A new build flag, _TIME_BITS, enables the usage of the newer 64-bit
time symbols for legacy ABI (where 32-bit time_t is default). The 64
bit time support is only enabled if LFS (_FILE_OFFSET_BITS=64) is
also used.
Different than LFS support, the y2038 symbols are added only for the
required ABIs (armhf, csky, hppa, i386, m68k, microblaze, mips32,
mips64-n32, nios2, powerpc32, sparc32, s390-32, and sh). The ABIs with
64-bit time support are unchanged, both for symbol and types
redirection.
On Linux the full 64-bit time support requires a minimum of kernel
version v5.1. Otherwise, the 32-bit fallbacks are used and might
results in error with overflow return code (EOVERFLOW).
The i686-gnu does not yet support 64-bit time.
This patch exports following rediretions to support 64-bit time:
* libc:
adjtime
adjtimex
clock_adjtime
clock_getres
clock_gettime
clock_nanosleep
clock_settime
cnd_timedwait
ctime
ctime_r
difftime
fstat
fstatat
futimens
futimes
futimesat
getitimer
getrusage
gettimeofday
gmtime
gmtime_r
localtime
localtime_r
lstat_time
lutimes
mktime
msgctl
mtx_timedlock
nanosleep
nanosleep
ntp_gettime
ntp_gettimex
ppoll
pselec
pselect
pthread_clockjoin_np
pthread_cond_clockwait
pthread_cond_timedwait
pthread_mutex_clocklock
pthread_mutex_timedlock
pthread_rwlock_clockrdlock
pthread_rwlock_clockwrlock
pthread_rwlock_timedrdlock
pthread_rwlock_timedwrlock
pthread_timedjoin_np
recvmmsg
sched_rr_get_interval
select
sem_clockwait
semctl
semtimedop
sem_timedwait
setitimer
settimeofday
shmctl
sigtimedwait
stat
thrd_sleep
time
timegm
timerfd_gettime
timerfd_settime
timespec_get
utime
utimensat
utimes
utimes
wait3
wait4
* librt:
aio_suspend
mq_timedreceive
mq_timedsend
timer_gettime
timer_settime
* libanl:
gai_suspend
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-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 patch removes the mknod and mknodat static wrapper and add the
symbols on the libc with the expected names.
Both the prototypes of the internal symbol linked by the static
wrappers and the inline redirectors are also removed from the installed
sys/stat.h header file. The wrapper implementation license LGPL
exception is also removed since it is no longer statically linked to
binaries.
Internally the _STAT_VER* definitions are moved to the arch-specific
xstatver.h file.
Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
This patch removes the stat, stat64, lstat, lstat64, fstat, fstat64,
fstatat, and fstatat64 static wrapper and add the symbol on the libc
with the expected names.
Both the prototypes of the internal symbol linked by the static
wrappers and the inline redirectors are also removed from the installed
sys/stat.h header file. The wrapper implementation license LGPL
exception is also removed since it is no longer statically linked to
binaries.
Internally the _STAT_VER* definitions are moved to a arch-specific
xstatver.h file. The internal defines that redirects internals
{f}stat{at} to their {f}xstat{at} counterparts are removed for Linux
(!NO_RTLD_HIDDEN). Hurd still requires them since {f}stat{at} pulls
extra objects that makes the loader build fail otherwise (I haven't
dig into why exactly).
Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
If build with optimization, stdio.h and sys/stat.h are defining some inlining
functions. This leads to test fails if glibc is build with the following
commands. (Note that the conformtests usually builds without optimization or
other CFLAGS):
<glibc>/configure CC="gcc -O3" --prefix=/usr
make
make subdirs=conform check
- FAIL: conform/XPG4/stdio.h/conform
- FAIL: conform/XPG42/stdio.h/conform
out-files:
...
PASSCOMBINED: Availability of variable optopt
PASSCOMBINED: Type of variable optopt
Namespace violation: "getc_unlocked"
Namespace violation: "getchar_unlocked"
Namespace violation: "putc_unlocked"
Namespace violation: "putchar_unlocked"
FAIL: Namespace of <stdio.h>
----------------------------------------------------------------------------
Total number of tests : 168
Number of failed tests : 1
Number of xfailed tests : 0
Number of skipped tests : 0
- FAIL: conform/POSIX2008/sys/stat.h/conform
out-file:
...
PASSCOMBINED: Availability of function utimensat
PASSCOMBINED: Type of function utimensat
Namespace violation: "mknodat"
FAIL: Namespace of <sys/stat.h>
----------------------------------------------------------------------------
Total number of tests : 97
Number of failed tests : 1
Number of xfailed tests : 0
Number of skipped tests : 0
For getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked in stdio.h,
those are defined "# ifdef __USE_POSIX" instead of "#ifdef __USE_POSIX199506"
for the non-inlining declaration. See also
"Bug 20014 - stdio.h namespace for pre-threads POSIX"
(https://sourceware.org/bugzilla/show_bug.cgi?id=20014).
For mknodat in sys/stat.h, those are defined "# ifdef __USE_ATFILE" instead of
the additional guard "# if defined __USE_MISC || defined __USE_XOPEN_EXTENDED".
As indicated by the bug report, the 'struct timespec' definition
is not defined for '_XOPEN_SOURCE=700' and '_POSIX_C_SOURCE=200112L'.
It is because current code only includes its definition if __USE_ATFILE
is defined and the define is only set with:
1. _GNU_SOURCE and/or _ATFILE_SOURCE definition.
2. _POSIX_C_SOURCE >= 200809L
However, the 'st_*' fields in 'struct stat' are defined if __USE_XOPEN2K8.
This patch uses the same logic for 'struct timespec' inclusion.
Tested on x86_64-linux-gnu.
* io/sys/stat.h: Use __USE_XOPEN2K8 insteaf of __USE_ATFILE for
struct timespec definition.
Many headers are expected to expose a subset of the type definitions
in time.h. time.h has a whole bunch of messy logic for conditionally
defining some its types and structs, but, as best I can tell, this
has never worked 100%. In particular, __need_timespec is ineffective
if _TIME_H has already been defined, which means that if you compile
#include <time.h>
#include <sched.h>
with e.g. -fsyntax-only -std=c89 -Wall -Wsystem-headers, you will get
In file included from test.c:2:0:
/usr/include/sched.h:74:57: warning: "struct timespec" declared inside
parameter list will not be visible outside of this definition or declaration
extern int sched_rr_get_interval (__pid_t __pid, struct timespec *__t) __THROW;
^~~~~~~~
And if you want to _use_ sched_rr_get_interval in a TU compiled that
way, you're hosed.
This patch replaces all of that with small bits/types/TYPE.h headers
as introduced earlier. time.h and bits/time.h are now *much* simpler,
and a lot of other headers are slightly simpler.
* time/time.h, bits/time.h, sysdeps/unix/sysv/linux/bits/time.h:
Remove all logic conditional on __need macros. Move all the
conditionally defined types to their own headers...
* time/bits/types/clock_t.h: Define clock_t here.
* time/bits/types/clockid_t.h: Define clockid_t here.
* time/bits/types/struct_itimerspec.h: Define struct itimerspec here.
* time/bits/types/struct_timespec.h: Define struct timespec here.
* time/bits/types/struct_timeval.h: Define struct timeval here.
* time/bits/types/struct_tm.h: Define struct tm here.
* time/bits/types/time_t.h: Define time_t here.
* time/bits/types/timer_t.h: Define timer_t here.
* time/Makefile: Install the new headers.
* bits/resource.h, io/fcntl.h, io/sys/poll.h, io/sys/stat.h
* io/utime.h, misc/sys/select.h, posix/sched.h, posix/sys/times.h
* posix/sys/types.h, resolv/netdb.h, rt/aio.h, rt/mqueue.h
* signal/signal.h, pthread/semaphore.h, sysdeps/nptl/pthread.h
* sysdeps/unix/sysv/linux/alpha/bits/resource.h
* sysdeps/unix/sysv/linux/alpha/sys/acct.h
* sysdeps/unix/sysv/linux/bits/resource.h
* sysdeps/unix/sysv/linux/bits/timex.h
* sysdeps/unix/sysv/linux/mips/bits/resource.h
* sysdeps/unix/sysv/linux/net/ppp_defs.h
* sysdeps/unix/sysv/linux/sparc/bits/resource.h
* sysdeps/unix/sysv/linux/sys/acct.h
* sysdeps/unix/sysv/linux/sys/timerfd.h
* sysvipc/sys/msg.h, sysvipc/sys/sem.h, sysvipc/sys/shm.h
* time/sys/time.h, time/sys/timeb.h
Use the new bits/types headers.
* include/time.h: Remove __need logic.
* include/bits/time.h
* include/bits/types/clock_t.h, include/bits/types/clockid_t.h
* include/bits/types/time_t.h, include/bits/types/timer_t.h
* include/bits/types/struct_itimerspec.h
* include/bits/types/struct_timespec.h
* include/bits/types/struct_timeval.h
* include/bits/types/struct_tm.h:
New wrapper headers.
sys/stat.h should define S_IFSOCK and S_ISSOCK for XPG4 (XNS), but
does not. This patch corrects the relevant header conditionals.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
[BZ #20076]
* io/sys/stat.h (S_IFSOCK): Define for [__USE_XOPEN_EXTENDED]
instead of [__USE_UNIX98].
(S_ISSOCK): Likewise.
* conform/Makefile (test-xfail-XPG4/sys/stat.h/conform): Remove
variable.
sys/stat.h declares fchmod if __USE_POSIX (i.e. POSIX.1:1990). But it
was actually added in 1993 and also in XPG4. This patch changes the
conditions to the correct __USE_POSIX199309 || __USE_XOPEN_EXTENDED.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
[BZ #20073]
* io/sys/stat.h (fchmod): Declare for
[__USE_POSIX199309 || __USE_XOPEN_EXTENDED], not [__USE_POSIX].
* conform/Makefile (test-xfail-XPG3/sys/stat.h/conform): Remove
variable.
This patch cleans up cases of __USE_MISC that are trivially redundant
after the recent substitution of __USE_MISC for __USE_BSD and
__USE_SVID: either in constructs such as "defined __USE_MISC ||
defined __USE_MISC", or else (in the bits/mman.h case) a conditional
on __USE_MISC nested inside another __USE_MISC conditional. (The
cleanups remaining after this patch are still quite large, but it
seems a reasonable piece to separate out.)
Tested x86_64.
* bits/mman.h [__USE_MISC]: Remove redundant conditionals.
* ctype/ctype.h [__USE_MISC]: Likewise.
* dirent/dirent.h [__USE_MISC]: Likewise.
* grp/grp.h [__USE_MISC]: Likewise.
* io/fcntl.h [__USE_MISC]: Likewise.
* io/sys/stat.h [__USE_MISC]: Likewise.
* libio/stdio.h [__USE_MISC]: Likewise.
* posix/unistd.h [__USE_MISC]: Likewise.
* pwd/pwd.h [__USE_MISC]: Likewise.
* stdlib.h [__USE_MISC]: Likewise.
* string/bits/string2.h [__USE_MISC]: Likewise.
* string/string.h [__USE_MISC]: Likewise.
* time/time.h [__USE_MISC]: Likewise.
* wcsmbs/wchar.h: mbsnrtowcs, open_wmemstream, wcpcpy, wcpncpy,
wcscasecmp, wcsdup, wcsncasecmp, wcsnlen, wcsnrtombs,
wcscasecmp_l, wcsncasecmp_l, wcscoll_l, and wcsxfrm_l.
* sysdeps/mach/hurd/bits/posix_opt.h: Reset value of macros from
200112L to 200809L.
* sysdeps/unix/sysv/linux/bits/posix_opt.h: Likewise.
* posix/getconf.c (vars): Add _SC_THREAD_ROBUST_PRIO_INHERIT and
_SC_THREAD_ROBUST_PRIO_PROTECT entries.
* bits/confname.h: Add _SC_THREAD_ROBUST_PRIO_INHERIT and
_SC_THREAD_ROBUST_PRIO_PROTECT.
* posix/unistd.h: fexecve is in POSIX 2008.
* time/time.h: strftime_l is in POSIX 2008.
* io/sys/stat.h: futimens is in POSIX 2008.
* string/strings.h: strcasecmp_l and strncasecmp_l are in POSIX 2008.
* string/string.h: stpcpy, stpncpy, strndup, strnlen, strsignal,
strcoll_l, strerror_l, and strxfrm_l are in POSIX 2008.
* stdlib/stdlib.h: mkdtemp is in POSIX 2008.
* sysdeps/unix/sysv/linux/bits/stat.h: Protect UTIME_NOW and
UTIME_OMIT only with __USE_ATFILE.
* sysdeps/unix/sysv/linux/ia64/bits/stat.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/stat.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/stat.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/stat.h: Likewise.
* sysdeps/unix/sysv/linux/x86_64/bits/stat.h: Likewise.
* io/sys/stat.h: Move mknodat definition into same conditional as
mknod.
* time/sys/time.h: futimesat is not among the functions accepted
into the POSIX standard.
* misc/bits/syslog.h (syslog): When __va_arg_pack is defined,
implement as __extern_always_inline function.
(vsyslog): Define as __extern_always_inline function unconditionally.
* libio/bits/stdio2.h (sprintf, snprintf, printf, fprintf):
When __va_arg_pack is defined, implement as __extern_always_inline
functions.
(vsprintf, vsnprintf, vprintf, vfprintf): Define as
__extern_always_inline functions unconditionally.
* libio/bits/stdio.h (vprintf): Ifdef out the inline when
bits/stdio2.h will be included.
* wcsmbs/bits/wchar2.h (__swprintf_alias): New redirect.
(swprintf, wprintf, fwprintf): When __va_arg_pack is defined,
implement as __extern_always_inline functions.
(vswprintf, vwprintf, vfwprintf): Define as
__extern_always_inline functions unconditionally.
* debug/tst-chk1.c (do_test): Enable remaining tests for C++.
2007-09-03 Jakub Jelinek <jakub@redhat.com>
* misc/sys/cdefs.h (__extern_inline, __extern_always_inline): Only
define in C++ for GCC 4.3+, in C++ always use __gnu_inline__
attribute.
* include/features.h (__USE_EXTERN_INLINES): Define only when
__extern_inline is defined.
* stdlib/stdlib.h: Include bits/stdlib.h when __extern_always_inline
is defined instead of when not __cplusplus.
* misc/sys/syslog.h: Include bits/syslog.h when __extern_always_inline
is defined instead of when not __cplusplus.
* socket/sys/socket.h: Include bits/socket2.h when
__extern_always_inline is defined instead of when not __cplusplus.
* libio/stdio.h: Include bits/stdio2.h when __extern_always_inline
is defined instead of when not __cplusplus.
* posix/unistd.h: Include bits/unistd.h when __extern_always_inline
is defined instead of when not __cplusplus.
* string/string.h: Include bits/string3.h when __extern_always_inline
is defined instead of when not __cplusplus.
* wcsmbs/wchar.h: Include bits/wchar2.h when __extern_always_inline
is defined instead of when not __cplusplus.
(btowc, wctob): Don't guard the inlines with ifndef __cplusplus.
* io/fcntl.h: Don't include bits/fcntl2.h if __extern_always_inline
is not defined.
* misc/bits/syslog-ldbl.h: Guard *_chk stuff with
defined __extern_always_inline instead of !defined __cplusplus.
* libio/bits/stdio-ldbl.h: Likewise.
* wcsmbs/bits/wchar-ldbl.h: Likewise.
* misc/bits/syslog.h (syslog): Don't define for C++.
(vsyslog): Use __extern_always_inline function for C++ instead of
a macro.
* libio/bits/stdio.h (__STDIO_INLINE): Define to __extern_inline
whenever that macro is defined.
(vprintf): Don't provide the inline for C++.
(fread_unlocked, fwrite_unlocked): Don't define the macros for C++.
* libio/bits/stdio2.h (sprintf, snprintf, printf, fprintf): Don't
define the macros for C++.
(vsprintf, vsnprintf, vprintf, vfprintf): Define as
__extern_always_inline functions for C++.
* io/sys/stat.h (stat, lstat, fstat, fstatat, mknod, mknodat,
stat64, lstat64, fstat64, fstatat64): Don't define if not
__USE_EXTERN_INLINES.
* wcsmbs/bits/wchar2.h: Fix #error message.
(swprintf, wprintf, fwprintf): Don't define the macros for C++.
(vswprintf, vwprintf, vfwprintf): Define using
__extern_always_inline functions for C++.
* string/bits/string3.h: Don't #undef macros if __cplusplus.
(memcpy, memmove, mempcpy, memset, bcopy, bzero, strcpy, stpcpy,
strncpy, strcat, strncat): Define as __extern_always_inline
functions instead of macros for C++.
* math/bits/cmathcalls.h: Guard __extern_inline routines with
defined __extern_inline.
* sysdeps/alpha/fpu/bits/mathinline.h (__MATH_INLINE): Define
to __extern_inline whenever that macro is defined.
* sysdeps/ia64/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/i386/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/i386/i486/bits/string.h (__STRING_INLINE): Likewise.
* sysdeps/s390/bits/string.h (__STRING_INLINE): Likewise.
* sysdeps/s390/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/powerpc/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/x86_64/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/sparc/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/unix/sysv/linux/sys/sysmacros.h (gnu_dev_major,
gnu_dev_minor, gnu_dev_makedev): Remove __extern_inline from
prototypes. Only provide __extern_inline routines if
__USE_EXTERN_INLINES.
* debug/Makefile: Add rules to build and run tst-{,lfs}chk{4,5,6}
tests.
* debug/tst-chk1.c (do_prepare, do_test): Allow compilation as C++.
For now avoid some *printf tests in C++. Skip all testing
if __USE_FORTIFY_LEVEL is defined, but __extern_always_inline macro
is not.
* debug/tst-chk4.cc: New file.
* debug/tst-chk5.cc: New file.
* debug/tst-chk6.cc: New file.
* debug/tst-lfschk4.cc: New file.
* debug/tst-lfschk5.cc: New file.
* debug/tst-lfschk6.cc: New file.
* include/wchar.h (__vfwprintf_chk, __vswprintf_chk): Avoid
prototypes in C++.
* include/stdio.h (__sprintf_chk, __snprintf_chk, __vsprintf_chk,
__vsnprintf_chk, __printf_chk, __fprintf_chk, __vprintf_chk,
__vfprintf_chk, __fgets_unlocked_chk, __fgets_chk): Likewise.
(__sched_setaffinity_new): If syscall was successful and
RESET_VGETCPU_CACHE is defined, use it before returning.
* sysdeps/unix/sysv/linux/x86_64/sched_setaffinity.c: New file.
define fstatat to fstatat64.
(fstatat64): Only provide prototype if __USE_LARGEFILE64,
similarly with the inline.
* io/fcntl.h (openat64): Only provide prototype if __USE_LARGEFILE64.
epoll_wait): Align with poll, make cancelable.
2005-11-15 Jakub Jelinek <jakub@redhat.com>
* io/sys/stat.h (fstatat): Don't use __THROW together with
__REDIRECT_NTH.
fchownat, and unlinkat.
(static-only-routines): Add fstatat and fstatat64.
(tests): Add tst-unlinkat, tst-fstatat, tst-futimesat, tst-renameat,
and tst-fchownat.
* io/Versions [GLIBC_2.4]: Add fchownat, __fxstatat, __fxstatat64,
and unlinkat.
* io/fcntl.h: Define AT_FDCWD, AT_SYMLINK_NOFOLLOW, and AT_REMOVEDIR.
* io/fstatat.c: New file.
* io/fstatat64.c: New file.
* io/sys/stat.h: Declare fstatat, fstatat64, __fxstatat, __fxstatat64
and define fstatat and fstatat64 inline functions.
* libio/stdio.h: Declare renameat.
* misc/Makefile (routines): Add futimesat.
* misc/Versions [GLIBC_2.4]: Add futimesat.
* posix/unistd.h: Declare fchownat and unlinkat.
* stdio-common/Makefile (routines): Add renameat.
* stdio-common/Versions [GLIBC_2.4]: Add renameat.
* sysdeps/generic/fchownat.c: New file.
* sysdeps/generic/futimesat.c: New file.
* sysdeps/generic/fxstatat.c: New file.
* sysdeps/generic/fxstatat64.c: New file.
* sysdeps/generic/renameat.c: New file.
* sysdeps/generic/unlinkat.c: New file.
* sysdeps/unix/sysv/linux/fchownat.c: New file.
* sysdeps/unix/sysv/linux/futimesat.c: New file.
* sysdeps/unix/sysv/linux/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/fxstatat64.c: New file.
* sysdeps/unix/sysv/linux/renameat.c: New file.
* sysdeps/unix/sysv/linux/unlinkat.c: New file.
* sysdeps/unix/sysv/linux/alpha/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/i386/fchownat.c: New file.
* sysdeps/unix/sysv/linux/i386/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/m68k/fchownat.c: New file.
* sysdeps/unix/sysv/linux/m68k/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/powerpc/fchownat.c: New file.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/s390/s390-32/fchownat.c: New file.
* sysdeps/unix/sysv/linux/s390/s390-32/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/sh/fchownat.c: New file.
* sysdeps/unix/sysv/linux/sh/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc32/fchownat.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc32/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/sparc/sparc64/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/wordsize-64/fxstatat.c: New file.
* sysdeps/unix/sysv/linux/wordsize-64/fxstatat64.c: New file.
* time/sys/time.h: Declare futimesat.
* include/fcntl.h: Declare __atfct_seterrno.
* sysdeps/unix/sysv/linux/openat.c (__atfct_seterrno): New function.
Split out from openat code and called.
(do_test): Allow openat to fail with ENOSYS. Handle AT_FDCWD.
* sysdeps/generic/openat.c: Handle AT_FDCWD.
* sysdeps/generic/openat64.c: Likewise.
* io/tst-unlinkat.c: New file.
* io/tst-fstatat.c: New file.
* io/tst-futimesat.c: New file.
* io/tst-renameat.c: New file.
* io/tst-fchownat.c: New file.
* io/tst-openat.c: Don't fail if openat is not implemented.
* sysdeps/unix/sysv/linux/powerpc/chown.c: Don't provide backward
compatibility code if new kernel is guaranteed.
* time/sys/time.h: Add a few nonnull attributes.
