-/* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1999, 2000, 2001,
- 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+/* Copyright (C) 1985-1988, 1990, 1992, 1999-2011
Free Software Foundation, Inc.
This file is part of GNU Emacs.
* Modified heavily since then.
*
* Synopsis:
- * unexec (new_name, old_name, data_start, bss_start, entry_address)
- * char *new_name, *old_name;
- * unsigned data_start, bss_start, entry_address;
+ * unexec (const char *new_name, const char *old_name);
*
* Takes a snapshot of the program and makes an a.out format file in the
* file named by the string argument new_name.
* If old_name is non-NULL, the symbol table will be taken from the given file.
* On some machines, an existing old_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.
- *
- * 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.
- *
*/
/* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
/* 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>
-#else
#include <config.h>
+#include <unexec.h>
+
extern void fatal (const char *msgid, ...);
-#endif
#include <sys/types.h>
+#include <stdint.h>
#include <stdio.h>
#include <sys/stat.h>
#include <memory.h>
#include <fcntl.h>
#if !defined (__NetBSD__) && !defined (__OpenBSD__)
#include <elf.h>
-#endif
+#endif /* not __NetBSD__ and not __OpenBSD__ */
#include <sys/mman.h>
#if defined (_SYSTYPE_SYSV)
#include <sys/elf_mips.h>
# define ElfW(type) ElfExpandBitsW (ELFSIZE, type)
#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.
*/
(*(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)))
/* Round X up to a multiple of Y. */
static ElfW(Addr)
-round_up (x, y)
- ElfW(Addr) x, y;
+round_up (ElfW(Addr) x, ElfW(Addr) y)
{
int rem = x % y;
if (rem == 0)
if NOERROR is 0; we return -1 if NOERROR is nonzero. */
static int
-find_section (name, section_names, file_name, old_file_h, old_section_h, noerror)
- char *name;
- char *section_names;
- char *file_name;
- ElfW(Ehdr) *old_file_h;
- ElfW(Shdr) *old_section_h;
- int noerror;
+find_section (const char *name, const char *section_names, const char *file_name,
+ ElfW(Ehdr) *old_file_h, ElfW(Shdr) *old_section_h, int noerror)
{
int idx;
*
*/
void
-unexec (new_name, old_name, data_start, bss_start, entry_address)
- char *new_name, *old_name;
- unsigned data_start, bss_start, entry_address;
+unexec (const char *new_name, const char *old_name)
{
int new_file, old_file, new_file_size;
+#if defined (emacs) || !defined (DEBUG)
+ void *new_break;
+#endif
+
/* Pointers to the base of the image of the two files. */
caddr_t old_base, new_base;
int n, nn;
int old_bss_index, old_sbss_index, old_plt_index;
int old_data_index, new_data2_index;
+#if defined _SYSTYPE_SYSV || defined __sgi
int old_mdebug_index;
+#endif
struct stat stat_buf;
int old_file_size;
/* Find the mdebug section, if any. */
+#if defined _SYSTYPE_SYSV || defined __sgi
old_mdebug_index = find_section (".mdebug", old_section_names,
old_name, old_file_h, old_section_h, 1);
+#endif
/* Find the old .bss section. Figure out parameters of the new
data2 and bss sections. */
old_name, old_file_h, old_section_h, 0);
#if defined (emacs) || !defined (DEBUG)
- new_bss_addr = (ElfW(Addr)) sbrk (0);
+ new_break = sbrk (0);
+ new_bss_addr = (ElfW(Addr)) new_break;
#else
new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
#endif
fprintf (stderr, "new_data2_incr %x\n", new_data2_incr);
#endif
- if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
+ if ((uintptr_t) new_bss_addr < (uintptr_t) old_bss_addr + old_bss_size)
fatal (".bss shrank when undumping???\n", 0, 0);
/* Set the output file to the right size. Allocate a buffer to hold
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. */
placed after the .bss section. Overlap can occur if the
section just before .bss has less-strict alignment; this
was observed between .symtab and .bss on Solaris 2.5.1
- (sparc) with GCC snapshot 960602. */
+ (sparc) with GCC snapshot 960602.
+
+> dump -h temacs
- if (NEW_SECTION_H (nn).sh_offset >= old_bss_offset)
+temacs:
+
+ **** SECTION HEADER TABLE ****
+[No] Type Flags Addr Offset Size Name
+ Link Info Adralgn Entsize
+
+[22] 1 3 0x335150 0x315150 0x4 .data.rel.local
+ 0 0 0x4 0
+
+[23] 8 3 0x335158 0x315158 0x42720 .bss
+ 0 0 0x8 0
+
+[24] 2 0 0 0x315154 0x1c9d0 .symtab
+ 25 1709 0x4 0x10
+ */
+
+ if (NEW_SECTION_H (nn).sh_offset >= old_bss_offset
+ || (NEW_SECTION_H (nn).sh_offset + NEW_SECTION_H (nn).sh_size
+ > new_data2_offset))
NEW_SECTION_H (nn).sh_offset += new_data2_incr;
/* Any section that was originally placed after the section
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), "end") == 0
- || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0
- || strcmp ((char *) (symnames + symp->st_name), "edata") == 0)
- memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
+ {
+ if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0
+ || strcmp ((char *) (symnames + symp->st_name), "end") == 0
+ || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0
+ || strcmp ((char *) (symnames + symp->st_name), "edata") == 0)
+ memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr));
+
+ /* Strictly speaking, #ifdef below is not necessary. But we
+ keep it to indicate that this kind of change may also be
+ necessary for other unexecs to support GNUstep. */
+#ifdef NS_IMPL_GNUSTEP
+ /* ObjC runtime modifies the values of some data structures
+ such as classes and selectors in the .data section after
+ loading. As the dump process copies the .data section
+ from the current process, that causes problems when the
+ modified classes are reinitialized in the dumped
+ executable. We copy such data from the old file, not
+ from the current process. */
+ if (strncmp ((char *) (symnames + symp->st_name),
+ "_OBJC_", sizeof ("_OBJC_") - 1) == 0)
+ {
+ caddr_t old, new;
+
+ new = ((symp->st_value - NEW_SECTION_H (symp->st_shndx).sh_addr)
+ + NEW_SECTION_H (symp->st_shndx).sh_offset + new_base);
+ /* "Unpatch" index. */
+ nn = symp->st_shndx;
+ if (nn > old_bss_index)
+ nn--;
+ old = ((symp->st_value - NEW_SECTION_H (symp->st_shndx).sh_addr)
+ + OLD_SECTION_H (nn).sh_offset + old_base);
+ memcpy (new, old, symp->st_size);
+ }
+#endif
+ }
}
/* This loop seeks out relocation sections for the data section, so
ElfW(Shdr) section = NEW_SECTION_H (n);
/* Cause a compilation error if anyone uses n instead of nn below. */
- struct {int a;} n;
- (void)n.a; /* Prevent `unused variable' warnings. */
+ #define n ((void) 0);
+ n /* Prevent 'macro "n" is not used' warnings. */
switch (section.sh_type)
{
}
break;
}
+
+ #undef n
}
/* Write out new_file, and free the buffers. */
if (write (new_file, new_base, new_file_size) != new_file_size)
-#ifndef emacs
- fatal ("Didn't write %d bytes: errno %d\n",
- new_file_size, errno);
-#else
fatal ("Didn't write %d bytes to %s: errno %d\n",
- new_file_size, new_base, errno);
-#endif
+ new_file_size, new_name, errno);
munmap (old_base, old_file_size);
munmap (new_base, new_file_size);
if (chmod (new_name, stat_buf.st_mode) == -1)
fatal ("Can't chmod (%s): errno %d\n", new_name, errno);
}
-
-/* arch-tag: e02e1512-95e2-4ef0-bba7-b6bce658f1e3
- (do not change this comment) */
HCoop / bpt / emacs.git / blobdiff