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We can generate x86-64 TLS code sequences for general and local dynamic models without PLT, which uses indirect call via GOT: call *__tls_get_addr@GOTPCREL(%rip) instead of direct call: call __tls_get_addr[@PLT] Since direct call is 4-byte long and indirect call, is 5-byte long, the extra one byte must be handled properly. For general dynamic model, one 0x66 prefix before call instruction is removed to make room for indirect call. For local dynamic model, we simply use 5-byte indirect call. TLS linker optimization is updated to recognize new instruction patterns. For local dynamic model to local exec model transition, we generate 4 0x66 prefixes, instead of 3, before mov instruction in 64-bit and generate a 5-byte nop, instead of 4-byte, before mov instruction in 32-bit. Since linker may convert call *__tls_get_addr@GOTPCREL(%rip) to addr32 call __tls_get_addr when producing static executable, both patterns are recognized. bfd/ * elf64-x86-64.c (elf_x86_64_link_hash_entry): Add tls_get_addr. (elf_x86_64_link_hash_newfunc): Initialize tls_get_addr to 2. (elf_x86_64_check_tls_transition): Check indirect call and direct call with the addr32 prefix for general and local dynamic models. Set the tls_get_addr feild. (elf_x86_64_convert_load_reloc): Always use addr32 prefix for indirect __tls_get_addr call via GOT. (elf_x86_64_relocate_section): Handle GD->LE, GD->IE and LD->LE transitions with indirect call and direct call with the addr32 prefix. ld/ * testsuite/ld-x86-64/pass.out: New file. * testsuite/ld-x86-64/tls-def1.c: Likewise. * testsuite/ld-x86-64/tls-gd1.S: Likewise. * testsuite/ld-x86-64/tls-ld1.S: Likewise. * testsuite/ld-x86-64/tls-main1.c: Likewise. * testsuite/ld-x86-64/tls.exp: Likewise. * testsuite/ld-x86-64/tlsbin2-nacl.rd: Likewise. * testsuite/ld-x86-64/tlsbin2.dd: Likewise. * testsuite/ld-x86-64/tlsbin2.rd: Likewise. * testsuite/ld-x86-64/tlsbin2.sd: Likewise. * testsuite/ld-x86-64/tlsbin2.td: Likewise. * testsuite/ld-x86-64/tlsbinpic2.s: Likewise. * testsuite/ld-x86-64/tlsgd10.dd: Likewise. * testsuite/ld-x86-64/tlsgd10.s: Likewise. * testsuite/ld-x86-64/tlsgd11.dd: Likewise. * testsuite/ld-x86-64/tlsgd11.s: Likewise. * testsuite/ld-x86-64/tlsgd12.d: Likewise. * testsuite/ld-x86-64/tlsgd12.s: Likewise. * testsuite/ld-x86-64/tlsgd13.d: Likewise. * testsuite/ld-x86-64/tlsgd13.s: Likewise. * testsuite/ld-x86-64/tlsgd14.dd: Likewise. * testsuite/ld-x86-64/tlsgd14.s: Likewise. * testsuite/ld-x86-64/tlsgd5c.s: Likewise. * testsuite/ld-x86-64/tlsgd6c.s: Likewise. * testsuite/ld-x86-64/tlsgd9.dd: Likewise. * testsuite/ld-x86-64/tlsgd9.s: Likewise. * testsuite/ld-x86-64/tlsld4.dd: Likewise. * testsuite/ld-x86-64/tlsld4.s: Likewise. * testsuite/ld-x86-64/tlsld5.dd: Likewise. * testsuite/ld-x86-64/tlsld5.s: Likewise. * testsuite/ld-x86-64/tlsld6.dd: Likewise. * testsuite/ld-x86-64/tlsld6.s: Likewise. * testsuite/ld-x86-64/tlspic2-nacl.rd: Likewise. * testsuite/ld-x86-64/tlspic2.dd: Likewise. * testsuite/ld-x86-64/tlspic2.rd: Likewise. * testsuite/ld-x86-64/tlspic2.sd: Likewise. * testsuite/ld-x86-64/tlspic2.td: Likewise. * testsuite/ld-x86-64/tlspic3.s: Likewise. * testsuite/ld-x86-64/tlspie2.s: Likewise. * testsuite/ld-x86-64/tlspie2a.d: Likewise. * testsuite/ld-x86-64/tlspie2b.d: Likewise. * testsuite/ld-x86-64/tlspie2c.d: Likewise. * testsuite/ld-x86-64/tlsgd5.dd: Updated. * testsuite/ld-x86-64/tlsgd6.dd: Likewise. * testsuite/ld-x86-64/x86-64.exp: Run libtlspic2.so, tlsbin2, tlsgd5b, tlsgd6b, tlsld4, tlsld5, tlsld6, tlsgd9, tlsgd10, tlsgd11, tlsgd14, tlsgd12, tlsgd13, tlspie2a, tlspie2b and tlspie2c. |
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emulparams | ||
emultempl | ||
po | ||
scripttempl | ||
testsuite | ||
.gitignore | ||
aclocal.m4 | ||
ChangeLog | ||
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-9197 | ||
ChangeLog-9899 | ||
config.in | ||
configure | ||
configure.ac | ||
configure.host | ||
configure.tgt | ||
deffile.h | ||
deffilep.y | ||
dep-in.sed | ||
elf-hints-local.h | ||
fdl.texi | ||
gen-doc.texi | ||
genscrba.sh | ||
genscripts.sh | ||
h8-doc.texi | ||
ld.h | ||
ld.texinfo | ||
ldbuildid.c | ||
ldbuildid.h | ||
ldcref.c | ||
ldctor.c | ||
ldctor.h | ||
ldemul.c | ||
ldemul.h | ||
ldexp.c | ||
ldexp.h | ||
ldfile.c | ||
ldfile.h | ||
ldgram.y | ||
ldint.texinfo | ||
ldlang.c | ||
ldlang.h | ||
ldlex-wrapper.c | ||
ldlex.h | ||
ldlex.l | ||
ldmain.c | ||
ldmain.h | ||
ldmisc.c | ||
ldmisc.h | ||
ldver.c | ||
ldver.h | ||
ldwrite.c | ||
ldwrite.h | ||
lexsup.c | ||
MAINTAINERS | ||
Makefile.am | ||
Makefile.in | ||
mri.c | ||
mri.h | ||
NEWS | ||
pe-dll.c | ||
pe-dll.h | ||
pep-dll.c | ||
pep-dll.h | ||
plugin.c | ||
plugin.h | ||
README | ||
stamp-h.in | ||
sysdep.h | ||
testplug2.c | ||
testplug3.c | ||
testplug4.c | ||
testplug.c | ||
TODO |
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.texinfo), as well as the
beginnings of an internals manual (ldint.texinfo).
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.texinfo 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) 2012-2016 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.