[PATCH] 8210810: Incorrect argument file parser behavior in certain cases
Bo Zhang
zhangbodut at gmail.com
Tue Sep 25 01:01:06 UTC 2018
Hi all,
This is my first time to try to submit a patch. Please forgive me if I did anything inappropriate. I’ve signed OCA.
Bug description:
8210810 <https://bugs.openjdk.java.net/browse/JDK-8210810>: Incorrect argument file parser behavior in certain cases
Previously, if a quoted backslash character appears at argument file
parser buffer boundary (i.e. 4096th/8192nd/... character of an argument
file is backslash '\'), the segment before the backslash character will
be added into argument twice due to a missing anchor position reset
operation.
For example, you have an argument file:
-cp "...a\\b"
and the 4096th and 4097th characters happen to be both '\', the result
generated by the argument file parser would be:
-cp "...aa\\b”
This patch fixes the issue by resetting anchor position correctly
in this case.
I’m a little surprised that this issue has existed for several years unnoticed.
Patch:
# HG changeset patch
# User Bo Zhang <zhangbodut at gmail.com>
# Date 1537835887 -28800
# Tue Sep 25 08:38:07 2018 +0800
# Node ID 34f2803ad62cde8c82e3dfcf0b66e80276bd7352
# Parent 16f0deae8fa6ef85f7230308e1fe7556bd007c39
8210810: Incorrect argument file parser behavior in certain cases
Previously, if a quoted backslash character appears at argument file
parser buffer boundary (i.e. 4096th/8192nd/... character of an argument
file is backslash '\'), the segment before the backslash character will
be added into argument twice due to a missing anchor position reset
operation.
For example, you have an argument file:
-cp "...a\\b"
and the 4096th and 4097th characters happen to be both '\', the result
generated by the argument file parser would be:
-cp "...aa\\b"
This patch fixes the issue by resetting anchor position correctly
in this case.
diff --git a/src/java.base/share/native/libjli/args.c b/src/java.base/share/native/libjli/args.c
--- a/src/java.base/share/native/libjli/args.c
+++ b/src/java.base/share/native/libjli/args.c
@@ -262,6 +262,8 @@
continue;
}
JLI_List_addSubstring(pctx->parts, anchor, nextc - anchor);
+ // anchor after backslash character
+ anchor = nextc + 1;
pctx->state = IN_ESCAPE;
break;
case '\'':
diff --git a/test/jdk/tools/launcher/Test8210810.java b/test/jdk/tools/launcher/Test8210810.java
new file mode 100644
--- /dev/null
+++ b/test/jdk/tools/launcher/Test8210810.java
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8210810
+ * @summary Incorrect argument file parser behavior when backslash appears at buffer boundary
+ * @modules java.base
+ * @author Bo Zhang
+ * @build TestHelper
+ * @run main Test8210810
+ */
+
+/*
+ * 8210810: Previously, if a quoted backslash character appears at argument file
+ * parser buffer boundary (i.e. 4096th/8192nd/... character of an argument
+ * file is backslash '\'), the segment before the backslash character will
+ * be added into argument twice due to a missing anchor position reset
+ * operation. This test creates a special argument file which can reproduce this issue.
+ */
+import java.io.File;
+import java.nio.file.Files;
+import java.io.IOException;
+import java.util.Arrays;
+
+public class Test8210810 extends TestHelper {
+ // Buffer size in args.c readArgFile() method
+ private static final int ARG_FILE_PARSER_BUF_SIZE = 4096;
+ public static void main(String... args) throws Exception {
+ new Test8210810().canParseArgFileCorrectly();
+ }
+
+ private void canParseArgFileCorrectly() throws IOException {
+ File testJar = createTestClassWhichPrintsClasspath();
+ File argFile = createArgFileWithSpecificClasspath();
+ TestResult result = doExec(javaCmd, "@argFile", "Foo");
+
+ long zCountInArgFile = countZ(new String(Files.readAllBytes(argFile.toPath())));
+ long zCountReadByParser = countZ(result.testOutput.get(0));
+ if(zCountInArgFile != zCountReadByParser) {
+ throw new RuntimeException("Classpath parsed by parser is different from argument file!");
+ }
+
+ testJar.delete();
+ argFile.delete();
+ }
+
+ private long countZ(String str) {
+ return str.chars().filter(ch -> ch == 'z').count();
+ }
+
+ private File createTestClassWhichPrintsClasspath() throws IOException {
+ File testJar = new File("test.jar");
+ testJar.delete();
+
+ StringBuilder tsrc = new StringBuilder();
+ tsrc.append("public static void main(String... args) {\n");
+ tsrc.append(" System.out.println(\"Classpath:\" + System.getProperty(\"java.class.path\"));\n");
+ tsrc.append("}\n");
+ createJar(testJar, new File("Foo"), tsrc.toString());
+ return testJar;
+ }
+
+ // Create a file whose 4096th and 4097th characters are both '\' (backslash)
+ // File content:
+ // |-cp "test.jar:zzzzz...zzz\\"|
+ private File createArgFileWithSpecificClasspath() throws IOException {
+ File argFile = new File("argFile");
+ argFile.delete();
+
+ StringBuilder arg = new StringBuilder("-cp \"test.jar");
+ arg.append(File.pathSeparator);
+
+ int fillingCharactersCount = ARG_FILE_PARSER_BUF_SIZE - 1 - arg.length();
+
+ for(int i = 0; i < fillingCharactersCount; ++i) {
+ arg.append('z');
+ }
+
+ arg.append('\\'); // 4096th character in the arg file
+ arg.append('\\'); // 4097th character in the arg file
+ arg.append('"');
+
+ createAFile(argFile, Arrays.asList(arg.toString()));
+ return argFile;
+ }
+}
Unit test:
Included in the patch. It creates a special argument file whose 4096th and 4097th characters are both ‘\’. Then it compares the classpath read in the VM and the classpath in the argument file to verify they’re identical.
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