When opening a temporary file without O_CLOEXEC we risk leaking the
file descriptor if another thread calls (fork and then) exec while we
have the fd open. Fix this by consistently passing O_CLOEXEC everywhere
where we open a file for internal use (and not to return it to the user,
in which case the API defines whether or not the close-on-exec flag
shall be set on the returned fd).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230419160207.65988-4-bugaevc@gmail.com>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date. Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.
Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions. These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.
The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively. These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:
https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dchttps://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
This reduces the possible error scenarios considerably because
no longer can file seek fail, leaving the file descriptor in an
inconsistent state and out of sync with the cache.
As a result, it is possible to avoid setting file_offset to -1
to make an error persistent. Instead, subsequent calls will retry
the operation and report any errors returned by the kernel.
This change also avoids reading the file from the start if pututline
is called multiple times, to work around lock acquisition failures
due to timeouts.
Change-Id: If21ea0c162c38830a89331ea93cddec14c0974de
This simplifies internal_getut_nolock and fixes a regression,
introduced in commit be6b16d975
("login: Acquire write lock early in pututline [BZ #24882]")
in pututxline because __utmp_equal can only compare process-related
utmp entries.
Fixes: be6b16d975
Change-Id: Ib8a85002f7f87ee41590846d16d7e52bdb82f5a5
It has been reported that due to lack of fairness in POSIX file
locking, the current reader-to-writer lock upgrade can result in
lack of forward progress. Acquiring the write lock directly
hopefully avoids this issue if there are only writers.
This also fixes bug 24882 due to the cache revalidation in
__libc_pututline.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Change-Id: I57e31ae30719e609a53505a0924dda101d46372e
Since l_whence is the second member of struct flock, it is written
twice. The double-assignment is technically undefined behavior due to
the lack of a sequence point.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Change-Id: I2baf9e70690e723c61051b25ccbd510aec15976c
The internal_getut_r function updates the file_offset variable and
therefore must always update last_entry as well.
Previously, if pututxline could not upgrade the read lock to a
write lock, internal_getut_r would update file_offset only,
without updating last_entry, and a subsequent call would not
overwrite the existing utmpx entry at file_offset, instead
creating a new entry. This has been observed to cause unbounded
file growth in high-load situations.
This commit removes the buffer argument to internal_getut_r and
updates the last_entry variable directly, along with file_offset.
Initially reported and fixed by Ondřej Lysoněk.
Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
Commit 06ab719d30 ("Fix Linux fcntl OFD
locks for non-LFS architectures (BZ#20251)") introduced the use of
fcntl64 into the utmp implementation. However, the lock file
structure was not updated to struct flock64 at that point.
If the file processing takes a long time for some reason, SIGALRM can
arrive while the file is still being processed. At that point, file
access will fail with EINTR. Disarming the timer after lock
acquisition avoids that. (If there was a previous alarm, it is the
responsibility of the caller to deal with the EINTR error.)
Commit 5a3afa9738 (login: Replace
macro-based control flow with function calls in utmp) introduced
a regression because after it, __libc_updwtmp attempts to unlock
the wrong file descriptor.
There is just one file-based implementation, so this dispatch
mechanism is unnecessary. Instead of the vtable pointer
__libc_utmp_jump_table, use a non-negative file_fd as the indicator
that the backend is initialized.
This patch fixes the OFD ("file private") locks for architectures that
support non-LFS flock definition (__USE_FILE_OFFSET64 not defined). The
issue in this case is both F_OFD_{GETLK,SETLK,SETLKW} and
F_{SET,GET}L{W}K64 expects a flock64 argument and when using old
F_OFD_* flags with a non LFS flock argument the kernel might interpret
the underlying data wrongly. Kernel idea originally was to avoid using
such flags in non-LFS syscall, but since GLIBC uses fcntl with LFS
semantic as default it is possible to provide the functionality and
avoid the bogus struct kernel passing by adjusting the struct manually
for the required flags.
The idea follows other LFS interfaces that provide two symbols:
1. A new LFS fcntl64 is added on default ABI with the usual macros to
select it for FILE_OFFSET_BITS=64.
2. The Linux non-LFS fcntl use a stack allocated struct flock64 for
F_OFD_{GETLK,SETLK,SETLKW} copy the results on the user provided
struct.
3. Keep a compat symbol with old broken semantic for architectures
that do not define __OFF_T_MATCHES_OFF64_T.
So for architectures which defines __USE_FILE_OFFSET64, fcntl64 will
aliased to fcntl and no adjustment would be required. So to actually
use F_OFD_* with LFS support the source must be built with LFS support
(_FILE_OFFSET_BITS=64).
Also F_OFD_SETLKW command is handled a cancellation point, as for
F_SETLKW{64}.
Checked on x86_64-linux-gnu and i686-linux-gnu.
[BZ #20251]
* NEWS: Mention fcntl64 addition.
* csu/check_fds.c: Replace __fcntl_nocancel by __fcntl64_nocancel.
* login/utmp_file.c: Likewise.
* sysdeps/posix/fdopendir.c: Likewise.
* sysdeps/posix/opendir.c: Likewise.
* sysdeps/unix/pt-fcntl.c: Likewise.
* include/fcntl.h (__libc_fcntl64, __fcntl64,
__fcntl64_nocancel_adjusted): New prototype.
(__fcntl_nocancel_adjusted): Remove prototype.
* io/Makefile (routines): Add fcntl64.
(CFLAGS-fcntl64.c): New rule.
* io/Versions [GLIBC_2.28] (fcntl64): New symbol.
[GLIBC_PRIVATE] (__libc_fcntl): Rename to __libc_fcntl64.
* io/fcntl.h (fcntl64): Add prototype and redirect if
__USE_FILE_OFFSET64 is defined.
* io/fcntl64.c: New file.
* manual/llio.text: Add a note for which commands fcntl acts a
cancellation point.
* nptl/Makefile (CFLAGS-fcntl64.c): New rule.
* sysdeps/mach/hurd/fcntl.c: Alias fcntl to fcntl64 symbols.
* sysdeps/mach/hurd/i386/libc.abilist [GLIBC_2.28] (fcntl, fcntl64):
New symbols.
* sysdeps/unix/sysv/linux/fcntl.c (__libc_fcntl): Fix F_GETLK64,
F_OFD_GETLK, F_SETLK64, F_SETLKW64, F_OFD_SETLK, and F_OFD_SETLKW for
non-LFS case.
* sysdeps/unix/sysv/linux/fcntl64.c: New file.
* sysdeps/unix/sysv/linux/fcntl_nocancel.c (__fcntl_nocancel): Rename
to __fcntl64_nocancel.
(__fcntl_nocancel_adjusted): Rename to __fcntl64_nocancel_adjusted.
* sysdeps/unix/sysv/linux/not-cancel.h (__fcntl_nocancel): Rename
to __fcntl64_nocancel.
* sysdeps/unix/sysv/linux/tst-ofdlocks.c: New file.
* sysdeps/unix/sysv/linux/tst-ofdlocks-compat.c: Likewise.
* sysdeps/unix/sysv/linux/Makefile (tests): Add tst-ofdlocks.
(tests-internal): Add tst-ofdlocks-compat.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist [GLIBC_2.28]
(fcntl64): New symbol.
* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise.
* sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libc.abilist [GLIBC_2.28] (fcntl,
fcntl64): Likewise.
* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilis: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
This patch consolidate the remaning non cancellable syscall definitions
on not-cancel.h header. They are:
* __fcntl_nocancel: Moved from fcntl.h to not-cancel.h.
* __sigsuspend_nocancel: Removed since 988f991b50 it is not used or
defined anymore.
* __nanosleep_nocancel: Removed since 6f33fd046b it is defined on
not-cancel.h.
Now all non-cancellable syscall definition are defined on not-cancel
(the only exceptions is the stdio symbol __fxprintf_nocancel which
uses non cancellable open and it is used on getopt implementation).
Checked on x86_64-linux-gnu and with build-many-glibc.py.
* include/fcntl.h (__fcntl_nocancel): Remove definition.
* include/signal.h (__sigsuspend_nocancel): Likewise.
* include/time.h (__nanosleep_nocancel): Likewise.
* sysdeps/generic/not-cancel.h (__fcntl_nocancel): New macro.
* login/utmp_file.c: Include non cancellable syscall header.
* sysdeps/unix/sysv/linux/not-cancel.h (__fcntl_nocancel): New
prototype.
This patch consolidates all the non cancellable fcntl calls to use
the __fcntl_nocancel identifier. For non cancellable targets it will
be just a macro to call the default respective symbol while on Linux
will be a internal one.
Since its prototype is already defined at internal fcntl.h header, it
is removed from not-cancel.h one.
Checked on x86_64-linux-gnu, x86_64-linux-gnu-x32, and i686-linux-gnu.
* login/utmp_file.c (timeout_handler): Replace fcntl_not_cancel with
__fcntl_nocancel.
* sysdeps/generic/not-cancel.h (fcntl_not_cancel): Remove macro.
* sysdeps/unix/sysv/linux/not-cancel.h (fcntl_not_cancel): Likewise.
This patch consolidates all the non cancellable write calls to use
the __write_nocancel identifier. For non cancellable targets it will
be just a macro to call the default respective symbol while on Linux
will be a internal one.
Checked on x86_64-linux-gnu, x86_64-linux-gnu-x32, and i686-linux-gnu.
* sysdeps/generic/not-cancel.h (write_not_cancel): Remove macro.
(__write_nocancel): New macro.
* sysdeps/unix/sysv/linux/not-cancel.h (__write_nocancel):
Rewrite as a function prototype.
(write_not_cancel): Remove macro.
* sysdeps/unix/sysv/linux/write.c (__write_nocancel): New function.
* gmon/gmon.c (ERR): Replace write_not_cancel with __write_nocancel.
(write_gmon): Likewise.
* libio/fileops.c (_IO_new_file_write): Likewise.
* login/utmp_file.c (pututline_file): Likewise.
(updwtmp_file): Likewise.
* stdio-common/psiginfo.c (psiginfo): Likewise.
* sysdeps/posix/spawni.c (__spawni_child): Likewise.
* sysdeps/unix/sysv/linux/gethostid.c (sethostid): Likewise.
* sysdeps/unix/sysv/linux/libc_fatal.c (backtrace_and_maps):
Likewise.
* sysdeps/unix/sysv/linux/pthread_setname.c (pthread_setname_np):
Likewise.
This patch consolidates all the non cancellable read calls to use
the __read_nocancel identifier. For non cancellable targets it will
be just a macro to call the default respective symbol while on Linux
will be a internal one.
Also, since it is used on libcrypto it is also exported in GLIBC_PRIVATE
namespace.
Checked on x86_64-linux-gnu, x86_64-linux-gnu-x32, and i686-linux-gnu.
* sysdeps/generic/not-cancel.h (read_not_cancel): Remove macro.
(__read_nocancel): New macro.
* sysdeps/unix/sysv/linux/Versions (libc) [GLIBC_PRIVATE]: Add
__read_nocancel.
* sysdeps/unix/sysv/linux/not-cancel.h (__read_nocancel): Remove
macro.
(__read_nocancel): New prototype.
* sysdeps/unix/sysv/linux/read.c (__read_nocancel): New function.
* catgets/open_catalog.c (__open_catalog): Replace read_not_cancel
with __read_nocancel.
* intl/loadmsgcat.c (read): Likewise.
* libio/fileops.c (_IO_file_read): Likewise.
* locale/loadlocale.c (_nl_load_locale): Likewise.
* login/utmp_file.c (getutent_r_file): Likewise.
(internal_getut_r): Likewise.
(getutline_r_file): Likewise.
* sysdeps/unix/sysv/linux/fips-private.h (fips_enable_p): Likewise.
* sysdeps/unix/sysv/linux/gethostid.c (gethostid): Likewise.
* sysdeps/unix/sysv/linux/getloadavg.c (getloadavg): Likewise.
* sysdeps/unix/sysv/linux/getlogin_r.c (__getlogin_r_loginuid):
Likewise.
* sysdeps/unix/sysv/linux/getsysstats.c (next_line): Likewise.
* sysdeps/unix/sysv/linux/i386/smp.h (is_smp_system): Likewise.
* sysdeps/unix/sysv/linux/ia64/has_cpuclock.c (has_cpuclock):
Likewise.
* sysdeps/unix/sysv/linux/libc_fatal.c (backtrace_and_maps):
Likewise.
* sysdeps/unix/sysv/linux/malloc-sysdep.h (check_may_shrink_heap):
Likewise.
* sysdeps/unix/sysv/linux/pthread_getname.c (pthread_getname_np):
Likewise.
* sysdeps/unix/sysv/linux/sysconf.c (__sysconf): Likewise.
The types affected are __sig_atomic_t, sig_atomic_t, __sigset_t,
sigset_t, sigval_t, sigevent_t, and siginfo_t. __sig_atomic_t is a
scalar, so it's now directly available from bits/types.h. The others
get bits/types/ headers.
Side effects include: There have been small changes to which
non-signal headers expose which subset of the signal-related types.
A couple of architectures' nested siginfo_t fields had to be renamed
to prevent undesired macro expansion. Internal code that wants to
manipulate signal masks must now include <sigsetops.h> (which is not
installed) and should be aware that __sigaddset, __sigandset,
__sigdelset, __sigemptyset, and __sigorset no longer return a value
(unlike the public API). Relatedly, the public signal.h no longer
declares any of those functions. The obsolete sigmask() macro no
longer has a system-specific definition -- in the cases where it
matters, it didn't work anyway.
New Linux architectures should create bits/siginfo-arch.h and/or
bits/siginfo-consts-arch.h to customize their siginfo_t, rather than
duplicating everything in bits/siginfo.h (which no longer exists).
Add new __SI_* macros if necessary. Ports to other operating systems
are strongly encouraged to generalize this scheme further.
* bits/sigevent-consts.h
* bits/siginfo-consts.h
* bits/types/__sigset_t.h
* bits/types/sigevent_t.h
* bits/types/siginfo_t.h
* sysdeps/unix/sysv/linux/bits/sigevent-consts.h
* sysdeps/unix/sysv/linux/bits/siginfo-consts.h
* sysdeps/unix/sysv/linux/bits/types/__sigset_t.h
* sysdeps/unix/sysv/linux/bits/types/sigevent_t.h
* sysdeps/unix/sysv/linux/bits/types/siginfo_t.h:
New system-dependent bits headers.
* sysdeps/unix/sysv/linux/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/bits/siginfo-consts-arch.h
* sysdeps/unix/sysv/linux/ia64/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/ia64/bits/siginfo-consts-arch.h
* sysdeps/unix/sysv/linux/mips/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/sparc/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/tile/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/tile/bits/siginfo-consts-arch.h
* sysdeps/unix/sysv/linux/x86/bits/siginfo-arch.h:
New Linux-only system-dependent bits headers.
* signal/bits/types/sig_atomic_t.h
* signal/bits/types/sigset_t.h
* signal/bits/types/sigval_t.h:
New non-system-dependent bits headers.
* sysdeps/generic/sigsetops.h
* sysdeps/unix/sysv/linux/sigsetops.h:
New internal headers.
* include/bits/types/sig_atomic_t.h
* include/bits/types/sigset_t.h
* include/bits/types/sigval_t.h:
New wrappers.
* signal/sigsetops.h
* bits/siginfo.h
* bits/sigset.h
* sysdeps/unix/sysv/linux/bits/siginfo.h
* sysdeps/unix/sysv/linux/bits/sigset.h
* sysdeps/unix/sysv/linux/ia64/bits/siginfo.h
* sysdeps/unix/sysv/linux/mips/bits/siginfo.h
* sysdeps/unix/sysv/linux/s390/bits/siginfo.h
* sysdeps/unix/sysv/linux/sparc/bits/siginfo.h
* sysdeps/unix/sysv/linux/tile/bits/siginfo.h
* sysdeps/unix/sysv/linux/x86/bits/siginfo.h:
Deleted.
* signal/Makefile, sysdeps/unix/sysv/linux/Makefile:
Update lists of installed headers.
* posix/bits/types.h: Define __sig_atomic_t here.
* signal/signal.h: Use the new bits headers; no need to handle
__need_sig_atomic_t nor __need_sigset_t. Don't use __sigmask
to define sigmask.
* include/signal.h: No need to handle __need_sig_atomic_t
nor __need_sigset_t. Don't define __sigemptyset.
* io/sys/poll.h, setjmp/setjmp.h
* sysdeps/arm/sys/ucontext.h, sysdeps/generic/sys/ucontext.h
* sysdeps/i386/sys/ucontext.h, sysdeps/m68k/sys/ucontext.h
* sysdeps/mach/hurd/i386/bits/sigcontext.h
* sysdeps/mips/sys/ucontext.h, sysdeps/powerpc/novmxsetjmp.h
* sysdeps/pthread/bits/sigthread.h
* sysdeps/unix/sysv/linux/hppa/sys/ucontext.h
* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h
* sysdeps/unix/sysv/linux/mips/sys/ucontext.h
* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h
* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
* sysdeps/unix/sysv/linux/s390/sys/ucontext.h
* sysdeps/unix/sysv/linux/sh/sys/ucontext.h
* sysdeps/unix/sysv/linux/sparc/sys/ucontext.h
* sysdeps/unix/sysv/linux/tile/sys/ucontext.h
* sysdeps/unix/sysv/linux/x86/sys/ucontext.h:
Use bits/types/__sigset_t.h.
* misc/sys/select.h, posix/spawn.h
* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
* sysdeps/unix/sysv/linux/sys/epoll.h
* sysdeps/unix/sysv/linux/sys/signalfd.h:
Use bits/types/sigset_t.h.
* resolv/netdb.h, rt/mqueue.h: Use bits/types/sigevent_t.h.
* rt/aio.h: Use bits/types/sigevent_t.h and bits/sigevent-consts.h.
* socket/sys/socket.h: Don't include bits/sigset.h.
* login/utmp_file.c, shadow/lckpwdf.c, signal/sigandset.c
* signal/sigisempty.c, stdlib/abort.c, sysdeps/posix/profil.c
* sysdeps/posix/sigignore.c, sysdeps/posix/sigintr.c
* sysdeps/posix/signal.c, sysdeps/posix/sigset.c
* sysdeps/posix/sprofil.c, sysdeps/posix/sysv_signal.c
* sysdeps/unix/sysv/linux/nptl-signals.h:
Include sigsetops.h.
* signal/sigaddset.c, signal/sigandset.c, signal/sigdelset.c
* signal/sigorset.c, stdlib/abort.c, sysdeps/posix/sigignore.c
* sysdeps/posix/signal.c, sysdeps/posix/sigset.c:
__sigaddset, __sigandset, __sigdelset, __sigemptyset, __sigorset
now return no value.
* signal/sigaddset.c, signal/sigdelset.c, signal/sigismem.c
Include <errno.h>, <signal.h>, and <sigsetops.h> instead of
"sigsetops.h".
* signal/sigsetops.c: Explicitly define __sigismember,
__sigaddset, and __sigdelset as compatibility symbols.
* signal/Versions: Correct commentary on __sigpause,
__sigaddset, __sigdelset, __sigismember.
* inet/rcmd.c: Include sigsetops.h. Convert old code using
__sigblock/__sigsetmask to use __sigprocmask and friends.
2008-08-13 Ulrich Drepper <drepper@redhat.com>
[BZ #6634]
* login/utmp_file.c (getutent_r_file): Take additional parameter.
Set to true if locking failed.
(getutid_r_file): Adjust caller.
(pututline_file): Likewise. Return NULL in this case.
Patch mostly by halesh.s@gmail.com.
* include/fcntl.h: Declare __have_o_cloexec.
* io/have_o_cloexec.c: New file.
* sysdeps/unix/opendir.c (__opendir): Use O_CLOEXEC is available.
(__alloc_dir): If O_CLOEXEC has been used, don't duplicate the
fcntl call if not necessary.
* login/utmp_file.c (setutent_file): Use __have_o_cloexec instead
of local variable.
