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jerboaajerboaa
committedJun 13, 2022
8287007: [cgroups] Consistently use stringStream throughout parsing code
Reviewed-by: iklam
·
jdk-21+2121-genzgc+1-8
1 parent 1769596 commit e0baf01

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5 files changed

+243
-34
lines changed

5 files changed

+243
-34
lines changed
 

‎src/hotspot/os/linux/cgroupV1Subsystem_linux.cpp

+10-24
Original file line numberDiff line numberDiff line change
@@ -37,40 +37,26 @@
3737
* on the contents of the mountinfo and cgroup files.
3838
*/
3939
void CgroupV1Controller::set_subsystem_path(char *cgroup_path) {
40-
char buf[MAXPATHLEN+1];
40+
stringStream ss;
4141
if (_root != NULL && cgroup_path != NULL) {
4242
if (strcmp(_root, "/") == 0) {
43-
int buflen;
44-
strncpy(buf, _mount_point, MAXPATHLEN);
45-
buf[MAXPATHLEN-1] = '\0';
43+
ss.print_raw(_mount_point);
4644
if (strcmp(cgroup_path,"/") != 0) {
47-
buflen = strlen(buf);
48-
if ((buflen + strlen(cgroup_path)) > (MAXPATHLEN-1)) {
49-
return;
50-
}
51-
strncat(buf, cgroup_path, MAXPATHLEN-buflen);
52-
buf[MAXPATHLEN-1] = '\0';
45+
ss.print_raw(cgroup_path);
5346
}
54-
_path = os::strdup(buf);
47+
_path = os::strdup(ss.base());
5548
} else {
5649
if (strcmp(_root, cgroup_path) == 0) {
57-
strncpy(buf, _mount_point, MAXPATHLEN);
58-
buf[MAXPATHLEN-1] = '\0';
59-
_path = os::strdup(buf);
50+
ss.print_raw(_mount_point);
51+
_path = os::strdup(ss.base());
6052
} else {
6153
char *p = strstr(cgroup_path, _root);
6254
if (p != NULL && p == _root) {
6355
if (strlen(cgroup_path) > strlen(_root)) {
64-
int buflen;
65-
strncpy(buf, _mount_point, MAXPATHLEN);
66-
buf[MAXPATHLEN-1] = '\0';
67-
buflen = strlen(buf);
68-
if ((buflen + strlen(cgroup_path) - strlen(_root)) > (MAXPATHLEN-1)) {
69-
return;
70-
}
71-
strncat(buf, cgroup_path + strlen(_root), MAXPATHLEN-buflen);
72-
buf[MAXPATHLEN-1] = '\0';
73-
_path = os::strdup(buf);
56+
ss.print_raw(_mount_point);
57+
const char* cg_path_sub = cgroup_path + strlen(_root);
58+
ss.print_raw(cg_path_sub);
59+
_path = os::strdup(ss.base());
7460
}
7561
}
7662
}

‎src/hotspot/os/linux/cgroupV2Subsystem_linux.cpp

+5-10
Original file line numberDiff line numberDiff line change
@@ -213,17 +213,12 @@ char* CgroupV2Subsystem::mem_limit_val() {
213213
}
214214

215215
char* CgroupV2Controller::construct_path(char* mount_path, char *cgroup_path) {
216-
char buf[MAXPATHLEN+1];
217-
int buflen;
218-
strncpy(buf, mount_path, MAXPATHLEN);
219-
buf[MAXPATHLEN] = '\0';
220-
buflen = strlen(buf);
221-
if ((buflen + strlen(cgroup_path)) > MAXPATHLEN) {
222-
return NULL;
216+
stringStream ss;
217+
ss.print_raw(mount_path);
218+
if (strcmp(cgroup_path, "/") != 0) {
219+
ss.print_raw(cgroup_path);
223220
}
224-
strncat(buf, cgroup_path, MAXPATHLEN-buflen);
225-
buf[MAXPATHLEN] = '\0';
226-
return os::strdup(buf);
221+
return os::strdup(ss.base());
227222
}
228223

229224
char* CgroupV2Subsystem::pids_max_val() {

‎test/hotspot/gtest/runtime/test_os_linux_cgroups.cpp

+86
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,86 @@
1+
/*
2+
* Copyright (c) 2022, Red Hat, Inc.
3+
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4+
*
5+
* This code is free software; you can redistribute it and/or modify it
6+
* under the terms of the GNU General Public License version 2 only, as
7+
* published by the Free Software Foundation.
8+
*
9+
* This code is distributed in the hope that it will be useful, but WITHOUT
10+
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11+
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12+
* version 2 for more details (a copy is included in the LICENSE file that
13+
* accompanied this code).
14+
*
15+
* You should have received a copy of the GNU General Public License version
16+
* 2 along with this work; if not, write to the Free Software Foundation,
17+
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18+
*
19+
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20+
* or visit www.oracle.com if you need additional information or have any
21+
* questions.
22+
*/
23+
24+
#include "precompiled.hpp"
25+
26+
#ifdef LINUX
27+
28+
#include "cgroupV1Subsystem_linux.hpp"
29+
#include "cgroupV2Subsystem_linux.hpp"
30+
#include "unittest.hpp"
31+
32+
typedef struct {
33+
const char* mount_path;
34+
const char* root_path;
35+
const char* cgroup_path;
36+
const char* expected_path;
37+
} TestCase;
38+
39+
TEST(os_linux_cgroup, set_cgroupv1_subsystem_path) {
40+
TestCase host = {
41+
"/sys/fs/cgroup/memory", // mount_path
42+
"/", // root_path
43+
"/user.slice/user-1000.slice/user@1000.service", // cgroup_path
44+
"/sys/fs/cgroup/memory/user.slice/user-1000.slice/user@1000.service" // expected_path
45+
};
46+
TestCase container_engine = {
47+
"/sys/fs/cgroup/mem", // mount_path
48+
"/user.slice/user-1000.slice/user@1000.service", // root_path
49+
"/user.slice/user-1000.slice/user@1000.service", // cgroup_path
50+
"/sys/fs/cgroup/mem" // expected_path
51+
};
52+
int length = 2;
53+
TestCase* testCases[] = { &host,
54+
&container_engine };
55+
for (int i = 0; i < length; i++) {
56+
CgroupV1Controller* ctrl = new CgroupV1Controller( (char*)testCases[i]->root_path,
57+
(char*)testCases[i]->mount_path);
58+
ctrl->set_subsystem_path((char*)testCases[i]->cgroup_path);
59+
ASSERT_STREQ(testCases[i]->expected_path, ctrl->subsystem_path());
60+
}
61+
}
62+
63+
TEST(os_linux_cgroup, set_cgroupv2_subsystem_path) {
64+
TestCase at_mount_root = {
65+
"/sys/fs/cgroup", // mount_path
66+
NULL, // root_path, ignored
67+
"/", // cgroup_path
68+
"/sys/fs/cgroup" // expected_path
69+
};
70+
TestCase sub_path = {
71+
"/sys/fs/cgroup", // mount_path
72+
NULL, // root_path, ignored
73+
"/foobar", // cgroup_path
74+
"/sys/fs/cgroup/foobar" // expected_path
75+
};
76+
int length = 2;
77+
TestCase* testCases[] = { &at_mount_root,
78+
&sub_path };
79+
for (int i = 0; i < length; i++) {
80+
CgroupV2Controller* ctrl = new CgroupV2Controller( (char*)testCases[i]->mount_path,
81+
(char*)testCases[i]->cgroup_path);
82+
ASSERT_STREQ(testCases[i]->expected_path, ctrl->subsystem_path());
83+
}
84+
}
85+
86+
#endif

‎test/jdk/jdk/internal/platform/cgroup/CgroupV1SubsystemControllerTest.java

+78
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,78 @@
1+
/*
2+
* Copyright (c) 2022, Red Hat, Inc.
3+
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4+
*
5+
* This code is free software; you can redistribute it and/or modify it
6+
* under the terms of the GNU General Public License version 2 only, as
7+
* published by the Free Software Foundation.
8+
*
9+
* This code is distributed in the hope that it will be useful, but WITHOUT
10+
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11+
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12+
* version 2 for more details (a copy is included in the LICENSE file that
13+
* accompanied this code).
14+
*
15+
* You should have received a copy of the GNU General Public License version
16+
* 2 along with this work; if not, write to the Free Software Foundation,
17+
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18+
*
19+
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20+
* or visit www.oracle.com if you need additional information or have any
21+
* questions.
22+
*/
23+
24+
import static org.junit.Assert.assertEquals;
25+
26+
import org.junit.Test;
27+
28+
import jdk.internal.platform.cgroupv1.CgroupV1SubsystemController;
29+
30+
/*
31+
* @test
32+
* @key cgroups
33+
* @requires os.family == "linux"
34+
* @modules java.base/jdk.internal.platform.cgroupv1
35+
* @library /test/lib
36+
* @run junit/othervm CgroupV1SubsystemControllerTest
37+
*/
38+
public class CgroupV1SubsystemControllerTest {
39+
40+
41+
/*
42+
* Common case: Containers
43+
*/
44+
@Test
45+
public void testCgPathEqualsRoot() {
46+
String root = "/machine.slice/libpod-7145e2e7dbeab5aa96bd79beed79eda286a2d299a0ee386e704cad9f53a70979.scope";
47+
String mountPoint = "/somemount";
48+
CgroupV1SubsystemController ctrl = new CgroupV1SubsystemController(root, mountPoint);
49+
ctrl.setPath("/machine.slice/libpod-7145e2e7dbeab5aa96bd79beed79eda286a2d299a0ee386e704cad9f53a70979.scope");
50+
assertEquals(mountPoint, ctrl.path());
51+
}
52+
53+
/*
54+
* Common case: Host
55+
*/
56+
@Test
57+
public void testCgPathNonEmptyRoot() {
58+
String root = "/";
59+
String mountPoint = "/sys/fs/cgroup/memory";
60+
CgroupV1SubsystemController ctrl = new CgroupV1SubsystemController(root, mountPoint);
61+
String cgroupPath = "/subpath";
62+
ctrl.setPath(cgroupPath);
63+
String expectedPath = mountPoint + cgroupPath;
64+
assertEquals(expectedPath, ctrl.path());
65+
}
66+
67+
@Test
68+
public void testCgPathSubstring() {
69+
String root = "/foo/bar/baz";
70+
String mountPoint = "/sys/fs/cgroup/memory";
71+
CgroupV1SubsystemController ctrl = new CgroupV1SubsystemController(root, mountPoint);
72+
String cgroupPath = "/foo/bar/baz/some";
73+
ctrl.setPath(cgroupPath);
74+
String expectedPath = mountPoint + "/some";
75+
assertEquals(expectedPath, ctrl.path());
76+
}
77+
78+
}

‎test/jdk/jdk/internal/platform/cgroup/CgroupV2SubsystemControllerTest.java

+64
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,64 @@
1+
/*
2+
* Copyright (c) 2022, Red Hat, Inc.
3+
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4+
*
5+
* This code is free software; you can redistribute it and/or modify it
6+
* under the terms of the GNU General Public License version 2 only, as
7+
* published by the Free Software Foundation.
8+
*
9+
* This code is distributed in the hope that it will be useful, but WITHOUT
10+
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11+
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12+
* version 2 for more details (a copy is included in the LICENSE file that
13+
* accompanied this code).
14+
*
15+
* You should have received a copy of the GNU General Public License version
16+
* 2 along with this work; if not, write to the Free Software Foundation,
17+
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18+
*
19+
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20+
* or visit www.oracle.com if you need additional information or have any
21+
* questions.
22+
*/
23+
24+
import static org.junit.Assert.assertEquals;
25+
26+
import org.junit.Test;
27+
28+
import jdk.internal.platform.cgroupv2.CgroupV2SubsystemController;
29+
30+
/*
31+
* @test
32+
* @key cgroups
33+
* @requires os.family == "linux"
34+
* @modules java.base/jdk.internal.platform.cgroupv2
35+
* @library /test/lib
36+
* @run junit/othervm CgroupV2SubsystemControllerTest
37+
*/
38+
public class CgroupV2SubsystemControllerTest {
39+
40+
41+
/*
42+
* Common case: No nested cgroup path (i.e. at the unified root)
43+
*/
44+
@Test
45+
public void testCgPathAtRoot() {
46+
String mountPoint = "/sys/fs/cgroup";
47+
String cgroupPath = "/";
48+
CgroupV2SubsystemController ctrl = new CgroupV2SubsystemController(mountPoint, cgroupPath);
49+
assertEquals(mountPoint, ctrl.path());
50+
}
51+
52+
/*
53+
* Cgroup path at a sub-path
54+
*/
55+
@Test
56+
public void testCgPathNonEmptyRoot() {
57+
String mountPoint = "/sys/fs/cgroup";
58+
String cgroupPath = "/foobar";
59+
CgroupV2SubsystemController ctrl = new CgroupV2SubsystemController(mountPoint, cgroupPath);
60+
String expectedPath = mountPoint + cgroupPath;
61+
assertEquals(expectedPath, ctrl.path());
62+
}
63+
64+
}

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