On platforms where long double has IEEE binary128 format as a third
option (initially, only powerpc64le), many exported functions are
redirected to their __*ieee128 equivalents. This redirection is
provided by installed headers such as stdio-ldbl.h, and is supposed to
work correctly with user code.
However, during the build of glibc, similar redirections are employed,
in internal headers, such as include/stdio.h, in order to avoid extra
PLT entries. These redirections conflict with the redirections to
__*ieee128, and must be avoided during the build. This patch protects
the second redirections with a test for __LONG_DOUBLE_USES_FLOAT128, a
new macro that is defined to 1 when functions that deal with long double
typed values reuses the _Float128 implementation (this is currently only
true for powerpc64le).
Tested for powerpc64le, x86_64, and with build-many-glibcs.py.
Co-authored-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Commit a2e8aa0d9e ("Block signals during
the initial part of dlopen") was deemed necessary because of
read-modify-write operations like the one in add_dependency in
elf/dl-lookup.c. In the old code, we check for any kind of NODELETE
status and bail out:
/* Redo the NODELETE check, as when dl_load_lock wasn't held
yet this could have changed. */
if (map->l_nodelete != link_map_nodelete_inactive)
goto out;
And then set pending status (during relocation):
if (flags & DL_LOOKUP_FOR_RELOCATE)
map->l_nodelete = link_map_nodelete_pending;
else
map->l_nodelete = link_map_nodelete_active;
If a signal arrives during relocation and the signal handler, through
lazy binding, adds a global scope dependency on the same map, it will
set map->l_nodelete to link_map_nodelete_active. This will be
overwritten with link_map_nodelete_pending by the dlopen relocation
code.
To avoid such problems in relation to the l_nodelete member, this
commit introduces two flags for active NODELETE status (irrevocable)
and pending NODELETE status (revocable until activate_nodelete is
invoked). As a result, NODELETE processing in dlopen does not
introduce further reasons why lazy binding from signal handlers
is unsafe during dlopen, and a subsequent commit can remove signal
blocking from dlopen.
This does not address pre-existing issues (unrelated to the NODELETE
changes) which make lazy binding in a signal handler during dlopen
unsafe, such as the use of malloc in both cases.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This patch adds the missing __libpthread_version_placeholder for
GLIBC_2.2.6 version from the nanosleep implementation move from
libpthread to libc (79a547b162).
It also fixes the wrong compat symbol definitions added by changing
back the version used on vfork check and remove the
__libpthread_version_placeholder added on some ABI (4f4bb489e0).
The __libpthread_version_placeholder is also refactored to make it
simpler to add new compat_symbols by adding a new macro
compat_symbol_unique which uses the compiler extension __COUNTER__
to generate unique strong alias to be used with compat_symbol.
Checked with a updated-abi on the all affected abis of the nanosleep
move.
Change-Id: I347a4dbdc931bb42b359456932dd1e17aa4d4078
This patch provides new __timer_settime64 explicit 64 bit function for setting
flags, interval and value of specified timer.
Moreover, a 32 bit version - __timer_settime has been refactored to internally
use __timer_settime64.
The __timer_settime is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversion to 64 bit struct
__timespec64 from struct timespec (and opposite when old_value pointer is
provided).
The new __timer_settime64 syscall available from Linux 5.1+ has been used, when
applicable.
The original INLINE_SYSCALL() macro has been replaced with
INLINE_SYSCALL_CALL() to avoid explicit passing the number of arguments.
Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make check PARALLELMFLAGS="-j8" && \\
make xcheck PARALLELMFLAGS="-j8"
- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
- Use of cross-test-ssh.sh for ARM (armv7):
make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck
Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with timer_settime64) and glibc build with v5.1 as
minimal kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports timer_settime64
syscall.
- Linux v4.19 (no timer_settime64 support) with default minimal kernel version
for contemporary glibc (3.2.0)
This kernel doesn't support timer_settime64 syscall, so the fallback to
timer_settime is tested.
Above tests were performed with Y2038 redirection applied as well as without
(so the __TIMESIZE != 64 execution path is checked as well).
No regressions were observed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch provides new __timer_gettime64 explicit 64 bit function for reading
status of specified timer. To be more precise - the remaining time and interval
set with timer_settime.
Moreover, a 32 bit version - __timer_gettime has been refactored to internally
use __timer_gettime64.
The __timer_gettime is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversion from 64 bit struct
__timespec64 to struct timespec.
The new __timer_gettime64 syscall available from Linux 5.1+ has been used, when
applicable.
The original INLINE_SYSCALL() macro has been replaced with
INLINE_SYSCALL_CALL() to avoid explicit passing the number of arguments.
Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make check PARALLELMFLAGS="-j8" && \\
make xcheck PARALLELMFLAGS="-j8"
- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
- Use of cross-test-ssh.sh for ARM (armv7):
make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck
Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with timer_gettime64) and glibc build with v5.1 as
minimal kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports timer_gettime64
syscall.
- Linux v4.19 (no timer_gettime64 support) with default minimal kernel version
for contemporary glibc (3.2.0)
This kernel doesn't support timer_gettime64 syscall, so the fallback to
timer_gettime is tested.
Above tests were performed with Y2038 redirection applied as well as without
(so the __TIMESIZE != 64 execution path is checked as well).
No regressions were observed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This change provides the glibc's internal struct itimerspec representation,
which is explicitly supporting 64 bit time (by using struct __timespec64).
Such representation is necessary to provide correct time after Y2038
(time_t overflow) on devices with __TIMESIZE == 32.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
With the clock_gettime64 call we prefer to use vDSO. There is no call
to clock_gettime64 on glibc with older headers and kernel 5.1+ if it
doesn't support vDSO.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Similarly to what has been done for printf-like functions, more
specifically to the internal implementation in __vfprintf_internal, this
patch extends __vstrfmon_l_internal to deal with long double values with
binary128 format (as a third format option and reusing the float128
implementation).
Tested for powerpc64le, powerpc64, x86_64, and with build-many-glibcs.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
ld.so symbols to be overriden by libc need to be extern to really get
overriden. __access happens to have never been exposed, putting it to
GLIBC_PRIVATE.
ld.so symbols to be overriden by libc need to be extern to really get
overriden. __getcwd happens to have never been exposed, putting it to
GLIBC_PRIVATE.
This introduces a “pending NODELETE” state in the link map, which is
flipped to the persistent NODELETE state late in dlopen, via
activate_nodelete. During initial relocation, symbol binding
records pending NODELETE state only. dlclose ignores pending NODELETE
state. Taken together, this results that a partially completed dlopen
is rolled back completely because new NODELETE mappings are unloaded.
Tested on x86_64-linux-gnu and i386-linux-gnu.
Change-Id: Ib2a3d86af6f92d75baca65431d74783ee0dbc292
When the commit
commit 03992356e6
Author: Zack Weinberg <zackw@panix.com>
Date: Sat Feb 10 11:58:35 2018 -0500
Use C99-compliant scanf under _GNU_SOURCE with modern compilers.
added the DEPRECATED_SCANF macro to select when redirections of *scanf
functions to their ISO C99 compliant versions should happen, it
accidentally missed doing it for vfwscanf, vwscanf, and vswscanf.
Tested for powerpc64le and with build-many-glibcs (i686-linux-gnu and
nios2-linux-gnu are failing with current master, and with this patch,
but I didn't see a regression).
Change-Id: I706b344a3fb50be017cdab9251d9da18a3ba8c60
issignalingf is a very small function used in some areas where
better performance (and smaller code) might be helpful.
Create inline implementation for issignalingf.
Reviewed-by: Joseph Myers <joseph@codesourcery.com>
l_audit ends up as an internal array with _rtld_global, and GCC 10
warns about this.
This commit does not change the layout of _rtld_global, so it is
suitable for backporting. Future changes could allocate more of the
audit state dynamically and remove it from always-allocated data
structures, to optimize the common case of inactive auditing.
Change-Id: Ic911100730f9124d4ea977ead8e13cee64b84d45
This patch provides new __ppoll64 explicit 64 bit function for handling polling
events (with struct timespec specified timeout) for a set of file descriptors.
Moreover, a 32 bit version - __ppoll has been refactored to internally use
__ppoll64.
The __ppoll is now supposed to be used on systems still supporting 32 bit time
(__TIMESIZE != 64) - hence the necessary conversion to 64 bit struct
__timespec64.
The new ppoll_time64 syscall available from Linux 5.1+ has been used, when
applicable.
The Linux kernel checks if passed tv_nsec value overflows, so there is no need
to repeat it in the glibc.
When ppoll syscall on systems supporting 32 bit time ABI is used, the check is
performed if passed data (which may have 64 bit tv_sec) fits into 32 bit range.
Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make check PARALLELMFLAGS="-j8" && \\
make xcheck PARALLELMFLAGS="-j8"
- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
- Use of cross-test-ssh.sh for ARM (armv7):
make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck
Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with ppoll_time64) and glibc build with v5.1 as
minimal kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports ppoll_time64
syscall.
- Linux v4.19 (no ppoll_time64 support) with default minimal kernel version for
contemporary glibc
This kernel doesn't support ppoll_time64 syscall, so the fallback to ppoll is
tested.
Above tests were performed with Y2038 redirection applied as well as without
(so the __TIMESIZE != 64 execution path is checked as well).
No regressions were observed.
The clock_nanosleep syscall is not supported on newer 32-bit platforms (such
as RV32). To fix this issue let's use clock_nanosleep_time64 if it is
avaliable.
The generic version is straightforward. For Hurd, its nanosleep
implementation is moved to clock_nanosleep with adjustments from
generic unix implementation.
The generic clock_nanosleep unix version is also removed since
it calls nanosleep.
Checked on x86_64-linux-gnu and powerpc64le-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
This patch provides new __futimens64 explicit 64 bit function for
setting access and modification time of file (by using its file descriptor).
Moreover, a 32 bit version - __futimens has been refactored to internally use
__futimens64.
The __futimens is now supposed to be used on systems still supporting
32 bit time (__TIMESIZE != 64) - hence the necessary conversions to 64 bit
struct __timespec64.
When pointer to struct __timespec64 is NULL - the file access and modification
time is set to the current one (by the kernel) and no conversions from struct
timespec to __timespec64 are performed.
The __futimens64 reuses __utimensat64_helper defined for __utimensat64.
The test procedure for __futimens64 is the same as for __utimensat64 conversion
patch.
This patch provides new __utimensat64 explicit 64 bit function for
setting access and modification time of a file. Moreover, a 32 bit version
- __utimensat has been refactored to internally use __utimensat64.
The __utimensat is now supposed to be used on systems still supporting
32 bit time (__TIMESIZE != 64) - hence the necessary conversions to 64 bit
struct __timespec64.
When pointer to struct __timespec64 is NULL - the file access and modification
time is set to the current one and no conversions from struct timespec to
__timespec64 are performed.
The new utimensat_time64 syscall available from Linux 5.1+ has been used,
when applicable.
The new helper function - __utimensat64_helper - has been introduced to
facilitate code re-usage on function providing futimens syscall handling.
The Linux kernel checks if passed tv_nsec value overflows, so there is no
need to repeat it in glibc.
When utimensat syscall on systems supporting 32 bit time ABI is used,
the check is performed if passed data (which may have 64 bit tv_sec) fits
into 32 bit range.
Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8"
- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
- Use of cross-test-ssh.sh for ARM (armv7):
make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck
Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with utimensat_time64) and glibc build with v5.1 as
minimal kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports utimensat_time64
syscall.
- Linux v4.19 (no utimensat_time64 support) with default minimal kernel
version for contemporary glibc
This kernel doesn't support utimensat_time64 syscall, so the fallback
to utimensat is tested.
The above tests were performed with Y2038 redirection applied as well as
without (so the __TIMESIZE != 64 execution path is checked as well).
No regressions were observed.
Also make the public prototype of gettimeofday declare its second
argument with type "void *" unconditionally, consistent with POSIX.
It is also consistent with POSIX.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Consolidate generic gettimeofday implementation to use clock_gettime.
Linux ports that still provide gettimeofday through vDSO are not
changed.
Remove sysdeps/unix/clock_gettime.c, which implemented clock_gettime
using gettimeofday; new OS ports must provide a real implementation of
clock_gettime.
Rename sysdeps/mach/gettimeofday.c to sysdeps/mach/clock_gettime.c and
convert into an implementation of clock_gettime. It only supports
CLOCK_REALTIME; Mach does not appear to have any support for monotonic
clocks. It uses __host_get_time, which provides at best microsecond
resolution. Hurd is currently using sysdeps/posix/clock_getres.c for
clock_getres; its output for CLOCK_REALTIME is based on
sysconf (_SC_CLK_TCK), and I do not know whether that gives the
correct result.
Unlike settimeofday, there are no known uses of gettimeofday's
vestigial "get time zone" feature that are not bugs. (The per-process
timezone support in localtime and friends is unrelated, and the
programs that set the kernel's offset between the hardware clock and
UTC do not need to read it back.) Therefore, this feature is dummied
out. Henceforth, if gettimeofday's "struct timezone" argument is not
NULL, it will write zeroes to both fields. Any program that is
actually looking at this data will thus think it is running in UTC,
which is probably more correct than whatever it was doing before.
[__]gettimeofday no longer has any internal callers, so we can now
remove its internal prototype and PLT bypass aliases. The
__gettimeofday@GLIBC_2.0 export remains, in case it is used by any
third-party code.
It also allows to simplify the arch-specific implementation on x86 and
powerpc to remove the hack to disable the internal route to non iFUNC
variant for internal symbol.
This patch also fixes a missing optimization on aarch64, powerpc, and
x86 where the code used on static build do not use the vDSO.
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
Co-authored-by: Zack Weinberg <zackw@panix.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
As for gettimeofday, time will be implemented based on clock_gettime
on all platforms and internal code should use clock_gettime
directly. In addition to removing a layer of indirection, this will
allow us to remove the PLT-bypass gunk for gettimeofday.
The changed code always assumes __clock_gettime (CLOCK_REALTIME)
or __clock_gettime (CLOCK_REALTIME_COARSE) (for Linux case) cannot
fail, using the same rationale for gettimeofday change. And internal
helper was added (time_now).
Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, and powerpc-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
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>
This patch provides new __clock_getres64 explicit 64 bit function for
getting the resolution (precision) of specified clock ID. Moreover, a
32 bit version - __clock_getres has been refactored to internally use
__clock_getres64.
The __clock_getres is now supposed to be used on systems still supporting
32 bit time (__TIMESIZE != 64) - hence the necessary conversion from 64 bit
struct __timespec64 to struct timespec.
The new clock_getres_time64 syscall available from Linux 5.1+ has been used,
when applicable.
On systems which are not supporting clock_getres_time64 (as their
clock_getres supports 64 bit time ABI) the vDSO syscall is attempted.
On the contrary the non-vDSO syscall is used for clock_getres_time64 as
up till now the kernel is not providing such interface.
No additional checks (i.e. if tv_nsec value overflow) are performed on
values returned via clock_getres{_time64} syscall, as it is assumed that
the Linux kernel will either return 0 and provide correct value or error.
The check for tv_sec being out of range on systems still supporting 32 bit
time (__TIMESIZE != 64) without Y2038 time support is also omitted as it is
_very_ unlikely that we would have a timer with resolution which exceeds 32
bit time_t range.
Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8"
- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
- Use of cross-test-ssh.sh for ARM (armv7):
make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck
Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with clock_getres_time64) and glibc build with v5.1 as
minimal kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
clock_getres_time64 syscall.
- Linux v4.19 (no clock_getres_time64 support) with default minimal kernel
version for contemporary glibc
This kernel doesn't support clock_getres_time64 syscall, so the fallback
to clock_getres is tested.
The above tests were performed with Y2038 redirection applied as well as
without (so the __TIMESIZE != 64 execution path is checked as well).
No regressions were observed.
The valid_nanoseconds () static inline function has been introduced to
check if nanoseconds value is in the correct range - greater or equal to
zero and less than 1000000000.
The explicit #include <time.h> has been added to files where it was
missing.
The __syscall_slong_t type for ns has been used to avoid issues on x32.
Tested with:
- scripts/build-many-glibcs.py
- make PARALLELMFLAGS="-j12" && make PARALLELMFLAGS="-j12" xcheck on x86_64
Besides semop being a subset of semtimedop, new 32-bit architectures
on Linux are not expected to provide the syscall (only the 64-bit time
semtimedop).
Also, Linux 5.1 only wired-up semtimedop for the 64-bit architectures
that missed it (powerpc, s390, and sparc). This simplifies the code
to support it.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
This patch provides new __clock_settime64 explicit 64 bit function for
setting the time. Moreover, a 32 bit version - __clock_settime - has been
refactored to internally use __clock_settime64.
The __clock_settime is now supposed to be used on systems still supporting
32 bit time (__TIMESIZE != 64) - hence the necessary conversion to 64 bit
struct timespec.
The new clock_settime64 syscall available from Linux 5.1+ has been used,
when applicable.
In this patch the internal padding (tv_pad) of struct __timespec64 is
left untouched (on systems with __WORDSIZE == 32) as Linux kernel ignores
upper 32 bits of tv_nsec.
Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8"
- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
- Use of cross-test-ssh.sh for ARM (armv7):
make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck
Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with clock_settime64) and glibc build with v5.1 as minimal
kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
__clock_settime64 syscalls.
- Linux v4.19 (no clock_settime64 support) with default minimal kernel
version for contemporary glibc
This kernel doesn't support __clock_settime64 syscalls, so the fallback
to clock_settime is tested.
The above tests were performed with Y2038 redirection applied as well as
without (so the __TIMESIZE != 64 execution path is checked as well).
No regressions were observed.
* include/time.h (__clock_settime64):
Add __clock_settime alias according to __TIMESIZE define
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime):
Refactor this function to be used only on 32 bit machines as a wrapper
on __clock_settime64.
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64): Add
* sysdeps/unix/sysv/linux/clock_settime.c (__clock_settime64):
Use clock_settime64 kernel syscall (available from 5.1+ Linux)
This patch replaces the fork+exec by posix_spawn on wordexp, which
allows a better scability on Linux and simplifies the thread
cancellation handling.
The only change which can not be implemented with posix_spawn the
/dev/null check to certify it is indeed the expected device. I am
not sure how effetive this check is since /dev/null tampering means
something very wrong with the system and this is the least of the
issues. My view is the tests is really out of the place and the
hardening provided is minimum.
If the idea is still to provide such check, I think a possibilty
would be to open /dev/null, check it, add a dup2 file action, and
close the file descriptor.
Checked on powerpc64le-linux-gnu and x86_64-linux-gnu.
* include/spawn.h (__posix_spawn_file_actions_addopen): New
prototype.
* posix/spawn_faction_addopen.c (posix_spawn_file_actions_addopen):
Add internal alias.
* posix/wordexp.c (create_environment, free_environment): New
functions.
(exec_comm_child, exec_comm): Use posix_spawn instead of fork+exec.
* posix/wordexp-test.c: Use libsupport.
Originally the public interface for getdents64 was declared in
<unistd.h> in 51ea67d548. Later, b8b3d5a14e moved it to <dirent.h>.
Fixes: b8b3d5a14e ("Linux: Move getdents64 to <dirent.h>")
The HURD requires explicit inclusion of <bits/types/struct_timeval.h> to use
struct timeval in ./include/time.h.
For this particular glibc port, the proper header hasn't been included before
inclusion of time.h.
Tested with build-many-glibcs.py with i686-gnu and x86_64-linux-gnu:
build-many-glibcs.py /home/lukma/work/glibc/glibc-many-build --keep all compilers i686-gnu
build-many-glibcs.py /home/lukma/work/glibc/glibc-many-build --keep all glibcs i686-gnu
Also run of xcheck on x86_64:
./src/configure --prefix=/usr
make PARALLELMFLAGS="-j12" && make xcheck PARALLELMFLAGS="-j12"
* include/time.h: Add #include <bits/types/struct_timeval.h>
With only two exceptions (sys/types.h and sys/param.h, both of which
historically might have defined BYTE_ORDER) the public headers that
include <endian.h> only want to be able to test __BYTE_ORDER against
__*_ENDIAN.
This patch creates a new bits/endian.h that can be included by any
header that wants to be able to test __BYTE_ORDER and/or
__FLOAT_WORD_ORDER against the __*_ENDIAN constants, or needs
__LONG_LONG_PAIR. It only defines macros in the implementation
namespace.
The existing bits/endian.h (which could not be included independently
of endian.h, and only defines __BYTE_ORDER and maybe __FLOAT_WORD_ORDER)
is renamed to bits/endianness.h. I also took the opportunity to
canonicalize the form of this header, which we are stuck with having
one copy of per architecture. Since they are so short, this means git
doesn’t understand that they were renamed from existing headers, sigh.
endian.h itself is a nonstandard header and its only remaining use
from a standard header is guarded by __USE_MISC, so I dropped the
__USE_MISC conditionals from around all of the public-namespace things
it defines. (This means, an application that requests strict library
conformance but includes endian.h will still see the definition of
BYTE_ORDER.)
A few changes to specific bits/endian(ness).h variants deserve
mention:
- sysdeps/unix/sysv/linux/ia64/bits/endian.h is moved to
sysdeps/ia64/bits/endianness.h. If I remember correctly, ia64 did
have selectable endianness, but we have assembly code in
sysdeps/ia64 that assumes it’s little-endian, so there is no reason
to treat the ia64 endianness.h as linux-specific.
- The C-SKY port does not fully support big-endian mode, the compile
will error out if __CSKYBE__ is defined.
- The PowerPC port had extra logic in its bits/endian.h to detect a
broken compiler, which strikes me as unnecessary, so I removed it.
- The only files that defined __FLOAT_WORD_ORDER always defined it to
the same value as __BYTE_ORDER, so I removed those definitions.
The SH bits/endian(ness).h had comments inconsistent with the
actual setting of __FLOAT_WORD_ORDER, which I also removed.
- I *removed* copyright boilerplate from the few bits/endian(ness).h
headers that had it; these files record a single fact in a fashion
dictated by an external spec, so I do not think they are copyrightable.
As long as I was changing every copy of ieee754.h in the tree, I
noticed that only the MIPS variant includes float.h, because it uses
LDBL_MANT_DIG to decide among three different versions of
ieee854_long_double. This patch makes it not include float.h when
GCC’s intrinsic __LDBL_MANT_DIG__ is available.
* string/endian.h: Unconditionally define LITTLE_ENDIAN,
BIG_ENDIAN, PDP_ENDIAN, and BYTE_ORDER. Condition byteswapping
macros only on !__ASSEMBLER__. Move the definitions of
__BIG_ENDIAN, __LITTLE_ENDIAN, __PDP_ENDIAN, __FLOAT_WORD_ORDER,
and __LONG_LONG_PAIR to...
* string/bits/endian.h: ...this new file, which includes
the renamed header bits/endianness.h for the definition of
__BYTE_ORDER and possibly __FLOAT_WORD_ORDER.
* string/Makefile: Install bits/endianness.h.
* include/bits/endian.h: New wrapper.
* bits/endian.h: Rename to bits/endianness.h.
Add multiple-include guard. Rewrite the comment explaining what
the machine-specific variants of this file should do.
* sysdeps/unix/sysv/linux/ia64/bits/endian.h:
Move to sysdeps/ia64.
* sysdeps/aarch64/bits/endian.h
* sysdeps/alpha/bits/endian.h
* sysdeps/arm/bits/endian.h
* sysdeps/csky/bits/endian.h
* sysdeps/hppa/bits/endian.h
* sysdeps/ia64/bits/endian.h
* sysdeps/m68k/bits/endian.h
* sysdeps/microblaze/bits/endian.h
* sysdeps/mips/bits/endian.h
* sysdeps/nios2/bits/endian.h
* sysdeps/powerpc/bits/endian.h
* sysdeps/riscv/bits/endian.h
* sysdeps/s390/bits/endian.h
* sysdeps/sh/bits/endian.h
* sysdeps/sparc/bits/endian.h
* sysdeps/x86/bits/endian.h:
Rename to endianness.h; canonicalize form of file; remove
redundant definitions of __FLOAT_WORD_ORDER.
* sysdeps/powerpc/bits/endianness.h: Remove logic to check for
broken compilers.
* ctype/ctype.h
* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
* sysdeps/arm/nptl/bits/pthreadtypes-arch.h
* sysdeps/csky/nptl/bits/pthreadtypes-arch.h
* sysdeps/ia64/ieee754.h
* sysdeps/ieee754/ieee754.h
* sysdeps/ieee754/ldbl-128/ieee754.h
* sysdeps/ieee754/ldbl-128ibm/ieee754.h
* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
* sysdeps/mips/ieee754/ieee754.h
* sysdeps/mips/nptl/bits/pthreadtypes-arch.h
* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
* sysdeps/nptl/pthread.h
* sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
* sysdeps/sh/nptl/bits/pthreadtypes-arch.h
* sysdeps/sparc/sparc32/ieee754.h
* sysdeps/unix/sysv/linux/generic/bits/stat.h
* sysdeps/unix/sysv/linux/generic/bits/statfs.h
* sysdeps/unix/sysv/linux/sys/acct.h
* wctype/bits/wctype-wchar.h:
Include bits/endian.h, not endian.h.
* sysdeps/unix/sysv/linux/hppa/pthread.h: Don’t include endian.h.
* sysdeps/mips/ieee754/ieee754.h: Use __LDBL_MANT_DIG__
in ifdefs, instead of LDBL_MANT_DIG. Only include float.h
when __LDBL_MANT_DIG__ is not predefined, in which case
define __LDBL_MANT_DIG__ to equal LDBL_MANT_DIG.
Those functions allow easy conversion between Y2038 safe struct
__timespec64 and other time related data structures (like struct timeval
or struct timespec).
* include/time.h (valid_timeval_to_timespec64): Add.
* include/time.h (valid_timespec_to_timespec64): Likewise.
* include/time.h (valid_timespec64_to_timespec): Likewise.
* include/time.h (valid_timespec64_to_timeval): Likewise.
This type is a glibc's "internal" type similar to struct timespec but
whose tv_sec field is a __time64_t rather than a time_t, which makes it
Y2038-proof and usable to pass syscalls between user code and Y2038-proof
kernel.
To support passing this structure to the kernel - the unnamed 32 bit
padding bit-field has been introduced. The placement of it depends on
the endianness of the SoC.
Tested on x86_64 and ARM.
In glibc 2.17, the functions clock_getcpuclockid, clock_getres,
clock_gettime, clock_nanosleep, and clock_settime were moved from
librt.so to libc.so, leaving compatibility stubs behind. Now that the
dynamic linker no longer insists on finding versioned symbols in the
same library that originally defined them, we do not need the stubs
anymore, and this means we don't need GLIBC_PRIVATE __-prefix aliases
for most of the functions anymore either. (clock_gettime still needs
one.) For ports added before 2.17, libc.so needs to provide two
symbol versions for each, the default at GLIBC_2.17 plus a compat
version matching what librt had.
While I'm at it, move the clock_*.c files and their tests from rt/ to
time/.
If the process is in a bad state, we used to print backtraces in
many cases. This is problematic because doing so could involve
a lot of work, like loading libgcc_s using the dynamic linker,
and this could itself be targeted by exploit writers. For example,
if the crashing process was forked from a long-lived process, the
addresses in the error message could be used to bypass ASLR.
Commit ed421fca42 ("Avoid backtrace from
__stack_chk_fail [BZ #12189]"), backtraces where no longer printed
because backtrace_and_maps was always called with do_abort == 1.
Rather than fixing this logic error, this change removes the backtrace
functionality from the sources. With the prevalence of external crash
handlers, it does not appear to be particularly useful. The crash
handler may also destroy useful information for debugging.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The resolution of C floating-point Clarification Request 25
<http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2397.htm#dr_25> is
that the totalorder and totalordermag functions should take pointer
arguments, and this has been adopted in C2X (with const added; note
that the integration of this change into C2X is present in the C
standard git repository but postdates the most recent public PDF
draft).
This patch updates glibc accordingly. As a defect resolution, the API
is changed unconditionally rather than supporting any sort of TS
18661-1 mode for compilation with the old version of the API. There
are compat symbols for existing binaries that pass floating-point
arguments directly. As a consequence of changing to pointer
arguments, there are no longer type-generic macros in tgmath.h for
these functions.
Because of the fairly complicated logic for creating libm function
aliases and determining the set of aliases to create in a given glibc
configuration, rather than duplicating all that in individual source
files to create the versioned and compat symbols, the source files for
the various versions of totalorder functions are set up to redefine
weak_alias before using libm_alias_* macros to create the symbols
required. In turn, this requires creating a separate alias for each
symbol version pointing to the same implementation (see binutils bug
<https://sourceware.org/bugzilla/show_bug.cgi?id=23840>), which is
done automatically using __COUNTER__. (As I noted in
<https://sourceware.org/ml/libc-alpha/2018-10/msg00631.html>, it might
well make sense for glibc's symbol versioning macros to do that alias
creation with __COUNTER__ themselves, which would somewhat simplify
the logic in the totalorder source files.)
It is of course desirable to test the compat symbols. I did this with
the generic libm-test machinery, but didn't wish to duplicate the
actual tables of test inputs and outputs, and thought it risky to
attempt to have a single object file refer to both default and compat
versions of the same function in order to test them together. Thus, I
created libm-test-compat_totalorder.inc and
libm-test-compat_totalordermag.inc which include the generated .c
files (with the processed version of those tables of inputs) from the
non-compat tests, and added appropriate dependencies. I think this
provides sufficient test coverage for the compat symbols without also
needing to make the special ldbl-96 and ldbl-128ibm tests (of
peculiarities relating to the representations of those formats that
can't be covered in the generic tests) run for the compat symbols.
Tests of compat symbols need to be internal tests, meaning _ISOMAC is
not defined. Making some libm-test tests into internal tests showed
up two other issues. GCC diagnoses duplicate macro definitions of
__STDC_* macros, including __STDC_WANT_IEC_60559_TYPES_EXT__; I added
an appropriate conditional and filed
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91451> for this issue.
On ia64, include/setjmp.h ends up getting included indirectly from
libm-symbols.h, resulting in conflicting definitions of the STR macro
(also defined in libm-test-driver.c); I renamed the macros in
include/setjmp.h. (It's arguable that we should have common internal
headers used everywhere for stringizing and concatenation macros.)
Tested for x86_64 and x86, and with build-many-glibcs.py.
* math/bits/mathcalls.h
[__GLIBC_USE (IEC_60559_BFP_EXT) || __MATH_DECLARING_FLOATN]
(totalorder): Take pointer arguments.
[__GLIBC_USE (IEC_60559_BFP_EXT) || __MATH_DECLARING_FLOATN]
(totalordermag): Likewise.
* manual/arith.texi (totalorder): Likewise.
(totalorderf): Likewise.
(totalorderl): Likewise.
(totalorderfN): Likewise.
(totalorderfNx): Likewise.
(totalordermag): Likewise.
(totalordermagf): Likewise.
(totalordermagl): Likewise.
(totalordermagfN): Likewise.
(totalordermagfNx): Likewise.
* math/tgmath.h (__TGMATH_BINARY_REAL_RET_ONLY): Remove macro.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (totalorder): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (totalordermag): Likewise.
* math/Versions (GLIBC_2.31): Add totalorder, totalorderf,
totalorderl, totalordermag, totalordermagf, totalordermagl,
totalorderf32, totalorderf64, totalorderf32x, totalordermagf32,
totalordermagf64, totalordermagf32x, totalorderf64x,
totalordermagf64x, totalorderf128 and totalordermagf128.
* math/Makefile (libm-test-funcs-noauto): Add compat_totalorder
and compat_totalordermag.
(libm-test-funcs-compat): New variable.
(libm-tests-compat): Likewise.
(tests): Do not include compat tests.
(tests-internal): Add compat tests.
($(foreach t,$(libm-tests-base),
$(objpfx)$(t)-compat_totalorder.o)): Depend
on $(objpfx)libm-test-totalorder.c.
($(foreach t,$(libm-tests-base),
$(objpfx)$(t)-compat_totalordermag.o): Depend on
$(objpfx)libm-test-totalordermag.c.
(tgmath3-macros): Remove totalorder and totalordermag.
* math/libm-test-compat_totalorder.inc: New file.
* math/libm-test-compat_totalordermag.inc: Likewise.
* math/libm-test-driver.c (struct test_ff_i_data): Update comment.
(RUN_TEST_fpfp_b): New macro.
(RUN_TEST_LOOP_fpfp_b): Likewise.
* math/libm-test-totalorder.inc (totalorder_test_data): Use
TEST_fpfp_b.
(totalorder_test): Condition on [!COMPAT_TEST].
(do_test): Likewise.
* math/libm-test-totalordermag.inc (totalordermag_test_data): Use
TEST_fpfp_b.
(totalordermag_test): Condition on [!COMPAT_TEST].
(do_test): Likewise.
* math/gen-tgmath-tests.py (Tests.add_all_tests): Remove
totalorder and totalordermag.
* math/test-tgmath.c (NCALLS): Change to 132.
(F(compile_test)): Do not call totalorder or totalordermag.
(F(totalorder)): Remove.
(F(totalordermag)): Likewise.
* include/float.h (__STDC_WANT_IEC_60559_TYPES_EXT__): Do not
define if [__STDC_WANT_IEC_60559_TYPES_EXT__].
* include/setjmp.h [!_ISOMAC] (STR_HELPER): Rename to
SJSTR_HELPER.
[!_ISOMAC] (STR): Rename to SJSTR. Update call to STR_HELPER.
[!_ISOMAC] (TEST_SIZE): Update call to STR.
[!_ISOMAC] (TEST_ALIGN): Likewise.
[!_ISOMAC] (TEST_OFFSET): Likewise.
* sysdeps/ieee754/dbl-64/s_totalorder.c: Include <shlib-compat.h>
and <first-versions.h>.
(__totalorder): Take pointer arguments. Add symbol versions and
compat symbols.
* sysdeps/ieee754/dbl-64/s_totalordermag.c: Include
<shlib-compat.h> and <first-versions.h>.
(__totalordermag): Take pointer arguments. Add symbol versions
and compat symbols.
* sysdeps/ieee754/dbl-64/wordsize-64/s_totalorder.c: Include
<shlib-compat.h> and <first-versions.h>.
(__totalorder): Take pointer arguments. Add symbol versions and
compat symbols.
* sysdeps/ieee754/dbl-64/wordsize-64/s_totalordermag.c: Include
<shlib-compat.h> and <first-versions.h>.
(__totalordermag): Take pointer arguments. Add symbol versions
and compat symbols.
* sysdeps/ieee754/float128/float128_private.h
(__totalorder_compatl): New macro.
(__totalordermag_compatl): Likewise.
* sysdeps/ieee754/flt-32/s_totalorderf.c: Include <shlib-compat.h>
and <first-versions.h>.
(__totalorderf): Take pointer arguments. Add symbol versions and
compat symbols.
* sysdeps/ieee754/flt-32/s_totalordermagf.c: Include
<shlib-compat.h> and <first-versions.h>.
(__totalordermagf): Take pointer arguments. Add symbol versions
and compat symbols.
* sysdeps/ieee754/ldbl-128/s_totalorderl.c: Include
<shlib-compat.h> and <first-versions.h>.
(__totalorderl): Take pointer arguments. Add symbol versions and
compat symbols.
* sysdeps/ieee754/ldbl-128/s_totalordermagl.c: Include
<shlib-compat.h> and <first-versions.h>.
(__totalordermagl): Take pointer arguments. Add symbol versions
and compat symbols.
* sysdeps/ieee754/ldbl-128ibm/s_totalorderl.c: Include
<shlib-compat.h>.
(__totalorderl): Take pointer arguments. Add symbol versions and
compat symbols.
* sysdeps/ieee754/ldbl-128ibm/s_totalordermagl.c: Include
<shlib-compat.h>.
(__totalordermagl): Take pointer arguments. Add symbol versions
and compat symbols.
* sysdeps/ieee754/ldbl-96/s_totalorderl.c: Include
<shlib-compat.h> and <first-versions.h>.
(__totalorderl): Take pointer arguments. Add symbol versions and
compat symbols.
* sysdeps/ieee754/ldbl-96/s_totalordermagl.c: Include
<shlib-compat.h> and <first-versions.h>.
(__totalordermagl): Take pointer arguments. Add symbol versions
and compat symbols.
* sysdeps/ieee754/ldbl-opt/nldbl-totalorder.c (totalorderl): Take
pointer arguments.
* sysdeps/ieee754/ldbl-opt/nldbl-totalordermag.c (totalordermagl):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/test-totalorderl-ldbl-128ibm.c
(do_test): Update calls to totalorderl and totalordermagl.
* sysdeps/ieee754/ldbl-96/test-totalorderl-ldbl-96.c (do_test):
Update calls to totalorderl and totalordermagl.
* sysdeps/mach/hurd/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/csky/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/riscv/rv64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
This patch starts preparation for C2X support in glibc headers by
adding a feature test macro _ISOC2X_SOURCE and corresponding
__GLIBC_USE (ISOC2X). (I chose to use the newer __GLIBC_USE style for
this rather than the older __USE_* macros tested with #ifdef.) As
with other such macros, C2X features are also enabled by compiling for
a standard newer than C17, or by using _GNU_SOURCE.
This patch does not itself enable anything new in the headers for C2X;
that is to be done in followup patches. (For example, most of the TS
18661-1 functions should be declared for C2X without any
__STDC_WANT_IEC_60559_BFP_EXT__ being needed, but the ones that
18661-1 adds to Annex F because of their close relation to IEEE 754
formats do still need the WANT macro in C2X.)
Once C2X becomes an actual standard we'll presumably move to using the
actual year in the feature test macro and __GLIBC_USE, with some
period when both macro spellings are accepted, as was done with
_ISOC9X_SOURCE.
Tested for x86_64.
* include/features.h (_ISOC2X_SOURCE): New feature test macro.
Undefine and define to 1 if [_GNU_SOURCE].
(__GLIBC_USE_ISOC2X): New macro. Undefine and redefine depending
on [_ISOC2X_SOURCE] and [__STDC_VERSION__ > 201710L].
(__USE_ISOC11): Also define to 1 if [_ISOC2X_SOURCE].
(__USE_ISOC99): Likewise.
(__USE_ISOC95): Likewise.
* manual/creature.texi (_ISOC2X_SOURCE): Document.
Now that there are no internal users of __sysctl left, it is possible
to add an unconditional deprecation warning to <sys/sysctl.h>.
To avoid a test failure due this warning in check-install-headers,
skip the test for sys/sysctl.h.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
