From 1a72feebcc79e5dbf44ed6d2cb7653b1fad901b0 Mon Sep 17 00:00:00 2001
From: Stefan Berger <stefanb@linux.ibm.com>
Date: Fri, 13 Oct 2023 14:43:06 -0400
Subject: [PATCH] [LibOS] Add testcase for reproducing checkpoint on sbrk issue

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
 libos/test/regression/fork_and_sbrk.c | 57 +++++++++++++++++++++++++++
 libos/test/regression/meson.build     |  1 +
 libos/test/regression/test_libos.py   |  5 +++
 libos/test/regression/tests.toml      |  1 +
 libos/test/regression/tests_musl.toml |  1 +
 5 files changed, 65 insertions(+)
 create mode 100644 libos/test/regression/fork_and_sbrk.c

diff --git a/libos/test/regression/fork_and_sbrk.c b/libos/test/regression/fork_and_sbrk.c
new file mode 100644
index 0000000000..b08281eae3
--- /dev/null
+++ b/libos/test/regression/fork_and_sbrk.c
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* Copyright (C) 2023 IBM Corporation
+ *                    Stefan Berger <stefanb@linux.ibm.com>
+ */
+
+#define _GNU_SOURCE
+#include <pthread.h>
+#include <err.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int proceed = 0;
+
+static void* thread_func(void* arg) {
+    while (__atomic_load_n(&proceed, __ATOMIC_ACQUIRE) == 0)
+        usleep(1);
+    proceed = 0;
+
+    usleep(10);
+    pid_t pid = fork();
+    if (pid < 0) {
+        perror("fork failed\n");
+        exit(1);
+    }
+    if (pid > 0) {
+        while (__atomic_load_n(&proceed, __ATOMIC_ACQUIRE) == 0)
+            usleep(1);
+        printf("TEST OK\n");
+    } else {
+        printf("Child started\n");
+    }
+    exit(0);
+}
+
+int main(int argc, char** argv) {
+    pthread_t forker;
+    if (pthread_create(&forker, NULL, thread_func, NULL) != 0) {
+        perror("pthread_create failed");
+        return 1;
+    }
+
+    proceed = 1;
+    while (__atomic_load_n(&proceed, __ATOMIC_ACQUIRE) == 1);
+
+    size_t i;
+    for (i = 0; i < 1024; i++) {
+        sbrk(0x10000);
+        sbrk(-0x10000);
+    }
+
+    proceed = 1;
+    sleep(1);
+
+    return 0;
+}
diff --git a/libos/test/regression/meson.build b/libos/test/regression/meson.build
index b46d27e395..956faf8185 100644
--- a/libos/test/regression/meson.build
+++ b/libos/test/regression/meson.build
@@ -41,6 +41,7 @@ tests = {
     'fork_and_mprotect': {},
     'fork_and_munmap': {},
     'fork_and_pthread_create': {},
+    'fork_and_sbrk': {},
     'fp_multithread': {
         'c_args': '-fno-builtin',  # see comment in the test's source
         'link_args': '-lm',
diff --git a/libos/test/regression/test_libos.py b/libos/test/regression/test_libos.py
index 6acf21588c..2878d22572 100644
--- a/libos/test/regression/test_libos.py
+++ b/libos/test/regression/test_libos.py
@@ -1018,6 +1018,11 @@ def test_163_fork_and_pthread_create(self):
             stdout, _ = self.run_binary(['fork_and_pthread_create'])
             self.assertIn("TEST OK", stdout)
 
+    def test_164_fork_and_sbrk(self):
+        for _ in range(0, 10):
+            stdout, _ = self.run_binary(['fork_and_sbrk'])
+            self.assertIn("TEST OK", stdout)
+
 class TC_31_Syscall(RegressionTestCase):
     def test_000_syscall_redirect(self):
         stdout, _ = self.run_binary(['syscall'])
diff --git a/libos/test/regression/tests.toml b/libos/test/regression/tests.toml
index 1a3f2f7efd..8a01fbacc7 100644
--- a/libos/test/regression/tests.toml
+++ b/libos/test/regression/tests.toml
@@ -44,6 +44,7 @@ manifests = [
   "fork_and_mprotect",
   "fork_and_munmap",
   "fork_and_pthread_create",
+  "fork_and_sbrk",
   "fork_disallowed",
   "fp_multithread",
   "fstat_cwd",
diff --git a/libos/test/regression/tests_musl.toml b/libos/test/regression/tests_musl.toml
index cbdb153beb..837c9846c0 100644
--- a/libos/test/regression/tests_musl.toml
+++ b/libos/test/regression/tests_musl.toml
@@ -46,6 +46,7 @@ manifests = [
   "fork_and_mprotect",
   "fork_and_munmap",
   "fork_and_pthread_create",
+  "fork_and_sbrk",
   "fork_disallowed",
   "fp_multithread",
   "fstat_cwd",