1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2018 Google, Inc.
4 *
5 * tgkill() should fail with EAGAIN when RLIMIT_SIGPENDING is reached with a
6 * real-time signal. Test this by starting a child thread with SIGRTMIN
7 * blocked and a limit of 0 pending signals, then attempting to deliver
8 * SIGRTMIN from the parent thread.
9 */
10
11 #include <pthread.h>
12 #include <signal.h>
13
14 #include "tst_safe_pthread.h"
15 #include "tst_test.h"
16 #include "tgkill.h"
17
thread_func(void * arg)18 static void *thread_func(void *arg)
19 {
20 const struct rlimit sigpending = {
21 .rlim_cur = 0,
22 .rlim_max = 0,
23 };
24 sigset_t sigrtmin;
25 int err;
26 pid_t *tid = arg;
27
28 sigemptyset(&sigrtmin);
29 sigaddset(&sigrtmin, SIGRTMIN);
30
31 err = pthread_sigmask(SIG_BLOCK, &sigrtmin, NULL);
32 if (err)
33 tst_brk(TBROK, "pthread_sigmask() failed: %s",
34 tst_strerrno(err));
35
36 SAFE_SETRLIMIT(RLIMIT_SIGPENDING, &sigpending);
37 *tid = sys_gettid();
38
39 TST_CHECKPOINT_WAKE_AND_WAIT(0);
40
41 return arg;
42 }
43
run(void)44 static void run(void)
45 {
46 pthread_t thread;
47 pid_t tid = -1;
48
49 SAFE_PTHREAD_CREATE(&thread, NULL, thread_func, &tid);
50
51 TST_CHECKPOINT_WAIT(0);
52
53 TEST(sys_tgkill(getpid(), tid, SIGRTMIN));
54 if (TST_RET && TST_ERR == EAGAIN)
55 tst_res(TPASS, "tgkill() failed with EAGAIN as expected");
56 else
57 tst_res(TFAIL | TTERRNO,
58 "tgkill() should have failed with EAGAIN");
59
60 TST_CHECKPOINT_WAKE(0);
61
62 SAFE_PTHREAD_JOIN(thread, NULL);
63 }
64
65 static struct tst_test test = {
66 .needs_checkpoints = 1,
67 .test_all = run,
68 };
69