-/* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1999, 2000
+/* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1999, 2000, 2001
Free Software Foundation, Inc.
This file is part of GNU Emacs.
*/
\f
+/* We do not use mmap because that fails with NFS.
+ Instead we read the whole file, modify it, and write it out. */
+
#ifndef emacs
#define fatal(a, b, c) fprintf (stderr, a, b, c), exit (1)
#include <string.h>
{
int new_file, old_file, new_file_size;
- /* Pointers to the base of the image of the two files. */
+ /* 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.
- */
+ /* 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 */
+ /* Point to the section name table in the old file. */
char *old_section_names;
ElfW(Addr) old_bss_addr, new_bss_addr;
int old_data_index, new_data2_index;
int old_mdebug_index;
struct stat stat_buf;
+ int old_file_size;
- /* Open the old file & map it into the address space. */
+ /* Open the old file, allocate a buffer of the right size, and read
+ in the file contents. */
old_file = open (old_name, O_RDONLY);
if (fstat (old_file, &stat_buf) == -1)
fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
- old_base = mmap ((caddr_t) 0, stat_buf.st_size, PROT_READ, MAP_SHARED,
- old_file, 0);
-
+ /* We cannot use malloc here because that may use sbrk. If it does,
+ we'd dump our temporary buffers with Emacs, and we'd have to be
+ extra careful to use the correct value of sbrk(0) after
+ allocating all buffers in the code below, which we aren't. */
+ old_file_size = stat_buf.st_size;
+ old_base = mmap (NULL, old_file_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE, -1, 0);
if (old_base == (caddr_t) -1)
- fatal ("Can't mmap (%s): errno %d\n", old_name, errno);
+ fatal ("Can't allocate buffer for %s\n", old_name);
-#ifdef DEBUG
- fprintf (stderr, "mmap (%s, %x) -> %x\n", old_name, stat_buf.st_size,
- old_base);
-#endif
+ if (read (old_file, old_base, stat_buf.st_size) != stat_buf.st_size)
+ fatal ("Didn't read all of %s: errno %d\n", old_name, errno);
/* Get pointers to headers & section names */
old_name, old_file_h, old_section_h, 1);
/* Find the old .bss section. Figure out parameters of the new
- * data2 and bss sections.
- */
+ data2 and bss sections. */
old_bss_index = find_section (".bss", old_section_names,
old_name, old_file_h, old_section_h, 0);
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.
- */
+ /* Set the output file to the right size. Allocate a buffer to hold
+ the image of the new file. 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)
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 ((caddr_t) 0, new_file_size, PROT_READ | PROT_WRITE,
- MAP_PRIVATE, new_file, 0);
-#else
- new_base = mmap ((caddr_t) 0, new_file_size, PROT_READ | PROT_WRITE,
- MAP_SHARED, new_file, 0);
-#endif
-
+ new_base = mmap (NULL, new_file_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE, -1, 0);
if (new_base == (caddr_t) -1)
- fatal ("Can't mmap (%s): errno %d\n", new_name, errno);
+ fatal ("Can't allocate buffer for %s\n", old_name);
new_file_h = (ElfW(Ehdr) *) new_base;
new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
((byte *) new_base + old_file_h->e_shoff + new_data2_size);
/* Make our new file, program and section headers as copies of the
- * originals.
- */
+ originals. */
memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
memcpy (new_program_h, old_program_h,
PATCH_INDEX (new_file_h->e_shstrndx);
/* Fix up file header. We'll add one section. Section header is
- * further away now.
- */
+ further away now. */
new_file_h->e_shoff += new_data2_size;
new_file_h->e_shnum += 1;
#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.
- */
+ 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--)
{
#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.
- */
+ 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,
}
}
-#ifdef UNEXEC_USE_MAP_PRIVATE
- if (lseek (new_file, 0, SEEK_SET) == -1)
- fatal ("Can't rewind (%s): errno %d\n", new_name, errno);
+ /* Write out new_file, and free the buffers. */
if (write (new_file, new_base, new_file_size) != new_file_size)
- fatal ("Can't write (%s): errno %d\n", new_name, errno);
-#endif
+ fatal ("Didn't write %d bytes to %s: errno %d\n",
+ new_file_size, new_base, errno);
+
+ munmap (old_base, old_file_size);
+ munmap (new_base, new_file_size);
/* Close the files and make the new file executable. */