1 /*
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  7  * published by the Free Software Foundation.
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  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).
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 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
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 24 
 25 /*
 26  * @test
 27  * @summary Tests how CDS works when critical library classes are replaced with JVMTI ClassFileLoadHook
 28  * @library /test/lib
 29  * @requires vm.cds
 30  * @build sun.hotspot.WhiteBox
 31  * @run driver ClassFileInstaller -jar whitebox.jar sun.hotspot.WhiteBox
 32  * @run main/othervm/native ReplaceCriticalClasses
 33  */
 34 
 35 import java.util.regex.Matcher;
 36 import java.util.regex.Pattern;
 37 import jdk.test.lib.cds.CDSTestUtils;
 38 import jdk.test.lib.cds.CDSOptions;
 39 import jdk.test.lib.process.OutputAnalyzer;
 40 import sun.hotspot.WhiteBox;
 41 
 42 public class ReplaceCriticalClasses {
 43     public static void main(String args[]) throws Throwable {
 44         ReplaceCriticalClasses rcc = new ReplaceCriticalClasses();
 45         rcc.process(args);
 46     }
 47 
 48     public void process(String args[]) throws Throwable {
 49         if (args.length == 0) {
 50             // Dump the shared archive in case it was not generated during the JDK build.
 51             // Put the archive at separate file to avoid clashes with concurrent tests.
 52             CDSOptions opts = new CDSOptions()
 53                 .setXShareMode("dump")
 54                 .setArchiveName(ReplaceCriticalClasses.class.getName() + ".jsa")
 55                 .setUseVersion(false)
 56                 .addSuffix("-showversion")
 57                 .addSuffix("-Xlog:cds");
 58             CDSTestUtils.run(opts).assertNormalExit("");
 59 
 60             launchChildProcesses(getTests());
 61         } else if (args.length == 3 && args[0].equals("child")) {
 62             Class klass = Class.forName(args[2].replace("/", "."));
 63             if (args[1].equals("-shared")) {
 64                 testInChild(true, klass);
 65             } else if (args[1].equals("-notshared")) {
 66                 testInChild(false, klass);
 67             } else {
 68                 throw new RuntimeException("Unknown child exec option " + args[1]);
 69             }
 70             return;
 71         } else {
 72             throw new RuntimeException("Usage: @run main/othervm/native ReplaceCriticalClasses");
 73         }
 74     }
 75 
 76     public String[] getTests() {
 77         String tests[] = {
 78             // CDS should be disabled -- these critical classes will be replaced
 79             // because JvmtiExport::early_class_hook_env() is true.
 80             "-early -notshared java/lang/Object",
 81             "-early -notshared java/lang/String",
 82             "-early -notshared java/lang/Cloneable",
 83             "-early -notshared java/io/Serializable",
 84             "-early -notshared java/lang/Module",
 85             "-early -notshared java/lang/ModuleLayer",
 86 
 87             // CDS should not be disabled -- these critical classes cannot be replaced because
 88             // JvmtiExport::early_class_hook_env() is false.
 89             "java/lang/Object",
 90             "java/lang/String",
 91             "java/lang/Cloneable",
 92             "java/io/Serializable",
 93             "java/lang/Module",
 94             "java/lang/ModuleLayer",
 95 
 96             // Replace classes that are loaded after JVMTI_PHASE_PRIMORDIAL. It's OK to replace
 97             // such
 98             // classes even when CDS is enabled. Nothing bad should happen.
 99             "-notshared java/util/Locale",
100             "-notshared sun/util/locale/BaseLocale",
101             "-notshared java/lang/Readable",
102         };
103         return tests;
104     }
105 
106     static void launchChildProcesses(String tests[]) throws Throwable {
107         int n = 0;
108         for (String s : tests) {
109             System.out.println("Test case[" + (n++) + "] = \"" + s + "\"");
110             String args[] = s.split("\\s+"); // split by space character
111             launchChild(args);
112         }
113     }
114 
115     static void launchChild(String args[]) throws Throwable {
116         if (args.length < 1) {
117             throw new RuntimeException("Invalid test case. Should be <-early> <-subgraph> <-notshared> <-nowhitebox> klassName subgraphKlass");
118         }
119         String klassName = null;
120         String subgraphKlass = null;
121         String early = "";
122         boolean subgraph = false;
123         boolean whitebox = true;
124         String shared = "-shared";
125 
126         for (int i=0; i<args.length-1; i++) {
127             String opt = args[i];
128             if (opt.equals("-early")) {
129                 early = "-early,";
130             } else if (opt.equals("-subgraph")) {
131                 subgraph = true;
132             } else if (opt.equals("-nowhitebox")) {
133                 whitebox = false;
134             } else if (opt.equals("-notshared")) {
135                 shared = opt;
136             } else {
137               if (!subgraph) {
138                 throw new RuntimeException("Unknown option: " + opt);
139               }
140             }
141         }
142         if (subgraph) {
143           klassName = args[args.length-2];
144           subgraphKlass = args[args.length-1];
145         } else {
146           klassName = args[args.length-1];
147         }
148         Class.forName(klassName.replace("/", ".")); // make sure it's a valid class
149         final String subgraphInit = "initialize_from_archived_subgraph " + subgraphKlass;
150 
151         // We will pass an option like "-agentlib:SimpleClassFileLoadHook=java/util/Locale,XXX,XXX".
152         // The SimpleClassFileLoadHook agent would attempt to hook the java/util/Locale class
153         // but leave the class file bytes unchanged (it replaces all bytes "XXX" with "XXX", i.e.,
154         // a no-op). JVMTI doesn't check the class file bytes returned by the agent, so as long
155         // as the agent returns a buffer, it will not load the class from CDS, and will instead
156         // load the class by parsing the buffer.
157         //
158         // Note that for safety we don't change the contents of the class file bytes. If in the
159         // future JVMTI starts checking the contents of the class file bytes, this test would need
160         // to be updated. (You'd see the test case with java/util/Locale staring to fail).
161         String agent = "-agentlib:SimpleClassFileLoadHook=" + early + klassName + ",XXX,XXX";
162 
163         CDSOptions opts = (new CDSOptions())
164             .setXShareMode("auto")
165             .setArchiveName(ReplaceCriticalClasses.class.getName() + ".jsa")
166             .setUseVersion(false)
167             .addSuffix("-showversion",
168                        "-Xlog:cds",
169                        "-XX:+UnlockDiagnosticVMOptions",
170                        agent);
171         if (whitebox) {
172             opts.addSuffix("-XX:+WhiteBoxAPI",
173                            "-Xbootclasspath/a:" + ClassFileInstaller.getJarPath("whitebox.jar"));
174         }
175         if (subgraph) {
176             opts.addSuffix("-Xlog:cds,cds+heap");
177         }
178 
179         opts.addSuffix("ReplaceCriticalClasses",
180                        "child",
181                        shared,
182                        klassName);
183 
184         final boolean expectDisable = !early.equals("");
185         final boolean checkSubgraph = subgraph;
186         final boolean expectShared = shared.equals("-shared");
187         CDSTestUtils.run(opts).assertNormalExit(out -> {
188                 if (expectDisable) {
189                     out.shouldContain("UseSharedSpaces: CDS is disabled because early JVMTI ClassFileLoadHook is in use.");
190                     System.out.println("CDS disabled as expected");
191                 }
192                 if (checkSubgraph) {
193                     if (expectShared) {
194                         if (!out.getOutput().contains("UseSharedSpaces: Unable to map at required address in java heap")) {
195                             out.shouldContain(subgraphInit);
196                             // If the subgraph is successfully initialized, the specified shared class must not be rewritten.
197                             out.shouldNotContain("Rewriting done.");
198                         }
199                     } else {
200                       out.shouldNotContain(subgraphInit);
201                     }
202                 }
203             });
204     }
205 
206     static void testInChild(boolean shouldBeShared, Class klass) {
207         try {
208             WhiteBox wb = WhiteBox.getWhiteBox();
209 
210             if (shouldBeShared && !wb.isSharedClass(klass)) {
211                 throw new RuntimeException(klass + " should be shared but but actually is not.");
212             }
213             if (!shouldBeShared && wb.isSharedClass(klass)) {
214                 throw new RuntimeException(klass + " should not be shared but actually is.");
215             }
216             System.out.println("wb.isSharedClass(" + klass + "): " + wb.isSharedClass(klass) + " == " + shouldBeShared);
217         } catch (UnsatisfiedLinkError e) {
218             System.out.println("WhiteBox is disabled -- because test has -nowhitebox");
219         }
220 
221         String strings[] = {
222             // interned strings from j.l.Object
223             "@",
224             "nanosecond timeout value out of range",
225             "timeoutMillis value is negative",
226 
227             // interned strings from j.l.Integer
228             "0",
229             "0X",
230             "0x",
231             "int"
232         };
233 
234         // Make sure the interned string table is same
235         for (String s : strings) {
236             String i = s.intern();
237             if (s != i) {
238                 throw new RuntimeException("Interned string mismatch: \"" + s + "\" @ " + System.identityHashCode(s) +
239                                            " vs \"" + i + "\" @ " + System.identityHashCode(i));
240             }
241         }
242         // We have tried to use ClassFileLoadHook to replace critical library classes (which may
243         // may not have succeeded, depending on whether the agent has requested
244         // can_generate_all_class_hook_events/can_generate_early_class_hook_events capabilities).
245         //
246         // In any case, the JVM should have started properly (perhaps with CDS disabled) and
247         // the above operations should succeed.
248         System.out.println("If I can come to here without crashing, things should be OK");
249     }
250 }