Joseph Myers [Thu, 1 Jul 2021 17:37:36 +0000 (17:37 +0000)]
Update syscall lists for Linux 5.13
Linux 5.13 has three new syscalls (landlock_create_ruleset,
landlock_add_rule, landlock_restrict_self). Update syscall-names.list
and regenerate the arch-syscall.h headers with build-many-glibcs.py
update-syscalls.
Stefan Liebler [Tue, 29 Jun 2021 09:37:28 +0000 (11:37 +0200)]
s390: Fix MEMCHR_Z900_G5 ifunc-variant if n>=0x80000000 [BZ #28024]
On s390 (31bit), the pointer to the first byte after s always wraps
around with n >= 0x80000000 and can lead to stop searching before
end of s.
Thus this patch just use NULL as byte after s in this case and
the srst instruction stops searching with "not found" when wrapping
around from top address to zero.
This is observable with testcase string/test-memchr
starting with commit "String: Add overflow tests for strnlen, memchr,
and strncat [BZ #27974]"
https://sourceware.org/git/?p=glibc.git;a=commit;h=da5a6fba0febbfc90896ce1b2eb75c6d8a88a72d
Stefan Liebler [Wed, 30 Jun 2021 14:17:37 +0000 (16:17 +0200)]
Fix extra PLT reference in libc.so due to __glob64_time64 if build with gcc 7.5 on 32bit.
Starting with recent commit 84f7ce84474c1648ce96884f1c91ca7b97ca3fc2
"posix: Add glob64 with 64-bit time_t support", elf/check-localplt
fails due to extra PLT reference __glob64_time64 in __glob64_time64
itself.
This is observable with gcc 7.5 on x86_64 with -m32 or s390x with
-m31. E.g. if build with gcc 10, gcc is generating a call to
__glob64_time64.localalias.
This patch is adding a hidden version of __glob64_time64 in the
same way as for __globfree64_time64.
Add hp-timing.h using the cntvct_el0 counter. Return timing in nanoseconds
so it is fully compatible with generic hp-timing. Don't set HP_TIMING_INLINE
in the dynamic linker since it adds unnecessary overheads and some ancient
kernels may not handle emulating cntcvt correctly. Currently cntvct_el0 is
only used for timing in the benchtests.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Optimize strnlen by avoiding UMINV which is slow on most cores. On Neoverse N1
large strings are 1.8x faster than the current version, and bench-strnlen is
50% faster overall. This version is MTE compatible.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Florian Weimer [Tue, 29 Jun 2021 20:17:05 +0000 (22:17 +0200)]
nptl_db: Re-use the ELF-to-abilist converter for ABI checking
The previous approach uses readelf -DWs, which does not produce
a stable output format (older binutils versions do not include
symbol version information). This commit re-uses scripts/abilist.awk
with a tweak to include GLIBC_PRIVATE symbols. This awk script
is based on objdump -T output, which appears to be stable over time.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
RFC 8335 defines the network utility PROBE, which builds off of the
capabilities of Ping to query more detailed interface information from
networking nodes.
The definitions included in this patchset have been accepted into the
linux net-next branch and will be included in Linux 5.13. This
patchset adds the same definitions to the glibc for use in the
iputils package.
Stefan Liebler [Mon, 28 Jun 2021 11:01:07 +0000 (13:01 +0200)]
s390x: Update math: redirect roundeven function
After recent commit 447954a206837b5f153869cfeeeab44631c3fac9
"math: redirect roundeven function", building on
s390x fails with:
Error: symbol `__roundevenl' is already defined
Similar to aarch64/riscv fix, this patch redirects target
specific functions for s390x:
commit 3213ed770cbc5821920d16caa93c85e92dd7b9f6
"Update math: redirect roundeven function"
Austin Group issue 62 [1] dropped the async-signal-safe requirement
for fork and provided a async-signal-safe _Fork replacement that
does not run the atfork handlers. It will be included in the next
POSIX standard.
It allow to close a long standing issue to make fork AS-safe (BZ#4737).
As indicated on the bug, besides the internal lock for the atfork
handlers itself; there is no guarantee that the handlers itself will
not introduce more AS-safe issues.
The idea is synchronize fork with the required internal locks to allow
children in multithread processes to use mostly of standard function
(even though POSIX states only AS-safe function should be used). On
signal handles, _Fork should be used intead and only AS-safe functions
should be used.
For testing, the new tst-_Fork only check basic usage. I also added
a new tst-mallocfork3 which uses the same strategy to check for
deadlock of tst-mallocfork2 but using threads instead of subprocesses
(and it does deadlock if it replaces _Fork with fork).
Florian Weimer [Mon, 28 Jun 2021 12:33:53 +0000 (14:33 +0200)]
nptl_db: Clean up main/rtld variable handling
Most symbols are now in libc.so.6. The "main" (exempted from
coverage checks) status is therefore not necessary. Use
DB_MAIN_VARIABLE for the remaining separate symbol,
__nptl_initial_report_events. DB_RTLD_VARIABLE is now unused, so
remove it.
Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
Florian Weimer [Mon, 28 Jun 2021 07:51:01 +0000 (09:51 +0200)]
Linux: Cleanups after librt move
librt.so is no longer installed for PTHREAD_IN_LIBC, and tests
are not linked against it. $(librt) is introduced globally for
shared tests that need to be linked for both PTHREAD_IN_LIBC
and !PTHREAD_IN_LIBC.
GLIBC_PRIVATE symbols that were needed during the transition are
removed again.
Florian Weimer [Mon, 28 Jun 2021 07:51:01 +0000 (09:51 +0200)]
Linux: Move timer_settime, __timer_settime64 from librt to libc
The symbols were moved using scripts/move-symbol-to-libc.py.
The way the ABI intransition is implemented is changed with this
commit: the implementation is now consolidated in one file with a
TIMER_T_WAS_INT_COMPAT check.
The shared librt is now empty, so this commit adds a placeholder
symbol at the base version, GLIBC_2.2, and potentially at the
GLIBC_2.3.3 version as well (the leftover from the int/timer_t ABI
transition).
Florian Weimer [Mon, 28 Jun 2021 07:51:01 +0000 (09:51 +0200)]
Linux: Move timer_gettime, __timer_gettime64 from librt to libc
The symbols were moved using scripts/move-symbol-to-libc.py.
The way the ABI intransition is implemented is changed with this
commit: the implementation is now consolidated in one file with a
TIMER_T_WAS_INT_COMPAT check.
Florian Weimer [Mon, 28 Jun 2021 07:51:00 +0000 (09:51 +0200)]
Linux: Move timer_getoverrun from librt to libc
The symbol was moved using scripts/move-symbol-to-libc.py.
The way the ABI intransition is implemented is changed with this
commit: the implementation is now consolidated in one file with a
TIMER_T_WAS_INT_COMPAT check.
Florian Weimer [Mon, 28 Jun 2021 07:51:00 +0000 (09:51 +0200)]
Linux: Move timer_create, timer_delete from librt to libc
The symbols were moved using scripts/move-symbol-to-libc.py.
timer_create and timer_delete are tied together via the int/timer_t
compatibility code. The way the ABI intransition is implemented
is changed with this commit: the implementation is now consolidated
in one file with a TIMER_T_WAS_INT_COMPAT check.
Florian Weimer [Mon, 28 Jun 2021 07:51:00 +0000 (09:51 +0200)]
Linux: Define TIMER_T_WAS_INT_COMPAT in kernel-posix-timers.h
This is almost equivalent to __WORDSIZE == 64
&& OTHER_SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_3_3), except
that this expression is true for mips64/n64 targets as well,
even though those did not undergo the timer_t transition.
Florian Weimer [Mon, 28 Jun 2021 06:33:57 +0000 (08:33 +0200)]
Install shared objects under their ABI names
Previously, the installed objects were named like libc-2.33.so,
and the ABI soname libc.so.6 was just a symbolic link.
The Makefile targets to install these symbolic links are no longer
needed after this, so they are removed with this commit. The more
general $(make-link) command (which invokes scripts/rellns-sh) is
retained because other symbolic links are still needed.
Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@rehdat.com>
Florian Weimer [Mon, 28 Jun 2021 06:33:57 +0000 (08:33 +0200)]
elf: Generalize name-based DSO recognition in ldconfig
This introduces <dl-is_dso.h> and the _dl_is_dso function. A
test ensures that the official names of libc.so, ld.so, and their
versioned names are recognized.
Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
This is only seen on installed systems because it was due to a
corrupted gconv-modules.cache. iconvconfig had the following issues
(it was specifically freeing fulldir that caused this issue, but other
cleanups are also needed) that this patch fixes.
- Add prefix only if dir starts with '/'
- Use asprintf instead of mempcpy so that the directory string is NULL
terminated
- Make a copy of the directory reference in new_module so that fulldir
can be freed within the same scope in handle_dir.
Shen-Ta Hsieh [Mon, 24 May 2021 01:43:12 +0000 (09:43 +0800)]
Use GCC builtins for roundeven functions if desired.
This patch is using the corresponding GCC builtin for roundevenf,
roundeven and roundevenl if the USE_FUNCTION_BUILTIN macros are defined
to one in math-use-builtins.h.
These builtin functions is supported since GCC 10.
The code of the generic implementation is not changed.
Signed-off-by: Shen-Ta Hsieh <ibmibmibm.tw@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Florian Weimer [Fri, 25 Jun 2021 08:51:31 +0000 (10:51 +0200)]
Linux: Move timer helper routines from librt to libc
This adds several temporary GLIBC_PRIVATE exports. The symbol names
are changed so that they all start with __timer_.
It is now possible to invoke the fork handler directly, so
pthread_atfork is no longer necessary. The associated error cannot
happen anymore, and cancellation handling can be removed from
the helper thread routine.
Florian Weimer [Fri, 25 Jun 2021 08:30:36 +0000 (10:30 +0200)]
Linux: Move lio_listio, lio_listio64 from librt to libc
The symbols were moved using scripts/move-symbol-to-libc.py.
Placeholder symbols are needed on some architectures, to keep the
GLIBC_2.1 and GLIBC_2.4 symbol versions around.
Florian Weimer [Fri, 25 Jun 2021 08:30:36 +0000 (10:30 +0200)]
rt: Rework lio_listio implementation
Move the common code into rt/lio_listio-common.c and include
the file in both rt/lio_listio.c and rt/lio_listio64.c. The common
code automatically defines both public symbols for __WORDSIZE == 64.
Florian Weimer [Fri, 25 Jun 2021 08:30:36 +0000 (10:30 +0200)]
Linux: Move aio_write, aio_write64 into libc
Both symbols have to be moved at the same time because they
are intertwined for __WORDSIZE == 64. The treatment of this case
is also changed to match more closely how the other files suppress
the declaration of the *64 identifier.
The symbols were moved using scripts/move-symbol-to-libc.py.
Florian Weimer [Fri, 25 Jun 2021 08:30:36 +0000 (10:30 +0200)]
Linux: Move aio_suspend, aio_suspend64, __aio_suspend_time64 to libc
The symbols were moved using scripts/move-symbol-to-libc.py.
There is a minor oddity here: This is generic code shared with Hurd,
and Hurd does not have time64 support. This is why the
versioned_symbol export for __aio_suspend_time64 is restricted to
the PTHREAD_IN_LIBC code.
Florian Weimer [Fri, 25 Jun 2021 08:30:36 +0000 (10:30 +0200)]
Linux: Move aio_read, aio_read64 into libc
Both symbols have to be moved at the same time because they
are intertwined for __WORDSIZE == 64. The treatment of this case
is also changed to match more closely how the other files suppress
the declaration of the *64 identifier.
The symbols were moved using scripts/move-symbol-to-libc.py.
It turns out that the _dl_next_tls_modid in _dl_map_object_from_fd keeps
returning the same modid over and over again if there is a gap and
more than TLS-using module is loaded in one dlopen call. This corrupts
TLS data structures. The bug is still present after a revert, but
empirically it is much more difficult to trigger (because it involves a
dlopen failure).
Florian Weimer [Fri, 25 Jun 2021 06:02:30 +0000 (08:02 +0200)]
elf: Fix glibc-hwcaps priorities with cache flags mismatches [BZ #27046]
If lib->flags (in the cache) did not match GLRO (dl_correct_cache_id),
searching for further glibc-hwcaps entries did not happen, and it
was possible that the best glibc-hwcaps was not found. By accident,
this causes a test failure for elf/tst-glibc-hwcaps-prepend-cache
on armv7l.
This commit changes the cache lookup logic to continue searching
if (a) no match has been found, (b) a named glibc-hwcaps match
has been found(), or (c) non-glibc-hwcaps match has been found
and the entry flags and cache default flags do not match.
_DL_CACHE_DEFAULT_ID is used instead of GLRO (dl_correct_cache_id)
because the latter is only written once on i386 if loading
of libc.so.5 libraries is selected, so GLRO (dl_correct_cache_id)
should probably removed in a future change.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Which words independently of s + maxlen overflowing. So the
second overflow check is unnecissary for correctness and
just extra overhead in the common no overflow case.
test-strlen.c, test-wcslen.c, test-strnlen.c and test-wcsnlen.c are
all passing
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
The pthread_atfork is similar between Linux and Hurd, only the compat
version bits differs. The generic version is place at sysdeps/pthread
with a common name.
It also fixes an issue with Hurd license, where the static-only object
did not use LGPL + exception.
Checked on x86_64-linux-gnu, i686-linux-gnu, and with a build for
i686-gnu.
The Linux nptl implementation is used as base for generic fork
implementation to handle the internal locks and mutexes. The
system specific bits are moved a new internal _Fork symbol.
(This new implementation will be used to provide a async-signal-safe
_Fork now that POSIX has clarified that fork might not be
async-signal-safe [1]).
For Hurd it means that the __nss_database_fork_prepare_parent and
__nss_database_fork_subprocess will be run in a slight different
order.
It is a wrapper for Linux clone syscall, to simplify the call to the
use only the most common arguments and remove architecture specific
handling (such as ia64 different name and signature).
x86: Fix tst-cpu-features-cpuinfo on Ryzen 9 (BZ #27873)
AMD define different flags for IRPB, IBRS, and STIPBP [1], so new
x86_64_cpu are added and IBRS_IBPB is only tested for Intel.
The SSDB is also defined and implemented different on AMD [2],
and also a new AMD_SSDB flag is added. It should map to the
cpuinfo 'ssdb' on recent AMD cpus.
It fixes tst-cpu-features-cpuinfo and tst-cpu-features-cpuinfo-static
on recent AMD cpus.
H.J. Lu [Wed, 23 Jun 2021 21:27:58 +0000 (14:27 -0700)]
x86: Copy IBT and SHSTK usable only if CET is enabled
IBT and SHSTK usable bits are copied from CPUID feature bits and later
cleared if kernel doesn't support CET. Copy IBT and SHSTK usable only
if CET is enabled so that they aren't set on CET capable processors
with non-CET enabled glibc.
Noah Goldstein [Wed, 9 Jun 2021 20:17:14 +0000 (16:17 -0400)]
String: Add overflow tests for strnlen, memchr, and strncat [BZ #27974]
This commit adds tests for a bug in the wide char variant of the
functions where the implementation may assume that maxlen for wcsnlen
or n for wmemchr/strncat will not overflow when multiplied by
sizeof(wchar_t).
These tests show the following implementations failing on x86_64:
wcsnlen-sse4_1
wcsnlen-avx2
wmemchr-sse2
wmemchr-avx2
strncat would fail as well if it where on a system that prefered
either of the wcsnlen implementations that failed as it relies on
wcsnlen.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Noah Goldstein [Wed, 23 Jun 2021 05:19:34 +0000 (01:19 -0400)]
x86-64: Add wcslen optimize for sse4.1
No bug. This comment adds the ifunc / build infrastructure
necessary for wcslen to prefer the sse4.1 implementation
in strlen-vec.S. test-wcslen.c is passing.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
H.J. Lu [Wed, 23 Jun 2021 03:42:10 +0000 (20:42 -0700)]
x86-64: Move strlen.S to multiarch/strlen-vec.S
Since strlen.S contains SSE2 version of strlen/strnlen and SSE4.1
version of wcslen/wcsnlen, move strlen.S to multiarch/strlen-vec.S
and include multiarch/strlen-vec.S from SSE2 and SSE4.1 variants.
This also removes the unused symbols, __GI___strlen_sse2 and
__GI___wcsnlen_sse4_1.
The usage of signals to implementation pthread cancellation is an
implementation detail and should not be visible through cancellation
entrypoints.
However now that pthread_cancel always send the SIGCANCEL, some
entrypoint might be interruptable and return EINTR to the caller
(for instance on sem_wait).
Using SA_RESTART hides this, since the cancellation handler should
either act uppon cancellation (if asynchronous cancellation is enable)
or ignore the cancellation internal signal.
Paul Eggert [Wed, 23 Jun 2021 15:57:35 +0000 (08:57 -0700)]
doc: _TIME_BITS defaults may change
* NEWS: Don't imply the default will always be 32-bit.
* manual/creature.texi (Feature Test Macros):
Say that _TIME_BITS and _FILE_OFFSET_BITS defaults
may change in future releases.
iconvconfig: Use common gconv module parsing function
Drop local copy of gconv file parsing and use the one in
gconv_parseconfdir.h instead. Now there is a single implementation of
configuration file parsing.
gconv_conf: Split out configuration file processing
Split configuration file processing into a separate header file and
include it. Macroize all calls that need to go through internal
interfaces so that iconvconfig can also use them.
The modules and nmodules parameters passed to add_modules, add_alias,
etc. are not used and are hence unnecessary. Remove them so that
their signatures match the functions in iconvconfig.
Reviewed-by: DJ Delorie <dj@redhat.com> Reviewed-by: Andreas Schwab <schwab@linux-m68k.org>
iconv: Remove alloca use in gconv-modules configuration parsing
The alloca sizes ought to be constrained to PATH_MAX, but replace them
with dynamic allocation to be safe. A static PATH_MAX array would
have worked too but Hurd does not have PATH_MAX and the code path is
not hot enough to micro-optimise this allocation. Revisit if any of
those realities change.
Andreas Schwab [Tue, 15 Jun 2021 21:09:25 +0000 (23:09 +0200)]
Remove unsused symbols from nptl/Versions
The (private) symbols __pthread_clock_gettime, __pthread_clock_settime and
__pthread_initialize_minimal haven't been defined by libpthread for some
time.
linux: Only use 64-bit syscall if required for clock_nanosleep
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for internal futex
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for utimensat family
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
The large timeout are already tests by io/tst-utimensat-skeleton.c.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for sigtimedwait
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for mq_timedsend
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for mq_timedreceive
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for timerfd_settime
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for semtimedop
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
It breaks the usage case of live migration like CRIU or similar
and most usages can be optimized away by either building glibc with
a minimum 5.1 kernel or by using the 32-bit syscall for the common
case.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Remove supports_time64 () from clock_gettime
It breaks the usage case of live migration like CRIU or similar.
The performance drawback is it would require an extra syscall
on older kernels without 64-bit time support.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Remove supports_time64 () from clock_getres
It breaks the usage case of live migration like CRIU or similar.
The performance drawback is it would require an extra syscall
on older kernels without 64-bit time support.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for select
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one. This also avoids the need
to use supports_time64() (which breaks the usage case of live migration
like CRIU or similar).
It also fixes an issue on 32-bit select call for !__ASSUME_PSELECT
(microblase with older kernels only) where the expected timeout
is a 'struct timeval' instead of 'struct timespec'.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for pselect
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one. This also avoids the need
to use supports_time64() (which breaks the usage case of live migration
like CRIU or similar).
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
linux: Only use 64-bit syscall if required for ppoll
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one. This also avoids the need
to use supports_time64() (which breaks the usage case of live migration
like CRIU or similar).
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
It is a simple wrapper over timer_create, timer_settime, and
sigaction. It will be used to check for large timeout to trigger an
EINTR and to avoid use a large timeout (as for alarm()).
git://sourceware.org / glibc.git / log