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* Typo: Rename HAVE_CLONE3_WAPPER to HAVE_CLONE3_WRAPPERH.J. Lu2021-07-283-3/+3
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* hurd: _Fork: unlock malloc before calling fork child hooksSamuel Thibault2021-07-271-0/+1
| | | | | The setitimer fork hook, fork_itimer, needs to call malloc inside __mach_setup_tls, so we need to unlock malloc before calling it.
* i386: Regenerate ulpsArjun Shankar2021-07-252-61/+61
| | | | | These failures were caught while building glibc master for Fedora Rawhide which is built with `-mtune=generic -msse2 -mfpmath=sse'.
* x86: Install <bits/platform/x86.h> [BZ #27958]H.J. Lu2021-07-2313-556/+560
| | | | | | | | | | | | | | | 1. Install <bits/platform/x86.h> for <sys/platform/x86.h> which includes <bits/platform/x86.h>. 2. Rename HAS_CPU_FEATURE to CPU_FEATURE_PRESENT which checks if the processor has the feature. 3. Rename CPU_FEATURE_USABLE to CPU_FEATURE_ACTIVE which checks if the feature is active. There may be other preconditions, like sufficient stack space or further setup for AMX, which must be satisfied before the feature can be used. This fixes BZ #27958. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Fix build and tests with --disable-tunablesSiddhesh Poyarekar2021-07-231-2/+6
| | | | | | | | | | | | | Remove unused code and declare __libc_mallopt when !IS_IN (libc) to allow the debug hook to build with --disable-tunables. Also, run tst-ifunc-isa-2* tests only when tunables are enabled since the result depends on it. Tested on x86_64. Reported-by: Matheus Castanho <msc@linux.ibm.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* hurd: Fix glob lstat compatibilitySamuel Thibault2021-07-221-1/+2
| | | | | | 84f7ce84474c ("posix: Add glob64 with 64-bit time_t support") replaced GLOB_NO_LSTAT with defining GLOB_LSTAT and GLOB_LSTAT64, but the posix and gnu versions of the change were missing in the commit.
* socket: Add time64 alias for setsockoptFlorian Weimer2021-07-2221-0/+23
| | | | | Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* socket: Add time64 alias for getsockoptFlorian Weimer2021-07-2221-0/+23
| | | | | Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Move malloc_{g,s}et_state to libc_malloc_debugSiddhesh Poyarekar2021-07-2258-58/+58
| | | | | | | | | | | | | | | | | | | | | | | These deprecated functions are only safe to call from __malloc_initialize_hook and as a result, are not useful in the general case. Move the implementations to libc_malloc_debug so that existing binaries that need it will now have to preload the debug DSO to work correctly. This also allows simplification of the core malloc implementation by dropping all the undumping support code that was added to make malloc_set_state work. One known breakage is that of ancient emacs binaries that depend on this. They will now crash when running with this libc. With LD_BIND_NOW=1, it will terminate immediately because of not being able to find malloc_set_state but with lazy binding it will crash in unpredictable ways. It will need a preloaded libc_malloc_debug.so so that its initialization hook is executed to allow its malloc implementation to work properly. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* glibc.malloc.check: Wean away from malloc hooksSiddhesh Poyarekar2021-07-2234-0/+234
| | | | | | | | | | | | | | | | | | The malloc-check debugging feature is tightly integrated into glibc malloc, so thanks to an idea from Florian Weimer, much of the malloc implementation has been moved into libc_malloc_debug.so to support malloc-check. Due to this, glibc malloc and malloc-check can no longer work together; they use altogether different (but identical) structures for heap management. This should not make a difference though since the malloc check hook is not disabled anywhere. malloc_set_state does, but it does so early enough that it shouldn't cause any problems. The malloc check tunable is now in the debug DSO and has no effect when the DSO is not preloaded. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* mtrace: Wean away from malloc hooksSiddhesh Poyarekar2021-07-2256-23/+66
| | | | | | | | | | | | | Wean mtrace away from the malloc hooks and move them into the debug DSO. Split the API away from the implementation so that we can add the API to libc.so as well as libc_malloc_debug.so, with the libc implementations being empty. Update localplt data since memalign no longer has any callers after this change. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* mcheck: Wean away from malloc hooks [BZ #23489]Siddhesh Poyarekar2021-07-2233-0/+264
| | | | | | | | | | | | | | | | | | | | | | | | Split the mcheck implementation into the debugging hooks and API so that the API can be replicated in libc and libc_malloc_debug.so. The libc APIs always result in failure. The mcheck implementation has also been moved entirely into libc_malloc_debug.so and with it, all of the hook initialization code can now be moved into the debug library. Now the initialization can be done independently of libc internals. With this patch, libc_malloc_debug.so can no longer be used with older libcs, which is not its goal anyway. tst-vfork3 breaks due to this since it spawns shell scripts, which in turn execute using the system glibc. Move the test to tests-container so that only the built glibc is used. This move also fixes bugs in the mcheck version of memalign and realloc, thus allowing removal of the tests from tests-mcheck exclusion list. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* Move malloc hooks into a compat DSOSiddhesh Poyarekar2021-07-2241-1/+308
| | | | | | | | | | | | | | | | | | | | | | | | Remove all malloc hook uses from core malloc functions and move it into a new library libc_malloc_debug.so. With this, the hooks now no longer have any effect on the core library. libc_malloc_debug.so is a malloc interposer that needs to be preloaded to get hooks functionality back so that the debugging features that depend on the hooks, i.e. malloc-check, mcheck and mtrace work again. Without the preloaded DSO these debugging features will be nops. These features will be ported away from hooks in subsequent patches. Similarly, legacy applications that need hooks functionality need to preload libc_malloc_debug.so. The symbols exported by libc_malloc_debug.so are maintained at exactly the same version as libc.so. Finally, static binaries will no longer be able to use malloc debugging features since they cannot preload the debugging DSO. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* posix: Add sysconf(_SC_{MIN,}SIGSTKSZ) supportSamuel Thibault2021-07-221-0/+15
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* ARC: elf: make type safeVineet Gupta2021-07-211-13/+10
| | | | Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: fp: (micro)optimize FPU_STATUS read by eliding FWE bit clearingVineet Gupta2021-07-211-8/+7
| | | | | | | | | | | | | | | | Any FPU_STATUS write needs setting the FWE bit (31) whcih just provides a "control signal" to enable explicit write (vs. the side-effect of FPU instructions). However this bit is RAZ and write-only, thus effectively never stored in FPU_STATUS register. Thus when reading the register there is no need to clear it. This shaves off a BCLR instruction from the fe*exceptino family of functions and while no big deal still makes sense to do. This came up when debugging a race in math/test-fenv-tls [1] [1]: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/54 Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* socket: Add time64 alias for sendmsgFlorian Weimer2021-07-2121-0/+23
| | | | | Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* socket: Add time64 alias for recvmsgFlorian Weimer2021-07-2121-0/+23
| | | | | Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* socket: Add time64 alias for sendmmsgFlorian Weimer2021-07-2124-0/+212
| | | | | Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Linux: Add time64 alias for prctlFlorian Weimer2021-07-2125-1/+72
| | | | | Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* io: Add time64 alias for fcntlFlorian Weimer2021-07-2121-0/+23
| | | | Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* misc: Add time64 alias for ioctlFlorian Weimer2021-07-2122-1/+24
| | | | | Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* RISC-V: Update rv64 ULPsDarius Rad2021-07-211-58/+64
| | | | | Generated on a Microsemi Polarfire Icicle Kit running Linux version 5.6.18. Same ULPs were also produced on QEMU 5.2.0 running Linux 5.10.46-1.
* hurd: Add support for spawn_do_closefromSamuel Thibault2021-07-192-1/+38
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* elf: Fix tst-cpu-features-cpuinfo on some AMD systems (BZ #28090)Adhemerval Zanella2021-07-193-1/+16
| | | | | | | | | | | | | | | The SSBD feature is implemented in 2 different ways on AMD processors: newer systems (Zen3) provides AMD_SSBD (function 8000_0008, EBX[24]), while older system provides AMD_VIRT_SSBD (function 8000_0008, EBX[25]). However for AMD_VIRT_SSBD, kernel shows both 'ssdb' and 'virt_ssdb' on /proc/cpuinfo; while for AMD_SSBD only 'ssdb' is provided. This now check is AMD_SSBD is set to check for 'ssbd', otherwise check if AMD_VIRT_SSDB is set to check for 'virt_ssbd'. Checked on x86_64-linux-gnu on a Ryzen 9 5900x. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* i386: Add the clone3 wrapperH.J. Lu2021-07-192-0/+125
| | | | | | | extern int clone3 (struct clone_args *__cl_args, size_t __size, int (*__func) (void *__arg), void *__arg); Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move res_query functions into libcFlorian Weimer2021-07-1964-228/+444
| | | | | | | | | | | | | | | This switches to public symbols without __ prefixes, due to improved namespace management in glibc. The script was used with --no-new-version to move the symbols __res_nquery, __res_nquerydomain, __res_nsearch, __res_query, __res_querydomain, __res_search, res_query, res_querydomain, res_search. The public symbols res_nquery, res_nquerydomain, res_nsearch, res_ownok, res_query, res_querydomain, res_search were added with make update-all-abi. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move res_mkquery, res_nmkquery into libcFlorian Weimer2021-07-1964-76/+148
| | | | | | | | | | | | | This switches to public symbols without __ prefixes, due to improved namespace management in glibc. The symbols res_mkquery, __res_mkquery, __res_nmkquery were moved with the script (using --no-new-version). res_mkquery@@GLIBC_2.34, res_nmkquery@@GLIBC_2.34 were added using make update-all-abi. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move res_send, res_nsend into libcFlorian Weimer2021-07-1964-62/+132
| | | | | | | | | | | Switch to public symbols without __ prefix (due to improved namespace management). __res_send, __res_nsend were moved using the script (with --no-new-version). res_send@@GLIBC_2.34 and res_nsend@@GLIBC_2.34 were added using make update-all-abi. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Rename res_comp.c to res-name-checking.c and move into libcFlorian Weimer2021-07-1964-124/+264
| | | | | | | | | | | | | | | This reflects what the remaining functions in the file do. The __res_dnok, __res_hnok, __res_mailok, __res_ownok were moved with the script, using --no-new-version, and turned into compat symbols. __libc_res_dnok@@GLIBC_PRIVATE and __libc_res_hnok@@GLIBC_PRIVATE are added for internal use, to avoid accidentally binding to compatibility symbols. The new public symbols res_dnok, res_hnok, res_mailok, res_ownok were added using make update-all-abi. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move dn_skipname to its own file and into libcFlorian Weimer2021-07-1964-31/+66
| | | | | | | | | | | | | | | And reformat it to GNU style. dn_skipname is used outside glibc, so do not deprecate it, and export it as dn_skipname (not __dn_skipname). Due to internal users, provide a __libc_dn_skipname alias, and keep __dn_skipname as a pure compatibility symbol. __dn_skipname@GLIBC_2.0 was moved using the script, and dn_skipname@@GLIBC_2.34 was added using make update-all-abi. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move dn_comp to its own file and into libcFlorian Weimer2021-07-1964-31/+66
| | | | | | | | | | | | | | | And reformat it to GNU style. dn_comp is used in various programs, so keep it as a non-deprecated symbol. Switch to dn_comp (not __dn_comp) for the ABI name. There are no internal users, so interposition is not a problem. The __dn_comp symbol was moved with scripts/move-symbol-to-libc.py --no-new-version. dn_comp@@GLIBC_2.34 was added with make update-all-abi. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move dn_expand to its own file and into libcFlorian Weimer2021-07-1964-45/+82
| | | | | | | | | | | | | | | | | | And reformat to GNU style. This switches back to the dn_expand name for the ABI symbol and turns __dn_expand into a compatibility symbol. With the improved namespace management in current glibc, it is no longer necessary to use a private namespace symbol. To avoid old code binding to a GLIBC_PRIVATE symbol by accident, use __libc_dn_expand for the internal symbol name. The symbols dn_expand, __dnexpand were moved using scripts/move-symbol-to-libc.py, followed by an adjustment to make dn_expand the only GLIBC_2.34 symbol. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move ns_name_compress into its own file and into libcFlorian Weimer2021-07-1964-31/+66
| | | | | | | | | And reformat to GNU style. The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move ns_name_pack into its own file and into libcFlorian Weimer2021-07-1964-31/+66
| | | | | | | | | And reformat to GNU style, and eliminate the labellen function. The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move ns_name_pton into its own file and into libcFlorian Weimer2021-07-1964-31/+66
| | | | | | | | | And reformat to GNU style, and eliminate the digits variable. The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move ns_name_uncompress into its own file and into libcFlorian Weimer2021-07-1964-31/+66
| | | | | | | | | | And reformat to GNU style. Check for negative error returns (instead of -1). The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move ns_name_skip to its own file and into libc (bug 28091)Florian Weimer2021-07-1964-31/+66
| | | | | | | | | | And reformat to GNU style. Avoid out-of-bounds pointer arithmetic. This also results in a fix of bug 28091 due to the additional packet length checks. The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>
* htl: Do not expose pthread hidden proto outside libpthreadSamuel Thibault2021-07-181-3/+3
| | | | Only libpthread.so can access them.
* resolv: Move ns_name_unpack to its own file and into libcFlorian Weimer2021-07-1564-31/+66
| | | | | | | | | | Reformat to GNU style. Avoid out-of-bounds buffer arithmetic. Eliminate the labellen function. The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* resolv: Move ns_name_ntop to its own file and into libcFlorian Weimer2021-07-1564-31/+66
| | | | | | | | | | | | Reformat to GNU style. Avoid out-of-bounds pointer arithmetic (e.g., use eom - dn < 2 instead of dn + 1 >= eom). Inline the labellen function and fold the compression pointer check into the length check (l >= 64). Assume ASCII encoding. The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* socket: Add hidden prototype for setsockoptFlorian Weimer2021-07-152-3/+4
| | | | | | Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* elf: Fix DTV gap reuse logic (BZ #27135)Adhemerval Zanella2021-07-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | This is updated version of the 572bd547d57a (reverted by 40ebfd016ad2) that fixes the _dl_next_tls_modid issues. This issue with 572bd547d57a patch is the DTV entry will be only update on dl_open_worker() with the update_tls_slotinfo() call after all dependencies are being processed by _dl_map_object_deps(). However _dl_map_object_deps() itself might call _dl_next_tls_modid(), and since the _dl_tls_dtv_slotinfo_list::map is not yet set the entry will be wrongly reused. This patch fixes by renaming the _dl_next_tls_modid() function to _dl_assign_tls_modid() and by passing the link_map so it can set the slotinfo value so a subsequente _dl_next_tls_modid() call will see the entry as allocated. The intermediary value is cleared up on remove_slotinfo() for the case a library fails to load with RTLD_NOW. This patch fixes BZ #27135. Checked on x86_64-linux-gnu. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
* Add static tests for __clone_internalH.J. Lu2021-07-146-0/+509
| | | | Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* x86-64: Add the clone3 wrapperH.J. Lu2021-07-142-0/+94
| | | | | | | extern int clone3 (struct clone_args *__cl_args, size_t __size, int (*__func) (void *__arg), void *__arg); Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Add an internal wrapper for clone, clone2 and clone3H.J. Lu2021-07-145-18/+170
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The clone3 system call (since Linux 5.3) provides a superset of the functionality of clone and clone2. It also provides a number of API improvements, including the ability to specify the size of the child's stack area which can be used by kernel to compute the shadow stack size when allocating the shadow stack. Add: extern int __clone_internal (struct clone_args *__cl_args, int (*__func) (void *__arg), void *__arg); to provide an abstract interface for clone, clone2 and clone3. 1. Simplify stack management for thread creation by passing both stack base and size to create_thread. 2. Consolidate clone vs clone2 differences into a single file. 3. Call __clone3 if HAVE_CLONE3_WAPPER is defined. If __clone3 returns -1 with ENOSYS, fall back to clone or clone2. 4. Use only __clone_internal to clone a thread. Since the stack size argument for create_thread is now unconditional, always pass stack size to create_thread. 5. Enable the public clone3 wrapper in the future after it has been added to all targets. NB: Sandbox will return ENOSYS on clone3 in both Chromium: The following revision refers to this bug: https://chromium.googlesource.com/chromium/src/+/218438259dd795456f0a48f67cbe5b4e520db88b commit 218438259dd795456f0a48f67cbe5b4e520db88b Author: Matthew Denton <mpdenton@chromium.org> Date: Thu Jun 03 20:06:13 2021 Linux sandbox: return ENOSYS for clone3 Because clone3 uses a pointer argument rather than a flags argument, we cannot examine the contents with seccomp, which is essential to preventing sandboxed processes from starting other processes. So, we won't be able to support clone3 in Chromium. This CL modifies the BPF policy to return ENOSYS for clone3 so glibc always uses the fallback to clone. Bug: 1213452 Change-Id: I7c7c585a319e0264eac5b1ebee1a45be2d782303 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2936184 Reviewed-by: Robert Sesek <rsesek@chromium.org> Commit-Queue: Matthew Denton <mpdenton@chromium.org> Cr-Commit-Position: refs/heads/master@{#888980} [modify] https://crrev.com/218438259dd795456f0a48f67cbe5b4e520db88b/sandbox/linux/seccomp-bpf-helpers/baseline_policy.cc and Firefox: https://hg.mozilla.org/integration/autoland/rev/ecb4011a0c76 Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* htl: Fix linking static examples against libpthreadSamuel Thibault2021-07-131-1/+1
| | | | libpthread.a uses some mach and hurd RPCs so we need to link them in.
* htl: Let libc call __pthread_mutex_{,try,un}lockSamuel Thibault2021-07-134-0/+6
| | | | | Now that NPTL was moved to libc, libc makes internal __pthread calls, so htl has to expose them internally.
* mcheck: Align struct hdr to MALLOC_ALIGNMENT bytes [BZ #28068]H.J. Lu2021-07-122-8/+0
| | | | | | | | | | | | 1. Align struct hdr to MALLOC_ALIGNMENT bytes so that malloc hooks in libmcheck align memory to MALLOC_ALIGNMENT bytes. 2. Remove tst-mallocalign1 from tests-exclude-mcheck for i386 and x32. 3. Add tst-pvalloc-fortify and tst-reallocarray to tests-exclude-mcheck since they use malloc_usable_size (see BZ #22057). This fixed BZ #28068. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* Linux: Use 32-bit vDSO for clock_gettime, gettimeofday, time (BZ# 28071)Adhemerval Zanella2021-07-125-12/+175
| | | | | | | | | | | | | | | | | | | | | | | | | | The previous approach defeats the vDSO optimization on older kernels because a failing clock_gettime64 system call is performed on every function call. It also results in a clobbered errno value, exposing an OpenJDK bug (JDK-8270244). This patch fixes by open-code INLINE_VSYSCALL macro and replace all INLINE_SYSCALL_CALL with INTERNAL_SYSCALL_CALLS. Now for __clock_gettime64x, the 64-bit vDSO is used and the 32-bit vDSO is tried before falling back to 64-bit syscalls. The previous code preferred 64-bit syscall for the case where the kernel provides 64-bit time_t syscalls *and* also a 32-bit vDSO (in this case the *64-bit* syscall should be preferable over the vDSO). All architectures that provides 32-bit vDSO (i386, mips, powerpc, s390) modulo sparc; but I am not sure if some kernels versions do provide only 32-bit vDSO while still providing 64-bit time_t syscall. Regardless, for such cases the 64-bit time_t syscall is used if the vDSO returns overflowed 32-bit time_t. Tested on i686-linux-gnu (with a time64 and non-time64 kernel), x86_64-linux-gnu. Built with build-many-glibcs.py. Co-authored-by: Florian Weimer <fweimer@redhat.com>