Initial revision

1 files changed, 952 insertions, 0 deletions

diff --git a/src/unexelf1.c b/src/unexelf1.c
new file mode 100644
index 00000000000..a832755167e
--- /dev/null
+++ b/src/unexelf1.c
@@ -0,0 +1,952 @@
+/* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992
+   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., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.
+
+In other words, you are welcome to use, share and improve this program.
+You are forbidden to forbid anyone else to use, share and improve
+what you give them.   Help stamp out software-hoarding!  */
+
+
+/*
+ * unexec.c - Convert a running program into an a.out file.
+ *
+ * Author:	Spencer W. Thomas
+ * 		Computer Science Dept.
+ * 		University of Utah
+ * Date:	Tue Mar  2 1982
+ * Modified heavily since then.
+ *
+ * Synopsis:
+ *	unexec (new_name, a_name, data_start, bss_start, entry_address)
+ *	char *new_name, *a_name;
+ *	unsigned data_start, bss_start, entry_address;
+ *
+ * Takes a snapshot of the program and makes an a.out format file in the
+ * file named by the string argument new_name.
+ * If a_name is non-NULL, the symbol table will be taken from the given file.
+ * On some machines, an existing a_name file is required.
+ *
+ * The boundaries within the a.out file may be adjusted with the data_start
+ * and bss_start arguments.  Either or both may be given as 0 for defaults.
+ *
+ * Data_start gives the boundary between the text segment and the data
+ * segment of the program.  The text segment can contain shared, read-only
+ * program code and literal data, while the data segment is always unshared
+ * and unprotected.  Data_start gives the lowest unprotected address.
+ * The value you specify may be rounded down to a suitable boundary
+ * as required by the machine you are using.
+ *
+ * Specifying zero for data_start means the boundary between text and data
+ * should not be the same as when the program was loaded.
+ * If NO_REMAP is defined, the argument data_start is ignored and the
+ * segment boundaries are never changed.
+ *
+ * Bss_start indicates how much of the data segment is to be saved in the
+ * a.out file and restored when the program is executed.  It gives the lowest
+ * unsaved address, and is rounded up to a page boundary.  The default when 0
+ * is given assumes that the entire data segment is to be stored, including
+ * the previous data and bss as well as any additional storage allocated with
+ * break (2).
+ *
+ * The new file is set up to start at entry_address.
+ *
+ * If you make improvements I'd like to get them too.
+ * harpo!utah-cs!thomas, thomas@Utah-20
+ *
+ */
+
+/* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
+ * ELF support added.
+ *
+ * Basic theory: the data space of the running process needs to be
+ * dumped to the output file.  Normally we would just enlarge the size
+ * of .data, scooting everything down.  But we can't do that in ELF,
+ * because there is often something between the .data space and the
+ * .bss space.
+ *
+ * In the temacs dump below, notice that the Global Offset Table
+ * (.got) and the Dynamic link data (.dynamic) come between .data1 and
+ * .bss.  It does not work to overlap .data with these fields.
+ *
+ * The solution is to create a new .data segment.  This segment is
+ * filled with data from the current process.  Since the contents of
+ * various sections refer to sections by index, the new .data segment
+ * is made the last in the table to avoid changing any existing index.
+
+ * This is an example of how the section headers are changed.  "Addr"
+ * is a process virtual address.  "Offset" is a file offset.
+
+raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
+
+temacs:
+
+           **** SECTION HEADER TABLE ****
+[No]    Type    Flags   Addr         Offset       Size          Name
+        Link    Info    Adralgn      Entsize
+
+[1]     1       2       0x80480d4    0xd4         0x13          .interp
+        0       0       0x1          0
+
+[2]     5       2       0x80480e8    0xe8         0x388         .hash
+        3       0       0x4          0x4
+
+[3]     11      2       0x8048470    0x470        0x7f0         .dynsym
+        4       1       0x4          0x10
+
+[4]     3       2       0x8048c60    0xc60        0x3ad         .dynstr
+        0       0       0x1          0
+
+[5]     9       2       0x8049010    0x1010       0x338         .rel.plt
+        3       7       0x4          0x8
+
+[6]     1       6       0x8049348    0x1348       0x3           .init
+        0       0       0x4          0
+
+[7]     1       6       0x804934c    0x134c       0x680         .plt
+        0       0       0x4          0x4
+
+[8]     1       6       0x80499cc    0x19cc       0x3c56f       .text
+        0       0       0x4          0
+
+[9]     1       6       0x8085f3c    0x3df3c      0x3           .fini
+        0       0       0x4          0
+
+[10]    1       2       0x8085f40    0x3df40      0x69c         .rodata
+        0       0       0x4          0
+
+[11]    1       2       0x80865dc    0x3e5dc      0xd51         .rodata1
+        0       0       0x4          0
+
+[12]    1       3       0x8088330    0x3f330      0x20afc       .data
+        0       0       0x4          0
+
+[13]    1       3       0x80a8e2c    0x5fe2c      0x89d         .data1
+        0       0       0x4          0
+
+[14]    1       3       0x80a96cc    0x606cc      0x1a8         .got
+        0       0       0x4          0x4
+
+[15]    6       3       0x80a9874    0x60874      0x80          .dynamic
+        4       0       0x4          0x8
+
+[16]    8       3       0x80a98f4    0x608f4      0x449c        .bss
+        0       0       0x4          0
+
+[17]    2       0       0            0x608f4      0x9b90        .symtab
+        18      371     0x4          0x10
+
+[18]    3       0       0            0x6a484      0x8526        .strtab
+        0       0       0x1          0
+
+[19]    3       0       0            0x729aa      0x93          .shstrtab
+        0       0       0x1          0
+
+[20]    1       0       0            0x72a3d      0x68b7        .comment
+        0       0       0x1          0
+
+raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
+
+xemacs:
+
+           **** SECTION HEADER TABLE ****
+[No]    Type    Flags   Addr         Offset       Size          Name
+        Link    Info    Adralgn      Entsize
+
+[1]     1       2       0x80480d4    0xd4         0x13          .interp
+        0       0       0x1          0
+
+[2]     5       2       0x80480e8    0xe8         0x388         .hash
+        3       0       0x4          0x4
+
+[3]     11      2       0x8048470    0x470        0x7f0         .dynsym
+        4       1       0x4          0x10
+
+[4]     3       2       0x8048c60    0xc60        0x3ad         .dynstr
+        0       0       0x1          0
+
+[5]     9       2       0x8049010    0x1010       0x338         .rel.plt
+        3       7       0x4          0x8
+
+[6]     1       6       0x8049348    0x1348       0x3           .init
+        0       0       0x4          0
+
+[7]     1       6       0x804934c    0x134c       0x680         .plt
+        0       0       0x4          0x4
+
+[8]     1       6       0x80499cc    0x19cc       0x3c56f       .text
+        0       0       0x4          0
+
+[9]     1       6       0x8085f3c    0x3df3c      0x3           .fini
+        0       0       0x4          0
+
+[10]    1       2       0x8085f40    0x3df40      0x69c         .rodata
+        0       0       0x4          0
+
+[11]    1       2       0x80865dc    0x3e5dc      0xd51         .rodata1
+        0       0       0x4          0
+
+[12]    1       3       0x8088330    0x3f330      0x20afc       .data
+        0       0       0x4          0
+
+[13]    1       3       0x80a8e2c    0x5fe2c      0x89d         .data1
+        0       0       0x4          0
+
+[14]    1       3       0x80a96cc    0x606cc      0x1a8         .got
+        0       0       0x4          0x4
+
+[15]    6       3       0x80a9874    0x60874      0x80          .dynamic
+        4       0       0x4          0x8
+
+[16]    8       3       0x80c6800    0x7d800      0             .bss
+        0       0       0x4          0
+
+[17]    2       0       0            0x7d800      0x9b90        .symtab
+        18      371     0x4          0x10
+
+[18]    3       0       0            0x87390      0x8526        .strtab
+        0       0       0x1          0
+
+[19]    3       0       0            0x8f8b6      0x93          .shstrtab
+        0       0       0x1          0
+
+[20]    1       0       0            0x8f949      0x68b7        .comment
+        0       0       0x1          0
+
+[21]    1       3       0x80a98f4    0x608f4      0x1cf0c       .data
+        0       0       0x4          0
+
+ * This is an example of how the file header is changed.  "Shoff" is
+ * the section header offset within the file.  Since that table is
+ * after the new .data section, it is moved.  "Shnum" is the number of
+ * sections, which we increment.
+ *
+ * "Phoff" is the file offset to the program header.  "Phentsize" and
+ * "Shentsz" are the program and section header entries sizes respectively.
+ * These can be larger than the apparent struct sizes.
+
+raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
+
+temacs:
+
+                    **** ELF HEADER ****
+Class        Data       Type         Machine     Version
+Entry        Phoff      Shoff        Flags       Ehsize
+Phentsize    Phnum      Shentsz      Shnum       Shstrndx
+
+1            1          2            3           1
+0x80499cc    0x34       0x792f4      0           0x34
+0x20         5          0x28         21          19
+
+raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
+
+xemacs:
+
+                    **** ELF HEADER ****
+Class        Data       Type         Machine     Version
+Entry        Phoff      Shoff        Flags       Ehsize
+Phentsize    Phnum      Shentsz      Shnum       Shstrndx
+
+1            1          2            3           1
+0x80499cc    0x34       0x96200      0           0x34
+0x20         5          0x28         22          19
+
+ * These are the program headers.  "Offset" is the file offset to the
+ * segment.  "Vaddr" is the memory load address.  "Filesz" is the
+ * segment size as it appears in the file, and "Memsz" is the size in
+ * memory.  Below, the third segment is the code and the fourth is the
+ * data: the difference between Filesz and Memsz is .bss
+
+raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
+
+temacs:
+ ***** PROGRAM EXECUTION HEADER *****
+Type        Offset      Vaddr       Paddr
+Filesz      Memsz       Flags       Align
+
+6           0x34        0x8048034   0
+0xa0        0xa0        5           0
+
+3           0xd4        0           0
+0x13        0           4           0
+
+1           0x34        0x8048034   0
+0x3f2f9     0x3f2f9     5           0x1000
+
+1           0x3f330     0x8088330   0
+0x215c4     0x25a60     7           0x1000
+
+2           0x60874     0x80a9874   0
+0x80        0           7           0
+
+raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
+
+xemacs:
+ ***** PROGRAM EXECUTION HEADER *****
+Type        Offset      Vaddr       Paddr
+Filesz      Memsz       Flags       Align
+
+6           0x34        0x8048034   0
+0xa0        0xa0        5           0
+
+3           0xd4        0           0
+0x13        0           4           0
+
+1           0x34        0x8048034   0
+0x3f2f9     0x3f2f9     5           0x1000
+
+1           0x3f330     0x8088330   0
+0x3e4d0     0x3e4d0     7           0x1000
+
+2           0x60874     0x80a9874   0
+0x80        0           7           0
+
+
+ */
+
+/* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
+ *
+ * The above mechanism does not work if the unexeced ELF file is being
+ * re-layout by other applications (such as `strip'). All the applications
+ * that re-layout the internal of ELF will layout all sections in ascending
+ * order of their file offsets. After the re-layout, the data2 section will
+ * still be the LAST section in the section header vector, but its file offset
+ * is now being pushed far away down, and causes part of it not to be mapped
+ * in (ie. not covered by the load segment entry in PHDR vector), therefore
+ * causes the new binary to fail.
+ *
+ * The solution is to modify the unexec algorithm to insert the new data2
+ * section header right before the new bss section header, so their file
+ * offsets will be in the ascending order. Since some of the section's (all
+ * sections AFTER the bss section) indexes are now changed, we also need to
+ * modify some fields to make them point to the right sections. This is done
+ * by macro PATCH_INDEX. All the fields that need to be patched are:
+ *
+ * 1. ELF header e_shstrndx field.
+ * 2. section header sh_link and sh_info field.
+ * 3. symbol table entry st_shndx field.
+ *
+ * The above example now should look like:
+
+           **** SECTION HEADER TABLE ****
+[No]    Type    Flags   Addr         Offset       Size          Name
+        Link    Info    Adralgn      Entsize
+
+[1]     1       2       0x80480d4    0xd4         0x13          .interp
+        0       0       0x1          0
+
+[2]     5       2       0x80480e8    0xe8         0x388         .hash
+        3       0       0x4          0x4
+
+[3]     11      2       0x8048470    0x470        0x7f0         .dynsym
+        4       1       0x4          0x10
+
+[4]     3       2       0x8048c60    0xc60        0x3ad         .dynstr
+        0       0       0x1          0
+
+[5]     9       2       0x8049010    0x1010       0x338         .rel.plt
+        3       7       0x4          0x8
+
+[6]     1       6       0x8049348    0x1348       0x3           .init
+        0       0       0x4          0
+
+[7]     1       6       0x804934c    0x134c       0x680         .plt
+        0       0       0x4          0x4
+
+[8]     1       6       0x80499cc    0x19cc       0x3c56f       .text
+        0       0       0x4          0
+
+[9]     1       6       0x8085f3c    0x3df3c      0x3           .fini
+        0       0       0x4          0
+
+[10]    1       2       0x8085f40    0x3df40      0x69c         .rodata
+        0       0       0x4          0
+
+[11]    1       2       0x80865dc    0x3e5dc      0xd51         .rodata1
+        0       0       0x4          0
+
+[12]    1       3       0x8088330    0x3f330      0x20afc       .data
+        0       0       0x4          0
+
+[13]    1       3       0x80a8e2c    0x5fe2c      0x89d         .data1
+        0       0       0x4          0
+
+[14]    1       3       0x80a96cc    0x606cc      0x1a8         .got
+        0       0       0x4          0x4
+
+[15]    6       3       0x80a9874    0x60874      0x80          .dynamic
+        4       0       0x4          0x8
+
+[16]    1       3       0x80a98f4    0x608f4      0x1cf0c       .data
+        0       0       0x4          0
+
+[17]    8       3       0x80c6800    0x7d800      0             .bss
+        0       0       0x4          0
+
+[18]    2       0       0            0x7d800      0x9b90        .symtab
+        19      371     0x4          0x10
+
+[19]    3       0       0            0x87390      0x8526        .strtab
+        0       0       0x1          0
+
+[20]    3       0       0            0x8f8b6      0x93          .shstrtab
+        0       0       0x1          0
+
+[21]    1       0       0            0x8f949      0x68b7        .comment
+        0       0       0x1          0
+
+ */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <memory.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <elf.h>
+#include <sys/mman.h>
+
+#ifdef __alpha__
+# include <sym.h>	/* get COFF debugging symbol table declaration */
+#endif
+
+#if __GNU_LIBRARY__ - 0 >= 6
+# include <link.h>	/* get ElfW etc */
+#endif
+
+#ifndef ElfW
+# ifdef __STDC__
+#  define ElfW(type)	Elf32_##type
+# else
+#  define ElfW(type)	Elf32_/**/type
+# endif
+#endif
+
+#ifndef emacs
+#define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
+#else
+#include <config.h>
+extern void fatal (char *, ...);
+#endif
+
+#ifndef ELF_BSS_SECTION_NAME
+#define ELF_BSS_SECTION_NAME ".bss"
+#endif
+
+/* Get the address of a particular section or program header entry,
+ * accounting for the size of the entries.
+ */
+/* 
+   On PPC Reference Platform running Solaris 2.5.1
+   the plt section is also of type NOBI like the bss section.
+   (not really stored) and therefore sections after the bss
+   section start at the plt offset. The plt section is always
+   the one just before the bss section.
+   Thus, we modify the test from
+      if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset)
+   to
+      if (NEW_SECTION_H (nn).sh_offset >= 
+               OLD_SECTION_H (old_bss_index-1).sh_offset)
+   This is just a hack. We should put the new data section
+   before the .plt section.
+   And we should not have this routine at all but use
+   the libelf library to read the old file and create the new
+   file.
+   The changed code is minimal and depends on prep set in m/prep.h
+   Erik Deumens
+   Quantum Theory Project
+   University of Florida
+   deumens@qtp.ufl.edu
+   Apr 23, 1996
+   */
+
+#define OLD_SECTION_H(n) \
+     (*(ElfW(Shdr) *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
+#define NEW_SECTION_H(n) \
+     (*(ElfW(Shdr) *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
+#define OLD_PROGRAM_H(n) \
+     (*(ElfW(Phdr) *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
+#define NEW_PROGRAM_H(n) \
+     (*(ElfW(Phdr) *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
+
+#define PATCH_INDEX(n) \
+  do { \
+	 if ((int) (n) >= old_bss_index) \
+	   (n)++; } while (0)
+typedef unsigned char byte;
+
+/* Round X up to a multiple of Y.  */
+
+int
+round_up (x, y)
+     int x, y;
+{
+  int rem = x % y;
+  if (rem == 0)
+    return x;
+  return x - rem + y;
+}
+
+/* ****************************************************************
+ * unexec
+ *
+ * driving logic.
+ *
+ * In ELF, this works by replacing the old .bss section with a new
+ * .data section, and inserting an empty .bss immediately afterwards.
+ *
+ */
+void
+unexec (new_name, old_name, data_start, bss_start, entry_address)
+     char *new_name, *old_name;
+     unsigned data_start, bss_start, entry_address;
+{
+  int new_file, old_file, new_file_size;
+
+  /* Pointers to the base of the image of the two files. */
+  caddr_t old_base, new_base;
+
+  /* Pointers to the file, program and section headers for the old and new
+   * files.
+   */
+  ElfW(Ehdr) *old_file_h, *new_file_h;
+  ElfW(Phdr) *old_program_h, *new_program_h;
+  ElfW(Shdr) *old_section_h, *new_section_h;
+
+  /* Point to the section name table in the old file */
+  char *old_section_names;
+
+  ElfW(Addr) old_bss_addr, new_bss_addr;
+  ElfW(Word) old_bss_size, new_data2_size;
+  ElfW(Off)  new_data2_offset;
+  ElfW(Addr) new_data2_addr;
+
+  int n, nn, old_bss_index, old_data_index, new_data2_index;
+  struct stat stat_buf;
+
+  /* Open the old file & map it into the address space. */
+
+  old_file = open (old_name, O_RDONLY);
+
+  if (old_file < 0)
+    fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
+
+  if (fstat (old_file, &stat_buf) == -1)
+    fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
+
+  old_base = mmap (0, stat_buf.st_size, PROT_READ, MAP_SHARED, old_file, 0);
+
+  if (old_base == (caddr_t) -1)
+    fatal ("Can't mmap (%s): errno %d\n", old_name, errno);
+
+#ifdef DEBUG
+  fprintf (stderr, "mmap (%s, %x) -> %x\n", old_name, stat_buf.st_size,
+	   old_base);
+#endif
+
+  /* Get pointers to headers & section names */
+
+  old_file_h = (ElfW(Ehdr) *) old_base;
+  old_program_h = (ElfW(Phdr) *) ((byte *) old_base + old_file_h->e_phoff);
+  old_section_h = (ElfW(Shdr) *) ((byte *) old_base + old_file_h->e_shoff);
+  old_section_names = (char *) old_base
+    + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset;
+
+  /* Find the old .bss section.  Figure out parameters of the new
+   * data2 and bss sections.
+   */
+
+  for (old_bss_index = 1; old_bss_index < (int) old_file_h->e_shnum;
+       old_bss_index++)
+    {
+#ifdef DEBUG
+      fprintf (stderr, "Looking for .bss - found %s\n",
+	       old_section_names + OLD_SECTION_H (old_bss_index).sh_name);
+#endif
+      if (!strcmp (old_section_names + OLD_SECTION_H (old_bss_index).sh_name,
+		   ELF_BSS_SECTION_NAME))
+	break;
+    }
+  if (old_bss_index == old_file_h->e_shnum)
+    fatal ("Can't find .bss in %s.\n", old_name, 0);
+
+  old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
+  old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
+#if defined(emacs) || !defined(DEBUG)
+  new_bss_addr = (ElfW(Addr)) sbrk (0);
+#else
+  new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
+#endif
+  new_data2_addr = old_bss_addr;
+  new_data2_size = new_bss_addr - old_bss_addr;
+  new_data2_offset = OLD_SECTION_H (old_bss_index).sh_offset;
+
+#ifdef DEBUG
+  fprintf (stderr, "old_bss_index %d\n", old_bss_index);
+  fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
+  fprintf (stderr, "old_bss_size %x\n", old_bss_size);
+  fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
+  fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
+  fprintf (stderr, "new_data2_size %x\n", new_data2_size);
+  fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
+#endif
+
+  if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
+    fatal (".bss shrank when undumping???\n", 0, 0);
+
+  /* Set the output file to the right size and mmap it.  Set
+   * pointers to various interesting objects.  stat_buf still has
+   * old_file data.
+   */
+
+  new_file = open (new_name, O_RDWR | O_CREAT, 0666);
+  if (new_file < 0)
+    fatal ("Can't creat (%s): errno %d\n", new_name, errno);
+
+  new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size;
+
+  if (ftruncate (new_file, new_file_size))
+    fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
+
+#ifdef UNEXEC_USE_MAP_PRIVATE
+  new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
+		   new_file, 0);
+#else
+  new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_SHARED,
+		   new_file, 0);
+#endif
+
+  if (new_base == (caddr_t) -1)
+    fatal ("Can't mmap (%s): errno %d\n", new_name, errno);
+
+  new_file_h = (ElfW(Ehdr) *) new_base;
+  new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
+  new_section_h = (ElfW(Shdr) *)
+    ((byte *) new_base + old_file_h->e_shoff + new_data2_size);
+
+  /* Make our new file, program and section headers as copies of the
+   * originals.
+   */
+
+  memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
+  memcpy (new_program_h, old_program_h,
+	  old_file_h->e_phnum * old_file_h->e_phentsize);
+
+  /* Modify the e_shstrndx if necessary. */
+  PATCH_INDEX (new_file_h->e_shstrndx);
+
+  /* Fix up file header.  We'll add one section.  Section header is
+   * further away now.
+   */
+
+  new_file_h->e_shoff += new_data2_size;
+  new_file_h->e_shnum += 1;
+
+#ifdef DEBUG
+  fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
+  fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
+  fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
+  fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
+#endif
+
+  /* Fix up a new program header.  Extend the writable data segment so
+   * that the bss area is covered too. Find that segment by looking
+   * for a segment that ends just before the .bss area.  Make sure
+   * that no segments are above the new .data2.  Put a loop at the end
+   * to adjust the offset and address of any segment that is above
+   * data2, just in case we decide to allow this later.
+   */
+
+  for (n = new_file_h->e_phnum - 1; n >= 0; n--)
+    {
+      /* Compute maximum of all requirements for alignment of section.  */
+      int alignment = (NEW_PROGRAM_H (n)).p_align;
+      if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment)
+	alignment = OLD_SECTION_H (old_bss_index).sh_addralign;
+
+      if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz > old_bss_addr)
+	fatal ("Program segment above .bss in %s\n", old_name, 0);
+
+      if (NEW_PROGRAM_H (n).p_type == PT_LOAD
+	  && (round_up ((NEW_PROGRAM_H (n)).p_vaddr
+			+ (NEW_PROGRAM_H (n)).p_filesz,
+			alignment)
+	      == round_up (old_bss_addr, alignment)))
+	break;
+    }
+  if (n < 0)
+    fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
+
+  NEW_PROGRAM_H (n).p_filesz += new_data2_size;
+  NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz;
+
+#if 0 /* Maybe allow section after data2 - does this ever happen? */
+  for (n = new_file_h->e_phnum - 1; n >= 0; n--)
+    {
+      if (NEW_PROGRAM_H (n).p_vaddr
+	  && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr)
+	NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size;
+
+      if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset)
+	NEW_PROGRAM_H (n).p_offset += new_data2_size;
+    }
+#endif
+
+  /* Fix up section headers based on new .data2 section.  Any section
+   * whose offset or virtual address is after the new .data2 section
+   * gets its value adjusted.  .bss size becomes zero and new address
+   * is set.  data2 section header gets added by copying the existing
+   * .data header and modifying the offset, address and size.
+   */
+  for (old_data_index = 1; old_data_index < (int) old_file_h->e_shnum;
+       old_data_index++)
+    if (!strcmp (old_section_names + OLD_SECTION_H (old_data_index).sh_name,
+		 ".data"))
+      break;
+  if (old_data_index == old_file_h->e_shnum)
+    fatal ("Can't find .data in %s.\n", old_name, 0);
+
+  /* Walk through all section headers, insert the new data2 section right
+     before the new bss section. */
+  for (n = 1, nn = 1; n < (int) old_file_h->e_shnum; n++, nn++)
+    {
+      caddr_t src;
+      /* If it is bss section, insert the new data2 section before it. */
+      if (n == old_bss_index)
+	{
+	  /* Steal the data section header for this data2 section. */
+	  memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index),
+		  new_file_h->e_shentsize);
+
+	  NEW_SECTION_H (nn).sh_addr = new_data2_addr;
+	  NEW_SECTION_H (nn).sh_offset = new_data2_offset;
+	  NEW_SECTION_H (nn).sh_size = new_data2_size;
+	  /* Use the bss section's alignment. This will assure that the
+	     new data2 section always be placed in the same spot as the old
+	     bss section by any other application. */
+	  NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign;
+
+	  /* Now copy over what we have in the memory now. */
+	  memcpy (NEW_SECTION_H (nn).sh_offset + new_base,
+		  (caddr_t) OLD_SECTION_H (n).sh_addr,
+		  new_data2_size);
+	  nn++;
+	}
+
+      memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n),
+	      old_file_h->e_shentsize);
+
+      /* The new bss section's size is zero, and its file offset and virtual
+	 address should be off by NEW_DATA2_SIZE. */
+      if (n == old_bss_index)
+	{
+	  /* NN should be `old_bss_index + 1' at this point. */
+	  NEW_SECTION_H (nn).sh_offset += new_data2_size;
+	  NEW_SECTION_H (nn).sh_addr += new_data2_size;
+	  /* Let the new bss section address alignment be the same as the
+	     section address alignment followed the old bss section, so
+	     this section will be placed in exactly the same place. */
+	  NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign;
+	  NEW_SECTION_H (nn).sh_size = 0;
+	}
+      else
+	{
+	  /* Any section that was original placed AFTER the bss
+	     section should now be off by NEW_DATA2_SIZE. */
+#ifdef SOLARIS_POWERPC
+	  /* On PPC Reference Platform running Solaris 2.5.1
+	     the plt section is also of type NOBI like the bss section.
+	     (not really stored) and therefore sections after the bss
+	     section start at the plt offset. The plt section is always
+	     the one just before the bss section.
+	     It would be better to put the new data section before
+	     the .plt section, or use libelf instead.
+	     Erik Deumens, deumens@qtp.ufl.edu.  */
+	  if (NEW_SECTION_H (nn).sh_offset
+	      >= OLD_SECTION_H (old_bss_index-1).sh_offset)
+	    NEW_SECTION_H (nn).sh_offset += new_data2_size;
+#else
+	  if (round_up (NEW_SECTION_H (nn).sh_offset,
+			OLD_SECTION_H (old_bss_index).sh_addralign)
+	      >= new_data2_offset)
+	    NEW_SECTION_H (nn).sh_offset += new_data2_size;
+#endif
+	  /* Any section that was originally placed after the section
+	     header table should now be off by the size of one section
+	     header table entry.  */
+	  if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff)
+	    NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize;
+	}
+
+      /* If any section hdr refers to the section after the new .data
+	 section, make it refer to next one because we have inserted
+	 a new section in between.  */
+
+      PATCH_INDEX (NEW_SECTION_H (nn).sh_link);
+      /* For symbol tables, info is a symbol table index,
+	 so don't change it.  */
+      if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB
+	  && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM)
+	PATCH_INDEX (NEW_SECTION_H (nn).sh_info);
+
+      /* Now, start to copy the content of sections.  */
+      if (NEW_SECTION_H (nn).sh_type == SHT_NULL
+	  || NEW_SECTION_H (nn).sh_type == SHT_NOBITS)
+	continue;
+
+      /* Write out the sections. .data and .data1 (and data2, called
+	 ".data" in the strings table) get copied from the current process
+	 instead of the old file.  */
+      if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
+	  || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name),
+		      ".data1"))
+	src = (caddr_t) OLD_SECTION_H (n).sh_addr;
+      else
+	src = old_base + OLD_SECTION_H (n).sh_offset;
+
+      memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src,
+	      NEW_SECTION_H (nn).sh_size);
+
+#ifdef __alpha__
+      /* Update Alpha COFF symbol table: */
+      if (strcmp (old_section_names + OLD_SECTION_H (n).sh_name, ".mdebug")
+	  == 0)
+	{
+	  pHDRR symhdr = (pHDRR) (NEW_SECTION_H (nn).sh_offset + new_base);
+
+	  symhdr->cbLineOffset += new_data2_size;
+	  symhdr->cbDnOffset += new_data2_size;
+	  symhdr->cbPdOffset += new_data2_size;
+	  symhdr->cbSymOffset += new_data2_size;
+	  symhdr->cbOptOffset += new_data2_size;
+	  symhdr->cbAuxOffset += new_data2_size;
+	  symhdr->cbSsOffset += new_data2_size;
+	  symhdr->cbSsExtOffset += new_data2_size;
+	  symhdr->cbFdOffset += new_data2_size;
+	  symhdr->cbRfdOffset += new_data2_size;
+	  symhdr->cbExtOffset += new_data2_size;
+	}
+#endif /* __alpha__ */
+
+      /* If it is the symbol table, its st_shndx field needs to be patched.  */
+      if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB
+	  || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM)
+	{
+	  ElfW(Shdr) *spt = &NEW_SECTION_H (nn);
+	  unsigned int num = spt->sh_size / spt->sh_entsize;
+	  ElfW(Sym) * sym = (ElfW(Sym) *) (NEW_SECTION_H (nn).sh_offset +
+					   new_base);
+	  for (; num--; sym++)
+	    {
+	      if ((sym->st_shndx == SHN_UNDEF)
+		  || (sym->st_shndx == SHN_ABS)
+		  || (sym->st_shndx == SHN_COMMON))
+		continue;
+
+	      PATCH_INDEX (sym->st_shndx);
+	    }
+	}
+    }
+
+  /* Update the symbol values of _edata and _end.  */
+  for (n = new_file_h->e_shnum - 1; n; n--)
+    {
+      byte *symnames;
+      ElfW(Sym) *symp, *symendp;
+
+      if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM
+	  && NEW_SECTION_H (n).sh_type != SHT_SYMTAB)
+	continue;
+
+      symnames = ((byte *) new_base
+		  + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset);
+      symp = (ElfW(Sym) *) (NEW_SECTION_H (n).sh_offset + new_base);
+      symendp = (ElfW(Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size);
+
+      for (; symp < symendp; symp ++)
+	if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
+	    || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0)
+	  memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
+    }
+
+  /* This loop seeks out relocation sections for the data section, so
+     that it can undo relocations performed by the runtime linker.  */
+  for (n = new_file_h->e_shnum - 1; n; n--)
+    {
+      ElfW(Shdr) section = NEW_SECTION_H (n);
+      switch (section.sh_type) {
+      default:
+	break;
+      case SHT_REL:
+      case SHT_RELA:
+	/* This code handles two different size structs, but there should
+	   be no harm in that provided that r_offset is always the first
+	   member.  */
+	nn = section.sh_info;
+	if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data")
+	    || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name),
+			".data1"))
+	  {
+	    ElfW(Addr) offset = NEW_SECTION_H (nn).sh_addr -
+	      NEW_SECTION_H (nn).sh_offset;
+	    caddr_t reloc = old_base + section.sh_offset, end;
+	    for (end = reloc + section.sh_size; reloc < end;
+		 reloc += section.sh_entsize)
+	      {
+		ElfW(Addr) addr = ((ElfW(Rel) *) reloc)->r_offset - offset;
+#ifdef __alpha__
+		/* The Alpha ELF binutils currently have a bug that
+		   sometimes results in relocs that contain all
+		   zeroes.  Work around this for now...  */
+		if (((ElfW(Rel) *) reloc)->r_offset == 0)
+		    continue;
+#endif
+		memcpy (new_base + addr, old_base + addr, sizeof(ElfW(Addr)));
+	      }
+	  }
+	break;
+      }
+    }
+
+#ifdef UNEXEC_USE_MAP_PRIVATE
+  if (lseek (new_file, 0, SEEK_SET) == -1)
+    fatal ("Can't rewind (%s): errno %d\n", new_name, errno);
+
+  if (write (new_file, new_base, new_file_size) != new_file_size)
+    fatal ("Can't write (%s): errno %d\n", new_name, errno);
+#endif
+
+  /* Close the files and make the new file executable.  */
+
+  if (close (old_file))
+    fatal ("Can't close (%s): errno %d\n", old_name, errno);
+
+  if (close (new_file))
+    fatal ("Can't close (%s): errno %d\n", new_name, errno);
+
+  if (stat (new_name, &stat_buf) == -1)
+    fatal ("Can't stat (%s): errno %d\n", new_name, errno);
+
+  n = umask (777);
+  umask (n);
+  stat_buf.st_mode |= 0111 & ~n;
+  if (chmod (new_name, stat_buf.st_mode) == -1)
+    fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
+}