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glibc/sysdeps/unix/sysv/linux/settimezone.c

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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>
2019-08-28 12:25:49 +00:00
/* Obsolete set system time. Linux version.
Update copyright dates with scripts/update-copyrights 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
2021-01-02 19:32:25 +00:00
Copyright (C) 2019-2021 Free Software Foundation, Inc.
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>
2019-08-28 12:25:49 +00:00
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <sys/time.h>
Remove tls.h inclusion from internal errno.h The tls.h inclusion is not really required and limits possible definition on more arch specific headers. This is a cleanup to allow inline functions on sysdep.h, more specifically on i386 and ia64 which requires to access some tls definitions its own. No semantic changes expected, checked with a build against all affected ABIs.
2020-02-04 13:29:04 +00:00
#include <stddef.h>
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>
2019-08-28 12:25:49 +00:00
#include <sysdep.h>
/* Set the system-wide timezone.
This call is restricted to the super-user.
This operation is considered obsolete, kernel support may not be
available on all architectures. */
int
__settimezone (const struct timezone *tz)
{
#ifdef __NR_settimeofday
return INLINE_SYSCALL_CALL (settimeofday, NULL, tz);
#else
__set_errno (ENOSYS);
return -1;
#endif
}
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