From: Szabolcs Nagy <szabolcs.nagy@arm.com>
To: libc-alpha@sourceware.org
Subject: [PATCH v2 07/14] elf: Add test case for [BZ #19329]
Date: Tue, 13 Apr 2021 09:19:53 +0100 [thread overview]
Message-ID: <8df69dbc6cc31456a99ef4165fd0eeffc4de4678.1618301209.git.szabolcs.nagy@arm.com> (raw)
In-Reply-To: <cover.1618301209.git.szabolcs.nagy@arm.com>
Test concurrent dlopen and pthread_create when the loaded modules have
TLS. This triggers dl-tls assertion failures more reliably than the
nptl/tst-stack4 test.
The dlopened module has 100 DT_NEEDED dependencies with TLS, they were
reused from an existing TLS test. The number of created threads during
dlopen depends on filesystem speed and hardware, but at most 3 threads
are alive at a time to limit resource usage.
---
v5:
- moved from nptl/ to elf/
- use many tls modules from another test (affects the timing a bit as
these need more relocation processing, but still detects the race)
- use xdlopen
- use stdatomic.h
- moved from tests-internal back to tests
- use acq/rel atomics instead of relaxed, this works too and cleaner.
- moved after bug fix patch.
v4:
- rebased, updated copyright year.
- moved to tests-internal because of <atomic.h>
v3:
- use the new test support code.
- better Makefile usage so modules are cleaned properly.
v2:
- undef NDEBUG.
- join nop threads so at most 3 threads exist at a time.
- remove stack size setting (resource usage is no longer a concern).
- stop creating threads after dlopen observably finished.
- print the number of threads created for debugging.
---
elf/Makefile | 9 ++++--
elf/tst-tls21.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++
elf/tst-tls21mod.c | 1 +
3 files changed, 76 insertions(+), 2 deletions(-)
create mode 100644 elf/tst-tls21.c
create mode 100644 elf/tst-tls21mod.c
diff --git a/elf/Makefile b/elf/Makefile
index b1344f1133..e9377608eb 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -223,7 +223,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
tst-single_threaded tst-single_threaded-pthread \
tst-tls-ie tst-tls-ie-dlmopen argv0test \
tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \
- tst-tls20
+ tst-tls20 tst-tls21
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
@@ -345,7 +345,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
libmarkermod2-1 libmarkermod2-2 \
libmarkermod3-1 libmarkermod3-2 libmarkermod3-3 \
libmarkermod4-1 libmarkermod4-2 libmarkermod4-3 libmarkermod4-4 \
- tst-tls20mod-bad
+ tst-tls20mod-bad tst-tls21mod
# Most modules build with _ISOMAC defined, but those filtered out
# depend on internal headers.
@@ -1932,3 +1932,8 @@ tst-tls20mod-bad.so-no-z-defs = yes
$(objpfx)tst-tls20: $(libdl) $(shared-thread-library)
$(objpfx)tst-tls20.out: $(objpfx)tst-tls20mod-bad.so \
$(tst-tls-many-dynamic-modules:%=$(objpfx)%.so)
+
+# Reuses tst-tls-many-dynamic-modules
+$(objpfx)tst-tls21: $(libdl) $(shared-thread-library)
+$(objpfx)tst-tls21.out: $(objpfx)tst-tls21mod.so
+$(objpfx)tst-tls21mod.so: $(tst-tls-many-dynamic-modules:%=$(objpfx)%.so)
diff --git a/elf/tst-tls21.c b/elf/tst-tls21.c
new file mode 100644
index 0000000000..560bf5813a
--- /dev/null
+++ b/elf/tst-tls21.c
@@ -0,0 +1,68 @@
+/* Test concurrent dlopen and pthread_create: BZ 19329.
+ Copyright (C) 2021 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; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <dlfcn.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdatomic.h>
+#include <support/xdlfcn.h>
+#include <support/xthread.h>
+
+#define THREADS 10000
+
+static atomic_int done;
+
+static void *
+start (void *a)
+{
+ /* Load a module with many dependencies that each have TLS. */
+ xdlopen ("tst-tls21mod.so", RTLD_LAZY);
+ atomic_store_explicit (&done, 1, memory_order_release);
+ return 0;
+}
+
+static void *
+nop (void *a)
+{
+ return 0;
+}
+
+static int
+do_test (void)
+{
+ pthread_t t1, t2;
+ int i;
+
+ /* Load a module with lots of dependencies and TLS. */
+ t1 = xpthread_create (0, start, 0);
+
+ /* Concurrently create lots of threads until dlopen is observably done. */
+ for (i = 0; i < THREADS; i++)
+ {
+ if (atomic_load_explicit (&done, memory_order_acquire) != 0)
+ break;
+ t2 = xpthread_create (0, nop, 0);
+ xpthread_join (t2);
+ }
+
+ xpthread_join (t1);
+ printf ("threads created during dlopen: %d\n", i);
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/elf/tst-tls21mod.c b/elf/tst-tls21mod.c
new file mode 100644
index 0000000000..206ece4fb3
--- /dev/null
+++ b/elf/tst-tls21mod.c
@@ -0,0 +1 @@
+int __thread x;
--
2.17.1
next prev parent reply other threads:[~2021-04-13 8:20 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 8:17 [PATCH v2 00/14] Dynamic TLS related data race fixes Szabolcs Nagy
2021-04-13 8:18 ` [PATCH v2 01/14] elf: Fix a DTV setup issue [BZ #27136] Szabolcs Nagy
2021-04-13 8:36 ` Andreas Schwab
2021-04-13 9:35 ` Szabolcs Nagy
2021-04-13 10:22 ` Andreas Schwab
2021-04-13 10:34 ` Szabolcs Nagy
2021-04-13 10:51 ` Andreas Schwab
2021-04-13 8:18 ` [PATCH v2 02/14] elf: Add a DTV setup test " Szabolcs Nagy
2021-04-14 18:06 ` Adhemerval Zanella
2021-04-15 9:53 ` Szabolcs Nagy
2021-04-13 8:18 ` [PATCH v2 03/14] elf: Fix comments and logic in _dl_add_to_slotinfo Szabolcs Nagy
2021-04-14 18:12 ` Adhemerval Zanella
2021-04-13 8:18 ` [PATCH v2 04/14] elf: Refactor _dl_update_slotinfo to avoid use after free Szabolcs Nagy
2021-04-14 18:20 ` Adhemerval Zanella
2021-04-13 8:19 ` [PATCH v2 05/14] elf: Fix data races in pthread_create and TLS access [BZ #19329] Szabolcs Nagy
2021-04-15 17:44 ` Adhemerval Zanella
2021-04-13 8:19 ` [PATCH v2 06/14] elf: Use relaxed atomics for racy accesses " Szabolcs Nagy
2021-04-15 18:21 ` Adhemerval Zanella
2021-04-16 9:12 ` Szabolcs Nagy
2021-05-11 2:56 ` Carlos O'Donell
2021-05-11 9:31 ` Szabolcs Nagy
2021-05-11 16:19 ` Szabolcs Nagy
2021-05-12 20:33 ` Carlos O'Donell
2021-04-13 8:19 ` Szabolcs Nagy [this message]
2021-04-15 19:21 ` [PATCH v2 07/14] elf: Add test case for " Adhemerval Zanella
2021-04-13 8:20 ` [PATCH v2 08/14] elf: Fix DTV gap reuse logic [BZ #27135] Szabolcs Nagy
2021-04-15 19:45 ` Adhemerval Zanella
2021-06-24 9:48 ` Florian Weimer
2021-06-24 12:27 ` Florian Weimer
2021-06-24 12:57 ` Adhemerval Zanella
2021-06-24 14:20 ` Florian Weimer
2021-06-24 18:58 ` Szabolcs Nagy
2021-04-13 8:20 ` [PATCH v2 09/14] x86_64: Avoid lazy relocation of tlsdesc [BZ #27137] Szabolcs Nagy
2021-04-13 14:02 ` H.J. Lu
2021-04-13 8:20 ` [PATCH v2 10/14] i386: " Szabolcs Nagy
2021-04-13 14:02 ` H.J. Lu
2021-04-13 8:21 ` [PATCH v2 11/14] x86_64: Remove lazy tlsdesc relocation related code Szabolcs Nagy
2021-04-13 14:03 ` H.J. Lu
2021-04-13 8:21 ` [PATCH v2 12/14] i386: " Szabolcs Nagy
2021-04-13 14:04 ` H.J. Lu
2021-04-13 8:21 ` [PATCH v2 13/14] elf: " Szabolcs Nagy
2021-04-15 19:52 ` Adhemerval Zanella
2021-04-13 8:21 ` [PATCH v2 14/14] RFC elf: Fix slow tls access after dlopen [BZ #19924] Szabolcs Nagy
2022-09-16 9:54 ` Carlos O'Donell
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