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Diffstat (limited to 'nptl/tst-create-detached.c')
| -rw-r--r-- | nptl/tst-create-detached.c | 138 |
1 files changed, 0 insertions, 138 deletions
diff --git a/nptl/tst-create-detached.c b/nptl/tst-create-detached.c deleted file mode 100644 index cd79c68..0000000 --- a/nptl/tst-create-detached.c +++ /dev/null @@ -1,138 +0,0 @@ -/* 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> |