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authorBryan Newbold <bnewbold@robocracy.org>2017-02-20 00:05:23 -0800
committerBryan Newbold <bnewbold@robocracy.org>2017-02-20 00:05:23 -0800
commit5ca6e8e6a4e5c022a6fb5d28f30219c22c99eda8 (patch)
tree9b744b9dbf39e716e56daa620e2f3041968caf19 /unexelf.c
downloadscm-5ca6e8e6a4e5c022a6fb5d28f30219c22c99eda8.tar.gz
scm-5ca6e8e6a4e5c022a6fb5d28f30219c22c99eda8.zip
Import Upstream version 4e6upstream/4e6
Diffstat (limited to 'unexelf.c')
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diff --git a/unexelf.c b/unexelf.c
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+++ b/unexelf.c
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+/* 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>
+
+#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) \
+ (*(Elf32_Shdr *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
+#define NEW_SECTION_H(n) \
+ (*(Elf32_Shdr *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
+#define OLD_PROGRAM_H(n) \
+ (*(Elf32_Phdr *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
+#define NEW_PROGRAM_H(n) \
+ (*(Elf32_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.
+ */
+ Elf32_Ehdr *old_file_h, *new_file_h;
+ Elf32_Phdr *old_program_h, *new_program_h;
+ Elf32_Shdr *old_section_h, *new_section_h;
+
+ /* Point to the section name table in the old file */
+ char *old_section_names;
+
+ Elf32_Addr old_bss_addr, new_bss_addr;
+ Elf32_Word old_bss_size, new_data2_size;
+ Elf32_Off new_data2_offset;
+ Elf32_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 = (Elf32_Ehdr *) old_base;
+ old_program_h = (Elf32_Phdr *) ((byte *) old_base + old_file_h->e_phoff);
+ old_section_h = (Elf32_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 = (Elf32_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 = (Elf32_Ehdr *) new_base;
+ new_program_h = (Elf32_Phdr *) ((byte *) new_base + old_file_h->e_phoff);
+ new_section_h = (Elf32_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);
+
+ /* 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)
+ {
+ Elf32_Shdr *spt = &NEW_SECTION_H (nn);
+ unsigned int num = spt->sh_size / spt->sh_entsize;
+ Elf32_Sym * sym = (Elf32_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;
+ Elf32_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 = (Elf32_Sym *) (NEW_SECTION_H (n).sh_offset + new_base);
+ symendp = (Elf32_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--)
+ {
+ Elf32_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"))
+ {
+ Elf32_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)
+ {
+ Elf32_Addr addr = ((Elf32_Rel *) reloc)->r_offset - offset;
+ memcpy (new_base + addr, old_base + addr, 4);
+ }
+ }
+ 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);
+}