Linux: rseq registration tests

These tests validate that rseq is registered from various execution
contexts (main thread, destructor, other threads, other threads created
from destructor, forked process (without exec), pthread_atfork handlers,
pthread setspecific destructors, signal handlers, atexit handlers).

tst-rseq.c only links against libc.so, testing registration of rseq in
a non-multithreaded environment.

tst-rseq-nptl.c also links against libpthread.so, testing registration
of rseq in a multithreaded environment.

See the Linux kernel selftests for extensive rseq stress-tests.
This commit is contained in:
Mathieu Desnoyers 2020-07-06 10:21:35 +02:00 committed by Florian Weimer
parent 6e29cb3f61
commit 8f4632deb3
4 changed files with 388 additions and 1 deletions

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@ -100,7 +100,11 @@ tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
test-errno-linux tst-memfd_create tst-mlock2 tst-pkey \
tst-rlimit-infinity tst-ofdlocks tst-gettid tst-gettid-kill \
tst-tgkill
tests-internal += tst-ofdlocks-compat tst-sigcontext-get_pc
# tst-rseq is an internal test because it requires a definition of __NR_rseq
# from the internal system call list.
tests-internal += tst-ofdlocks-compat tst-sigcontext-get_pc \
tst-rseq
CFLAGS-tst-sigcontext-get_pc.c = -fasynchronous-unwind-tables
@ -301,4 +305,8 @@ endif
ifeq ($(subdir),nptl)
tests += tst-align-clone tst-getpid1
# tst-rseq-nptl is an internal test because it requires a definition of
# __NR_rseq from the internal system call list.
tests-internal += tst-rseq-nptl
endif

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@ -0,0 +1,256 @@
/* Restartable Sequences NPTL test.
Copyright (C) 2020 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
/* These tests validate that rseq is registered from various execution
contexts (main thread, destructor, other threads, other threads created
from destructor, forked process (without exec), pthread_atfork handlers,
pthread setspecific destructors, signal handlers, atexit handlers).
See the Linux kernel selftests for extensive rseq stress-tests. */
#include <stdio.h>
#include <support/check.h>
#include <support/xthread.h>
#include <sys/rseq.h>
#include <unistd.h>
#ifdef RSEQ_SIG
# include <array_length.h>
# include <errno.h>
# include <error.h>
# include <pthread.h>
# include <signal.h>
# include <stdlib.h>
# include <string.h>
# include <support/namespace.h>
# include <support/xsignal.h>
# include <syscall.h>
# include <sys/types.h>
# include <sys/wait.h>
# include "tst-rseq.h"
static pthread_key_t rseq_test_key;
static void
atfork_prepare (void)
{
if (!rseq_thread_registered ())
{
printf ("error: rseq not registered in pthread atfork prepare\n");
support_record_failure ();
}
}
static void
atfork_parent (void)
{
if (!rseq_thread_registered ())
{
printf ("error: rseq not registered in pthread atfork parent\n");
support_record_failure ();
}
}
static void
atfork_child (void)
{
if (!rseq_thread_registered ())
{
printf ("error: rseq not registered in pthread atfork child\n");
support_record_failure ();
}
}
static void
rseq_key_destructor (void *arg)
{
/* Cannot use deferred failure reporting after main returns. */
if (!rseq_thread_registered ())
FAIL_EXIT1 ("rseq not registered in pthread key destructor");
}
static void
atexit_handler (void)
{
/* Cannot use deferred failure reporting after main returns. */
if (!rseq_thread_registered ())
FAIL_EXIT1 ("rseq not registered in atexit handler");
}
static void
do_rseq_main_test (void)
{
TEST_COMPARE (atexit (atexit_handler), 0);
rseq_test_key = xpthread_key_create (rseq_key_destructor);
TEST_COMPARE (pthread_atfork (atfork_prepare, atfork_parent, atfork_child), 0);
xraise (SIGUSR1);
TEST_COMPARE (pthread_setspecific (rseq_test_key, (void *) 1l), 0);
TEST_VERIFY_EXIT (rseq_thread_registered ());
}
static void
cancel_routine (void *arg)
{
if (!rseq_thread_registered ())
{
printf ("error: rseq not registered in cancel routine\n");
support_record_failure ();
}
}
static pthread_barrier_t cancel_thread_barrier;
static pthread_cond_t cancel_thread_cond = PTHREAD_COND_INITIALIZER;
static pthread_mutex_t cancel_thread_mutex = PTHREAD_MUTEX_INITIALIZER;
static void
test_cancel_thread (void)
{
pthread_cleanup_push (cancel_routine, NULL);
(void) xpthread_barrier_wait (&cancel_thread_barrier);
/* Wait forever until cancellation. */
xpthread_cond_wait (&cancel_thread_cond, &cancel_thread_mutex);
pthread_cleanup_pop (0);
}
static void *
thread_function (void * arg)
{
int i = (int) (intptr_t) arg;
xraise (SIGUSR1);
if (i == 0)
test_cancel_thread ();
TEST_COMPARE (pthread_setspecific (rseq_test_key, (void *) 1l), 0);
return rseq_thread_registered () ? NULL : (void *) 1l;
}
static void
sighandler (int sig)
{
if (!rseq_thread_registered ())
{
printf ("error: rseq not registered in signal handler\n");
support_record_failure ();
}
}
static void
setup_signals (void)
{
struct sigaction sa;
sigemptyset (&sa.sa_mask);
sigaddset (&sa.sa_mask, SIGUSR1);
sa.sa_flags = 0;
sa.sa_handler = sighandler;
xsigaction (SIGUSR1, &sa, NULL);
}
static int
do_rseq_threads_test (int nr_threads)
{
pthread_t th[nr_threads];
int i;
int result = 0;
xpthread_barrier_init (&cancel_thread_barrier, NULL, 2);
for (i = 0; i < nr_threads; ++i)
th[i] = xpthread_create (NULL, thread_function,
(void *) (intptr_t) i);
(void) xpthread_barrier_wait (&cancel_thread_barrier);
xpthread_cancel (th[0]);
for (i = 0; i < nr_threads; ++i)
{
void *v;
v = xpthread_join (th[i]);
if (i != 0 && v != NULL)
{
printf ("error: join %d successful, but child failed\n", i);
result = 1;
}
else if (i == 0 && v == NULL)
{
printf ("error: join %d successful, child did not fail as expected\n", i);
result = 1;
}
}
xpthread_barrier_destroy (&cancel_thread_barrier);
return result;
}
static void
subprocess_callback (void *closure)
{
do_rseq_main_test ();
}
static void
do_rseq_fork_test (void)
{
support_isolate_in_subprocess (subprocess_callback, NULL);
}
static int
do_rseq_test (void)
{
int t[] = { 1, 2, 6, 5, 4, 3, 50 };
int i, result = 0;
if (!rseq_available ())
FAIL_UNSUPPORTED ("kernel does not support rseq, skipping test");
setup_signals ();
xraise (SIGUSR1);
do_rseq_main_test ();
for (i = 0; i < array_length (t); i++)
if (do_rseq_threads_test (t[i]))
result = 1;
do_rseq_fork_test ();
return result;
}
static void __attribute__ ((destructor))
do_rseq_destructor_test (void)
{
/* Cannot use deferred failure reporting after main returns. */
if (do_rseq_test ())
FAIL_EXIT1 ("rseq not registered within destructor");
xpthread_key_delete (rseq_test_key);
}
#else /* RSEQ_SIG */
static int
do_rseq_test (void)
{
FAIL_UNSUPPORTED ("glibc does not define RSEQ_SIG, skipping test");
return 0;
}
#endif /* RSEQ_SIG */
static int
do_test (void)
{
return do_rseq_test ();
}
#include <support/test-driver.c>

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@ -0,0 +1,64 @@
/* Restartable Sequences single-threaded tests.
Copyright (C) 2020 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
/* These tests validate that rseq is registered from main in an executable
not linked against libpthread. */
#include <support/check.h>
#include <stdio.h>
#include <sys/rseq.h>
#include <unistd.h>
#ifdef RSEQ_SIG
# include <errno.h>
# include <error.h>
# include <stdlib.h>
# include <string.h>
# include <syscall.h>
# include "tst-rseq.h"
static void
do_rseq_main_test (void)
{
TEST_VERIFY_EXIT (rseq_thread_registered ());
}
static void
do_rseq_test (void)
{
if (!rseq_available ())
{
FAIL_UNSUPPORTED ("kernel does not support rseq, skipping test");
}
do_rseq_main_test ();
}
#else /* RSEQ_SIG */
static void
do_rseq_test (void)
{
FAIL_UNSUPPORTED ("glibc does not define RSEQ_SIG, skipping test");
}
#endif /* RSEQ_SIG */
static int
do_test (void)
{
do_rseq_test ();
return 0;
}
#include <support/test-driver.c>

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@ -0,0 +1,59 @@
/* Restartable Sequences tests header.
Copyright (C) 2020 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <error.h>
#include <stdbool.h>
#include <stdint.h>
#include <support/check.h>
#include <syscall.h>
#include <sys/rseq.h>
static inline bool
rseq_thread_registered (void)
{
int32_t v;
__atomic_load (&__rseq_abi.cpu_id, &v, __ATOMIC_RELAXED);
return v >= 0;
}
static inline int
sys_rseq (struct rseq *rseq_abi, uint32_t rseq_len, int flags, uint32_t sig)
{
return syscall (__NR_rseq, rseq_abi, rseq_len, flags, sig);
}
static inline bool
rseq_available (void)
{
int rc;
rc = sys_rseq (NULL, 0, 0, 0);
if (rc != -1)
FAIL_EXIT1 ("Unexpected rseq return value %d", rc);
switch (errno)
{
case ENOSYS:
return false;
case EINVAL:
/* rseq is implemented, but detected an invalid rseq_len parameter. */
return true;
default:
FAIL_EXIT1 ("Unexpected rseq error %s", strerror (errno));
}
}