When converting between addresses in ELF headers [octets] and bfd
LMA/VMA [bytes], the number of octets per byte needs to be
incorporated.
In ld, the SIZEOF_HEADERS linker script statement must be resolved to
bytes instead of octets.
include/
* elf/internal.h (struct elf_internal_phdr): Add unit (octets)
to several member field comments.
(Elf_Internal_Shdr): likewise.
bfd/
* elf.c (_bfd_elf_make_section_from_shdr): Introduce new temp
opb. Divide Elf_Internal_Shdr::sh_addr by opb when setting
section LMA/VMA.
(_bfd_elf_make_section_from_phdr): Similarly.
(elf_fake_sections): Fix calculation of
Elf_Internal_shdr::sh_addr from section VMA.
(_bfd_elf_map_sections_to_segments): Fix mixup between octets
and bytes.
(assign_file_positions_for_load_sections): Fix calculations of
Elf_Internal_shdr::p_vaddr and p_paddr from section LMA/VMA. Fix
comparison between program header address and section LMA.
(assign_file_positions_for_non_load_sections): Likewise.
(rewrite_elf_program_header): Likewise. Introduce new temp opb.
(IS_CONTAINED_BY_VMA): Add parameter opb.
(IS_CONTAINED_BY_LMA,IS_SECTION_IN_INPUT_SEGMENT,
INCLUDE_SECTION_IN_SEGMENT): Likewise.
(copy_elf_program_header): Update call to ELF_SECTION_IN_SEGMENT.
Fix calculations of p_addr_valid and p_vaddr_offset.
* elflink.c (elf_link_add_object_symbols): Multiply section VMA
with octets per byte when comparing against p_vaddr.
ld/
* ldexp.c (fold_name): Return SIZEOF_HEADERS in bytes.
This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
README for LD
This is the GNU linker. It is distributed with other "binary
utilities" which should be in ../binutils. See ../binutils/README for
more general notes, including where to send bug reports.
There are many features of the linker:
* The linker uses a Binary File Descriptor library (../bfd)
that it uses to read and write object files. This helps
insulate the linker itself from the format of object files.
* The linker supports a number of different object file
formats. It can even handle multiple formats at once:
Read two input formats and write a third.
* The linker can be configured for cross-linking.
* The linker supports a control language.
* There is a user manual (ld.texi), as well as the
beginnings of an internals manual (ldint.texi).
Installation
============
See ../binutils/README.
If you want to make a cross-linker, you may want to specify
a different search path of -lfoo libraries than the default.
You can do this by setting the LIB_PATH variable in ./Makefile
or using the --with-lib-path configure switch.
To build just the linker, make the target all-ld from the top level
directory (one directory above this one).
Porting to a new target
=======================
See the ldint.texi manual.
Reporting bugs etc
===========================
See ../binutils/README.
Known problems
==============
The Solaris linker normally exports all dynamic symbols from an
executable. The GNU linker does not do this by default. This is
because the GNU linker tries to present the same interface for all
similar targets (in this case, all native ELF targets). This does not
matter for normal programs, but it can make a difference for programs
which try to dlopen an executable, such as PERL or Tcl. You can make
the GNU linker export all dynamic symbols with the -E or
--export-dynamic command line option.
HP/UX 9.01 has a shell bug that causes the linker scripts to be
generated incorrectly. The symptom of this appears to be "fatal error
- scanner input buffer overflow" error messages. There are various
workarounds to this:
* Build and install bash, and build with "make SHELL=bash".
* Update to a version of HP/UX with a working shell (e.g., 9.05).
* Replace "(. ${srcdir}/scripttempl/${SCRIPT_NAME}.sc)" in
genscripts.sh with "sh ${srcdir}..." (no parens) and make sure the
emulparams script used exports any shell variables it sets.
Copyright (C) 2012-2020 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
502794d432