Do not relocate absolute symbols by the base address. Such symbols have
SHN_ABS as the section index and their value is not supposed to be
affected by relocation as per the ELF gABI[1]:
"SHN_ABS
The symbol has an absolute value that will not change because of
relocation."
The reason for our non-conformance here seems to be an old SysV linker
bug causing symbols like _DYNAMIC to be incorrectly emitted as absolute
symbols[2]. However in a previous discussion it was pointed that this
is seriously flawed by preventing the lone purpose of the existence of
absolute symbols from being used[3]:
"On the contrary, the only interpretation that makes sense to me is that
it will not change because of relocation at link time or at load time.
Absolute symbols, from the days of the earliest linking loaders, have
been used to represent addresses that are outside the address space of
the module (e.g., memory-mapped addresses or kernel gateway pages).
They've even been used to represent true symbolic constants (e.g.,
system entry point numbers, sizes, version numbers). There's no other
way to represent a true absolute symbol, while the meaning you seek is
easily represented by giving the symbol a non-negative st_shndx value."
and we ought to stop supporting our current broken interpretation.
Update processing for dladdr(3) and dladdr1(3) so that SHN_ABS symbols
are ignored, because under the corrected interpretation they do not
represent addresses within a mapped file and therefore are not supposed
to be considered.
References:
[1] "System V Application Binary Interface - DRAFT - 19 October 2010",
The SCO Group, Section "Symbol Table",
<http://www.sco.com/developers/gabi/2012-12-31/ch4.symtab.html>
[2] Alan Modra, "Absolute symbols"
<https://sourceware.org/ml/binutils/2012-05/msg00019.html>
[3] Cary Coutant, "Re: Absolute symbols"
<https://sourceware.org/ml/binutils/2012-05/msg00020.html>
[BZ #19818]
* sysdeps/generic/ldsodefs.h (SYMBOL_ADDRESS): Handle SHN_ABS
symbols.
* elf/dl-addr.c (determine_info): Ignore SHN_ABS symbols.
* elf/tst-absolute-sym.c: New file.
* elf/tst-absolute-sym-lib.c: New file.
* elf/tst-absolute-sym-lib.lds: New file.
* elf/Makefile (tests): Add `tst-absolute-sym'.
(modules-names): Add `tst-absolute-sym-lib'.
(LDLIBS-tst-absolute-sym-lib.so): New variable.
($(objpfx)tst-absolute-sym-lib.so): New dependency.
($(objpfx)tst-absolute-sym): New dependency.
Wrap symbol address run-time calculation into a macro and use it
throughout, replacing inline calculations.
There are a couple of variants, most of them different in a functionally
insignificant way. Most calculations are right following RESOLVE_MAP,
at which point either the map or the symbol returned can be checked for
validity as the macro sets either both or neither. In some places both
the symbol and the map has to be checked however.
My initial implementation therefore always checked both, however that
resulted in code larger by as much as 0.3%, as many places know from
elsewhere that no check is needed. I have decided the size growth was
unacceptable.
Having looked closer I realized that it's the map that is the culprit.
Therefore I have modified LOOKUP_VALUE_ADDRESS to accept an additional
boolean argument telling it to access the map without checking it for
validity. This in turn has brought quite nice results, with new code
actually being smaller for i686, and MIPS o32, n32 and little-endian n64
targets, unchanged in size for x86-64 and, unusually, marginally larger
for big-endian MIPS n64, as follows:
i686:
text data bss dec hex filename
152255 4052 192 156499 26353 ld-2.27.9000-base.so
152159 4052 192 156403 262f3 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/el:
text data bss dec hex filename
142906 4396 260 147562 2406a ld-2.27.9000-base.so
142890 4396 260 147546 2405a ld-2.27.9000-elf-symbol-value.so
MIPS/n32/el:
text data bss dec hex filename
142267 4404 260 146931 23df3 ld-2.27.9000-base.so
142171 4404 260 146835 23d93 ld-2.27.9000-elf-symbol-value.so
MIPS/n64/el:
text data bss dec hex filename
149835 7376 408 157619 267b3 ld-2.27.9000-base.so
149787 7376 408 157571 26783 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/eb:
text data bss dec hex filename
142870 4396 260 147526 24046 ld-2.27.9000-base.so
142854 4396 260 147510 24036 ld-2.27.9000-elf-symbol-value.so
MIPS/n32/eb:
text data bss dec hex filename
142019 4404 260 146683 23cfb ld-2.27.9000-base.so
141923 4404 260 146587 23c9b ld-2.27.9000-elf-symbol-value.so
MIPS/n64/eb:
text data bss dec hex filename
149763 7376 408 157547 2676b ld-2.27.9000-base.so
149779 7376 408 157563 2677b ld-2.27.9000-elf-symbol-value.so
x86-64:
text data bss dec hex filename
148462 6452 400 155314 25eb2 ld-2.27.9000-base.so
148462 6452 400 155314 25eb2 ld-2.27.9000-elf-symbol-value.so
[BZ #19818]
* sysdeps/generic/ldsodefs.h (LOOKUP_VALUE_ADDRESS): Add `set'
parameter.
(SYMBOL_ADDRESS): New macro.
[!ELF_FUNCTION_PTR_IS_SPECIAL] (DL_SYMBOL_ADDRESS): Use
SYMBOL_ADDRESS for symbol address calculation.
* elf/dl-runtime.c (_dl_fixup): Likewise.
(_dl_profile_fixup): Likewise.
* elf/dl-symaddr.c (_dl_symbol_address): Likewise.
* elf/rtld.c (dl_main): Likewise.
* sysdeps/aarch64/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/alpha/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/arm/dl-machine.h (elf_machine_rel): Likewise.
(elf_machine_rela): Likewise.
* sysdeps/hppa/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/hppa/dl-symaddr.c (_dl_symbol_address): Likewise.
* sysdeps/i386/dl-machine.h (elf_machine_rel): Likewise.
(elf_machine_rela): Likewise.
* sysdeps/ia64/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/m68k/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/microblaze/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/mips/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC):
Likewise.
(elf_machine_reloc): Likewise.
(elf_machine_got_rel): Likewise.
* sysdeps/mips/dl-trampoline.c (__dl_runtime_resolve): Likewise.
* sysdeps/nios2/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/riscv/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/s390/s390-32/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/s390/s390-64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/sh/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/tile/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/x86_64/dl-machine.h (elf_machine_rela): Likewise.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Three of the functions defined by internal-signals.h were not actually
fulfilling their contracts when the sysdeps/generic version of that
file was used. Also, the Linux version included several more headers
than the generic version, which is the root cause of a build failure
on Hurd (already addressed in another way, but I think it is proper to
make the headers match).
* sysdeps/generic/internal-signals.h: Include signal.h,
sigsetops.h, and stdbool.h.
(__libc_signal_block_all): Actually block all signals.
(__libc_signal_block_app): Likewise.
(__libc_signal_restore_set): Actually restore the signal mask.
This patch filters out the internal NPTL signals (SIGCANCEL/SIGTIMER and
SIGSETXID) from signal functions. GLIBC on Linux requires both signals to
proper implement pthread cancellation, posix timers, and set*id posix
thread synchronization.
And not filtering out the internal signal is troublesome:
- A conformant program on a architecture that does not filter out the
signals might inadvertently disable pthread asynchronous cancellation,
set*id synchronization or posix timers.
- It might also to security issues if SIGSETXID is masked and set*id
functions are called (some threads might have effective user or group
id different from the rest).
The changes are basically:
- Change __is_internal_signal to bool and used on all signal function
that has a signal number as input. Also for signal function which accepts
signals sets (sigset_t) it assumes that canonical function were used to
add/remove signals which lead to some input simplification.
- Fix tst-sigset.c to avoid check for SIGCANCEL/SIGTIMER and SIGSETXID.
It is rewritten to check each signal indidually and to check realtime
signals using canonical macros.
- Add generic __clear_internal_signals and __is_internal_signal
version since both symbols are used on generic implementations.
- Remove superflous sysdeps/nptl/sigfillset.c.
- Remove superflous SIGTIMER handling on Linux __is_internal_signal
since it is the same of SIGCANCEL.
- Remove dangling define and obvious comment on nptl/sigaction.c.
Checked on x86_64-linux-gnu.
[BZ #22391]
* nptl/sigaction.c (__sigaction): Use __is_internal_signal to
check for internal nptl signals.
* nptl/sigaction.c (__sigaction): Likewise.
* signal/sigaddset.c (sigaddset): Likewise.
* signal/sigdelset.c (sigdelset): Likewise.
* sysdeps/posix/signal.c (__bsd_signal): Likewise.
* sysdeps/posix/sigset.c (sigset): Call and check sigaddset return
value.
* signal/sigfillset.c (sigfillset): User __clear_internal_signals
to filter out internal nptl signals.
* signal/tst-sigset.c (do_test): Check ech signal indidually and
also check realtime signals using standard macros.
* sysdeps/generic/internal-signals.h (__clear_internal_signals,
__is_internal_signal, __libc_signal_block_all,
__libc_signal_block_app, __libc_signal_restore_set): New functions.
* sysdeps/nptl/sigfillset.c: Remove file.
* sysdeps/unix/sysv/linux/internal-signals.h (__is_internal_signal):
Change return to bool.
(__clear_internal_signals): Remove SIGTIMER clean since it is
equal to SIGCANEL on Linux.
* sysdeps/unix/sysv/linux/sigtimedwait.c (__sigtimedwait): Assume
signal set was constructed using standard functions.
Reported-by: Yury Norov <ynorov@caviumnetworks.com>
Refactor the sincos implementation - rather than rely on odd partial inlining
of preprocessed portions from sin and cos, explicitly write out the cases.
This makes sincos much easier to maintain and provides an additional 16-20%
speedup between 0 and 2^27. The overall speedup of sincos is 48% over this range.
Between 0 and PI it is 66% faster.
* sysdeps/ieee754/dbl-64/s_sin.c (__sin): Cleanup ifdefs.
(__cos): Likewise.
* sysdeps/ieee754/dbl-64/s_sin.c (__sincos): Refactor using the same
logic as sin and cos.
Refactor duplicated code into do_sin. Since all calls to do_sin use copysign to
set the sign of the result, move it inside do_sin. Small inputs use a separate
polynomial, so move this into do_sin as well (the check is based on the more
conservative case when doing large range reduction, but could be relaxed).
* sysdeps/ieee754/dbl-64/s_sin.c (do_sin): Use TAYLOR_SIN for small
inputs. Return correct sign.
(do_sincos): Remove small input check before do_sin, let do_sin set
the sign.
(__sin): Likewise.
(__cos): Likewise.
For huge inputs use the improved do_sincos function as well. Now no cases use
the correction factor returned by do_sin, do_cos and TAYLOR_SIN, so remove it.
* sysdeps/ieee754/dbl-64/s_sin.c (TAYLOR_SIN): Remove cor parameter.
(do_cos): Remove corp parameter and calculations.
(do_sin): Likewise.
(do_sincos): Remove cor variable.
(__sin): Use do_sincos for huge inputs.
(__cos): Likewise.
* sysdeps/ieee754/dbl-64/s_sincos.c (__sincos): Likewise.
(reduce_and_compute_sincos): Remove unused function.
This patch improves the accuracy of the range reduction. When the input is
large (2^27) and very close to a multiple of PI/2, using 110 bits of PI is not
enough. Improve range reduction accuracy to 136 bits. As a result the special
checks for results close to zero can be removed. The ULP of the polynomials is
at worst 0.55ULP, so there is no reason for the slow functions, and they can be
removed.
* sysdeps/ieee754/dbl-64/s_sin.c (reduce_sincos_1): Rename to
reduce_sincos, improve accuracy to 136 bits.
(do_sincos_1): Rename to do_sincos, remove fallbacks to slow functions.
(__sin): Use improved reduction and simplified do_sincos calculation.
(__cos): Likewise.
* sysdeps/ieee754/dbl-64/s_sincos.c (__sincos): Likewise.
This patch removes the large range reduction code and defers to the huge range
reduction code. The first level range reducer supports inputs up to 2^27,
which is way too large given that inputs for sin/cos are typically small
(< 10), and optimizing for a smaller range would give a significant speedup.
Input values above 2^27 are practically never used, so there is no reason for
supporting range reduction between 2^27 and 2^48. Removing it significantly
simplifies code and enables further speedups. There is about a 2.3x slowdown
in this range due to __branred being extremely slow (a better algorithm could
easily more than double performance).
* sysdeps/ieee754/dbl-64/s_sin.c (reduce_sincos_2): Remove function.
(do_sincos_2): Likewise.
(__sin): Remove middle range reduction case.
(__cos): Likewise.
* sysdeps/ieee754/dbl-64/s_sincos.c (__sincos): Remove middle range
reduction case.
This series of patches removes the slow patchs from sin, cos and sincos.
Besides greatly simplifying the implementation, the new version is also much
faster for inputs up to PI (41% faster) and for large inputs needing range
reduction (27% faster).
ULP is ~0.55 with no errors found after testing 1.6 billion inputs across most
of the range with mpsin and mpcos. The number of incorrectly rounded results
(ie. ULP >0.5) is at most ~2750 per million inputs between 0.125 and 0.5,
the average is ~850 per million between 0 and PI.
Tested on AArch64 and x86_64 with no regressions.
The first patch removes the slow paths for the cases where the input is small
and doesn't require range reduction. Update ULP tables for sin, cos and sincos
on AArch64 and x86_64.
* sysdeps/aarch64/libm-test-ulps: Update ULP for sin, cos, sincos.
* sysdeps/ieee754/dbl-64/s_sin.c (__sin): Remove slow paths for small
inputs.
(__cos): Likewise.
* sysdeps/x86_64/fpu/libm-test-ulps: Update ULP for sin, cos, sincos.
This patch assumes O_DIRECTORY works as defined by POSIX on opendir
implementation (aligning with other glibc code, for instance pwd). This
allows remove both the fallback code to handle system with missing or
broken O_DIRECTORY along with the Linux specific opendir.c which just
advertise the working flag.
Checked on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
sparcv9-linux-gnu, sparc64-linux-gnu, powerpc-linux-gnu, and
powerpc64le-linux-gnu.
* sysdeps/posix/opendir.c (o_directory_works, tryopen_o_directory):
Remove definitions.
(opendir_oflags): Use O_DIRECTORY regardless.
(__opendir, __opendirat): Remove need_isdir_precheck usage.
* sysdeps/unix/sysv/linux/opendir.c: Remove file.
* htl/cthreads-compat.c (__cthread_detach): Call __pthread_detach
instead of pthread_detach.
(__cthread_fork): Call __pthread_create instead of pthread_create.
(__cthread_keycreate): Call __pthread_key_create instead of
pthread_key_create.
(__cthread_getspecific): Call __pthread_getspecific instead of
pthread_getspecific.
(__cthread_setspecific): Call __pthread_setspecific instead of
pthread_setspecific.
* htl/pt-alloc.c (__pthread_alloc): Call __pthread_mutex_lock and
__pthread_mutex_unlock instead of pthread_mutex_lock and
pthread_mutex_unlock.
* htl/pt-cleanup.c (__pthread_get_cleanup_stack): Rename to
___pthread_get_cleanup_stack.
(__pthread_get_cleanup_stack): New strong alias.
* htl/pt-create.c: Include <pthreadP.h>.
(entry_point): Call __pthread_exit instead of pthread_exit.
(pthread_create): Rename to __pthread_create.
(pthread_create): New strong alias.
* htl/pt-detach.c (pthread_detach): Rename to __pthread_detach.
(pthread_detach): New strong alias.
(__pthread_detach): Call __pthread_cond_broadcast instead of
pthread_cond_broadcast.
* htl/pt-exit.c (__pthread_exit): Call __pthread_setcancelstate
instead of pthread_setcancelstate.
* htl/pt-testcancel.c: Include <pthreadP.h>.
(pthread_testcancel): Call __pthread_exit instead of pthread_exit.
* sysdeps/htl/pt-attr-getstack.c: Include <pthreadP.h>
(__pthread_attr_getstack): Call __pthread_attr_getstackaddr and
__pthread_attr_getstacksize instead of pthread_attr_getstackaddr and
pthread_attr_getstacksize.
* sysdeps/htl/pt-attr-getstackaddr.c (pthread_attr_getstackaddr):
Rename to __pthread_attr_getstackaddr.
(pthread_attr_getstackaddr): New strong alias.
* sysdeps/htl/pt-attr-getstacksize.c (pthread_attr_getstacksize):
Rename to __pthread_attr_getstacksize.
(pthread_attr_getstacksize): New strong alias.
* sysdeps/htl/pt-attr-setstack.c: Include <pthreadP.h>.
(pthread_attr_setstack): Rename to __pthread_attr_setstack.
(pthread_attr_setstack): New strong alias.
(__pthread_attr_setstack): Call __pthread_attr_getstacksize,
__pthread_attr_setstacksize and __pthread_attr_setstackaddr instead of
pthread_attr_getstacksize, pthread_attr_setstacksize and
pthread_attr_setstackaddr.
* sysdeps/htl/pt-attr-setstackaddr.c (pthread_attr_setstackaddr):
Rename to __pthread_attr_setstackaddr.
(pthread_attr_setstackaddr): New strong alias.
* sysdeps/htl/pt-attr-setstacksize.c (pthread_attr_setstacksize):
Rename to __pthread_attr_setstacksize.
(pthread_attr_setstacksize): New strong alias.
* sysdeps/htl/pt-cond-timedwait.c: Include <pthreadP.h>.
(__pthread_cond_timedwait_internal): Use __pthread_exit instead of
pthread_exit.
* sysdeps/htl/pt-key-create.c: Include <pthreadP.h>.
(__pthread_key_create): New hidden def.
* sysdeps/htl/pt-key.h: Include <pthreadP.h>.
* sysdeps/htl/pthreadP.h (_pthread_mutex_init,
__pthread_cond_broadcast, __pthread_create, __pthread_detach,
__pthread_exit, __pthread_key_create, __pthread_getspecific,
__pthread_setspecific, __pthread_setcancelstate,
__pthread_attr_getstackaddr, __pthread_attr_setstackaddr,
__pthread_attr_getstacksize, __pthread_attr_setstacksize,
__pthread_attr_setstack, ___pthread_get_cleanup_stack): New
declarations.
(__pthread_key_create, _pthread_mutex_init): New hidden declarations.
* sysdeps/mach/hurd/htl/pt-attr-setstackaddr.c
(pthread_attr_setstackaddr): Rename to __pthread_attr_setstackaddr.
(pthread_attr_setstackaddr): New strong alias.
* sysdeps/mach/hurd/htl/pt-attr-setstacksize.c
(pthread_attr_setstacksize): Rename to __pthread_attr_setstacksize.
(pthread_attr_setstacksize): New strong alias.
* sysdeps/mach/hurd/htl/pt-docancel.c: Include <pthreadP.h>.
(call_exit): Call __pthread_exit instead of pthread_exit.
* sysdeps/mach/hurd/htl/pt-mutex-init.c: Include <pthreadP.h>.
(_pthread_mutex_init): New hidden definition.
* sysdeps/mach/hurd/htl/pt-sysdep.c: Include <pthreadP.h>.
(_init_routine): Call __pthread_attr_init and __pthread_attr_setstack
instead of pthread_attr_init and pthread_attr_setstack.
Contributed by
Agustina Arzille <avarzille@riseup.net>
Amos Jeffries <squid3@treenet.co.nz>
David Michael <fedora.dm0@gmail.com>
Marco Gerards <marco@gnu.org>
Marcus Brinkmann <marcus@gnu.org>
Neal H. Walfield <neal@gnu.org>
Pino Toscano <toscano.pino@tiscali.it>
Richard Braun <rbraun@sceen.net>
Roland McGrath <roland@gnu.org>
Samuel Thibault <samuel.thibault@ens-lyon.org>
Thomas DiModica <ricinwich@yahoo.com>
Thomas Schwinge <tschwinge@gnu.org>
* htl: New directory.
* sysdeps/htl: New directory.
* sysdeps/hurd/htl: New directory.
* sysdeps/i386/htl: New directory.
* sysdeps/mach/htl: New directory.
* sysdeps/mach/hurd/htl: New directory.
* sysdeps/mach/hurd/i386/htl: New directory.
* nscd/Depend, resolv/Depend, rt/Depend: Add htl dependency.
* sysdeps/mach/hurd/i386/Implies: Add mach/hurd/i386/htl imply.
* sysdeps/mach/hurd/i386/libpthread.abilist: New file.
This patch fixes 3dc214977 for sparc. Different than other architectures
SPARC kernel Kconfig does not define CONFIG_CLONE_BACKWARDS, however it
has the same ABI as if it did, implemented by sparc-specific code
(sparc_do_fork).
It also has a unique return value convention for clone:
Parent --> %o0 == child's pid, %o1 == 0
Child --> %o0 == parent's pid, %o1 == 1
Which required a special macro to correct issue the syscall
(INLINE_CLONE_SYSCALL).
Checked on sparc64-linux-gnu and sparcv9-linux-gnu.
* sysdeps/unix/sysv/linux/arch-fork.h [__ASSUME_CLONE_BACKWARDS]
(arch_fork): Issue INLINE_CLONE_SYSCALL if defined.
* sysdeps/unix/sysv/linux/sparc/kernel-features.h
(__ASSUME_CLONE_BACKWARDS): Define.
When there is no login uid Linux sets /proc/self/loginid to the sentinel
value of, (uid_t) -1. If this is set we can return early and avoid
needlessly looking up the sentinel value in any configured nss
databases.
Checked on aarch64-linux-gnu.
* sysdeps/unix/sysv/linux/getlogin_r.c (__getlogin_r_loginuid): Return
early when linux sentinel value is set.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Linux kernel architectures have various arrangements for umount
syscalls. There is a syscall that takes flags, and an older one that
does not. Newer architectures have only the one taking flags, under
the name umount2 (or under the name umount, in the ia64 case). Older
architectures may have both, under the names umount2 and umount (or
under the names umount and oldumount, in the alpha case). glibc then
has several similar implementations of the umount function (no flags)
in terms of either the __umount2 function, or the corresponding
syscall, or in terms of the old syscall under either of its names.
This patch simplifies the implementations in glibc by always using the
__umount2 function to implement the umount function on all systems
using the Linux kernel. The linux/generic implementation is moved to
sysdeps/unix/sysv/linux (without any changes to code or comments) and
all the other variants are removed. (This will have the effect of
causing the new syscall to be used in some cases that previously used
the old one, but as discussed for previous changes, such a change to
the underlying syscalls used is OK.)
There remain two variants of how the __umount2 function is
implemented, either in umount2.S, or, for ia64, in syscalls.list.
Tested with build-many-glibcs.py.
[BZ #16552]
* sysdeps/unix/sysv/linux/generic/umount.c: Move to ....
* sysdeps/unix/sysv/linux/umount.c: ... here.
* sysdeps/unix/sysv/linux/arm/umount.c: Remove file.
* sysdeps/unix/sysv/linux/hppa/umount.c: Likewise.
* sysdeps/unix/sysv/linux/ia64/umount.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/umount.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/umount.c: Likewise.
* sysdeps/unix/sysv/linux/umount.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/umount.c: Likewise.
