_start : 0;
+ if (entry)
nhdr.a_entry = entry;
/*
lseek (new, N_TRELOFF (nhdr), L_SET);
write (new, old + N_TRELOFF (ohdr), stat.st_size - N_TRELOFF (ohdr));
+ /* Some other BSD systems use this file.
+ We don't know whether this change is right for them. */
+#ifdef UNDO_RELOCATION
+ /* Undo the relocations done at startup by ld.so.
+ It will do these relocations again when we start the dumped Emacs.
+ Doing them twice gives incorrect results. */
+ {
+ unsigned long daddr = N_DATADDR (ohdr);
+ unsigned long rel, erel;
+#ifdef SUNOS4
+#ifdef SUNOS4_SHARED_LIBRARIES
+ extern struct link_dynamic _DYNAMIC;
+
+ /* SunOS4.x's ld_rel is relative to N_TXTADDR. */
+ if (!ohdr.a_dynamic)
+ /* This was statically linked. */
+ rel = erel = 0;
+ else if (_DYNAMIC.ld_version < 2)
+ {
+ rel = _DYNAMIC.ld_un.ld_1->ld_rel + N_TXTADDR (ohdr);
+ erel = _DYNAMIC.ld_un.ld_1->ld_hash + N_TXTADDR (ohdr);
+ }
+ else
+ {
+ rel = _DYNAMIC.ld_un.ld_2->ld_rel + N_TXTADDR (ohdr);
+ erel = _DYNAMIC.ld_un.ld_2->ld_hash + N_TXTADDR (ohdr);
+ }
+#else /* not SUNOS4_SHARED_LIBRARIES */
+ rel = erel = 0;
+#endif /* not SUNOS4_SHARED_LIBRARIES */
+#ifdef sparc
+#define REL_INFO_TYPE struct reloc_info_sparc
+#else
+#define REL_INFO_TYPE struct relocation_info
+#endif /* sparc */
+#define REL_TARGET_ADDRESS(r) (((REL_INFO_TYPE *)(r))->r_address)
+#endif /* SUNOS4 */
+#if defined (__FreeBSD__) || defined (__NetBSD__)
+ extern struct _dynamic _DYNAMIC;
+
+ /* FreeBSD's LD_REL is a virtual address itself. */
+ rel = LD_REL (&_DYNAMIC);
+ erel = rel + LD_RELSZ (&_DYNAMIC);
+#define REL_INFO_TYPE struct relocation_info
+#define REL_TARGET_ADDRESS(r) (((REL_INFO_TYPE *)(r))->r_address)
+#endif
+
+ for (; rel < erel; rel += sizeof (REL_INFO_TYPE))
+ {
+ /* This is the virtual address where ld.so will do relocation. */
+ unsigned long target = REL_TARGET_ADDRESS (rel);
+ /* This is the offset in the data segment. */
+ unsigned long segoffset = target - daddr;
+
+ /* If it is located below data_start, we have to do nothing here,
+ because the old data has been already written to the location. */
+ if (target < (unsigned long)&data_start)
+ continue;
+
+ lseek (new, N_DATOFF (nhdr) + segoffset, L_SET);
+ write (new, old + N_DATOFF (ohdr) + segoffset, sizeof (unsigned long));
+ }
+ }
+#endif /* UNDO_RELOCATION */
+
fchmod (new, 0755);
}
return;
/* Restore the break */
- brk (Brk);
+ brk ((char *) brk_value);
/* If nothing to remap: we are done! */
if (rd_only_len == 0)
* First try argv[0], will almost always succeed as shells tend to give
* the full path from the hash list rather than using execvp ()
*/
- if (is_it (progname))
+ if (is_it (progname))
return;
/*
* If argv[0] is a full path and does not exist, not much sense in
* searching further
*/
- if (strchr (progname, '/'))
+ if (strchr (progname, '/'))
return;
/*
}
}
-is_it (path)
- char *path;
+is_it (filename)
+ char *filename;
{
int fd;
- long paths_cookie;
+ long filenames_cookie;
struct exec hdr;
/*
* Open an executable and check for a valid header!
- * Can't bcmp() the header with what we had, it may have been stripped!
+ * Can't bcmp the header with what we had, it may have been stripped!
* so we may save looking at non executables with the same name, mostly
* directories.
*/
- fd = open (path, O_RDONLY);
+ fd = open (filename, O_RDONLY);
if (fd != -1)
{
if (read (fd, &hdr, sizeof (hdr)) == sizeof (hdr)
{
/* compare cookies */
lseek (fd, N_DATOFF (hdr) + (int)&cookie - N_DATADDR (hdr), L_SET);
- read (fd, &paths_cookie, sizeof (paths_cookie));
- if (paths_cookie == cookie)
+ read (fd, &filenames_cookie, sizeof (filenames_cookie));
+ if (filenames_cookie == cookie)
{ /* Eureka */
/*
* should the shared library decide to indirect through
* addresses in the data segment not part of __DYNAMIC
*/
- mmap (data_start, rd_only_len, PROT_READ | PROT_EXEC,
+ mmap ((char *) data_start, rd_only_len, PROT_READ | PROT_EXEC,
MAP_FILE | MAP_SHARED | MAP_FIXED, fd,
N_DATOFF (hdr) + data_start - N_DATADDR (hdr));
close (fd);
}
return 0;
}
+
+/* arch-tag: 30227420-2c6f-4700-a4f8-9e45e52f53b1
+ (do not change this comment) */