On Linux/i386, programs and shared libraries compiled with
-mtls-dialect=gnu may fail silently at run-time against glibc without
the GNU TLS run-time fix for:
https://sourceware.org/bugzilla/show_bug.cgi?id=32996
The glibc version tag, GLIBC_ABI_GNU_TLS, has been added to indicate
that glibc has the working GNU TLS run-time:
commit ed1b7a5a489ab555a27fad9c101ebe2e1c1ba881
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Mon Jul 28 12:16:11 2025 -0700
i386: Add GLIBC_ABI_GNU_TLS version [BZ #33221]
Add the --gnu-tls-tag option to x86-64 ELF linker to add the
GLIBC_ABI_GNU_TLS version dependency in output programs and shared
libraries when linking against glibc if input relocatable object files
call ___tls_get_addr. The output will fail to load and run at run-time
against glibc which doesn't define the GLIBC_ABI_GNU_TLS version.
Add the --enable-gnu-tls-tag configure option to enable --gnu-tls-tag
by default. If unspecified, linker will add the GLIBC_ABI_GNU_TLS
version dependency if input call ___tls_get_addr and libc.so defines
the GLIBC_ABI_GNU2_TLS version.
bfd/
PR ld/33287
* elf-linker-x86.h (elf_linker_x86_params): Add
gnu_tls_version_tag.
* elf32-i386.c (elf_backend_add_glibc_version_dependency): Add
GLIBC_ABI_GNU_TLS support.
* elfxx-x86.c (_bfd_x86_elf_link_check_relocs): Set
has_tls_get_addr_call to 1 if ___tls_get_addr is used.
* elfxx-x86.h (elf_x86_link_hash_table): Add has_tls_get_addr_call.
ld/
PR ld/33287
* Mention --gnu-tls-tag, --no-gnu-tls-tag and --enable-gnu-tls-tag.
* config.in: Regenerated.
* configure: Likewise.
* configure.ac: Add --enable-gnu-tls-tag.
* ld.texi: Document --gnu-tls-tag and --enable-gnu-tls-tag.
* ldlex.h (option_values): Add OPTION_GNU_TLS_VERSION_TAG and
OPTION_NO_GNU_TLS_VERSION_TAG.
* emultempl/elf-i386-glibc.em (elf_i386_glibc_before_parse):
Initialize params.gnu_tls_version_tag.
(PARSE_AND_LIST_LONGOPTS_386): New.
(PARSE_AND_LIST_OPTIONS_386): Likewise.
(PARSE_AND_LIST_ARGS_CASES_386): Likewise.
(PARSE_AND_LIST_LONGOPTS): Append $PARSE_AND_LIST_LONGOPTS_386.
(PARSE_AND_LIST_OPTIONS): Append $PARSE_AND_LIST_OPTIONS_386.
(PARSE_AND_LIST_ARGS_CASES): Append
$PARSE_AND_LIST_ARGS_CASES_386.
* testsuite/ld-i386/gnu-tls-1.s: Likewise.
* testsuite/ld-i386/gnu-tls-1a.rd: Likewise.
* testsuite/ld-i386/gnu-tls-1b.rd: Likewise.
* testsuite/ld-i386/i386.exp: Run PR ld/33287 tests.
(cherry picked from commit fbcdc06c23)
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
On Linux/x86-64, programs and shared libraries created with -z mark-plt
have the GLIBC_2.36 version tag dependency since -z mark-plt uses the
r_addend field of the R_X86_64_JUMP_SLOT relocation to store the offset
of the indirect branch instruction. Glibc versions which don't have the
commit added to glibc 2.36:
commit f8587a61892cbafd98ce599131bf4f103466f084
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri May 20 19:21:48 2022 -0700
x86-64: Ignore r_addend for R_X86_64_GLOB_DAT/R_X86_64_JUMP_SLOT
won't ignore the r_addend value in the R_X86_64_JUMP_SLOT relocation. If
glibc versions defines GLIBC_ABI_DT_X86_64_PLT version tag with
commit 399384e0c8193e31aea014220ccfa24300ae5938
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Thu Aug 14 07:03:20 2025 -0700
x86-64: Add GLIBC_ABI_DT_X86_64_PLT [BZ #33212]
to indicate inclusion of the commit:
commit f8587a61892cbafd98ce599131bf4f103466f084
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri May 20 19:21:48 2022 -0700
x86-64: Ignore r_addend for R_X86_64_GLOB_DAT/R_X86_64_JUMP_SLOT
we can add GLIBC_ABI_DT_X86_64_PLT version tag dependency, instead of
GLIBC_2.36 version tag dependency.
PR ld/33213
* elf-bfd.h (_bfd_elf_link_add_glibc_version_dependency): Change
return type to bool.
* elf64-x86-64.c (elf_x86_64_add_glibc_version_dependency): Add
GLIBC_ABI_DT_X86_64_PLT version tag dependency, instead of,
GLIBC_2.36 version tag dependency, for -z mark-plt if libc.so
defines GLIBC_ABI_DT_X86_64_PLT version tag.
* elflink.c (_bfd_elf_link_add_glibc_version_dependency): Change
return type to bool. Return false if elf_link_add_glibc_verneed
returns false.
(cherry picked from commit 66e4999f34)
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
On Linux/x86, programs and shared libraries compiled with
-mtls-dialect=gnu2 may fail silently at run-time against glibc without
the GNU2 TLS run-time fixes for:
https://sourceware.org/bugzilla/show_bug.cgi?id=31501https://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. Add the --gnu2-tls-tag
option to i386/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_386_TLS_DESC_CALL or
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 input object files have R_386_TLS_DESC_CALL or
R_X86_64_TLSDESC_CALL relocation and libc.so defines the GLIBC_ABI_GNU2_TLS
version.
Update elf_link_add_glibc_verneed to properly add the GLIBC_2.36 version
dependency when -z mark-plt -z nopack-relative-relocs passed to x86-64
ELF linker.
bfd/
PR ld/33130
* elf-bfd.h (_bfd_elf_link_add_glibc_version_dependency): Add
a pointer to bool argument.
* elf-linker-x86.h (elf_linker_x86_params): Add
gnu2_tls_version_tag.
* elf32-i386.c (elf_i386_scan_relocs): Set has_tls_desc_call to
1 for R_386_TLS_DESC_CALL.
(elf_i386_add_glibc_version_dependency): New. Undef before
FreeBSD support.
* elf64-x86-64.c (elf_x86_64_scan_relocs): Set has_tls_desc_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.
(elf_backend_add_glibc_version_dependency): Undef before CloudABI
support and redefine for elf32-x86-64.
* elflink.c (elf_link_add_glibc_verneed): Changed to return bool.
Remove the pointer to elf_find_verdep_info argument. Add a
pointer to bool argument, auto_version. Return true if linked
against glibc. Otherwise return false. If the version dependency
is added, set *auto_version to true. 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_tls_desc_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_VERSION_TAG and
OPTION_NO_GNU2_TLS_VERSION_TAG.
* emulparams/elf32_x86_64.sh (EXTRA_EM_FILE): Changed to
"elf-x86-64-glibc".
* emulparams/elf_i386.sh (EXTRA_EM_FILE): Set to "elf-i386-glibc".
* emulparams/elf_i386_fbsd.sh (EXTRA_EM_FILE): New. Set to
"elf-x86".
* emulparams/elf_i386_haiku.sh (EXTRA_EM_FILE): Likewise.
* emulparams/elf_x86_64.sh (EXTRA_EM_FILE): Likewise.
* emulparams/elf_x86_64_cloudabi.sh (EXTRA_EM_FILE): New. Set to
"elf-x86-64".
* emulparams/elf_x86_64_fbsd.sh (EXTRA_EM_FILE): New. Set to
"elf-x86-64".
* emulparams/elf_x86_64_haiku.sh (EXTRA_EM_FILE): Likewise.
* (EXTRA_EM_FILE): Likewise.
* (EXTRA_EM_FILE): Likewise.
* emultempl/elf-i386-glibc.em: New file.
* emultempl/elf-x86-64-glibc.em: Likewise.
* emultempl/elf-x86-64.em: Likewise.
* emultempl/elf-x86-glibc.em: Likewise.
* emultempl/elf-x86.em (elf_x86_64_before_parse): Removed.
(LDEMUL_BEFORE_PARSE): Likewise.
(elf_x86_64_before_allocation): Likewise.
(LDEMUL_BEFORE_ALLOCATION): Likewise.
* emultempl/solaris2-x86-64.em: New file.
* testsuite/ld-i386/gnu2-tls-1.s: Likewise.
* testsuite/ld-i386/gnu2-tls-1a.rd: Likewise.
* testsuite/ld-i386/gnu2-tls-1b.rd: Likewise.
* testsuite/ld-x86-64/gnu2-tls-1.s: Likewise.
* testsuite/ld-x86-64/gnu2-tls-1a.rd: Likewise.
* testsuite/ld-x86-64/gnu2-tls-1b.rd: Likewise.
* testsuite/ld-x86-64/mark-plt-2.rd: Likewise.
* testsuite/ld-x86-64/mark-plt-2.s: Likewise.
* testsuite/ld-i386/i386.exp: Run GLIBC_ABI_GNU2_TLS tests.
* testsuite/ld-x86-64/x86-64.exp: Likewise.
(cherry picked from commit 0d1e88f8bf)
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
