/* Copyright (C) 1985, 1986, 1987, 1988, 1990, 1992, 1999, 2000, 2001,
- 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
This file is part of GNU Emacs.
* unexec.c - Convert a running program into an a.out file.
*
* Author: Spencer W. Thomas
- * Computer Science Dept.
- * University of Utah
+ * Computer Science Dept.
+ * University of Utah
* Date: Tue Mar 2 1982
* Modified heavily since then.
*
#include <elf.h>
#endif
#include <sys/mman.h>
-#if defined (__sony_news) && defined (_SYSTYPE_SYSV)
+#if defined (_SYSTYPE_SYSV)
#include <sys/elf_mips.h>
#include <sym.h>
-#endif /* __sony_news && _SYSTYPE_SYSV */
+#endif /* _SYSTYPE_SYSV */
#if __sgi
#include <syms.h> /* for HDRR declaration */
#endif /* __sgi */
-#ifdef BROKEN_NOCOMBRELOC
-#include <assert.h>
-#endif
#ifndef MAP_ANON
#ifdef MAP_ANONYMOUS
ElfW(Word) old_bss_size, new_data2_size;
ElfW(Off) new_data2_offset;
ElfW(Addr) new_data2_addr;
+ ElfW(Off) old_bss_offset;
+ ElfW(Word) new_data2_incr;
int n, nn;
int old_bss_index, old_sbss_index, old_plt_index;
int old_mdebug_index;
struct stat stat_buf;
int old_file_size;
-#ifdef BROKEN_NOCOMBRELOC
- int unreloc_sections[10], n_unreloc_sections;
-#endif
/* Open the old file, allocate a buffer of the right size, and read
in the file contents. */
{
old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr;
old_bss_size = OLD_SECTION_H (old_bss_index).sh_size;
+ old_bss_offset = OLD_SECTION_H (old_bss_index).sh_offset;
new_data2_index = old_bss_index;
}
else if (old_plt_index != -1
+ OLD_SECTION_H (old_plt_index).sh_size;
if (old_sbss_index != -1)
old_bss_size += OLD_SECTION_H (old_sbss_index).sh_size;
+ old_bss_offset = OLD_SECTION_H (old_plt_index).sh_offset;
new_data2_index = old_plt_index;
}
else
old_bss_addr = OLD_SECTION_H (old_sbss_index).sh_addr;
old_bss_size = OLD_SECTION_H (old_bss_index).sh_size
+ OLD_SECTION_H (old_sbss_index).sh_size;
+ old_bss_offset = OLD_SECTION_H (old_sbss_index).sh_offset;
new_data2_index = old_sbss_index;
}
#endif
new_data2_addr = old_bss_addr;
new_data2_size = new_bss_addr - old_bss_addr;
- new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset +
- (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr);
+ new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset
+ + (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr);
+ /* This is the amount by which the sections following the bss sections
+ must be shifted in the image. It can differ from new_data2_size if
+ the end of the old .data section (and thus the offset of the .bss
+ section) was unaligned. */
+ new_data2_incr = new_data2_size + (new_data2_offset - old_bss_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, "old_bss_offset %x\n", old_bss_offset);
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);
+ fprintf (stderr, "new_data2_incr %x\n", new_data2_incr);
#endif
if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
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;
+ new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_incr;
if (ftruncate (new_file, new_file_size))
fatal ("Can't ftruncate (%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);
+ ((byte *) new_base + old_file_h->e_shoff + new_data2_incr);
/* Make our new file, program and section headers as copies of the
originals. */
/* 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_shoff += new_data2_incr;
new_file_h->e_shnum += 1;
#ifdef DEBUG
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;
+ NEW_PROGRAM_H (n).p_offset += new_data2_incr;
}
#endif
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. */
)
{
/* NN should be `old_s?bss_index + 1' at this point. */
- NEW_SECTION_H (nn).sh_offset =
- NEW_SECTION_H (new_data2_index).sh_offset + new_data2_size;
- NEW_SECTION_H (nn).sh_addr =
- NEW_SECTION_H (new_data2_index).sh_addr + new_data2_size;
+ NEW_SECTION_H (nn).sh_offset = new_data2_offset + new_data2_size;
+ NEW_SECTION_H (nn).sh_addr = new_data2_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. */
else
{
/* Any section that was originally placed after the .bss
- section should now be off by NEW_DATA2_SIZE. If a
+ section should now be off by NEW_DATA2_INCR. If a
section overlaps the .bss section, consider it to be
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. */
-#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 (NEW_SECTION_H (nn).sh_offset + NEW_SECTION_H (nn).sh_size
- > new_data2_offset)
- NEW_SECTION_H (nn).sh_offset += new_data2_size;
-#endif
+ (sparc) with GCC snapshot 960602.
+
+> dump -h temacs
+
+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
header table should now be off by the size of one section
header table entry. */
}
#endif /* __alpha__ */
-#if defined (__sony_news) && defined (_SYSTYPE_SYSV)
+#if defined (_SYSTYPE_SYSV)
if (NEW_SECTION_H (nn).sh_type == SHT_MIPS_DEBUG
&& old_mdebug_index != -1)
- {
+ {
int diff = NEW_SECTION_H(nn).sh_offset
- OLD_SECTION_H(old_mdebug_index).sh_offset;
HDRR *phdr = (HDRR *)(NEW_SECTION_H (nn).sh_offset + new_base);
phdr->cbExtOffset += diff;
}
}
-#endif /* __sony_news && _SYSTYPE_SYSV */
+#endif /* _SYSTYPE_SYSV */
#if __sgi
/* Adjust the HDRR offsets in .mdebug and copy the
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
that it can undo relocations performed by the runtime linker. */
-#ifndef BROKEN_NOCOMBRELOC
for (n = new_file_h->e_shnum - 1; n; n--)
{
ElfW(Shdr) section = NEW_SECTION_H (n);
break;
}
}
-#else /* BROKEN_NOCOMBRELOC */
- for (n = 1, n_unreloc_sections = 0; n < new_file_h->e_shnum; n++)
- if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data")
- || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".sdata")
- || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".lit4")
- || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".lit8")
-#ifdef IRIX6_5 /* see above */
- || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".got")
-#endif
- || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".sdata1")
- || !strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data1"))
- {
- assert (n_unreloc_sections
- < (sizeof (unreloc_sections) / sizeof (unreloc_sections[0])));
- unreloc_sections[n_unreloc_sections++] = n;
-#ifdef DEBUG
- fprintf (stderr, "section %d: %s\n", n,
- old_section_names + NEW_SECTION_H (n).sh_name);
-#endif
- }
-
- for (n = new_file_h->e_shnum - 1; n; n--)
- {
- ElfW(Shdr) section = NEW_SECTION_H (n);
- caddr_t reloc, end;
- ElfW(Addr) addr, offset;
- int target;
-
- 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. */
- for (reloc = old_base + section.sh_offset,
- end = reloc + section.sh_size;
- reloc < end;
- reloc += section.sh_entsize)
- {
- addr = ((ElfW(Rel) *) reloc)->r_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 (addr == 0)
- continue;
-#endif
- for (nn = 0; nn < n_unreloc_sections; nn++)
- {
- target = unreloc_sections[nn];
- if (NEW_SECTION_H (target).sh_addr <= addr
- && addr < (NEW_SECTION_H (target).sh_addr +
- NEW_SECTION_H (target).sh_size))
- {
- offset = (NEW_SECTION_H (target).sh_addr -
- NEW_SECTION_H (target).sh_offset);
- memcpy (new_base + addr - offset,
- old_base + addr - offset,
- sizeof (ElfW(Addr)));
-#ifdef DEBUG
- fprintf (stderr, "unrelocate: [%08lx] <= %08lx\n",
- (long) addr,
- (long) *((long *) (new_base + addr - offset)));
-#endif
- break;
- }
- }
- }
- break;
- }
- }
-#endif /* BROKEN_NOCOMBRELOC */
/* Write out new_file, and free the buffers. */
new_file_size, errno);
#else
fatal ("Didn't write %d bytes to %s: errno %d\n",
- new_file_size, new_base, errno);
+ new_file_size, new_name, errno);
#endif
munmap (old_base, old_file_size);
munmap (new_base, new_file_size);