Go to file
Szabolcs Nagy 83b5323261 elf: Avoid deadlock between pthread_create and ctors [BZ #28357]
The fix for bug 19329 caused a regression such that pthread_create can
deadlock when concurrent ctors from dlopen are waiting for it to finish.
Use a new GL(dl_load_tls_lock) in pthread_create that is not taken
around ctors in dlopen.

The new lock is also used in __tls_get_addr instead of GL(dl_load_lock).

The new lock is held in _dl_open_worker and _dl_close_worker around
most of the logic before/after the init/fini routines.  When init/fini
routines are running then TLS is in a consistent, usable state.
In _dl_open_worker the new lock requires catching and reraising dlopen
failures that happen in the critical section.

The new lock is reinitialized in a fork child, to keep the existing
behaviour and it is kept recursive in case malloc interposition or TLS
access from signal handlers can retake it.  It is not obvious if this
is necessary or helps, but avoids changing the preexisting behaviour.

The new lock may be more appropriate for dl_iterate_phdr too than
GL(dl_load_write_lock), since TLS state of an incompletely loaded
module may be accessed.  If the new lock can replace the old one,
that can be a separate change.

Fixes bug 28357.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-10-04 15:07:05 +01:00
argp Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
assert Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
benchtests benchtests: Improve reliability of memcmp benchmarks 2021-09-24 18:04:05 -05:00
bits Add missing braces to bsearch inline implementation [BZ #28400] 2021-09-30 20:40:12 +02:00
catgets Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
ChangeLog.old Update ChangeLog.old/ChangeLog.23. 2021-08-01 21:33:43 -04:00
conform Use $(pie-default) with conformtest 2021-09-17 19:24:14 +00:00
crypt Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
csu Extend struct r_debug to support multiple namespaces [BZ #15971] 2021-09-19 13:51:35 -07:00
ctype Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
debug Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
dirent Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
dlfcn Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
elf elf: Avoid deadlock between pthread_create and ctors [BZ #28357] 2021-10-04 15:07:05 +01:00
gmon Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
gnulib Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
grp Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
gshadow Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
hesiod Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
htl htl: Fix sigset of main thread 2021-09-26 02:40:26 +02:00
hurd Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
iconv iconvconfig: Fix behaviour with --prefix [BZ #28199] 2021-09-13 20:48:35 +05:30
iconvdata Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
include misc: Add __get_nprocs_sched 2021-09-27 09:13:06 -03:00
inet Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
intl Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
io io: Do not skip timestamps tests for 32-bit time_t 2021-10-04 10:51:55 -03:00
libio Add C2X _PRINTF_NAN_LEN_MAX 2021-09-30 20:53:34 +00:00
locale locale: Add missing second argument to _Static_assert in C-collate-seq.c 2021-09-06 19:43:37 +02:00
localedata Update to Unicode 14.0.0 [BZ #28390] 2021-10-04 08:54:27 +02:00
login Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
mach Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
malloc misc: Add __get_nprocs_sched 2021-09-27 09:13:06 -03:00
manual Add C2X _PRINTF_NAN_LEN_MAX 2021-09-30 20:53:34 +00:00
math Add exp10 macro to <tgmath.h> (bug 26108) 2021-09-30 20:40:34 +00:00
mathvec Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
misc misc: Add __get_nprocs_sched 2021-09-27 09:13:06 -03:00
nis Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
nptl nptl: pthread_kill must send signals to a specific thread [BZ #28407] 2021-10-01 18:16:41 +02:00
nptl_db Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
nscd Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
nss Fix failing nss/tst-nss-files-hosts-long with local resolver 2021-09-07 21:41:38 +02:00
po po/nl.po: Update Dutch translation. 2021-08-01 20:52:28 -04:00
posix elf: Avoid deadlock between pthread_create and ctors [BZ #28357] 2021-10-04 15:07:05 +01:00
pwd Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
resolv Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
resource y2038: Add support for 64-bit time on legacy ABIs 2021-06-15 10:42:11 -03:00
rt Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
scripts build-many-glibcs.py: add powerpc64le glibc variant without multiarch 2021-09-24 14:32:35 -05:00
setjmp nptl: Move __pthread_unwind_next into libc 2021-04-21 19:49:50 +02:00
shadow Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
signal Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
socket Linux: Simplify __opensock and fix race condition [BZ #28353] 2021-09-28 18:55:49 +02:00
soft-fp Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
stdio-common vfprintf: Unify argument handling in process_arg 2021-09-23 11:19:20 +02:00
stdlib Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
string Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
sunrpc Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
support support: Add check for TID zero in support_wait_for_thread_exit 2021-10-01 18:16:41 +02:00
sysdeps elf: Avoid deadlock between pthread_create and ctors [BZ #28357] 2021-10-04 15:07:05 +01:00
sysvipc Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
termios Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
time time: Ignore interval nanoseconds on tst-itimer 2021-10-04 10:51:55 -03:00
timezone Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
wcsmbs Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
wctype Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
.gitattributes Assume __NR_openat is always defined 2016-03-23 23:35:08 +01:00
.gitignore Add *.pyc to .gitignore 2015-05-18 15:26:26 +05:30
abi-tags Remove the bulk of the NaCl port. 2017-05-20 08:09:10 -04:00
aclocal.m4 configure: Replaced obsolete AC_TRY_COMPILE 2021-06-04 10:16:00 -03:00
config.h.in x86-64: Remove assembler AVX512DQ check 2021-08-24 07:05:35 -07:00
config.make.in Add pthread-in-libc, libpthread-routines-var, librt-routines-var 2021-05-03 08:13:32 +02:00
configure configure: Fix check for INSERT in linker script 2021-09-13 12:39:20 -07:00
configure.ac configure: Fix check for INSERT in linker script 2021-09-13 12:39:20 -07:00
CONTRIBUTED-BY Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
COPYING
COPYING.LIB
extra-lib.mk Rename cppflags-iterator.mk to libof-iterator.mk, remove extra-modules.mk. 2017-05-09 07:06:29 -04:00
gen-locales.mk Improve gen-locales.mk and gen-locale.sh to make test files with @ options work 2018-02-27 17:01:57 +01:00
INSTALL Update install.texi, and regenerate INSTALL. 2021-08-01 16:48:43 -04:00
libc-abis riscv: support GNU indirect function 2021-01-10 21:25:13 -05:00
libof-iterator.mk Rename cppflags-iterator.mk to libof-iterator.mk, remove extra-modules.mk. 2017-05-09 07:06:29 -04:00
LICENSES Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
MAINTAINERS Add MAINTAINERS 2017-05-11 13:38:30 -04:00
Makeconfig Run conform/ tests using newly built libc 2021-09-17 13:12:10 +00:00
Makefile testrun.sh: Add support for --tool=rpctrace 2021-09-10 01:24:10 +02:00
Makefile.help Update copyright dates with scripts/update-copyrights 2021-01-02 12:17:34 -08:00
Makefile.in New make target to only build benchmark binaries 2016-04-20 10:23:28 +05:30
Makerules Install shared objects under their ABI names 2021-06-28 08:33:57 +02:00
NEWS Update to Unicode 14.0.0 [BZ #28390] 2021-10-04 08:54:27 +02:00
o-iterator.mk
README Documentation for the RISC-V 32-bit port 2020-08-27 08:17:44 -07:00
Rules Move malloc hooks into a compat DSO 2021-07-22 18:37:59 +05:30
SHARED-FILES Mention today's regex merge in SHARED-FILES 2021-09-21 18:00:10 -07:00
shlib-versions Move malloc hooks into a compat DSO 2021-07-22 18:37:59 +05:30
test-skeleton.c Remove "Contributed by" lines 2021-09-03 22:06:44 +05:30
version.h Open master branch for glibc 2.35 development 2021-08-01 21:54:40 -04:00

This directory contains the sources of the GNU C Library.
See the file "version.h" for what release version you have.

The GNU C Library is the standard system C library for all GNU systems,
and is an important part of what makes up a GNU system.  It provides the
system API for all programs written in C and C-compatible languages such
as C++ and Objective C; the runtime facilities of other programming
languages use the C library to access the underlying operating system.

In GNU/Linux systems, the C library works with the Linux kernel to
implement the operating system behavior seen by user applications.
In GNU/Hurd systems, it works with a microkernel and Hurd servers.

The GNU C Library implements much of the POSIX.1 functionality in the
GNU/Hurd system, using configurations i[4567]86-*-gnu.

When working with Linux kernels, this version of the GNU C Library
requires Linux kernel version 3.2 or later.

Also note that the shared version of the libgcc_s library must be
installed for the pthread library to work correctly.

The GNU C Library supports these configurations for using Linux kernels:

	aarch64*-*-linux-gnu
	alpha*-*-linux-gnu
	arc*-*-linux-gnu
	arm-*-linux-gnueabi
	csky-*-linux-gnuabiv2
	hppa-*-linux-gnu
	i[4567]86-*-linux-gnu
	x86_64-*-linux-gnu	Can build either x86_64 or x32
	ia64-*-linux-gnu
	m68k-*-linux-gnu
	microblaze*-*-linux-gnu
	mips-*-linux-gnu
	mips64-*-linux-gnu
	powerpc-*-linux-gnu	Hardware or software floating point, BE only.
	powerpc64*-*-linux-gnu	Big-endian and little-endian.
	s390-*-linux-gnu
	s390x-*-linux-gnu
	riscv32-*-linux-gnu
	riscv64-*-linux-gnu
	sh[34]-*-linux-gnu
	sparc*-*-linux-gnu
	sparc64*-*-linux-gnu

If you are interested in doing a port, please contact the glibc
maintainers; see https://www.gnu.org/software/libc/ for more
information.

See the file INSTALL to find out how to configure, build, and install
the GNU C Library.  You might also consider reading the WWW pages for
the C library at https://www.gnu.org/software/libc/.

The GNU C Library is (almost) completely documented by the Texinfo manual
found in the `manual/' subdirectory.  The manual is still being updated
and contains some known errors and omissions; we regret that we do not
have the resources to work on the manual as much as we would like.  For
corrections to the manual, please file a bug in the `manual' component,
following the bug-reporting instructions below.  Please be sure to check
the manual in the current development sources to see if your problem has
already been corrected.

Please see https://www.gnu.org/software/libc/bugs.html for bug reporting
information.  We are now using the Bugzilla system to track all bug reports.
This web page gives detailed information on how to report bugs properly.

The GNU C Library is free software.  See the file COPYING.LIB for copying
conditions, and LICENSES for notices about a few contributions that require
these additional notices to be distributed.  License copyright years may be
listed using range notation, e.g., 1996-2015, indicating that every year in
the range, inclusive, is a copyrightable year that would otherwise be listed
individually.