diff mbox series

[1/3] syscalls/tgkill01: add new test

Message ID 1551943728-16222-2-git-send-email-sumit.garg@linaro.org
State Superseded
Headers show
Series syscalls: add tgkill test-cases | expand

Commit Message

Sumit Garg March 7, 2019, 7:28 a.m. UTC
From: Greg Hackmann <ghackmann@google.com>

tgkill() delivers a signal to a specific thread.  Test this by
installing a SIGUSR1 handler which records the current pthread ID.
Start a number of threads in parallel, then one-by-one call tgkill(...,
tid, SIGUSR1) and check that the expected pthread ID was recorded.

Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---
 runtest/syscalls                            |   2 +
 testcases/kernel/syscalls/tgkill/.gitignore |   1 +
 testcases/kernel/syscalls/tgkill/Makefile   |  10 ++
 testcases/kernel/syscalls/tgkill/tgkill.h   |  22 +++++
 testcases/kernel/syscalls/tgkill/tgkill01.c | 138 ++++++++++++++++++++++++++++
 5 files changed, 173 insertions(+)
 create mode 100644 testcases/kernel/syscalls/tgkill/.gitignore
 create mode 100644 testcases/kernel/syscalls/tgkill/Makefile
 create mode 100644 testcases/kernel/syscalls/tgkill/tgkill.h
 create mode 100644 testcases/kernel/syscalls/tgkill/tgkill01.c

Comments

Li Wang March 12, 2019, 1:29 p.m. UTC | #1
On Thu, Mar 7, 2019 at 3:29 PM Sumit Garg <sumit.garg@linaro.org> wrote:

> From: Greg Hackmann <ghackmann@google.com>
>
> tgkill() delivers a signal to a specific thread.  Test this by
> installing a SIGUSR1 handler which records the current pthread ID.
> Start a number of threads in parallel, then one-by-one call tgkill(...,
> tid, SIGUSR1) and check that the expected pthread ID was recorded.
>
> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
>
Reviewed-by: Li Wang <liwang@redhat.com>

This patch set looks pretty good to me. Just have a tiny comments for PATCH
1/3 in below.


> ---
>  runtest/syscalls                            |   2 +
>  testcases/kernel/syscalls/tgkill/.gitignore |   1 +
>  testcases/kernel/syscalls/tgkill/Makefile   |  10 ++
>  testcases/kernel/syscalls/tgkill/tgkill.h   |  22 +++++
>  testcases/kernel/syscalls/tgkill/tgkill01.c | 138
> ++++++++++++++++++++++++++++
>  5 files changed, 173 insertions(+)
>  create mode 100644 testcases/kernel/syscalls/tgkill/.gitignore
>  create mode 100644 testcases/kernel/syscalls/tgkill/Makefile
>  create mode 100644 testcases/kernel/syscalls/tgkill/tgkill.h
>  create mode 100644 testcases/kernel/syscalls/tgkill/tgkill01.c
>
> diff --git a/runtest/syscalls b/runtest/syscalls
> index b43de7a..9ed1214 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -1395,6 +1395,8 @@ syslog10 syslog10
>  syslog11 syslog11
>  syslog12 syslog12
>
> +tgkill01 tgkill01
> +
>  time01 time01
>  time02 time02
>
> diff --git a/testcases/kernel/syscalls/tgkill/.gitignore
> b/testcases/kernel/syscalls/tgkill/.gitignore
> new file mode 100644
> index 0000000..f4566fd
> --- /dev/null
> +++ b/testcases/kernel/syscalls/tgkill/.gitignore
> @@ -0,0 +1 @@
> +tgkill01
> diff --git a/testcases/kernel/syscalls/tgkill/Makefile
> b/testcases/kernel/syscalls/tgkill/Makefile
> new file mode 100644
> index 0000000..a51080c
> --- /dev/null
> +++ b/testcases/kernel/syscalls/tgkill/Makefile
> @@ -0,0 +1,10 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +# Copyright (c) 2018 Google, Inc.
> +
> +top_srcdir             ?= ../../../..
> +
> +include $(top_srcdir)/include/mk/testcases.mk
> +
> +include $(top_srcdir)/include/mk/generic_leaf_target.mk
> +
> +LDLIBS                 += -pthread
> diff --git a/testcases/kernel/syscalls/tgkill/tgkill.h
> b/testcases/kernel/syscalls/tgkill/tgkill.h
> new file mode 100644
> index 0000000..a7d96f4
> --- /dev/null
> +++ b/testcases/kernel/syscalls/tgkill/tgkill.h
> @@ -0,0 +1,22 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2018 Google, Inc.
> + */
> +
> +#ifndef TGKILL_H
> +#define TGKILL_H
> +
> +#include "config.h"
> +#include "lapi/syscalls.h"
> +
> +static inline int sys_tgkill(int tgid, int tid, int sig)
> +{
> +       return tst_syscall(__NR_tgkill, tgid, tid, sig);
> +}
> +
> +static inline pid_t sys_gettid(void)
> +{
> +       return tst_syscall(__NR_gettid);
> +}
> +
> +#endif /* TGKILL_H */
> diff --git a/testcases/kernel/syscalls/tgkill/tgkill01.c
> b/testcases/kernel/syscalls/tgkill/tgkill01.c
> new file mode 100644
> index 0000000..1fb1171
> --- /dev/null
> +++ b/testcases/kernel/syscalls/tgkill/tgkill01.c
> @@ -0,0 +1,138 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2018 Google, Inc.
> + *
> + * tgkill() delivers a signal to a specific thread.  Test this by
> installing
> + * a SIGUSR1 handler which records the current pthread ID.  Start a number
> + * of threads in parallel, then one-by-one call tgkill(..., tid, SIGUSR1)
> + * and check that the expected pthread ID was recorded.
> + */
> +
> +#include <pthread.h>
> +
> +#include "tst_safe_pthread.h"
> +#include "tst_test.h"
> +#include "tgkill.h"
> +
> +struct thread_state {
> +       pthread_t thread;
> +       pid_t tid;
> +};
> +
> +static char *str_threads;
> +static int n_threads = 10;
> +static struct thread_state *threads;
> +
> +static pthread_t sigusr1_thread;
> +
> +static int test_running;
> +static pthread_cond_t test_running_cond = PTHREAD_COND_INITIALIZER;
> +static pthread_mutex_t test_running_mutex = PTHREAD_MUTEX_INITIALIZER;
> +
> +static void sigusr1_handler(int signum __attribute__((unused)))
> +{
> +       sigusr1_thread = pthread_self();
> +}
> +
> +static void *thread_func(void *arg)
> +{
> +       struct thread_state *thread = arg;
> +
> +       /**
> +        * There is no standard way to map pthread -> tid, so we will have
> the
> +        * child stash its own tid then notify the parent that the stashed
> tid
> +        * is available.
> +        */
> +       thread->tid = sys_gettid();
> +
> +       TST_CHECKPOINT_WAKE(0);
> +
> +       pthread_mutex_lock(&test_running_mutex);
> +       while (test_running)
> +               pthread_cond_wait(&test_running_cond, &test_running_mutex);
> +       pthread_mutex_unlock(&test_running_mutex);
> +
> +       return arg;
> +}
> +
> +static void start_thread(struct thread_state *thread)
> +{
> +       SAFE_PTHREAD_CREATE(&thread->thread, NULL, thread_func, thread);
> +
> +       TST_CHECKPOINT_WAIT(0);
> +}
> +
> +static void stop_threads(void)
> +{
> +       int i;
> +
> +       test_running = 0;
> +       pthread_cond_broadcast(&test_running_cond);
> +
> +       for (i = 0; i < n_threads; i++) {
> +               if (threads[i].tid == -1)
> +                       continue;
> +
> +               SAFE_PTHREAD_JOIN(threads[i].thread, NULL);
> +               threads[i].tid = -1;
> +       }
>

Maybe we can add free() to release the allocated memory here.

  if (threads)
        free(threads);



> +}
> +
> +static void run(void)
> +{
> +       int i;
> +
> +       for (i = 0; i < n_threads; i++)
> +               threads[i].tid = -1;
> +
> +       test_running = 1;
> +       for (i = 0; i < n_threads; i++)
> +               start_thread(&threads[i]);
> +
> +       for (i = 0; i < n_threads; i++) {
> +               sigusr1_thread = pthread_self();
> +
> +               TEST(sys_tgkill(getpid(), threads[i].tid, SIGUSR1));
> +               if (TST_RET) {
> +                       tst_res(TFAIL | TTERRNO, "tgkill() failed");
> +                       return;
> +               }
> +
> +               while (pthread_equal(sigusr1_thread, pthread_self()))
> +                       usleep(1000);
> +
> +               if (!pthread_equal(sigusr1_thread, threads[i].thread)) {
> +                       tst_res(TFAIL, "SIGUSR1 delivered to wrong
> thread");
> +                       return;
> +               }
> +       }
> +
> +       stop_threads();
>

Since we have set the .cleanup function as stop_threads() in tst_test
struct, I think
we can remove it here.

> +       tst_res(TPASS, "SIGUSR1 delivered to correct threads");
> +}
> +
> +static void setup(void)
> +{
> +       if (tst_parse_int(str_threads, &n_threads, 1, INT_MAX))
> +               tst_brk(TBROK, "Invalid number of threads '%s'",
> str_threads);
> +
> +       threads = SAFE_MALLOC(sizeof(*threads) * n_threads);
> +
> +       struct sigaction sigusr1 = {
> +               .sa_handler = sigusr1_handler,
> +       };
> +       SAFE_SIGACTION(SIGUSR1, &sigusr1, NULL);
> +}
> +
> +static struct tst_option options[] = {
> +       {"t:", &str_threads, "-t       Number of threads (default 10)"},
> +       {NULL, NULL, NULL},
> +};
> +
> +static struct tst_test test = {
> +       .options = options,
> +       .needs_checkpoints = 1,
> +       .setup = setup,
> +       .test_all = run,
> +       .cleanup = stop_threads,
> +};
> --
> 2.7.4
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>
Sumit Garg March 12, 2019, 1:49 p.m. UTC | #2
On Tue, 12 Mar 2019 at 19:00, Li Wang <liwang@redhat.com> wrote:
>
>
>
> On Thu, Mar 7, 2019 at 3:29 PM Sumit Garg <sumit.garg@linaro.org> wrote:
>>
>> From: Greg Hackmann <ghackmann@google.com>
>>
>> tgkill() delivers a signal to a specific thread.  Test this by
>> installing a SIGUSR1 handler which records the current pthread ID.
>> Start a number of threads in parallel, then one-by-one call tgkill(...,
>> tid, SIGUSR1) and check that the expected pthread ID was recorded.
>>
>> Signed-off-by: Greg Hackmann <ghackmann@google.com>
>> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
>
> Reviewed-by: Li Wang <liwang@redhat.com>
>
> This patch set looks pretty good to me. Just have a tiny comments for PATCH 1/3 in below.

Thanks for your review.

>
>>
>> ---
>>  runtest/syscalls                            |   2 +
>>  testcases/kernel/syscalls/tgkill/.gitignore |   1 +
>>  testcases/kernel/syscalls/tgkill/Makefile   |  10 ++
>>  testcases/kernel/syscalls/tgkill/tgkill.h   |  22 +++++
>>  testcases/kernel/syscalls/tgkill/tgkill01.c | 138 ++++++++++++++++++++++++++++
>>  5 files changed, 173 insertions(+)
>>  create mode 100644 testcases/kernel/syscalls/tgkill/.gitignore
>>  create mode 100644 testcases/kernel/syscalls/tgkill/Makefile
>>  create mode 100644 testcases/kernel/syscalls/tgkill/tgkill.h
>>  create mode 100644 testcases/kernel/syscalls/tgkill/tgkill01.c
>>
>> diff --git a/runtest/syscalls b/runtest/syscalls
>> index b43de7a..9ed1214 100644
>> --- a/runtest/syscalls
>> +++ b/runtest/syscalls
>> @@ -1395,6 +1395,8 @@ syslog10 syslog10
>>  syslog11 syslog11
>>  syslog12 syslog12
>>
>> +tgkill01 tgkill01
>> +
>>  time01 time01
>>  time02 time02
>>
>> diff --git a/testcases/kernel/syscalls/tgkill/.gitignore b/testcases/kernel/syscalls/tgkill/.gitignore
>> new file mode 100644
>> index 0000000..f4566fd
>> --- /dev/null
>> +++ b/testcases/kernel/syscalls/tgkill/.gitignore
>> @@ -0,0 +1 @@
>> +tgkill01
>> diff --git a/testcases/kernel/syscalls/tgkill/Makefile b/testcases/kernel/syscalls/tgkill/Makefile
>> new file mode 100644
>> index 0000000..a51080c
>> --- /dev/null
>> +++ b/testcases/kernel/syscalls/tgkill/Makefile
>> @@ -0,0 +1,10 @@
>> +# SPDX-License-Identifier: GPL-2.0-or-later
>> +# Copyright (c) 2018 Google, Inc.
>> +
>> +top_srcdir             ?= ../../../..
>> +
>> +include $(top_srcdir)/include/mk/testcases.mk
>> +
>> +include $(top_srcdir)/include/mk/generic_leaf_target.mk
>> +
>> +LDLIBS                 += -pthread
>> diff --git a/testcases/kernel/syscalls/tgkill/tgkill.h b/testcases/kernel/syscalls/tgkill/tgkill.h
>> new file mode 100644
>> index 0000000..a7d96f4
>> --- /dev/null
>> +++ b/testcases/kernel/syscalls/tgkill/tgkill.h
>> @@ -0,0 +1,22 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Copyright (c) 2018 Google, Inc.
>> + */
>> +
>> +#ifndef TGKILL_H
>> +#define TGKILL_H
>> +
>> +#include "config.h"
>> +#include "lapi/syscalls.h"
>> +
>> +static inline int sys_tgkill(int tgid, int tid, int sig)
>> +{
>> +       return tst_syscall(__NR_tgkill, tgid, tid, sig);
>> +}
>> +
>> +static inline pid_t sys_gettid(void)
>> +{
>> +       return tst_syscall(__NR_gettid);
>> +}
>> +
>> +#endif /* TGKILL_H */
>> diff --git a/testcases/kernel/syscalls/tgkill/tgkill01.c b/testcases/kernel/syscalls/tgkill/tgkill01.c
>> new file mode 100644
>> index 0000000..1fb1171
>> --- /dev/null
>> +++ b/testcases/kernel/syscalls/tgkill/tgkill01.c
>> @@ -0,0 +1,138 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Copyright (c) 2018 Google, Inc.
>> + *
>> + * tgkill() delivers a signal to a specific thread.  Test this by installing
>> + * a SIGUSR1 handler which records the current pthread ID.  Start a number
>> + * of threads in parallel, then one-by-one call tgkill(..., tid, SIGUSR1)
>> + * and check that the expected pthread ID was recorded.
>> + */
>> +
>> +#include <pthread.h>
>> +
>> +#include "tst_safe_pthread.h"
>> +#include "tst_test.h"
>> +#include "tgkill.h"
>> +
>> +struct thread_state {
>> +       pthread_t thread;
>> +       pid_t tid;
>> +};
>> +
>> +static char *str_threads;
>> +static int n_threads = 10;
>> +static struct thread_state *threads;
>> +
>> +static pthread_t sigusr1_thread;
>> +
>> +static int test_running;
>> +static pthread_cond_t test_running_cond = PTHREAD_COND_INITIALIZER;
>> +static pthread_mutex_t test_running_mutex = PTHREAD_MUTEX_INITIALIZER;
>> +
>> +static void sigusr1_handler(int signum __attribute__((unused)))
>> +{
>> +       sigusr1_thread = pthread_self();
>> +}
>> +
>> +static void *thread_func(void *arg)
>> +{
>> +       struct thread_state *thread = arg;
>> +
>> +       /**
>> +        * There is no standard way to map pthread -> tid, so we will have the
>> +        * child stash its own tid then notify the parent that the stashed tid
>> +        * is available.
>> +        */
>> +       thread->tid = sys_gettid();
>> +
>> +       TST_CHECKPOINT_WAKE(0);
>> +
>> +       pthread_mutex_lock(&test_running_mutex);
>> +       while (test_running)
>> +               pthread_cond_wait(&test_running_cond, &test_running_mutex);
>> +       pthread_mutex_unlock(&test_running_mutex);
>> +
>> +       return arg;
>> +}
>> +
>> +static void start_thread(struct thread_state *thread)
>> +{
>> +       SAFE_PTHREAD_CREATE(&thread->thread, NULL, thread_func, thread);
>> +
>> +       TST_CHECKPOINT_WAIT(0);
>> +}
>> +
>> +static void stop_threads(void)
>> +{
>> +       int i;
>> +
>> +       test_running = 0;
>> +       pthread_cond_broadcast(&test_running_cond);
>> +
>> +       for (i = 0; i < n_threads; i++) {
>> +               if (threads[i].tid == -1)
>> +                       continue;
>> +
>> +               SAFE_PTHREAD_JOIN(threads[i].thread, NULL);
>> +               threads[i].tid = -1;
>> +       }
>
>
> Maybe we can add free() to release the allocated memory here.
>
>   if (threads)
>         free(threads);
>

Ok, will add this here.

>
>>
>> +}
>> +
>> +static void run(void)
>> +{
>> +       int i;
>> +
>> +       for (i = 0; i < n_threads; i++)
>> +               threads[i].tid = -1;
>> +
>> +       test_running = 1;
>> +       for (i = 0; i < n_threads; i++)
>> +               start_thread(&threads[i]);
>> +
>> +       for (i = 0; i < n_threads; i++) {
>> +               sigusr1_thread = pthread_self();
>> +
>> +               TEST(sys_tgkill(getpid(), threads[i].tid, SIGUSR1));
>> +               if (TST_RET) {
>> +                       tst_res(TFAIL | TTERRNO, "tgkill() failed");
>> +                       return;
>> +               }
>> +
>> +               while (pthread_equal(sigusr1_thread, pthread_self()))
>> +                       usleep(1000);
>> +
>> +               if (!pthread_equal(sigusr1_thread, threads[i].thread)) {
>> +                       tst_res(TFAIL, "SIGUSR1 delivered to wrong thread");
>> +                       return;
>> +               }
>> +       }
>> +
>> +       stop_threads();
>
>
> Since we have set the .cleanup function as stop_threads() in tst_test struct, I think
> we can remove it here.

Makes sense, will remove it.

-Sumit

>>
>> +       tst_res(TPASS, "SIGUSR1 delivered to correct threads");
>> +}
>> +
>> +static void setup(void)
>> +{
>> +       if (tst_parse_int(str_threads, &n_threads, 1, INT_MAX))
>> +               tst_brk(TBROK, "Invalid number of threads '%s'", str_threads);
>> +
>> +       threads = SAFE_MALLOC(sizeof(*threads) * n_threads);
>> +
>> +       struct sigaction sigusr1 = {
>> +               .sa_handler = sigusr1_handler,
>> +       };
>> +       SAFE_SIGACTION(SIGUSR1, &sigusr1, NULL);
>> +}
>> +
>> +static struct tst_option options[] = {
>> +       {"t:", &str_threads, "-t       Number of threads (default 10)"},
>> +       {NULL, NULL, NULL},
>> +};
>> +
>> +static struct tst_test test = {
>> +       .options = options,
>> +       .needs_checkpoints = 1,
>> +       .setup = setup,
>> +       .test_all = run,
>> +       .cleanup = stop_threads,
>> +};
>> --
>> 2.7.4
>>
>>
>> --
>> Mailing list info: https://lists.linux.it/listinfo/ltp
>
>
>
> --
> Regards,
> Li Wang
Cyril Hrubis March 14, 2019, 2:04 p.m. UTC | #3
Hi!
> +static void run(void)
> +{
> +	int i;
> +
> +	for (i = 0; i < n_threads; i++)
> +		threads[i].tid = -1;
> +
> +	test_running = 1;
> +	for (i = 0; i < n_threads; i++)
> +		start_thread(&threads[i]);

Just a minor nit these threads should actully be started in the test
setup() since we stop them in the test cleanup(), otherwise the test
breaks with the looping -i option.
Sumit Garg March 15, 2019, 9:48 a.m. UTC | #4
On Thu, 14 Mar 2019 at 19:34, Cyril Hrubis <chrubis@suse.cz> wrote:
>
> Hi!
> > +static void run(void)
> > +{
> > +     int i;
> > +
> > +     for (i = 0; i < n_threads; i++)
> > +             threads[i].tid = -1;
> > +
> > +     test_running = 1;
> > +     for (i = 0; i < n_threads; i++)
> > +             start_thread(&threads[i]);
>
> Just a minor nit these threads should actully be started in the test
> setup() since we stop them in the test cleanup(), otherwise the test
> breaks with the looping -i option.
>

Makes sense, will fix it.

-Sumit

> --
> Cyril Hrubis
> chrubis@suse.cz
diff mbox series

Patch

diff --git a/runtest/syscalls b/runtest/syscalls
index b43de7a..9ed1214 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1395,6 +1395,8 @@  syslog10 syslog10
 syslog11 syslog11
 syslog12 syslog12
 
+tgkill01 tgkill01
+
 time01 time01
 time02 time02
 
diff --git a/testcases/kernel/syscalls/tgkill/.gitignore b/testcases/kernel/syscalls/tgkill/.gitignore
new file mode 100644
index 0000000..f4566fd
--- /dev/null
+++ b/testcases/kernel/syscalls/tgkill/.gitignore
@@ -0,0 +1 @@ 
+tgkill01
diff --git a/testcases/kernel/syscalls/tgkill/Makefile b/testcases/kernel/syscalls/tgkill/Makefile
new file mode 100644
index 0000000..a51080c
--- /dev/null
+++ b/testcases/kernel/syscalls/tgkill/Makefile
@@ -0,0 +1,10 @@ 
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2018 Google, Inc.
+
+top_srcdir		?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
+
+LDLIBS			+= -pthread
diff --git a/testcases/kernel/syscalls/tgkill/tgkill.h b/testcases/kernel/syscalls/tgkill/tgkill.h
new file mode 100644
index 0000000..a7d96f4
--- /dev/null
+++ b/testcases/kernel/syscalls/tgkill/tgkill.h
@@ -0,0 +1,22 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2018 Google, Inc.
+ */
+
+#ifndef TGKILL_H
+#define TGKILL_H
+
+#include "config.h"
+#include "lapi/syscalls.h"
+
+static inline int sys_tgkill(int tgid, int tid, int sig)
+{
+	return tst_syscall(__NR_tgkill, tgid, tid, sig);
+}
+
+static inline pid_t sys_gettid(void)
+{
+	return tst_syscall(__NR_gettid);
+}
+
+#endif /* TGKILL_H */
diff --git a/testcases/kernel/syscalls/tgkill/tgkill01.c b/testcases/kernel/syscalls/tgkill/tgkill01.c
new file mode 100644
index 0000000..1fb1171
--- /dev/null
+++ b/testcases/kernel/syscalls/tgkill/tgkill01.c
@@ -0,0 +1,138 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2018 Google, Inc.
+ *
+ * tgkill() delivers a signal to a specific thread.  Test this by installing
+ * a SIGUSR1 handler which records the current pthread ID.  Start a number
+ * of threads in parallel, then one-by-one call tgkill(..., tid, SIGUSR1)
+ * and check that the expected pthread ID was recorded.
+ */
+
+#include <pthread.h>
+
+#include "tst_safe_pthread.h"
+#include "tst_test.h"
+#include "tgkill.h"
+
+struct thread_state {
+	pthread_t thread;
+	pid_t tid;
+};
+
+static char *str_threads;
+static int n_threads = 10;
+static struct thread_state *threads;
+
+static pthread_t sigusr1_thread;
+
+static int test_running;
+static pthread_cond_t test_running_cond = PTHREAD_COND_INITIALIZER;
+static pthread_mutex_t test_running_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static void sigusr1_handler(int signum __attribute__((unused)))
+{
+	sigusr1_thread = pthread_self();
+}
+
+static void *thread_func(void *arg)
+{
+	struct thread_state *thread = arg;
+
+	/**
+	 * There is no standard way to map pthread -> tid, so we will have the
+	 * child stash its own tid then notify the parent that the stashed tid
+	 * is available.
+	 */
+	thread->tid = sys_gettid();
+
+	TST_CHECKPOINT_WAKE(0);
+
+	pthread_mutex_lock(&test_running_mutex);
+	while (test_running)
+		pthread_cond_wait(&test_running_cond, &test_running_mutex);
+	pthread_mutex_unlock(&test_running_mutex);
+
+	return arg;
+}
+
+static void start_thread(struct thread_state *thread)
+{
+	SAFE_PTHREAD_CREATE(&thread->thread, NULL, thread_func, thread);
+
+	TST_CHECKPOINT_WAIT(0);
+}
+
+static void stop_threads(void)
+{
+	int i;
+
+	test_running = 0;
+	pthread_cond_broadcast(&test_running_cond);
+
+	for (i = 0; i < n_threads; i++) {
+		if (threads[i].tid == -1)
+			continue;
+
+		SAFE_PTHREAD_JOIN(threads[i].thread, NULL);
+		threads[i].tid = -1;
+	}
+}
+
+static void run(void)
+{
+	int i;
+
+	for (i = 0; i < n_threads; i++)
+		threads[i].tid = -1;
+
+	test_running = 1;
+	for (i = 0; i < n_threads; i++)
+		start_thread(&threads[i]);
+
+	for (i = 0; i < n_threads; i++) {
+		sigusr1_thread = pthread_self();
+
+		TEST(sys_tgkill(getpid(), threads[i].tid, SIGUSR1));
+		if (TST_RET) {
+			tst_res(TFAIL | TTERRNO, "tgkill() failed");
+			return;
+		}
+
+		while (pthread_equal(sigusr1_thread, pthread_self()))
+			usleep(1000);
+
+		if (!pthread_equal(sigusr1_thread, threads[i].thread)) {
+			tst_res(TFAIL, "SIGUSR1 delivered to wrong thread");
+			return;
+		}
+	}
+
+	stop_threads();
+	tst_res(TPASS, "SIGUSR1 delivered to correct threads");
+}
+
+static void setup(void)
+{
+	if (tst_parse_int(str_threads, &n_threads, 1, INT_MAX))
+		tst_brk(TBROK, "Invalid number of threads '%s'", str_threads);
+
+	threads = SAFE_MALLOC(sizeof(*threads) * n_threads);
+
+	struct sigaction sigusr1 = {
+		.sa_handler = sigusr1_handler,
+	};
+	SAFE_SIGACTION(SIGUSR1, &sigusr1, NULL);
+}
+
+static struct tst_option options[] = {
+	{"t:", &str_threads, "-t       Number of threads (default 10)"},
+	{NULL, NULL, NULL},
+};
+
+static struct tst_test test = {
+	.options = options,
+	.needs_checkpoints = 1,
+	.setup = setup,
+	.test_all = run,
+	.cleanup = stop_threads,
+};