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Zack Weinberg c3f9aef063 Use clock_settime to implement settimeofday.
Unconditionally, on all ports, use clock_settime to implement
settimeofday.  Remove sysdeps/unix/clock_settime.c, which implemented
clock_settime by calling settimeofday; new OS ports must henceforth
provide a real implementation of clock_settime.

Hurd had a real implementation of settimeofday but not of
clock_settime; this patch converts it into an implementation of
clock_settime.  It only supports CLOCK_REALTIME and microsecond
resolution; Hurd/Mach does not appear to have any support for
finer-resolution clocks.

The vestigial "set time zone" feature of settimeofday complicates the
generic settimeofday implementation a little.  The only remaining uses
of this feature that aren't just bugs, are using it to inform the
Linux kernel of the offset between the hardware clock and UTC, on
systems where the hardware clock doesn't run in UTC (usually because
of dual-booting with Windows).  There currently isn't any other way to
do this.  However, the callers that do this call settimeofday with
_only_ the timezone argument non-NULL.  Therefore, glibc's new
behavior is: callers of settimeofday must supply one and only one of
the two arguments.  If both arguments are non-NULL, or both arguments
are NULL, the call fails and sets errno to EINVAL.

When only the timeval argument is supplied, settimeofday calls
__clock_settime(CLOCK_REALTIME), same as stime.

When only the timezone argument is supplied, settimeofday calls a new
internal function called __settimezone.  On Linux, only, this function
will pass the timezone structure to the settimeofday system call.  On
all other operating systems, and on Linux architectures that don't
define __NR_settimeofday, __settimezone is a stub that always sets
errno to ENOSYS and returns -1.

The settimeoday syscall is enabled on Linux by the flag
COMPAT_32BIT_TIME, which is an option to either 32-bits ABIs or COMPAT
builds (defined usually by 64-bit kernels that want to support 32-bit
 ABIs, such as x86).  The idea to future 64-bit time_t only ABIs
is to not provide settimeofday syscall.

The same semantics are implemented for Linux/Alpha's GLIBC_2.0 compat
symbol for settimeofday.

There are no longer any internal callers of __settimeofday, so the
internal prototype is removed.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
2019-10-30 17:05:14 -03:00
argp Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
assert Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
benchtests Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
bits Define __STATFS_MATCHES_STATFS64 2019-10-24 09:14:26 -07:00
catgets Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
ChangeLog.old Undo accidental commit to ChangeLog.19. 2019-10-18 16:09:10 -04:00
conform sysvipc: Set ipc_perm mode as mode_t (BZ#18231) 2019-10-10 17:33:27 -03:00
crypt Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
csu Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
ctype Split up endian.h to minimize exposure of BYTE_ORDER. 2019-10-01 14:54:46 -07:00
debug Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
dirent Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
dlfcn dlfcn: Remove remnants of caller sensitivity from dlinfo 2019-10-16 18:21:30 +02:00
elf elf: Use nocancel pread64() instead of lseek()+read() 2019-10-18 15:55:33 -04:00
gmon Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
gnulib Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
grp Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
gshadow Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
hesiod Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
htl Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
hurd time: Introduce function to check correctness of nanoseconds value 2019-10-27 21:49:25 +01:00
iconv Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
iconvdata Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
include Use clock_settime to implement settimeofday. 2019-10-30 17:05:14 -03:00
inet Change most internal uses of __gettimeofday to __clock_gettime. 2019-10-30 17:04:10 -03:00
intl Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
io time: Introduce function to check correctness of nanoseconds value 2019-10-27 21:49:25 +01:00
libio Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
locale loadarchive: guard against locale-archive corruption (Bug #25115) 2019-10-18 20:40:54 -04:00
localedata Add Transliterations for Unicode Misc. Mathematical Symbols-A/B [BZ #23132] 2019-10-25 19:45:55 +02:00
login Change most internal uses of __gettimeofday to __clock_gettime. 2019-10-30 17:04:10 -03:00
mach Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
malloc Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
manual manual: Remove warning in the documentation of the abort function 2019-10-11 20:15:24 +02:00
math Remove x64 _finite tests and references 2019-10-21 14:29:12 -03:00
mathvec Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
misc Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
nis Change most internal uses of __gettimeofday to __clock_gettime. 2019-10-30 17:04:10 -03:00
nptl Change most internal uses of __gettimeofday to __clock_gettime. 2019-10-30 17:04:10 -03:00
nptl_db Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
nscd Change most internal uses of __gettimeofday to __clock_gettime. 2019-10-30 17:04:10 -03:00
nss Comment out initgroups from example nsswitch.conf (Bug 25146) 2019-10-29 13:08:24 -04:00
po Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
posix posix: Use posix_spawn for wordexp 2019-10-09 17:48:41 -03:00
pwd Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
resolv Change most internal uses of __gettimeofday to __clock_gettime. 2019-10-30 17:04:10 -03:00
resource Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
rt Set the expects flags to clock_nanosleep 2019-09-25 16:28:45 -07:00
scripts Use binutils 2.33 branch in build-many-glibcs.py. 2019-09-30 22:21:39 +00:00
setjmp Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
shadow Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
signal Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
socket Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
soft-fp Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
stdio-common Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
stdlib Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
string string/endian.h: Restore the __USE_MISC conditionals 2019-10-02 12:26:06 -07:00
sunrpc Change most internal uses of __gettimeofday to __clock_gettime. 2019-10-30 17:04:10 -03:00
support Change most internal uses of __gettimeofday to __clock_gettime. 2019-10-30 17:04:10 -03:00
sysdeps Use clock_settime to implement settimeofday. 2019-10-30 17:05:14 -03:00
sysvipc Remove libc_hidden_def from __semtimedop stub 2019-10-17 21:36:34 +02:00
termios Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
time Use clock_settime to implement settimeofday. 2019-10-30 17:05:14 -03:00
timezone Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
wcsmbs Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
wctype Split up endian.h to minimize exposure of BYTE_ORDER. 2019-10-01 14:54:46 -07:00
.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 LIBC_SLIBDIR_RTLDDIR: substitute arguments in single quotes 2018-01-25 17:20:28 +01:00
config.h.in sparc: Assume GOTDATA support in the toolchain 2019-10-09 19:15:33 +02:00
config.make.in Make --bindir effective 2019-05-14 11:04:33 -03:00
configure Fix http: URL in 'configure' 2019-09-09 14:16:40 -07:00
configure.ac Fix http: URL in 'configure' 2019-09-09 14:16:40 -07:00
COPYING Update to latest versions of GPL-2.0 and LGPL-2.1 2013-09-09 12:52:48 +10:00
COPYING.LIB Update to latest versions of GPL-2.0 and LGPL-2.1 2013-09-09 12:52:48 +10:00
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 Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
libc-abis libc-abis: Define ABSOLUTE ABI [BZ #19818][BZ #23307] 2018-07-05 18:06:43 +01:00
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 Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
Makefile Install charmaps uncompressed in testroot 2019-10-24 17:01:04 -04:00
Makefile.help Add run-one-test convenience target and makefile help text 2019-10-18 15:46:04 -04:00
Makefile.in New make target to only build benchmark binaries 2016-04-20 10:23:28 +05:30
Makerules Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
NEWS Use clock_settime to implement settimeofday. 2019-10-30 17:05:14 -03:00
o-iterator.mk Fri Mar 17 12:58:37 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu> 1995-03-17 18:42:51 +00:00
README Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
Rules Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
shlib-versions Extend NSS test suite 2017-07-17 15:52:44 -04:00
test-skeleton.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
version.h Open master for 2.31 development. 2019-08-01 00:41:53 -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
	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
	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
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individually.