binutils-gdb/ld
H.J. Lu 382aae0632 x86: Only allow S + A relocations against absolute symbol
Since value of non-preemptible absolute symbol (SHN_ABS) won't change,
only relocations, which can be resolved as absolute value + addend, and
GOTPCREL relocations, where absolute value + addend is stored in the GOT
slot, against non-preemptible absolute symbol are allowed in PIE and
shared library.

Also convert load relocation to R_386_32, R_X86_64_32S or R_X86_64_32 for
relocation against non-preemptible absolute symbol.  Don't convert to
R_X86_64_32S nor R_X86_64_32 for non-preemptible absolute symbol if they
overflow.

bfd/

	PR ld/25749
	PR ld/25754
	* elf32-i386.c (elf_i386_convert_load_reloc): Convert load
	relocation to R_386_32 for relocation against non-preemptible
	absolute symbol.
	(elf_i386_check_relocs): Call _bfd_elf_x86_valid_reloc_p.  Don't
	allocate dynamic relocation for non-preemptible absolute symbol.
	(elf_i386_relocate_section): Pass sec to
	GENERATE_DYNAMIC_RELOCATION_P.
	* elf64-x86-64.c (R_X86_64_converted_reloc_bit): Moved.
	(elf_x86_64_convert_load_reloc): Covert load relocation to
	R_X86_64_32S or R_X86_64_32 for relocation against non-preemptible
	absolute symbol.  Don't convert to R_X86_64_32S nor R_X86_64_32
	for non-preemptible absolute symbol if they overflow.
	(elf_x86_64_check_relocs): Call _bfd_elf_x86_valid_reloc_p.  Set
	tls_type for GOT slot to GOT_ABS for non-preemptible absolute
	symbol.  Don't allocate dynamic relocation for non-preemptible
	absolute symbol.
	(elf_x86_64_relocate_section): Don't generate relative relocation
	for GOTPCREL relocations aganst local absolute symbol.  Pass sec
	to GENERATE_DYNAMIC_RELOCATION_P.
	* elfxx-x86.c (elf_x86_allocate_dynrelocs): No dynamic relocation
	against non-preemptible absolute symbol.
	(_bfd_elf_x86_valid_reloc_p): New function.
	(_bfd_x86_elf_size_dynamic_sections): No dynamic relocation for
	GOT_ABS GOT slot.
	* elfxx-x86.h (GENERATE_DYNAMIC_RELOCATION_P): Add an SEC
	argument.  Don't generate dynamic relocation against
	non-preemptible absolute symbol.
	(ABS_SYMBOL_P): New.
	(GENERATE_RELATIVE_RELOC_P): Don't generate relative relocation
	against non-preemptible absolute symbol.
	(GOT_ABS): New.
	(R_X86_64_converted_reloc_bit): New.  Moved from elf64-x86-64.c.
	(_bfd_elf_x86_valid_reloc_p): New.

ld/

	PR ld/25749
	PR ld/25754
	* testsuite/ld-elf/linux-x86.exp: Run ld/25749 tests.
	* testsuite/ld-elf/pr25749-1.c: New file.
	* testsuite/ld-elf/pr25749-1a.c: Likewise.
	* testsuite/ld-elf/pr25749-1b.c: Likewise.
	* testsuite/ld-elf/pr25749-1b.err: Likewise.
	* testsuite/ld-elf/pr25749-1c.c: Likewise.
	* testsuite/ld-elf/pr25749-1d.c: Likewise.
	* testsuite/ld-elf/pr25749-2.c: Likewise.
	* testsuite/ld-elf/pr25749-2a.s: Likewise.
	* testsuite/ld-elf/pr25749-2b.s: Likewise.
	* testsuite/ld-elf/pr25749.rd: Likewise.
	* testsuite/ld-elf/pr25754-1a.c: Likewise.
	* testsuite/ld-elf/pr25754-1b.s: Likewise.
	* testsuite/ld-elf/pr25754-2a.c: Likewise.
	* testsuite/ld-elf/pr25754-2b.err: Likewise.
	* testsuite/ld-elf/pr25754-2b.s: Likewise.
	* testsuite/ld-elf/pr25754-3a.c: Likewise.
	* testsuite/ld-elf/pr25754-3b.s: Likewise.
	* testsuite/ld-elf/pr25754-4a.c: Likewise.
	* testsuite/ld-elf/pr25754-4b.s: Likewise.
	* testsuite/ld-elf/pr25754-4c.s: Likewise.
	* testsuite/ld-elf/pr25754-5a.c: Likewise.
	* testsuite/ld-elf/pr25754-5b.s: Likewise.
	* testsuite/ld-elf/pr25754-5c.s: Likewise.
	* testsuite/ld-elf/pr25754-6a.c: Likewise.
	* testsuite/ld-elf/pr25754-6b.s: Likewise.
	* testsuite/ld-x86-64/pr19609-6a.d: Don't expect linker error.
2020-04-01 14:31:47 -07:00
..
emulparams ld: Set COMMONPAGESIZE for i386 Solaris 2020-03-28 05:06:58 -07:00
emultempl Fix objcopy's --preserve-dates command line option so that it will work with PE format files. 2020-03-30 16:30:02 +01:00
po i386msdos uninitialised read 2020-03-23 23:26:12 +10:30
scripttempl MSP430: Remove unused linker script template elf32msp430_3.sc 2020-01-16 13:45:29 +00:00
testsuite x86: Only allow S + A relocations against absolute symbol 2020-04-01 14:31:47 -07:00
.gitignore
ChangeLog x86: Only allow S + A relocations against absolute symbol 2020-04-01 14:31:47 -07:00
ChangeLog-0001
ChangeLog-0203
ChangeLog-2004
ChangeLog-2005
ChangeLog-2006
ChangeLog-2007
ChangeLog-2008
ChangeLog-2009
ChangeLog-2010
ChangeLog-2011
ChangeLog-2012
ChangeLog-2013
ChangeLog-2014
ChangeLog-2015
ChangeLog-2016
ChangeLog-2017
ChangeLog-2018 ChangeLog rotation 2019-01-01 21:25:40 +10:30
ChangeLog-2019 ChangeLog rotation 2020-01-01 18:12:08 +10:30
ChangeLog-9197
ChangeLog-9899
MAINTAINERS Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
Makefile.am i386msdos uninitialised read 2020-03-23 23:26:12 +10:30
Makefile.in i386msdos uninitialised read 2020-03-23 23:26:12 +10:30
NEWS Add support for non-contiguous memory regions 2020-03-13 14:44:45 +00:00
README Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
TODO
aclocal.m4 bfd, ld: add CTF section linking 2019-10-03 17:04:56 +01:00
config.in Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
configure Update version to 2.34.50. Regenerate configure and .pot files. 2020-01-18 14:12:07 +00:00
configure.ac Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
configure.host Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
configure.tgt i386-moss and i386-openbsd ld config 2020-02-06 13:56:29 +10:30
deffile.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
deffilep.y Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
dep-in.sed
elf-hints-local.h
fdl.texi
gen-doc.texi Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
genscrba.sh Automatic makefile dependencies for generated ld/e*.c 2019-04-13 12:13:22 +09:30
genscripts.sh Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
h8-doc.texi Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ld.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ld.texi Add support for non-contiguous memory regions 2020-03-13 14:44:45 +00:00
ldbuildid.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldbuildid.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldcref.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldctor.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldctor.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldelf.c Don't merge sections with differing MASKPROC or MASKOS flags 2020-03-11 15:00:44 +10:30
ldelf.h ELF: Discard a section if any of its linked-to sections has been discarded 2020-02-06 19:43:03 -08:00
ldelfgen.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldelfgen.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldemul.c ELF: Discard a section if any of its linked-to sections has been discarded 2020-02-06 19:43:03 -08:00
ldemul.h ELF: Discard a section if any of its linked-to sections has been discarded 2020-02-06 19:43:03 -08:00
ldexp.c Fix several mix up between octets and bytes in ELF program headers 2020-03-13 15:37:11 +10:30
ldexp.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldfile.c Extend the linker's error message for missing libraries if there is an almost match. 2020-04-01 17:25:28 +01:00
ldfile.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldgram.y Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldint.texi Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldlang.c Non-contiguous memory regions support: Avoid calls to abort 2020-03-18 10:09:43 +00:00
ldlang.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldlex-wrapper.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldlex.h Add support for non-contiguous memory regions 2020-03-13 14:44:45 +00:00
ldlex.l Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldmain.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldmain.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldmisc.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldmisc.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldver.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldver.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldwrite.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
ldwrite.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
lexsup.c Add support for non-contiguous memory regions 2020-03-13 14:44:45 +00:00
mri.c Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
mri.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
pe-dll.c Fix objcopy's --preserve-dates command line option so that it will work with PE format files. 2020-03-30 16:30:02 +01:00
pe-dll.h For PE format files, the base relocation table is necessary if the image is loaded at a different image base than specified in the PE header. This patch provides a new option --enable-reloc-section to force the generation of this section. 2020-01-03 12:57:15 +00:00
pep-dll.c For PE format files, the base relocation table is necessary if the image is loaded at a different image base than specified in the PE header. This patch provides a new option --enable-reloc-section to force the generation of this section. 2020-01-03 12:57:15 +00:00
pep-dll.h For PE format files, the base relocation table is necessary if the image is loaded at a different image base than specified in the PE header. This patch provides a new option --enable-reloc-section to force the generation of this section. 2020-01-03 12:57:15 +00:00
plugin.c bfd_cleanup for object_p 2020-03-02 19:30:48 +10:30
plugin.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
stamp-h.in
sysdep.h Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
testplug.c Silence warnings due to plugin API change 2020-03-20 12:59:54 +10:30
testplug2.c Silence warnings due to plugin API change 2020-03-20 12:59:54 +10:30
testplug3.c Silence warnings due to plugin API change 2020-03-20 12:59:54 +10:30
testplug4.c Silence warnings due to plugin API change 2020-03-20 12:59:54 +10:30

README

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		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.