[PATCH v2] x86-64: Add GLIBC_ABI_GNU2_TLS version dependency
Sam James
sam@gentoo.org
Fri Aug 15 05:04:34 GMT 2025
"H.J. Lu" <hjl.tools@gmail.com> writes:
> On Linux/x86-64, programs and shared libraries compiled with
> -mtls-dialect=gnu2 may fail silently at run-time against glibc without
> the GNU2 TLS run-time fix for:
>
> https://sourceware.org/bugzilla/show_bug.cgi?id=31372
>
> A version tag, GLIBC_ABI_GNU2_TLS, has been added to glibc to indicate
> that glibc has the working GNU2 TLS run-time by:
>
> commit 9df8fa397d515dc86ff5565f6c45625e672d539e
> Author: H.J. Lu <hjl.tools@gmail.com>
> Date: Mon Jul 28 12:18:22 2025 -0700
>
> x86-64: Add GLIBC_ABI_GNU2_TLS version [BZ #33129]
>
> Add the --gnu2-tls-tag option to x86-64 ELF linker to add the
> GLIBC_ABI_GNU2_TLS version dependency in output programs and shared
> libraries when linking against glibc if input relocatable object files
> have R_X86_64_TLSDESC_CALL relocation. The output will fail to load and
> run at run-time against glibc which doesn't define the GLIBC_ABI_GNU2_TLS
> version.
>
> Add the --enable-gnu2-tls-tag configure option to enable --gnu2-tls-tag
> by default. If unspecified, linker will add the GLIBC_ABI_GNU2_TLS
> version dependency if inputs have R_X86_64_TLSDESC_CALL relocation and
> libc.so defines the GLIBC_ABI_GNU2_TLS version.
>
> bfd/
>
> PR ld/33130
> * elf-linker-x86.h (elf_linker_x86_params): Add gnu2_tls.
> * elf64-x86-64.c (elf_x86_64_scan_relocs): Set has_tlsdesc_call
> to 1 for R_X86_64_TLSDESC_CALL.
> (elf_x86_64_add_glibc_version_dependency): Add GLIBC_ABI_GNU2_TLS
> version dependency if GLIBC_ABI_GNU2_TLS dependency isn't disabled
> and has_tlsdesc_call isn't 0.
> * elflink.c (elf_link_add_glibc_verneed): Add a pointer to bool
> argument, auto_version. If *auto_version is true, add the
> version dependency only if libc.so defines the version.
> (_bfd_elf_link_add_glibc_version_dependency): Add a pointer to
> bool argument and pass it to elf_link_add_glibc_verneed.
> (_bfd_elf_link_add_dt_relr_dependency): Pass NULL to
> _bfd_elf_link_add_glibc_version_dependency.
> * elfxx-x86.h (elf_x86_link_hash_table): Add has_tlsdesc_call.
>
> ld/
>
> PR ld/33130
> * NEWS: Mention --gnu2-tls-tag, --no-gnu2-tls-tag and
> --enable-gnu2-tls-tag.
> * config.in: Regenerated.
> * configure: Likewise.
> * configure.ac: Add --enable-gnu2-tls-tag.
> * ld.texi: Document --gnu2-tls-tag/--no-gnu2-tls-tag.
> * ldlex.h (option_values): Add OPTION_GNU2_TLS_TAG and
> OPTION_NO_GNU2_TLS_TAG.
> * emulparams/elf32_x86_64.sh (EXTRA_EM_FILE): Changed to
> "elf-x86-64".
> * emulparams/elf_x86_64.sh (EXTRA_EM_FILE): Likewise.
> * emultempl/elf-x86-64.em: New file.
> * emultempl/elf-x86.em (elf_x86_64_before_parse): Removed.
> (LDEMUL_BEFORE_PARSE): Likewise.
> (elf_x86_64_before_allocation): Likewise.
> * testsuite/ld-x86-64/gnu2-tls-1.rd: New file.
> * testsuite/ld-x86-64/gnu2-tls-1a.od: New file.
> * testsuite/ld-x86-64/gnu2-tls-1a.s: Likewise.
> * testsuite/ld-x86-64/gnu2-tls-1b.od: Likewise.
> * testsuite/ld-x86-64/gnu2-tls-1b.s: Likewise.
> * testsuite/ld-x86-64/gnu2-tls-1c.od: Likewise.
> * testsuite/ld-x86-64/gnu2-tls-2.rd: Likewise.
> * testsuite/ld-x86-64/gnu2-tls-2.s: Likewise.
> * testsuite/ld-x86-64/x86-64.exp: Run GLIBC_ABI_GNU2_TLS tests.
Thanks. It looks good to me. I didn't check .em changes still.
>
> Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
> ---
> bfd/elf-bfd.h | 2 +-
> bfd/elf-linker-x86.h | 8 ++
> bfd/elf64-x86-64.c | 30 ++++++--
> bfd/elflink.c | 41 ++++++++--
> bfd/elfxx-x86.h | 4 +
> ld/NEWS | 6 ++
> ld/config.in | 4 +
> ld/configure | 29 ++++++-
> ld/configure.ac | 19 +++++
> ld/emulparams/elf32_x86_64.sh | 2 +-
> ld/emulparams/elf_x86_64.sh | 2 +-
> ld/emultempl/elf-x86-64.em | 107 ++++++++++++++++++++++++++
> ld/emultempl/elf-x86.em | 58 --------------
> ld/ld.texi | 13 ++++
> ld/ldlex.h | 3 +
> ld/testsuite/ld-x86-64/gnu2-tls-1.rd | 7 ++
> ld/testsuite/ld-x86-64/gnu2-tls-1a.od | 13 ++++
> ld/testsuite/ld-x86-64/gnu2-tls-1a.s | 14 ++++
> ld/testsuite/ld-x86-64/gnu2-tls-1b.od | 13 ++++
> ld/testsuite/ld-x86-64/gnu2-tls-1b.s | 9 +++
> ld/testsuite/ld-x86-64/gnu2-tls-1c.od | 13 ++++
> ld/testsuite/ld-x86-64/gnu2-tls-2.rd | 4 +
> ld/testsuite/ld-x86-64/gnu2-tls-2.s | 13 ++++
> ld/testsuite/ld-x86-64/x86-64.exp | 45 ++++++++++-
> 24 files changed, 384 insertions(+), 75 deletions(-)
> create mode 100644 ld/emultempl/elf-x86-64.em
> create mode 100644 ld/testsuite/ld-x86-64/gnu2-tls-1.rd
> create mode 100644 ld/testsuite/ld-x86-64/gnu2-tls-1a.od
> create mode 100644 ld/testsuite/ld-x86-64/gnu2-tls-1a.s
> create mode 100644 ld/testsuite/ld-x86-64/gnu2-tls-1b.od
> create mode 100644 ld/testsuite/ld-x86-64/gnu2-tls-1b.s
> create mode 100644 ld/testsuite/ld-x86-64/gnu2-tls-1c.od
> create mode 100644 ld/testsuite/ld-x86-64/gnu2-tls-2.rd
> create mode 100644 ld/testsuite/ld-x86-64/gnu2-tls-2.s
>
> diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
> index accdd6d41a8..feb470fc477 100644
> --- a/bfd/elf-bfd.h
> +++ b/bfd/elf-bfd.h
> @@ -2632,7 +2632,7 @@ extern bool _bfd_elf_link_output_relocs
> struct elf_link_hash_entry **);
>
> extern void _bfd_elf_link_add_glibc_version_dependency
> - (struct elf_find_verdep_info *, const char *const []);
> + (struct elf_find_verdep_info *, const char *const [], bool *);
>
> extern void _bfd_elf_link_add_dt_relr_dependency
> (struct elf_find_verdep_info *);
> diff --git a/bfd/elf-linker-x86.h b/bfd/elf-linker-x86.h
> index 2c98257038f..7656b0a7932 100644
> --- a/bfd/elf-linker-x86.h
> +++ b/bfd/elf-linker-x86.h
> @@ -72,6 +72,14 @@ struct elf_linker_x86_params
> /* Mark PLT with dynamic tags. */
> unsigned int mark_plt : 1;
>
> + /* Add the GLIBC_ABI_GNU2_TLS version dependency if input object files
> + have R_X86_64_TLSDESC_CALL relocation:
> + 0: Disable.
> + 1: Enable.
> + 2: Auto. Enable if libc.so has the GLIBC_ABI_GNU2_TLS version.
> + */
> + unsigned int gnu2_tls : 2;
> +
> /* X86-64 ISA level needed. */
> unsigned int isa_level;
>
> diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
> index b6f97b5b69b..03873a9ed6b 100644
> --- a/bfd/elf64-x86-64.c
> +++ b/bfd/elf64-x86-64.c
> @@ -2694,6 +2694,10 @@ elf_x86_64_scan_relocs (bfd *abfd, struct bfd_link_info *info,
> eh->zero_undefweak &= 0x2;
> break;
>
> + case R_X86_64_TLSDESC_CALL:
> + htab->has_tlsdesc_call = 1;
> + goto need_got;
> +
> case R_X86_64_GOTTPOFF:
> case R_X86_64_CODE_4_GOTTPOFF:
> case R_X86_64_CODE_5_GOTTPOFF:
> @@ -2715,7 +2719,7 @@ elf_x86_64_scan_relocs (bfd *abfd, struct bfd_link_info *info,
> case R_X86_64_GOTPLT64:
> case R_X86_64_GOTPC32_TLSDESC:
> case R_X86_64_CODE_4_GOTPC32_TLSDESC:
> - case R_X86_64_TLSDESC_CALL:
> +need_got:
> /* This symbol requires a global offset table entry. */
> {
> int tls_type, old_tls_type;
> @@ -6243,7 +6247,8 @@ elf_x86_64_add_glibc_version_dependency
> (struct elf_find_verdep_info *rinfo)
> {
> unsigned int i = 0;
> - const char *version[3] = { NULL, NULL, NULL };
> + const char *version[4] = { NULL, NULL, NULL, NULL };
> + bool auto_version[4] = { false, false, false, false };
> struct elf_x86_link_hash_table *htab;
>
> if (rinfo->info->enable_dt_relr)
> @@ -6253,14 +6258,27 @@ elf_x86_64_add_glibc_version_dependency
> }
>
> htab = elf_x86_hash_table (rinfo->info, X86_64_ELF_DATA);
> - if (htab != NULL && htab->params->mark_plt)
> + if (htab != NULL)
> {
> - version[i] = "GLIBC_2.36";
> - i++;
> + if (htab->params->gnu2_tls && htab->has_tlsdesc_call)
> + {
> + version[i] = "GLIBC_ABI_GNU2_TLS";
> + /* 2 == auto, enable if libc.so defines the GLIBC_ABI_GNU2_TLS
> + version. */
> + if (htab->params->gnu2_tls == 2)
> + auto_version[i] = true;
> + i++;
> + }
> + if (htab->params->mark_plt)
> + {
> + version[i] = "GLIBC_2.36";
> + i++;
> + }
> }
>
> if (i != 0)
> - _bfd_elf_link_add_glibc_version_dependency (rinfo, version);
> + _bfd_elf_link_add_glibc_version_dependency (rinfo, version,
> + auto_version);
> }
>
> static const struct bfd_elf_special_section
> diff --git a/bfd/elflink.c b/bfd/elflink.c
> index 7b0375406ac..86bb14aae37 100644
> --- a/bfd/elflink.c
> +++ b/bfd/elflink.c
> @@ -2286,13 +2286,16 @@ _bfd_elf_export_symbol (struct elf_link_hash_entry *h, void *data)
> /* Return the glibc version reference if VERSION_DEP is added to the
> list of glibc version dependencies successfully. VERSION_DEP will
> be put into the .gnu.version_r section. GLIBC_MINOR_BASE is the
> - pointer to the glibc minor base version. */
> + pointer to the glibc minor base version. If AUTO_VERSION isn't
> + NULL and *AUTO_VERSION is true, add VERSION_DEP to the version
> + dependency list only if libc.so defines VERSION_DEP. */
>
> static Elf_Internal_Verneed *
> elf_link_add_glibc_verneed (struct elf_find_verdep_info *rinfo,
> Elf_Internal_Verneed *glibc_verref,
> const char *version_dep,
> - int *glibc_minor_base)
> + int *glibc_minor_base,
> + bool *auto_version)
> {
> Elf_Internal_Verneed *t;
> Elf_Internal_Vernaux *a;
> @@ -2345,6 +2348,32 @@ elf_link_add_glibc_verneed (struct elf_find_verdep_info *rinfo,
> /* Skip if it isn't linked against glibc. */
> if (minor_version < 0)
> return NULL;
> +
> + if (auto_version && *auto_version)
> + {
> + /* Add VERSION_DEP to the version dependency list only if
> + libc.so defines VERSION_DEP. */
> +
> + bool defined = false;
> + Elf_Internal_Verdef *d;
> +
> + for (d = elf_tdata (t->vn_bfd)->verdef;
> + d != NULL;
> + d = d->vd_nextdef)
> + if (strcmp (d->vd_nodename, version_dep) == 0)
> + {
> + defined = true;
> + break;
> + }
> +
> + if (!defined)
> + {
> + /* Set *AUTO_VERSION to false to indicate that libc.so
> + doesn't define VERSION_DEP. */
> + *auto_version = false;
> + return NULL;
> + }
> + }
> }
>
> /* Skip if 2.GLIBC_MINOR_BASE includes VERSION_DEP. */
> @@ -2380,7 +2409,8 @@ elf_link_add_glibc_verneed (struct elf_find_verdep_info *rinfo,
> void
> _bfd_elf_link_add_glibc_version_dependency
> (struct elf_find_verdep_info *rinfo,
> - const char *const version_dep[])
> + const char *const version_dep[],
> + bool *auto_version)
> {
> Elf_Internal_Verneed *t = NULL;
> int glibc_minor_base = INT_MAX;
> @@ -2388,11 +2418,12 @@ _bfd_elf_link_add_glibc_version_dependency
> do
> {
> t = elf_link_add_glibc_verneed (rinfo, t, *version_dep,
> - &glibc_minor_base);
> + &glibc_minor_base, auto_version);
> /* Return if there is no glibc version reference. */
> if (t == NULL)
> return;
> version_dep++;
> + auto_version++;
> }
> while (*version_dep != NULL);
> }
> @@ -2410,7 +2441,7 @@ _bfd_elf_link_add_dt_relr_dependency (struct elf_find_verdep_info *rinfo)
> "GLIBC_ABI_DT_RELR",
> NULL
> };
> - _bfd_elf_link_add_glibc_version_dependency (rinfo, version);
> + _bfd_elf_link_add_glibc_version_dependency (rinfo, version, NULL);
> }
> }
>
> diff --git a/bfd/elfxx-x86.h b/bfd/elfxx-x86.h
> index f6ee6a65356..8fd2d81ab6b 100644
> --- a/bfd/elfxx-x86.h
> +++ b/bfd/elfxx-x86.h
> @@ -670,6 +670,10 @@ struct elf_x86_link_hash_table
> /* Number of relative reloc generation pass. */
> unsigned int generate_relative_reloc_pass;
>
> + /* TRUE if inputs have R_X86_64_TLSDESC_CALL relocation. This is
> + only used for x86-64. */
> + unsigned int has_tlsdesc_call : 1;
> +
> /* Value used to fill the unused bytes of the first PLT entry. This
> is only used for i386. */
> bfd_byte plt0_pad_byte;
> diff --git a/ld/NEWS b/ld/NEWS
> index 54c1df5aadf..cfb5c9c81df 100644
> --- a/ld/NEWS
> +++ b/ld/NEWS
> @@ -1,5 +1,11 @@
> -*- text -*-
>
> +* Add --gnu2-tls-tag/--no-gnu2-tls-tag options to x86-64 ELF linker to
> + add the GLIBC_ABI_GNU2_TLS version dependency in output if input object
> + files have R_X86_64_TLSDESC_CALL relocation. Also added
> + --enable-gnu2-tls-tag configure option to enable --gnu2-tls-tag by
> + default.
> +
> * NaCl target support is removed.
>
> Changes in 2.45:
> diff --git a/ld/config.in b/ld/config.in
> index 37812241bd9..021577dbe4d 100644
> --- a/ld/config.in
> +++ b/ld/config.in
> @@ -31,6 +31,10 @@
> when a .note-GNU-stack section is missing. */
> #undef DEFAULT_LD_EXECSTACK
>
> +/* Define to 1 if you want to enable --gnu2-tls-tag in ELF x86-64 linker by
> + default. */
> +#undef DEFAULT_LD_GNU2_TLS_TAG
> +
> /* Define to 1 if you want to enable --rosegment in the ELF linker by default.
> */
> #undef DEFAULT_LD_ROSEGMENT
> diff --git a/ld/configure b/ld/configure
> index 124b44182bc..9c694525488 100755
> --- a/ld/configure
> +++ b/ld/configure
> @@ -851,6 +851,7 @@ enable_textrel_check
> enable_separate_code
> enable_rosegment
> enable_mark_plt
> +enable_gnu2_tls_tag
> enable_memory_seal
> enable_warn_execstack
> enable_error_execstack
> @@ -1548,6 +1549,8 @@ Optional Features:
> --enable-separate-code enable -z separate-code in ELF linker by default
> --enable-rosegment enable --rosegment in the ELF linker by default
> --enable-mark-plt enable -z mark-plt in ELF x86-64 linker by default
> + --enable-gnu2-tls-tag enable --gnu2-tls-tag in ELF x86-64 linker by
> + default
> --enable-memory-seal enable -z memory-seal in ELF linker by default
> --enable-warn-execstack enable warnings when creating an executable stack
> --enable-error-execstack
> @@ -11514,7 +11517,7 @@ else
> lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
> lt_status=$lt_dlunknown
> cat > conftest.$ac_ext <<_LT_EOF
> -#line 11517 "configure"
> +#line 11520 "configure"
> #include "confdefs.h"
>
> #if HAVE_DLFCN_H
> @@ -11620,7 +11623,7 @@ else
> lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
> lt_status=$lt_dlunknown
> cat > conftest.$ac_ext <<_LT_EOF
> -#line 11623 "configure"
> +#line 11626 "configure"
> #include "confdefs.h"
>
> #if HAVE_DLFCN_H
> @@ -15507,6 +15510,18 @@ esac
> fi
>
>
> +# Decide if --gnu2-tls-tag should be enabled in ELF x86-64 linker
> +# by default.
> +ac_default_ld_enable_gnu2_tls_tag=unset
> +# Check whether --enable-gnu2-tls-tag was given.
> +if test "${enable_gnu2_tls_tag+set}" = set; then :
> + enableval=$enable_gnu2_tls_tag; case "${enableval}" in
> + yes) ac_default_ld_enable_gnu2_tls_tag=1 ;;
> + no) ac_default_ld_enable_gnu2_tls_tag=0 ;;
> +esac
> +fi
> +
> +
> # Decide if -z memory-seal should be enabled in ELF linker by default.
> ac_default_ld_z_memory_seal=unset
> # Check whether --enable-memory-seal was given.
> @@ -18981,6 +18996,16 @@ cat >>confdefs.h <<_ACEOF
> _ACEOF
>
>
> +if test "${ac_default_ld_enable_gnu2_tls_tag}" = unset; then
> + # Default to enable --gnu2-tls-tag if libc.so has the GLIBC_ABI_GNU2_TLS
> + # version.
> + ac_default_ld_enable_gnu2_tls_tag=2
> +fi
> +
> +cat >>confdefs.h <<_ACEOF
> +#define DEFAULT_LD_GNU2_TLS_TAG $ac_default_ld_enable_gnu2_tls_tag
> +_ACEOF
> +
>
>
> cat >>confdefs.h <<_ACEOF
> diff --git a/ld/configure.ac b/ld/configure.ac
> index e306c1ded4a..d4801fb1333 100644
> --- a/ld/configure.ac
> +++ b/ld/configure.ac
> @@ -245,6 +245,17 @@ AC_ARG_ENABLE(mark-plt,
> no) ac_default_ld_z_mark_plt=0 ;;
> esac])
>
> +# Decide if --gnu2-tls-tag should be enabled in ELF x86-64 linker
> +# by default.
> +ac_default_ld_enable_gnu2_tls_tag=unset
> +AC_ARG_ENABLE(gnu2-tls-tag,
> + AS_HELP_STRING([--enable-gnu2-tls-tag],
> + [enable --gnu2-tls-tag in ELF x86-64 linker by default]),
> +[case "${enableval}" in
> + yes) ac_default_ld_enable_gnu2_tls_tag=1 ;;
> + no) ac_default_ld_enable_gnu2_tls_tag=0 ;;
> +esac])
> +
> # Decide if -z memory-seal should be enabled in ELF linker by default.
> ac_default_ld_z_memory_seal=unset
> AC_ARG_ENABLE(memory-seal,
> @@ -646,6 +657,14 @@ AC_DEFINE_UNQUOTED(DEFAULT_LD_Z_MEMORY_SEAL,
> $ac_default_ld_z_memory_seal,
> [Define to 1 if you want to enable -z memory_seal in ELF linker by default.])
>
> +if test "${ac_default_ld_enable_gnu2_tls_tag}" = unset; then
> + # Default to enable --gnu2-tls-tag if libc.so has the GLIBC_ABI_GNU2_TLS
> + # version.
> + ac_default_ld_enable_gnu2_tls_tag=2
I like the new auto mode. I was reaching for something like this earlier
but I couldn't figure out how I wanted it to work at the time.
> +fi
> +AC_DEFINE_UNQUOTED(DEFAULT_LD_GNU2_TLS_TAG,
> + $ac_default_ld_enable_gnu2_tls_tag,
> + [Define to 1 if you want to enable --gnu2-tls-tag in ELF x86-64 linker by default.])
>
> AC_DEFINE_UNQUOTED(DEFAULT_LD_WARN_EXECSTACK,
> $ac_default_ld_warn_execstack,
> diff --git a/ld/emulparams/elf32_x86_64.sh b/ld/emulparams/elf32_x86_64.sh
> index 6a92eec129d..4807413d133 100644
> --- a/ld/emulparams/elf32_x86_64.sh
> +++ b/ld/emulparams/elf32_x86_64.sh
> @@ -20,7 +20,7 @@ COMMONPAGESIZE="CONSTANT (COMMONPAGESIZE)"
> ARCH="i386:x64-32"
> MACHINE=
> TEMPLATE_NAME=elf
> -EXTRA_EM_FILE="elf-x86"
> +EXTRA_EM_FILE="elf-x86-64"
> GENERATE_SHLIB_SCRIPT=yes
> GENERATE_PIE_SCRIPT=yes
> NO_SMALL_DATA=yes
> diff --git a/ld/emulparams/elf_x86_64.sh b/ld/emulparams/elf_x86_64.sh
> index 92449745c7a..39cbf2ca189 100644
> --- a/ld/emulparams/elf_x86_64.sh
> +++ b/ld/emulparams/elf_x86_64.sh
> @@ -21,7 +21,7 @@ COMMONPAGESIZE="CONSTANT (COMMONPAGESIZE)"
> ARCH="i386:x86-64"
> MACHINE=
> TEMPLATE_NAME=elf
> -EXTRA_EM_FILE="elf-x86"
> +EXTRA_EM_FILE="elf-x86-64"
> GENERATE_SHLIB_SCRIPT=yes
> GENERATE_PIE_SCRIPT=yes
> NO_SMALL_DATA=yes
> diff --git a/ld/emultempl/elf-x86-64.em b/ld/emultempl/elf-x86-64.em
> new file mode 100644
> index 00000000000..972563b3e07
> --- /dev/null
> +++ b/ld/emultempl/elf-x86-64.em
> @@ -0,0 +1,107 @@
> +# This shell script emits a C file. -*- C -*-
> +# Copyright (C) 2025 Free Software Foundation, Inc.
> +#
> +# This file is part of the GNU Binutils.
> +#
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the license, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program; see the file COPYING3. If not,
> +# see <http://www.gnu.org/licenses/>.
> +#
> +
> +# This file is sourced from elf.em, and defines x86-64 specific routines.
> +#
> +
> +source_em ${srcdir}/emultempl/elf-x86.em
> +
> +fragment <<EOF
> +static void
> +elf_x86_64_before_parse (void)
> +{
> + params.mark_plt = DEFAULT_LD_Z_MARK_PLT;
> + params.gnu2_tls = DEFAULT_LD_GNU2_TLS_TAG;
> +
> + elf_x86_before_parse ();
> +}
> +
> +static void
> +elf_x86_64_before_allocation (void)
> +{
> + if (!bfd_link_relocatable (&link_info)
> + && is_elf_hash_table (link_info.hash)
> + && expld.phase != lang_mark_phase_enum)
> + {
> + struct elf_link_hash_table *htab = elf_hash_table (&link_info);
> + /* Run one_lang_size_sections_pass to estimate the output section
> + layout before sizing dynamic sections. */
> + expld.dataseg.phase = exp_seg_none;
> + expld.phase = lang_mark_phase_enum;
> + /* NB: Exclude linker created GOT setions when estimating output
> + section layout as sizing dynamic sections may change linker
> + created GOT sections. */
> + if (htab->sgot != NULL)
> + htab->sgot->flags |= SEC_EXCLUDE;
> + if (htab->sgotplt != NULL)
> + htab->sgotplt->flags |= SEC_EXCLUDE;
> + one_lang_size_sections_pass (NULL, false);
> + /* Restore linker created GOT setions. */
> + if (htab->sgot != NULL)
> + htab->sgot->flags &= ~SEC_EXCLUDE;
> + if (htab->sgotplt != NULL)
> + htab->sgotplt->flags &= ~SEC_EXCLUDE;
> + lang_reset_memory_regions ();
> + }
> +
> + gld${EMULATION_NAME}_before_allocation ();
> +}
> +EOF
> +
> +LDEMUL_BEFORE_PARSE=elf_x86_64_before_parse
> +LDEMUL_BEFORE_ALLOCATION=elf_x86_64_before_allocation
> +
> +# Define some shell vars to insert bits of code into the standard elf
> +# parse_args and list_options functions.
> +#
> +
> +PARSE_AND_LIST_LONGOPTS_X86_64='
> + { "gnu2-tls-tag", no_argument, NULL, OPTION_GNU2_TLS_TAG },
> + { "no-gnu2-tls-tag", no_argument, NULL, OPTION_NO_GNU2_TLS_TAG },
> +'
> +
> +PARSE_AND_LIST_OPTIONS_X86_64='
> + if (DEFAULT_LD_GNU2_TLS_TAG == 0)
> + fprintf (file, _("\
> + --gnu2-tls-tag Add GLIBC_ABI_GNU2_TLS dependency\n\
> + --no-gnu2-tls-tag Do not add GLIBC_ABI_GNU2_TLS dependency (default)\n"));
> + else if (DEFAULT_LD_GNU2_TLS_TAG == 1)
> + fprintf (file, _("\
> + --gnu2-tls-tag Add GLIBC_ABI_GNU2_TLS dependency (default)\n\
> + --no-gnu2-tls-tag Do not add GLIBC_ABI_GNU2_TLS dependency\n"));
> + else
> + fprintf (file, _("\
> + --gnu2-tls-tag Add GLIBC_ABI_GNU2_TLS dependency (auto)\n\
> + --no-gnu2-tls-tag Do not add GLIBC_ABI_GNU2_TLS dependency\n"));
> +'
> +
> +PARSE_AND_LIST_ARGS_CASES_X86_64='
> + case OPTION_GNU2_TLS_TAG:
> + params.gnu2_tls = 1;
> + break;
> +
> + case OPTION_NO_GNU2_TLS_TAG:
> + params.gnu2_tls = 0;
> + break;
> +'
> +
> +PARSE_AND_LIST_LONGOPTS="$PARSE_AND_LIST_LONGOPTS $PARSE_AND_LIST_LONGOPTS_X86_64"
> +PARSE_AND_LIST_OPTIONS="$PARSE_AND_LIST_OPTIONS $PARSE_AND_LIST_OPTIONS_X86_64"
> +PARSE_AND_LIST_ARGS_CASES="$PARSE_AND_LIST_ARGS_CASES $PARSE_AND_LIST_ARGS_CASES_X86_64"
> diff --git a/ld/emultempl/elf-x86.em b/ld/emultempl/elf-x86.em
> index f72a0cd0d4a..411a4d62294 100644
> --- a/ld/emultempl/elf-x86.em
> +++ b/ld/emultempl/elf-x86.em
> @@ -56,61 +56,3 @@ EOF
>
> LDEMUL_BEFORE_PARSE=elf_x86_before_parse
> fi
> -
> -case x${OUTPUT_FORMAT}${CALL_NOP_BYTE} in
> - x*x86-64*0x67)
> -fragment <<EOF
> -
> -static void
> -elf_x86_64_before_parse (void)
> -{
> - params.mark_plt = DEFAULT_LD_Z_MARK_PLT;
> -
> - elf_x86_before_parse ();
> -}
> -EOF
> -
> - LDEMUL_BEFORE_PARSE=elf_x86_64_before_parse
> - ;;
> -esac
> -
> -case x${OUTPUT_FORMAT} in
> - x*x86-64*)
> -fragment <<EOF
> -
> -static void
> -elf_x86_64_before_allocation (void)
> -{
> - if (!bfd_link_relocatable (&link_info)
> - && is_elf_hash_table (link_info.hash)
> - && expld.phase != lang_mark_phase_enum)
> - {
> - struct elf_link_hash_table *htab = elf_hash_table (&link_info);
> - /* Run one_lang_size_sections_pass to estimate the output section
> - layout before sizing dynamic sections. */
> - expld.dataseg.phase = exp_seg_none;
> - expld.phase = lang_mark_phase_enum;
> - /* NB: Exclude linker created GOT setions when estimating output
> - section layout as sizing dynamic sections may change linker
> - created GOT sections. */
> - if (htab->sgot != NULL)
> - htab->sgot->flags |= SEC_EXCLUDE;
> - if (htab->sgotplt != NULL)
> - htab->sgotplt->flags |= SEC_EXCLUDE;
> - one_lang_size_sections_pass (NULL, false);
> - /* Restore linker created GOT setions. */
> - if (htab->sgot != NULL)
> - htab->sgot->flags &= ~SEC_EXCLUDE;
> - if (htab->sgotplt != NULL)
> - htab->sgotplt->flags &= ~SEC_EXCLUDE;
> - lang_reset_memory_regions ();
> - }
> -
> - gld${EMULATION_NAME}_before_allocation ();
> -}
> -
> -EOF
> -
> -LDEMUL_BEFORE_ALLOCATION=elf_x86_64_before_allocation
> - ;;
> -esac
> diff --git a/ld/ld.texi b/ld/ld.texi
> index 413335ad765..c400a6461f4 100644
> --- a/ld/ld.texi
> +++ b/ld/ld.texi
> @@ -1743,6 +1743,19 @@ Supported for Linux/i386 and Linux/x86_64.
>
> @end table
>
> +@item --gnu2-tls-tag
> +@itemx --no-gnu2-tls-tag
> +Add @code{GLIBC_ABI_GNU2_TLS} version tag dependency in output programs
> +and shared libraries when linking against glibc if input relocatable
> +object files have @code{R_X86_64_TLSDESC_CALL} relocation. The output
> +will fail to load and run at run-time against glibc which doesn't define
> +the @code{GLIBC_ABI_GNU2_TLS} version. Unless disabled by the
> +@option{--disable-gnu2-tls-tag} configure option at the linker build
> +time, when no options are specified, linker will add the
Maybe to correspond with --help: "when no options are specified (auto),"
> +@code{GLIBC_ABI_GNU2_TLS} version dependency if inputs have
> +@code{R_X86_64_TLSDESC_CALL} relocation ad libc.so defines the
and
> +@code{GLIBC_ABI_GNU2_TLS} version.
version tag.
> Supported for Linux/x86_64.
> +
> Other keywords are ignored for Solaris compatibility.
>
> @kindex -(
> diff --git a/ld/ldlex.h b/ld/ldlex.h
> index 815da76a4c0..58bbd5771da 100644
> --- a/ld/ldlex.h
> +++ b/ld/ldlex.h
> @@ -471,6 +471,9 @@ enum option_values
> OPTION_NO_LITERAL_MOVEMENT,
> OPTION_ABI_WINDOWED,
> OPTION_ABI_CALL0,
> + /* Used by emultempl/elf-x86-64.em. */
> + OPTION_GNU2_TLS_TAG,
> + OPTION_NO_GNU2_TLS_TAG,
> };
>
> /* The initial parser states. */
> diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-1.rd b/ld/testsuite/ld-x86-64/gnu2-tls-1.rd
> new file mode 100644
> index 00000000000..3eb926a227c
> --- /dev/null
> +++ b/ld/testsuite/ld-x86-64/gnu2-tls-1.rd
> @@ -0,0 +1,7 @@
> +#...
> +Version needs section '.gnu.version_r' contains 1 entry:
> + Addr: 0x[0-9a-f]+ +Offset: 0x[0-9a-f]+ +Link: +[0-9]+ +\(.dynstr\)
> + +0+: Version: 1 +File: libc\.so\.6(|\.1) +Cnt: +[0-9]+
> +#...
> + 0x[a-f0-9]+: Name: GLIBC_ABI_GNU2_TLS Flags: none Version: [0-9]+
> +#pass
> diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-1a.od b/ld/testsuite/ld-x86-64/gnu2-tls-1a.od
> new file mode 100644
> index 00000000000..e237b26898d
> --- /dev/null
> +++ b/ld/testsuite/ld-x86-64/gnu2-tls-1a.od
> @@ -0,0 +1,13 @@
> +
> +.*: +file format .*
> +#...
> +[a-f0-9]+ <main>:
> + +[a-f0-9]+: 48 83 ec 08 sub \$0x8,%rsp
> + +[a-f0-9]+: 48 8d 05 ([0-9a-f]{2} ){4} lea 0x[a-f0-9]+\(%rip\),%rax # [a-f0-9]+ <foo@@Base\+0x[a-f0-9]+>
> + +[a-f0-9]+: 66 2e 0f 1f 84 00 00 00 00 00 cs nopw 0x0\(%rax,%rax,1\)
> + +[a-f0-9]+: ff 10 call \*\(%rax\)
> + +[a-f0-9]+: 64 8b 00 mov %fs:\(%rax\),%eax
> + +[a-f0-9]+: 48 83 c4 08 add \$0x8,%rsp
> + +[a-f0-9]+: c3 ret
> + +[a-f0-9]+: 90 nop
> +#pass
> diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-1a.s b/ld/testsuite/ld-x86-64/gnu2-tls-1a.s
> new file mode 100644
> index 00000000000..b8c004538ff
> --- /dev/null
> +++ b/ld/testsuite/ld-x86-64/gnu2-tls-1a.s
> @@ -0,0 +1,14 @@
> + .section .text.startup,"ax",@progbits
> + .p2align 4
> + .globl main
> + .type main, @function
> +main:
> + subq $8, %rsp
> + leaq foo@TLSDESC(%rip), %rax
> + .nops 10
> + call *foo@TLSCALL(%rax)
> + movl %fs:(%rax), %eax
> + addq $8, %rsp
> + ret
> + .size main, .-main
> + .section .note.GNU-stack,"",@progbits
> diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-1b.od b/ld/testsuite/ld-x86-64/gnu2-tls-1b.od
> new file mode 100644
> index 00000000000..8bd685006bd
> --- /dev/null
> +++ b/ld/testsuite/ld-x86-64/gnu2-tls-1b.od
> @@ -0,0 +1,13 @@
> +
> +.*: +file format .*
> +#...
> +[a-f0-9]+ <main>:
> + +[a-f0-9]+: 48 83 ec 08 sub \$0x8,%rsp
> + +[a-f0-9]+: 48 c7 c0 fc ff ff ff mov \$0xfffffffffffffffc,%rax
> + +[a-f0-9]+: 66 2e 0f 1f 84 00 00 00 00 00 cs nopw 0x0\(%rax,%rax,1\)
> + +[a-f0-9]+: 66 90 xchg %ax,%ax
> + +[a-f0-9]+: 64 8b 00 mov %fs:\(%rax\),%eax
> + +[a-f0-9]+: 48 83 c4 08 add \$0x8,%rsp
> + +[a-f0-9]+: c3 ret
> + +[a-f0-9]+: 90 nop
> +#pass
> diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-1b.s b/ld/testsuite/ld-x86-64/gnu2-tls-1b.s
> new file mode 100644
> index 00000000000..fcc355f7e5c
> --- /dev/null
> +++ b/ld/testsuite/ld-x86-64/gnu2-tls-1b.s
> @@ -0,0 +1,9 @@
> + .text
> + .globl foo
> + .section .tbss,"awT",@nobits
> + .align 4
> + .type foo, @object
> + .size foo, 4
> +foo:
> + .zero 4
> + .section .note.GNU-stack,"",@progbits
> diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-1c.od b/ld/testsuite/ld-x86-64/gnu2-tls-1c.od
> new file mode 100644
> index 00000000000..8bd685006bd
> --- /dev/null
> +++ b/ld/testsuite/ld-x86-64/gnu2-tls-1c.od
> @@ -0,0 +1,13 @@
> +
> +.*: +file format .*
> +#...
> +[a-f0-9]+ <main>:
> + +[a-f0-9]+: 48 83 ec 08 sub \$0x8,%rsp
> + +[a-f0-9]+: 48 c7 c0 fc ff ff ff mov \$0xfffffffffffffffc,%rax
> + +[a-f0-9]+: 66 2e 0f 1f 84 00 00 00 00 00 cs nopw 0x0\(%rax,%rax,1\)
> + +[a-f0-9]+: 66 90 xchg %ax,%ax
> + +[a-f0-9]+: 64 8b 00 mov %fs:\(%rax\),%eax
> + +[a-f0-9]+: 48 83 c4 08 add \$0x8,%rsp
> + +[a-f0-9]+: c3 ret
> + +[a-f0-9]+: 90 nop
> +#pass
> diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-2.rd b/ld/testsuite/ld-x86-64/gnu2-tls-2.rd
> new file mode 100644
> index 00000000000..33ef8acb232
> --- /dev/null
> +++ b/ld/testsuite/ld-x86-64/gnu2-tls-2.rd
> @@ -0,0 +1,4 @@
> +#failif
> +#...
> + 0x[a-f0-9]+: Name: GLIBC_ABI_GNU2_TLS Flags: none Version: [0-9]+
> +#...
> diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-2.s b/ld/testsuite/ld-x86-64/gnu2-tls-2.s
> new file mode 100644
> index 00000000000..d957eb71f6d
> --- /dev/null
> +++ b/ld/testsuite/ld-x86-64/gnu2-tls-2.s
> @@ -0,0 +1,13 @@
> + .text
> + .p2align 4
> + .globl func
> + .type func, @function
> +func:
> + leaq foo@tlsld(%rip), %rdi
> + call __tls_get_addr@PLT
> + data16 leaq foo@tlsgd(%rip), %rdi
> + .value 0x6666
> + rex64
> + call __tls_get_addr@PLT
> + .size func, .-func
> + .section .note.GNU-stack,"",@progbits
> diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
> index 6b86bc3d018..65be6b97790 100644
> --- a/ld/testsuite/ld-x86-64/x86-64.exp
> +++ b/ld/testsuite/ld-x86-64/x86-64.exp
> @@ -2358,7 +2358,7 @@ run_dump_test "ibt-plt-3b-x32"
> run_dump_test "ibt-plt-3c-x32"
> run_dump_test "ibt-plt-3d-x32"
>
> -# Skip -z mark-plt tests on MUSL.
> +# Skip -z mark-plt and --gnu2-tls-tag tests on MUSL.
> if { [istarget "x86_64-*-musl*"]} {
> set ASFLAGS "$saved_ASFLAGS"
> return
> @@ -2384,6 +2384,49 @@ if { [check_compiler_available] } {
> {readelf {-W --version-info} mark-plt-1b.rd}} \
> "mark-plt-1.so" \
> ] \
> + [list \
> + "Build gnu2-tls-1.so" \
> + "-shared -Wl,--no-as-needed,--gnu2-tls-tag" \
Don't we want $NOPIE_CFLAGS/$NOPIE_LDFLAGS for the non-PIE variants, so
we get test coverage with --enable-default-pie GCC?
(Otherwise the tests are the same.)
I think we have other issues here too that are pre-existing though so
maybe we should deal with that later.
> + "-fPIC" \
> + { gnu2-tls-1a.s gnu2-tls-1b.s } \
> + {{objdump {-dw} gnu2-tls-1a.od}
> + {readelf {-W --version-info} gnu2-tls-1.rd}} \
> + "gnu2-tls-1.so" \
> + ] \
> + [list \
> + "Build gnu2-tls-1-no-gnu2-tls.so" \
> + "-shared -Wl,--no-as-needed,--gnu2-tls-tag" \
> + "-fPIC" \
> + { gnu2-tls-1.s } \
> + {{readelf {-W --version-info} gnu2-tls-2.rd}} \
> + "gnu2-tls-1-no-gnu2-tls.so" \
> + ] \
> + [list \
> + "Build gnu2-tls-1 (PDE)" \
> + "-Wl,--no-as-needed,--gnu2-tls-tag" \
> + "-fPIC" \
> + { gnu2-tls-1a.s gnu2-tls-1b.s } \
> + {{objdump {-dw} gnu2-tls-1b.od}
> + {readelf {-W --version-info} gnu2-tls-2.rd}} \
> + "gnu2-tls-1.pde" \
> + ] \
> + [list \
> + "Build gnu2-tls-1 (PIE)" \
> + "-pie -Wl,--no-as-needed,--gnu2-tls-tag" \
> + "-fPIC" \
> + { gnu2-tls-1a.s gnu2-tls-1b.s } \
> + {{objdump {-dw} gnu2-tls-1c.od}
> + {readelf {-W --version-info} gnu2-tls-2.rd}} \
> + "gnu2-tls-1.pie" \
> + ] \
> + [list \
> + "Build gnu2-tls-2.so" \
> + "-shared -Wl,--no-as-needed,--gnu2-tls-tag" \
> + "-fPIC" \
> + { gnu2-tls-2.s } \
> + {{readelf {-W --version-info} gnu2-tls-2.rd}} \
> + "gnu2-tls-2.s.so" \
> + ] \
> ]
> }
More information about the Binutils
mailing list