From 9d0e30329c23b5ad736fda3f174208c25970dbce Mon Sep 17 00:00:00 2001
From: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date: Tue, 13 Dec 2016 12:28:41 +0000
Subject: [PATCH] elf: Add test case for [BZ #19329]
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.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
---
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
---
Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=patch;h=9d0e30329c23b5ad736fda3f174208c25970dbce]
Comment: Hunks from elf/Makefile are refreshed as per glibc 2.31 codebase.
Signed-off-by: Akash Hadke <akash.hadke@kpit.com>
Signed-off-by: Akash Hadke <hadkeakash4@gmail.com>
---
diff --git a/elf/Makefile b/elf/Makefile
index d3e909637a..3241cb6046 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -201,7 +201,7 @@
tst-unwind-ctor tst-unwind-main tst-audit13 \
tst-sonamemove-link tst-sonamemove-dlopen tst-dlopen-tlsmodid \
tst-dlopen-self tst-auditmany tst-initfinilazyfail tst-dlopenfail \
- tst-dlopenfail-2
+ tst-dlopenfail-2 tst-tls21
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
@@ -312,7 +312,7 @@
tst-auditmanymod7 tst-auditmanymod8 tst-auditmanymod9 \
tst-initlazyfailmod tst-finilazyfailmod \
tst-dlopenfailmod1 tst-dlopenfaillinkmod tst-dlopenfailmod2 \
- tst-dlopenfailmod3 tst-ldconfig-ld-mod
+ tst-dlopenfailmod3 tst-ldconfig-ld-mod tst-tls21mod
# Most modules build with _ISOMAC defined, but those filtered out
# depend on internal headers.
modules-names-tests = $(filter-out ifuncmod% tst-libc_dlvsym-dso tst-tlsmod%,\
@@ -1697,5 +1697,10 @@
$(objpfx)tst-dlopen-nodelete-reloc-mod16.so
LDFLAGS-tst-dlopen-nodelete-reloc-mod17.so = -Wl,--no-as-needed
+# Reuses tst-tls-many-dynamic-modules
+$(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)
+
$(objpfx)tst-ldconfig-ld_so_conf-update.out: $(objpfx)tst-ldconfig-ld-mod.so
$(objpfx)tst-ldconfig-ld_so_conf-update: $(libdl)
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;
--
2.27.0