binutils-gdb/ld
H.J. Lu 241e64e3b4 x86: Add a GNU_PROPERTY_X86_ISA_1_USED note if needed
When -z separate-code, which is enabled by default for Linux/x86, is
used to create executable, ld won't place any data in the code-only
PT_LOAD segment.  If there are no data sections placed before the
code-only PT_LOAD segment, the program headers won't be mapped into
any PT_LOAD segment.  When the executable tries to access it (based
on the program header address passed in AT_PHDR), it will lead to
segfault.  This patch inserts a GNU_PROPERTY_X86_ISA_1_USED note if
there may be no data sections before the text section so that the
first PT_LOAD segment won't be code-only and will contain the program
header.

Testcases are adjusted to either pass "-z noseparate-code" to ld or
discard the .note.gnu.property section.  A Linux/x86 run-time test is
added.

bfd/

	PR ld/23428
	* elfxx-x86.c (_bfd_x86_elf_link_setup_gnu_properties): If the
	separate code program header is needed, make sure that the first
	read-only PT_LOAD segment has no code by adding a
	GNU_PROPERTY_X86_ISA_1_USED note.

ld/

	PR ld/23428
	* testsuite/ld-elf/linux-x86.S: New file.
	* testsuite/ld-elf/linux-x86.exp: Likewise.
	* testsuite/ld-elf/pr23428.c: Likewise.
	* testsuite/ld-elf/sec64k.exp: Pass "-z noseparate-code" to ld
	for Linux/x86 targets.
	* testsuite/ld-i386/abs-iamcu.d: Likewise.
	* testsuite/ld-i386/abs.d: Likewise.
	* testsuite/ld-i386/pr12718.d: Likewise.
	* testsuite/ld-i386/pr12921.d: Likewise.
	* testsuite/ld-x86-64/abs-k1om.d: Likewise.
	* testsuite/ld-x86-64/abs-l1om.d: Likewise.
	* testsuite/ld-x86-64/abs.d: Likewise.
	* testsuite/ld-x86-64/pr12718.d: Likewise.
	* testsuite/ld-x86-64/pr12921.d: Likewise.
	* testsuite/ld-linkonce/zeroeh.ld: Discard .note.gnu.property
	section.
	* testsuite/ld-scripts/print-memory-usage.t: Likewise.
	* testsuite/ld-scripts/size-2.t: Likewise.
	* testsuite/lib/ld-lib.exp (run_ld_link_exec_tests): Use ld
	to create executable if language is "asm".
2018-07-20 09:19:00 -07:00
..
emulparams S/390: Improve partial relro support for 64 bit 2018-07-18 13:20:06 +02:00
emultempl ld: Enable using separate linker script for -z relro 2018-07-18 13:20:06 +02:00
po Updated French translation for gold and Spanish translation for ld. 2018-07-18 08:37:38 +01:00
scripttempl Define various symbols conditionally in shared libraries 2018-06-08 20:17:34 +09:30
testsuite x86: Add a GNU_PROPERTY_X86_ISA_1_USED note if needed 2018-07-20 09:19:00 -07:00
.gitignore
aclocal.m4 Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
ChangeLog x86: Add a GNU_PROPERTY_X86_ISA_1_USED note if needed 2018-07-20 09:19:00 -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-9197
ChangeLog-9899
config.in Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
configure Regenerate configure and pot files with updated binutils version number. 2018-06-24 19:13:01 +01:00
configure.ac Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
configure.host
configure.tgt RISC-V: Add riscv-*-* configure support, and minor cleanup. 2018-07-05 17:49:11 -07:00
deffile.h
deffilep.y
dep-in.sed
elf-hints-local.h
fdl.texi
gen-doc.texi Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
genscrba.sh
genscripts.sh ld: Enable using separate linker script for -z relro 2018-07-18 13:20:06 +02:00
h8-doc.texi Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
ld.h
ld.texi Fix use of "command line X" in binutils doc 2018-07-02 11:18:24 +01:00
ldbuildid.c
ldbuildid.h
ldcref.c
ldctor.c
ldctor.h
ldemul.c
ldemul.h
ldexp.c LD: Export relative-from-absolute symbol marking to BFD 2018-07-17 20:04:53 +01:00
ldexp.h
ldfile.c
ldfile.h
ldgram.y
ldint.texi Fix use of "command line X" in binutils doc 2018-07-02 11:18:24 +01:00
ldlang.c ld: Set non_ir_ref_regular for --undefined SYMBOL 2018-07-04 06:29:13 -07:00
ldlang.h
ldlex-wrapper.c
ldlex.h [MicroBlaze] PIC data text relative 2018-04-17 14:47:13 -07:00
ldlex.l
ldmain.c [MicroBlaze] PIC data text relative 2018-04-17 14:47:13 -07:00
ldmain.h
ldmisc.c
ldmisc.h
ldver.c
ldver.h
ldwrite.c
ldwrite.h
lexsup.c ld: Properly display default for -z separate-code 2018-07-04 06:22:51 -07:00
MAINTAINERS
Makefile.am Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
Makefile.in Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
mri.c
mri.h
NEWS Fix use of "command line X" in binutils doc 2018-07-02 11:18:24 +01:00
pe-dll.c
pe-dll.h
pep-dll.c
pep-dll.h
plugin.c ld: Set non_ir_ref_regular for --undefined SYMBOL 2018-07-04 06:29:13 -07:00
plugin.h
README Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
stamp-h.in
sysdep.h
testplug2.c
testplug3.c
testplug4.c
testplug.c
TODO

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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) 2012-2018 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.