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65810f0ef0
lll_robust_unlock on i386 and x86_64 first sets the futex word to FUTEX_WAITERS|0 before calling __lll_unlock_wake, which will set the futex word to 0. If the thread is killed between these steps, then the futex word will be FUTEX_WAITERS|0, and the kernel (at least current upstream) will not set it to FUTEX_OWNER_DIED|FUTEX_WAITERS because 0 is not equal to the TID of the crashed thread. The lll_robust_lock assembly code on i386 and x86_64 is not prepared to deal with this case because the fastpath tries to only CAS 0 to TID and not FUTEX_WAITERS|0 to TID; the slowpath simply waits until it can CAS 0 to TID or the futex_word has the FUTEX_OWNER_DIED bit set. This issue is fixed by removing the custom x86 assembly code and using the generic C code instead. However, instead of adding more duplicate code to the custom x86 lowlevellock.h, the code of the lll_robust* functions is inlined into the single call sites that exist for each of these functions in the pthread_mutex_* functions. The robust mutex paths in the latter have been slightly reorganized to make them simpler. This patch is meant to be easy to backport, so C11-style atomics are not used. [BZ #20985] * nptl/Makefile: Adapt. * nptl/pthread_mutex_cond_lock.c (LLL_ROBUST_MUTEX_LOCK): Remove. (LLL_ROBUST_MUTEX_LOCK_MODIFIER): New. * nptl/pthread_mutex_lock.c (LLL_ROBUST_MUTEX_LOCK): Remove. (LLL_ROBUST_MUTEX_LOCK_MODIFIER): New. (__pthread_mutex_lock_full): Inline lll_robust* functions and adapt. * nptl/pthread_mutex_timedlock.c (pthread_mutex_timedlock): Inline lll_robust* functions and adapt. * nptl/pthread_mutex_unlock.c (__pthread_mutex_unlock_full): Likewise. * sysdeps/nptl/lowlevellock.h (__lll_robust_lock_wait, __lll_robust_lock, lll_robust_cond_lock, __lll_robust_timedlock_wait, __lll_robust_timedlock, __lll_robust_unlock): Remove. * sysdeps/unix/sysv/linux/i386/lowlevellock.h (lll_robust_lock, lll_robust_cond_lock, lll_robust_timedlock, lll_robust_unlock): Remove. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (lll_robust_lock, lll_robust_cond_lock, lll_robust_timedlock, lll_robust_unlock): Remove. * sysdeps/unix/sysv/linux/sparc/lowlevellock.h (__lll_robust_lock_wait, __lll_robust_lock, lll_robust_cond_lock, __lll_robust_timedlock_wait, __lll_robust_timedlock, __lll_robust_unlock): Remove. * nptl/lowlevelrobustlock.c: Remove file. * nptl/lowlevelrobustlock.sym: Likewise. * sysdeps/unix/sysv/linux/i386/lowlevelrobustlock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/lowlevelrobustlock.S: Likewise. |
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argp | ||
assert | ||
benchtests | ||
bits | ||
catgets | ||
conform | ||
crypt | ||
csu | ||
ctype | ||
debug | ||
dirent | ||
dlfcn | ||
elf | ||
gmon | ||
gnulib | ||
grp | ||
gshadow | ||
hesiod | ||
hurd | ||
iconv | ||
iconvdata | ||
include | ||
inet | ||
intl | ||
io | ||
libidn | ||
libio | ||
locale | ||
localedata | ||
login | ||
mach | ||
malloc | ||
manual | ||
math | ||
mathvec | ||
misc | ||
nis | ||
nptl | ||
nptl_db | ||
nscd | ||
nss | ||
po | ||
posix | ||
pwd | ||
resolv | ||
resource | ||
rt | ||
scripts | ||
setjmp | ||
shadow | ||
signal | ||
socket | ||
soft-fp | ||
stdio-common | ||
stdlib | ||
streams | ||
string | ||
sunrpc | ||
support | ||
sysdeps | ||
sysvipc | ||
termios | ||
time | ||
timezone | ||
wcsmbs | ||
wctype | ||
.gitattributes | ||
.gitignore | ||
abi-tags | ||
aclocal.m4 | ||
BUGS | ||
ChangeLog | ||
ChangeLog.1 | ||
ChangeLog.2 | ||
ChangeLog.3 | ||
ChangeLog.4 | ||
ChangeLog.5 | ||
ChangeLog.6 | ||
ChangeLog.7 | ||
ChangeLog.8 | ||
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ChangeLog.10 | ||
ChangeLog.11 | ||
ChangeLog.12 | ||
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ChangeLog.14 | ||
ChangeLog.15 | ||
ChangeLog.16 | ||
ChangeLog.17 | ||
ChangeLog.old-ports | ||
ChangeLog.old-ports-aarch64 | ||
ChangeLog.old-ports-aix | ||
ChangeLog.old-ports-alpha | ||
ChangeLog.old-ports-am33 | ||
ChangeLog.old-ports-arm | ||
ChangeLog.old-ports-cris | ||
ChangeLog.old-ports-hppa | ||
ChangeLog.old-ports-ia64 | ||
ChangeLog.old-ports-linux-generic | ||
ChangeLog.old-ports-m68k | ||
ChangeLog.old-ports-microblaze | ||
ChangeLog.old-ports-mips | ||
ChangeLog.old-ports-powerpc | ||
ChangeLog.old-ports-tile | ||
config.h.in | ||
config.make.in | ||
configure | ||
configure.ac | ||
CONFORMANCE | ||
COPYING | ||
COPYING.LIB | ||
cppflags-iterator.mk | ||
extra-lib.mk | ||
extra-modules.mk | ||
gen-locales.mk | ||
INSTALL | ||
libc-abis | ||
LICENSES | ||
Makeconfig | ||
Makefile | ||
Makefile.in | ||
Makerules | ||
NAMESPACE | ||
NEWS | ||
o-iterator.mk | ||
README | ||
README.pretty-printers | ||
README.tunables | ||
Rules | ||
shlib-versions | ||
test-skeleton.c | ||
version.h | ||
WUR-REPORT |
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. The current GNU/Hurd support requires out-of-tree patches that will eventually be incorporated into an official GNU C Library release. When working with Linux kernels, this version of the GNU C Library requires Linux kernel version 3.2 or later on all architectures except i[4567]86 and x86_64, where Linux kernel version 2.6.32 or later suffices. 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 arm-*-linux-gnueabi hppa-*-linux-gnu Not currently functional without patches. 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 sh[34]-*-linux-gnu sparc*-*-linux-gnu sparc64*-*-linux-gnu tilegx-*-linux-gnu tilepro-*-linux-gnu If you are interested in doing a port, please contact the glibc maintainers; see http://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 http://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 http://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.