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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2020-06-07 02:03:45 +0000
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2020-06-07 13:35:54 +0200
commitd6d74ec16c77126c59db264ebfa04d08d5b4c5c0 (patch)
tree95fded09b6a9d8ce35273d43c3f8e3d960bd0554 /sysdeps/pthread/tst-create-detached.c
parentbe22a151f3e2c2e4b9127d4fa30b269f30a7ea2e (diff)
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htl: Enable more tests
* htl/Makefile: Remove rules adding libpthread.so and libpthread.a to link lines. * nptl/Makefile: Move rules adding libpthread.so and libpthread.a to link lines to... * sysdeps/pthread/Makefile: ... here. * nptl/eintr.c, tst-align.c tst-align3.c tst-atfork1.c tst-backtrace1.c tst-bad-schedattr.c tst-cancel-self-canceltype.c tst-cancel-self-cleanup.c tst-cancel-self-testcancel.c tst-cancel1.c tst-cancel10.c tst-cancel12.c tst-cancel14.c tst-cancel15.c tst-cancel18.c tst-cancel19.c tst-cancel2.c tst-cancel22.c tst-cancel23.c tst-cancel26.c tst-cancel27.c tst-cancel28.c tst-cancel3.c tst-cancel8.c tst-cancelx1.c tst-cancelx10.c tst-cancelx12.c tst-cancelx14.c tst-cancelx15.c tst-cancelx18.c tst-cancelx2.c tst-cancelx3.c tst-cancelx8.c tst-cleanup0.c tst-cleanup0.expect tst-cleanup1.c tst-cleanup2.c tst-cleanup3.c tst-cleanupx0.c tst-cleanupx0.expect tst-cleanupx1.c tst-cleanupx2.c tst-cleanupx3.c tst-clock1.c tst-create-detached.c tst-detach1.c tst-eintr2.c tst-eintr3.c tst-eintr4.c tst-eintr5.c tst-exec1.c tst-exec2.c tst-exec3.c tst-exit1.c tst-exit2.c tst-exit3.c tst-flock1.c tst-fork1.c tst-fork2.c tst-fork3.c tst-fork4.c tst-getpid3.c tst-kill1.c tst-kill2.c tst-kill3.c tst-kill4.c tst-kill5.c tst-kill6.c tst-locale1.c tst-locale2.c tst-memstream.c tst-popen1.c tst-raise1.c tst-sem5.c tst-setuid3.c tst-signal4.c tst-signal5.c tst-signal6.c tst-signal8.c tst-stack1.c tst-stdio1.c tst-stdio2.c tst-sysconf.c tst-tls1.c tst-tls2.c tst-tsd1.c tst-tsd2.c tst-tsd5.c tst-tsd6.c tst-umask1.c tst-unload.c tst-unwind-thread.c tst-vfork1.c tst-vfork1x.c tst-vfork2.c tst-vfork2x.c: Move tests to... * sysdeps/pthread: ... here. Rename tst-popen1.c -> tst-pt-popen1.c tst-align.c -> tst-pt-align.c tst-align3.c -> tst-pt-align3.c tst-sysconf.c -> tst-pt-sysconf.c tst-tls1.c -> tst-pt-tls1.c tst-tls2.c -> tst-pt-tls2.c tst-vfork1.c -> tst-pt-vfork1.c tst-vfork2.c -> tst-pt-vfork2.c to avoid conflicting with libio/tst-popen1.c, elf/tst-align.c, posix/tst-sysconf.c, elf/tst-tls1.c, elf/tst-tls2.c, posix/tst-vfork1.c, posix/tst-vfork2.c. * nptl/Makefile: Move corresponding tests references and special rules to... * sysdeps/pthread/Makefile: ... here. * sysdeps/pthread/tst-stack1.c (do_test): Do not clamp stack size to PTHREAD_STACK_MIN if not defined. Tested on linux-x86_64 and hurd-i386
Diffstat (limited to 'sysdeps/pthread/tst-create-detached.c')
-rw-r--r--sysdeps/pthread/tst-create-detached.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/sysdeps/pthread/tst-create-detached.c b/sysdeps/pthread/tst-create-detached.c
new file mode 100644
index 0000000000..cd79c68908
--- /dev/null
+++ b/sysdeps/pthread/tst-create-detached.c
@@ -0,0 +1,138 @@
+/* Bug 20116: Test rapid creation of detached threads.
+ Copyright (C) 2017-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If
+ not, see <https://www.gnu.org/licenses/>. */
+
+/* The goal of the test is to trigger a failure if the parent touches
+ any part of the thread descriptor after the detached thread has
+ exited. We test this by creating many detached threads with large
+ stacks. The stacks quickly fill the the stack cache and subsequent
+ threads will start to cause the thread stacks to be immediately
+ unmapped to satisfy the stack cache max. With the stacks being
+ unmapped the parent's read of any part of the thread descriptor will
+ trigger a segfault. That segfault is what we are trying to cause,
+ since any segfault is a defect in the implementation. */
+
+#include <pthread.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <sys/resource.h>
+#include <support/xthread.h>
+
+/* Number of threads to create. */
+enum { threads_to_create = 100000 };
+
+/* Number of threads which should spawn other threads. */
+enum { creator_threads = 2 };
+
+/* Counter of threads created so far. This is incremented by all the
+ running creator threads. */
+static unsigned threads_created;
+
+/* Thread callback which does nothing, so that the thread exits
+ immediatedly. */
+static void *
+do_nothing (void *arg)
+{
+ return NULL;
+}
+
+/* Attribute indicating that the thread should be created in a detached
+ fashion. */
+static pthread_attr_t detached;
+
+/* Barrier to synchronize initialization. */
+static pthread_barrier_t barrier;
+
+static void *
+creator_thread (void *arg)
+{
+ int ret;
+ xpthread_barrier_wait (&barrier);
+
+ while (true)
+ {
+ pthread_t thr;
+ /* Thread creation will fail if the kernel does not free old
+ threads quickly enough, so we do not report errors. */
+ ret = pthread_create (&thr, &detached, do_nothing, NULL);
+ if (ret == 0 && __atomic_add_fetch (&threads_created, 1, __ATOMIC_SEQ_CST)
+ >= threads_to_create)
+ break;
+ }
+
+ return NULL;
+}
+
+static int
+do_test (void)
+{
+ /* Limit the size of the process, so that memory allocation will
+ fail without impacting the entire system. */
+ {
+ struct rlimit limit;
+ if (getrlimit (RLIMIT_AS, &limit) != 0)
+ {
+ printf ("FAIL: getrlimit (RLIMIT_AS) failed: %m\n");
+ return 1;
+ }
+ /* This limit, 800MB, is just a heuristic. Any value can be
+ picked. */
+ long target = 800 * 1024 * 1024;
+ if (limit.rlim_cur == RLIM_INFINITY || limit.rlim_cur > target)
+ {
+ limit.rlim_cur = target;
+ if (setrlimit (RLIMIT_AS, &limit) != 0)
+ {
+ printf ("FAIL: setrlimit (RLIMIT_AS) failed: %m\n");
+ return 1;
+ }
+ }
+ }
+
+ xpthread_attr_init (&detached);
+
+ xpthread_attr_setdetachstate (&detached, PTHREAD_CREATE_DETACHED);
+
+ /* A large thread stack seems beneficial for reproducing a race
+ condition in detached thread creation. The goal is to reach the
+ limit of the runtime thread stack cache such that the detached
+ thread's stack is unmapped after exit and causes a segfault when
+ the parent reads the thread descriptor data stored on the the
+ unmapped stack. */
+ xpthread_attr_setstacksize (&detached, 16 * 1024 * 1024);
+
+ xpthread_barrier_init (&barrier, NULL, creator_threads);
+
+ pthread_t threads[creator_threads];
+
+ for (int i = 0; i < creator_threads; ++i)
+ threads[i] = xpthread_create (NULL, creator_thread, NULL);
+
+ for (int i = 0; i < creator_threads; ++i)
+ xpthread_join (threads[i]);
+
+ xpthread_attr_destroy (&detached);
+
+ xpthread_barrier_destroy (&barrier);
+
+ return 0;
+}
+
+#define TIMEOUT 100
+#include <support/test-driver.c>