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* nptl: rseq failure after registration on main thread is fatalFlorian Weimer2021-12-091-1/+2
| | | | | | | | | | | | | | | | | | | | This simplifies the application programming model. Browser sandboxes have already been fixed: Sandbox is incompatible with rseq registration <https://bugzilla.mozilla.org/show_bug.cgi?id=1651701> Allow rseq in the Linux sandboxes. r=gcp <https://hg.mozilla.org/mozilla-central/rev/042425712eb1> Sandbox needs to support rseq system call <https://bugs.chromium.org/p/chromium/issues/detail?id=1104160> Linux sandbox: Allow rseq(2) <https://chromium.googlesource.com/chromium/src.git/+/230675d9ac8f1> Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
* nptl: Add glibc.pthread.rseq tunable to control rseq registrationFlorian Weimer2021-12-091-1/+9
| | | | | | | | This tunable allows applications to register the rseq area instead of glibc. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* nptl: Add rseq registrationFlorian Weimer2021-12-092-0/+17
| | | | | | | | | | | | The rseq area is placed directly into struct pthread. rseq registration failure is not treated as an error, so it is possible that threads run with inconsistent registration status. <sys/rseq.h> is not yet installed as a public header. Co-Authored-By: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* misc, nptl: Remove stray references to __condvar_load_64_relaxedFlorian Weimer2021-12-061-1/+1
| | | | | | The function was renamed to __atomic_wide_counter_load_relaxed in commit 8bd336a00a5311bf7a9e99b3b0e9f01ff5faa74b ("nptl: Extract <bits/atomic_wide_counter.h> from pthread_cond_common.c").
* nptl: Increase default TCB alignment to 32Florian Weimer2021-12-032-1/+4
| | | | | | | | | | rseq support will use a 32-byte aligned field in struct pthread, so the whole struct needs to have at least that alignment. nptl/tst-tls3mod.c uses TCB_ALIGNMENT, therefore include <descr.h> to obtain the fallback definition. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* nptl: Do not set signal mask on second setjmp return [BZ #28607]Florian Weimer2021-11-241-2/+2
| | | | | | | | | | | | __libc_signal_restore_set was in the wrong place: It also ran when setjmp returned the second time (after pthread_exit or pthread_cancel). This is observable with blocked pending signals during thread exit. Fixes commit b3cae39dcbfa2432b3f3aa28854d8ac57f0de1b8 ("nptl: Start new threads with all signals blocked [BZ #25098]"). Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nptl: Extract <bits/atomic_wide_counter.h> from pthread_cond_common.cFlorian Weimer2021-11-173-179/+52
| | | | | | | | | | | | | And make it an installed header. This addresses a few aliasing violations (which do not seem to result in miscompilation due to the use of atomics), and also enables use of wide counters in other parts of the library. The debug output in nptl/tst-cond22 has been adjusted to print the 32-bit values instead because it avoids a big-endian/little-endian difference. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Move assignment out of the CAS conditionH.J. Lu2021-11-152-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | Update commit 49302b8fdf9103b6fc0a398678668a22fa19574c Author: H.J. Lu <hjl.tools@gmail.com> Date: Thu Nov 11 06:54:01 2021 -0800 Avoid extra load with CAS in __pthread_mutex_clocklock_common [BZ #28537] Replace boolean CAS with value CAS to avoid the extra load. and commit 0b82747dc48d5bf0871bdc6da8cb6eec1256355f Author: H.J. Lu <hjl.tools@gmail.com> Date: Thu Nov 11 06:31:51 2021 -0800 Avoid extra load with CAS in __pthread_mutex_lock_full [BZ #28537] Replace boolean CAS with value CAS to avoid the extra load. by moving assignment out of the CAS condition.
* Add LLL_MUTEX_READ_LOCK [BZ #28537]H.J. Lu2021-11-121-0/+7
| | | | | | | | | | | | | | | | CAS instruction is expensive. From the x86 CPU's point of view, getting a cache line for writing is more expensive than reading. See Appendix A.2 Spinlock in: https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/xeon-lock-scaling-analysis-paper.pdf The full compare and swap will grab the cache line exclusive and cause excessive cache line bouncing. Add LLL_MUTEX_READ_LOCK to do an atomic load and skip CAS in spinlock loop if compare may fail to reduce cache line bouncing on contended locks. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
* Avoid extra load with CAS in __pthread_mutex_clocklock_common [BZ #28537]H.J. Lu2021-11-121-5/+5
| | | | | | Replace boolean CAS with value CAS to avoid the extra load. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
* Avoid extra load with CAS in __pthread_mutex_lock_full [BZ #28537]H.J. Lu2021-11-121-5/+5
| | | | | | Replace boolean CAS with value CAS to avoid the extra load. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
* nptl: Fix tst-cancel7 and tst-cancelx7 pidfile raceStafford Horne2021-10-181-6/+3
| | | | | | | | | | | | | | The check for waiting for the pidfile to be created looks wrong. At the point when ACCESS is run the pid file will always be created and accessible as it is created during DO_PREPARE. This means that thread cancellation may be performed before the pid is written to the pidfile. This was found to be flaky when testing on my OpenRISC platform. Fix this by using the semaphore to wait for pidfile pid write completion. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nptl: pthread_kill must send signals to a specific thread [BZ #28407]Florian Weimer2021-10-011-3/+1
| | | | | | | | | | | | | | | | | The choice between the kill vs tgkill system calls is not just about the TID reuse race, but also about whether the signal is sent to the whole process (and any thread in it) or to a specific thread. This was caught by the openposix test suite: LTP: openposix test suite - FAIL: SIGUSR1 is member of new thread pendingset. <https://gitlab.com/cki-project/kernel-tests/-/issues/764> Fixes commit 526c3cf11ee9367344b6b15d669e4c3cb461a2be ("nptl: Fix race between pthread_kill and thread exit (bug 12889)"). Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* nptl: Add CLOCK_MONOTONIC support for PI mutexesAdhemerval Zanella2021-10-012-23/+26
| | | | | | | | | | | | | | | Linux added FUTEX_LOCK_PI2 to support clock selection (commit bf22a6976897977b0a3f1aeba6823c959fc4fdae). With the new flag we can now proper support CLOCK_MONOTONIC for pthread_mutex_clocklock with Priority Inheritance. If kernel does not support, EINVAL is returned instead. The difference is the futex operation will be issued and the kernel will advertise the missing support (instead of hard-code error return). Checked on x86_64-linux-gnu and i686-linux-gnu on Linux 5.14, 5.11, and 4.15.
* nptl: Use FUTEX_LOCK_PI2 when availableAdhemerval Zanella2021-10-013-2/+67
| | | | | | | | | | | This patch uses the new futex PI operation provided by Linux v5.14 when it is required. The futex_lock_pi64() is moved to futex-internal.c (since it used on two different places and its code size might be large depending of the kernel configuration) and clockid is added as an argument. Co-authored-by: Kurt Kanzenbach <kurt@linutronix.de>
* nptl: Avoid setxid deadlock with blocked signals in thread exit [BZ #28361]Florian Weimer2021-09-231-2/+10
| | | | | | | | | | | | | | | | | | | | | | As part of the fix for bug 12889, signals are blocked during thread exit, so that application code cannot run on the thread that is about to exit. This would cause problems if the application expected signals to be delivered after the signal handler revealed the thread to still exist, despite pthread_kill can no longer be used to send signals to it. However, glibc internally uses the SIGSETXID signal in a way that is incompatible with signal blocking, due to the way the setxid handshake delays thread exit until the setxid operation has completed. With a blocked SIGSETXID, the handshake can never complete, causing a deadlock. As a band-aid, restore the previous handshake protocol by not blocking SIGSETXID during thread exit. The new test sysdeps/pthread/tst-pthread-setuid-loop.c is based on a downstream test by Martin Osvald. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* nptl: pthread_kill needs to return ESRCH for old programs (bug 19193)Florian Weimer2021-09-201-8/+29
| | | | | | The fix for bug 19193 breaks some old applications which appear to use pthread_kill to probe if a thread is still running, something that is not supported by POSIX.
* nptl: Fix race between pthread_kill and thread exit (bug 12889)Florian Weimer2021-09-134-25/+63
| | | | | | | | | | | A new thread exit lock and flag are introduced. They are used to detect that the thread is about to exit or has exited in __pthread_kill_internal, and the signal is not sent in this case. The test sysdeps/pthread/tst-pthread_cancel-select-loop.c is derived from a downstream test originally written by Marek Polacek. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nptl: pthread_kill, pthread_cancel should not fail after exit (bug 19193)Florian Weimer2021-09-132-5/+11
| | | | | | | | | | | | | | This closes one remaining race condition related to bug 12889: if the thread already exited on the kernel side, returning ESRCH is not correct because that error is reserved for the thread IDs (pthread_t values) whose lifetime has ended. In case of a kernel-side exit and a valid thread ID, no signal needs to be sent and cancellation does not have an effect, so just return 0. sysdeps/pthread/tst-kill4.c triggers undefined behavior and is removed with this commit. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Remove "Contributed by" linesSiddhesh Poyarekar2021-09-03176-177/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | We stopped adding "Contributed by" or similar lines in sources in 2012 in favour of git logs and keeping the Contributors section of the glibc manual up to date. Removing these lines makes the license header a bit more consistent across files and also removes the possibility of error in attribution when license blocks or files are copied across since the contributed-by lines don't actually reflect reality in those cases. Move all "Contributed by" and similar lines (Written by, Test by, etc.) into a new file CONTRIBUTED-BY to retain record of these contributions. These contributors are also mentioned in manual/contrib.texi, so we just maintain this additional record as a courtesy to the earlier developers. The following scripts were used to filter a list of files to edit in place and to clean up the CONTRIBUTED-BY file respectively. These were not added to the glibc sources because they're not expected to be of any use in future given that this is a one time task: https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* nptl: Fix tst-cancel7 and tst-cancelx7 race condition (BZ #14232)Adhemerval Zanella2021-08-261-57/+57
| | | | | | | | | | A mapped temporary file and a semaphore is used to synchronize the pid information on the created file, the semaphore is updated once the file contents is flushed. Checked on x86_64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* Fix build of nptl/tst-thread_local1.cc with GCC 12Joseph Myers2021-08-021-0/+1
| | | | | | | | | | | | | | | The test nptl/tst-thread_local1.cc fails to build with GCC mainline because of changes to what libstdc++ headers implicitly include what other headers: tst-thread_local1.cc: In function 'int do_test()': tst-thread_local1.cc:177:5: error: variable 'std::array<std::pair<const char*, std::function<void(void* (*)(void*))> >, 2> do_thread_X' has initializer but incomplete type 177 | do_thread_X | ^~~~~~~~~~~ Fix this by adding an explicit include of <array>. Tested with build-many-glibcs.py for aarch64-linux-gnu.
* Move malloc hooks into a compat DSOSiddhesh Poyarekar2021-07-221-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* Add an internal wrapper for clone, clone2 and clone3H.J. Lu2021-07-142-70/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Reduce <limits.h> pollution due to dynamic PTHREAD_STACK_MINFlorian Weimer2021-07-121-0/+3
| | | | | | | | | | | | | | | | | | | | <limits.h> used to be a header file with no declarations. GCC's libgomp includes it in a #pragma GCC visibility hidden block. Including <unistd.h> from <limits.h> (indirectly) declares everything in <unistd.h> with hidden visibility, resulting in linker failures. This commit avoids C declarations in assembler mode and only declares __sysconf in <limits.h> (and not the entire contents of <unistd.h>). The __sysconf symbol is already part of the ABI. PTHREAD_STACK_MIN is no longer defined for __USE_DYNAMIC_STACK_SIZE && __ASSEMBLER__ because there is no possible definition. Additionally, PTHREAD_STACK_MIN is now defined by <pthread.h> for __USE_MISC because this is what developers expect based on the macro name. It also helps to avoid libgomp linker failures in GCC because libgomp includes <pthread.h> before its visibility hacks. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Define PTHREAD_STACK_MIN to sysconf(_SC_THREAD_STACK_MIN)H.J. Lu2021-07-091-3/+12
| | | | | | | | | | | | | The constant PTHREAD_STACK_MIN may be too small for some processors. Rename _SC_SIGSTKSZ_SOURCE to _DYNAMIC_STACK_SIZE_SOURCE. When _DYNAMIC_STACK_SIZE_SOURCE or _GNU_SOURCE are defined, define PTHREAD_STACK_MIN to sysconf(_SC_THREAD_STACK_MIN) which is changed to MIN (PTHREAD_STACK_MIN, sysconf(_SC_MINSIGSTKSZ)). Consolidate <bits/local_lim.h> with <bits/pthread_stack_min.h> to provide a constant target specific PTHREAD_STACK_MIN value. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Force building with -fno-commonFlorian Weimer2021-07-095-10/+7
| | | | | | | | | | As a result, is not necessary to specify __attribute__ ((nocommon)) on individual definitions. GCC 10 defaults to -fno-common on all architectures except ARC, but this change is compatible with older GCC versions and ARC, too. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* nptl: Use out-of-line wake function in __libc_lock_unlock slow pathFlorian Weimer2021-07-092-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This slightly reduces code size, as can be seen below. __libc_lock_unlock is usually used along with __libc_lock_lock in the same function. __libc_lock_lock already has an out-of-line slow path, so this change should not introduce many additional non-leaf functions. This change also fixes a link failure in 32-bit Arm thumb mode because commit 1f9c804fbd699104adefbce9e56d2c8aa711b6b9 ("nptl: Use internal low-level lock type for !IS_IN (libc)") introduced __libc_do_syscall calls outside of libc. Before x86-64: text data bss dec hex filename 1937748 20456 54896 2013100 1eb7ac libc.so.6 25601 856 12768 39225 9939 nss/libnss_db.so.2 40310 952 25144 66406 10366 nss/libnss_files.so.2 After x86-64: text data bss dec hex filename 1935312 20456 54896 2010664 1eae28 libc.so.6 25559 864 12768 39191 9917 nss/libnss_db.so.2 39764 960 25144 65868 1014c nss/libnss_files.so.2 Before i686: 2110961 11272 39144 2161377 20fae1 libc.so.6 27243 428 12652 40323 9d83 nss/libnss_db.so.2 43062 476 25028 68566 10bd6 nss/libnss_files.so.2 After i686: 2107347 11272 39144 2157763 20ecc3 libc.so.6 26929 432 12652 40013 9c4d nss/libnss_db.so.2 43132 480 25028 68640 10c20 nss/libnss_files.so.2 Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nptl: Reduce the GLIBC_PRIVATE ABIFlorian Weimer2021-07-076-52/+15
| | | | | | | The remaining symbols are mostly used by libthread_db. __pthread_get_minstack has to remain exported even though unused. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nptl: Remove GLIBC_2.34 versions of __pthread_mutex_lock, __pthread_mutex_unlockFlorian Weimer2021-07-073-6/+6
| | | | | | | | Now that there are no internal users anymore, these new symbol versions can be removed from the public ABI. The compatibility symbols remain. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nptl: Add glibc.pthread.stack_cache_size tunableFlorian Weimer2021-06-283-4/+16
| | | | | | | The valgrind/helgrind test suite needs a way to make stack dealloction more prompt, and this feature seems to be generally useful. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* nptl: Export libthread_db-used symbols under GLIBC_PRIVATEFlorian Weimer2021-06-282-5/+66
| | | | | | | This allows distributions to strip debugging information from libc.so.6 without impacting the debugging experience. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Linux: Cleanups after librt moveFlorian Weimer2021-06-281-9/+0
| | | | | | | | | | | | 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. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Linux: Move aio_init from librt into libcFlorian Weimer2021-06-251-0/+1
| | | | | | | | | This commit also moves the aio_misc and aio_sigquue helper, so GLIBC_PRIVATE exports need to be added. The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Consolidate pthread_atforkAdhemerval Zanella2021-06-243-84/+0
| | | | | | | | | | | | 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.
* nptl: Use SA_RESTART for SIGCANCEL handlerAdhemerval Zanella2021-06-231-1/+5
| | | | | | | | | | | | | | | | 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. Checked on x86_64-linux-gnu and i686-linux-gnu.
* Remove unsused symbols from nptl/VersionsAndreas Schwab2021-06-221-6/+0
| | | | | | 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 internal futexAdhemerval Zanella2021-06-221-18/+34
| | | | | | | | | | | 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. Reviewed-by: Lukasz Majewski <lukma@denx.de>
* nptl: Move pthreadP.h into sysdeps directoryFlorian Weimer2021-06-221-739/+0
| | | | | | | | This mirrors the situation on Hurd. These directories are on the include search part, so #include <pthreadP.h> works after this change on both Hurd and nptl. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nptl: Export _pthread_cleanup_push, _pthread_cleanup_pop againFlorian Weimer2021-06-152-0/+6
| | | | | | | | | | These were turned into compat symbols as part of the libpthread move. It turns out they are used by language run-time libraries (e.g., the GCC D front end), so it makes to preserve them as external symbols even though they are not declared in any header file. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* y2038: Add test coverageAdhemerval Zanella2021-06-152-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is enabled through a new rule, tests-y2038, which is built only when the ABI supports the comapt 64-bit time_t (defined by the header time64-compat.h, which also enables the creation of the symbol Version for Linux). It means the tests are not built for ABI which already provide default 64-bit time_t. The new rule already adds the required LFS and 64-bit time_t compiler flags. The current coverage is: * libc: - adjtime tst-adjtime-time64 - adjtimex tst-adjtimex-time64 - clock_adjtime tst-clock_adjtime-time64 - clock_getres tst-clock-time64, tst-cpuclock1-time64 - clock_gettime tst-clock-time64, tst-clock2-time64, tst-cpuclock1-time64 - clock_nanosleep tst-clock_nanosleep-time64, tst-cpuclock1-time64 - clock_settime tst-clock2-time64 - cnd_timedwait tst-cnd-timedwait-time64 - ctime tst-ctime-time64 - ctime_r tst-ctime-time64 - difftime tst-difftime-time64 - fstat tst-stat-time64 - fstatat tst-stat-time64 - futimens tst-futimens-time64 - futimes tst-futimes-time64 - futimesat tst-futimesat-time64 - fts_* tst-fts-time64 - getitimer tst-itimer-timer64 - getrusage - gettimeofday tst-clock_nanosleep-time64 - glob / globfree tst-gnuglob64-time64 - gmtime tst-gmtime-time64 - gmtime_r tst-gmtime-time64 - lstat tst-stat-time64 - localtime tst-y2039-time64 - localtime_t tst-y2039-time64 - lutimes tst-lutimes-time64 - mktime tst-mktime4-time64 - mq_timedreceive tst-mqueue{1248}-time64 - mq_timedsend tst-mqueue{1248}-time64 - msgctl test-sysvmsg-time64 - mtx_timedlock tst-mtx-timedlock-time64 - nanosleep tst-cpuclock{12}-time64, tst-mqueue8-time64, tst-clock-time64 - nftw / ftw ftwtest-time64 - ntp_adjtime tst-ntp_adjtime-time64 - ntp_gettime tst-ntp_gettime-time64 - ntp_gettimex tst-ntp_gettimex-time64 - ppoll tst-ppoll-time64 - pselect tst-pselect-time64 - pthread_clockjoin_np tst-join14-time64 - pthread_cond_clockwait tst-cond11-time64 - pthread_cond_timedwait tst-abstime-time64 - pthread_mutex_clocklock tst-abstime-time64 - pthread_mutex_timedlock tst-abstime-time64 - pthread_rwlock_clockrdlock tst-abstime-time64, tst-rwlock14-time64 - pthread_rwlock_clockwrlock tst-abstime-time64, tst-rwlock14-time64 - pthread_rwlock_timedrdlock tst-abstime-time64, tst-rwlock14-time64 - pthread_rwlock_timedwrlock tst-abstime-time64, tst-rwlock14-time64 - pthread_timedjoin_np tst-join14-time64 - recvmmsg tst-cancel4_2-time64 - sched_rr_get_interval tst-sched_rr_get_interval-time64 - select tst-select-time64 - sem_clockwait tst-sem5-time64 - sem_timedwait tst-sem5-time64 - semctl test-sysvsem-time64 - semtimedop test-sysvsem-time64 - setitimer tst-mqueue2-time64, tst-itimer-timer64 - settimeofday tst-settimeofday-time64 - shmctl test-sysvshm-time64 - sigtimedwait tst-sigtimedwait-time64 - stat tst-stat-time64 - thrd_sleep tst-thrd-sleep-time64 - time tst-mqueue{1248}-time64 - timegm tst-timegm-time64 - timer_gettime tst-timer4-time64 - timer_settime tst-timer4-time64 - timerfd_gettime tst-timerfd-time64 - timerfd_settime tst-timerfd-time64 - timespec_get tst-timespec_get-time64 - timespec_getres tst-timespec_getres-time64 - utime tst-utime-time64 - utimensat tst-utimensat-time64 - utimes tst-utimes-time64 - wait3 tst-wait3-time64 - wait4 tst-wait4-time64 * librt: - aio_suspend tst-aio6-time64 - mq_timedreceive tst-mqueue{1248}-time64 - mq_timedsend tst-mqueue{1248}-time64 - timer_gettime tst-timer4-time64 - timer_settime tst-timer4-time64 * libanl: - gai_suspend Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* y2038: Add support for 64-bit time on legacy ABIsAdhemerval Zanella2021-06-1510-24/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A new build flag, _TIME_BITS, enables the usage of the newer 64-bit time symbols for legacy ABI (where 32-bit time_t is default). The 64 bit time support is only enabled if LFS (_FILE_OFFSET_BITS=64) is also used. Different than LFS support, the y2038 symbols are added only for the required ABIs (armhf, csky, hppa, i386, m68k, microblaze, mips32, mips64-n32, nios2, powerpc32, sparc32, s390-32, and sh). The ABIs with 64-bit time support are unchanged, both for symbol and types redirection. On Linux the full 64-bit time support requires a minimum of kernel version v5.1. Otherwise, the 32-bit fallbacks are used and might results in error with overflow return code (EOVERFLOW). The i686-gnu does not yet support 64-bit time. This patch exports following rediretions to support 64-bit time: * libc: adjtime adjtimex clock_adjtime clock_getres clock_gettime clock_nanosleep clock_settime cnd_timedwait ctime ctime_r difftime fstat fstatat futimens futimes futimesat getitimer getrusage gettimeofday gmtime gmtime_r localtime localtime_r lstat_time lutimes mktime msgctl mtx_timedlock nanosleep nanosleep ntp_gettime ntp_gettimex ppoll pselec pselect pthread_clockjoin_np pthread_cond_clockwait pthread_cond_timedwait pthread_mutex_clocklock pthread_mutex_timedlock pthread_rwlock_clockrdlock pthread_rwlock_clockwrlock pthread_rwlock_timedrdlock pthread_rwlock_timedwrlock pthread_timedjoin_np recvmmsg sched_rr_get_interval select sem_clockwait semctl semtimedop sem_timedwait setitimer settimeofday shmctl sigtimedwait stat thrd_sleep time timegm timerfd_gettime timerfd_settime timespec_get utime utimensat utimes utimes wait3 wait4 * librt: aio_suspend mq_timedreceive mq_timedsend timer_gettime timer_settime * libanl: gai_suspend Reviewed-by: Lukasz Majewski <lukma@denx.de> Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* nptl: Avoid async cancellation to wrongly update __nptl_nthreads (BZ #19366)Adhemerval Zanella2021-06-091-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The testcase provided on BZ#19366 may update __nptl_nthreads in a wrong order, triggering an early process exit because the thread decrement the value twice. The issue is once the thread exits without acting on cancellation, it decreaments '__nptl_nthreads' and then atomically set 'cancelhandling' with EXITING_BIT (thus preventing further cancellation handler to act). The issue happens if a SIGCANCEL is received between checking '__ntpl_nthreads' and setting EXITING_BIT. To avoid it, the '__nptl_nthreads' decrement is moved after EXITING_BIT. It does fully follow the POSIX XSH 2.9.5 Thread Cancellation under the heading Thread Cancellation Cleanup Handlers that states that when a cancellation request is acted upon, or when a thread calls pthread_exit(), the thread first disables cancellation by setting its cancelability state to PTHREAD_CANCEL_DISABLE and its cancelability type to PTHREAD_CANCEL_DEFERRED. The issue is '__pthread_enable_asynccancel' explicit enabled assynchrnous cancellation, so an interrupted syscall within the cancellation cleanup handlers might see an invalid cancelling type (a possible fix might be possible with my proposed solution to BZ#12683). Trying to come up with a test is quite hard since it requires to mimic the timing issue described below, however I see that the bug report reproducer does not early exit anymore. Checked on x86_64-linux-gnu.
* nptl: Use pthread_kill on pthread_cancelAdhemerval Zanella2021-06-093-11/+15
| | | | | | | | | | It consolidates the tgkill call and it is the first step of making pthread_cancel async-signal-safe. It also fix a possible issue where the 'struct pthread' tid is not read atomically, which might send an invalid cancellation signal (similar to what db988e50a87f613cb6b9e98a2fc66a4848bc3546 fixed for pthread_join). Checked on x86_64-linux-gnu and aarch64-linux-gnu.
* nptl: Implement raise in terms of pthread_killAdhemerval Zanella2021-06-094-15/+36
| | | | | | | | | | | | | | | | Now that pthread_kill is provided by libc.so it is possible to implement the generic POSIX implementation as 'pthread_kill(pthread_self(), sig)'. For Linux implementation, pthread_kill read the targeting TID from the TCB. For raise, this it not possible because it would make raise fail when issue after vfork (where creates the resulting process has a different TID from the parent, but its TCB is not updated as for pthread_create). To make raise use pthread_kill, it is make usable from vfork by getting the target thread id through gettid syscall. Checked on x86_64-linux-gnu and aarch64-linux-gnu.
* nptl: Move cancel type out of cancelhandlingAdhemerval Zanella2021-06-097-170/+34
| | | | | | | | | | | | | | Now that the thread cancellation type is not accessed concurrently anymore, it is possible to move it out the cancelhandling. By removing the cancel state out of the internal thread cancel handling state there is no need to check if cancelled bit was set in CAS operation. It allows simplifing the cancellation wrappers and the CANCEL_CANCELED_AND_ASYNCHRONOUS is removed. Checked on x86_64-linux-gnu and aarch64-linux-gnu.
* nptl: Move cancel state out of cancelhandlingAdhemerval Zanella2021-06-0911-60/+31
| | | | | | | | | | | | | | | Now that thread cancellation state is not accessed concurrently anymore, it is possible to move it out the 'cancelhandling'. The code is also simplified: CANCELLATION_P is replaced with a internal pthread_testcancel call and the CANCELSTATE_BIT{MASK} is removed. With this behavior pthread_setcancelstate does not require to act on cancellation if cancel type is asynchronous (is already handled either by pthread_setcanceltype or by the signal handler). Checked on x86_64-linux-gnu and aarch64-linux-gnu.
* nptl: Remove CANCELING_BITMASKAdhemerval Zanella2021-06-094-106/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | The CANCELING_BITMASK is used as an optimization to avoid sending the signal when pthread_cancel is called in a concurrent manner. This requires then to put both the cancellation state and type on a shared state (cancelhandling), since 'pthread_cancel' checks whether cancellation is enabled and asynchrnous to either cancel itself of sending the signal. It also requires handle the CANCELING_BITMASK on __pthread_disable_asynccancel, however this incurs in the same issues described on BZ#12683: the cancellation is acted upon even *after* syscall returns with user visible side-effects. This patch removes this optimization and simplifies the pthread cancellation implementation: pthread_cancel now first checks if cancellation is already pending and if not always, sends a signal if the target is not itself. The SIGCANCEL handler is also simpified since there is not need to setup a CAS loop. It also allows to move both the cancellation state and mode out of 'cancelhadling' (it is done in subsequent patches). Checked on x86_64-linux-gnu and aarch64-linux-gnu.
* nptl: Install cancellation handler on pthread_cancelAdhemerval Zanella2021-06-094-45/+28
| | | | | | | | Now that cancellation is not used anymore to handle thread setup creation failure, the sighandle can be installed only when pthread_cancel is actually used. Checked on x86_64-linux-gnu and aarch64-linux-gnu.
* nptl: Deallocate the thread stack on setup failure (BZ #19511)Adhemerval Zanella2021-06-093-88/+80
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To setup either the thread scheduling parameters or affinity, pthread_create enforce synchronization on created thread to wait until its parent either release PD ownership or send a cancellation signal if a failure occurs. However, cancelling the thread does not deallocate the newly created stack since cancellation expects that a pthread_join to deallocate any allocated thread resouces (threads stack or TLS). This patch changes on how the thread resource is deallocate in case of failure to be synchronous, where the creating thread will signal the created thread to exit early so it could be joined. The creating thread will be reponsible for the resource cleanup before returning to the caller. To signal the creating thread that a failure has occured, an unused 'struct pthread' member, parent_cancelhandling_unsed, now indicates whether the setup has failed so creating thread can proper exit. This strategy also simplifies by not using thread cancellation and thus not running libgcc_so load in the signal handler (which is avoided in thread cancellation since 'pthread_cancel' is the one responsible to dlopen libgcc_s). Another advantage is since the early exit is move to first step at thread creation, the signal mask is not already set and thus it can not act on change ID setxid handler. Checked on x86_64-linux-gnu and aarch64-linux-gnu.
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-03 21:23:12 +0000