changeset 54615:5d48ae032588

8219579: Remove redundant signature parsing from the verifier Summary: Change verifier signature checking into asserts because ClassFileParser checks signatures for files being verified. Reviewed-by: lfoltan, coleenp, redestad, dholmes
author hseigel
date Thu, 14 Mar 2019 09:38:17 -0400
parents 153419748bf8
children 70a818b1d9db
files src/hotspot/share/classfile/verifier.cpp src/hotspot/share/runtime/arguments.cpp src/hotspot/share/runtime/signature.cpp src/hotspot/share/runtime/signature.hpp test/hotspot/jtreg/runtime/verifier/BadSignatures.jcod test/hotspot/jtreg/runtime/verifier/TestSigParse.java
diffstat 6 files changed, 520 insertions(+), 39 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/classfile/verifier.cpp	Mon Feb 25 15:41:24 2019 +0100
+++ b/src/hotspot/share/classfile/verifier.cpp	Thu Mar 14 09:38:17 2019 -0400
@@ -632,10 +632,9 @@
   int32_t max_locals = m->max_locals();
   constantPoolHandle cp(THREAD, m->constants());
 
-  if (!SignatureVerifier::is_valid_method_signature(m->signature())) {
-    class_format_error("Invalid method signature");
-    return;
-  }
+  // Method signature was checked in ClassFileParser.
+  assert(SignatureVerifier::is_valid_method_signature(m->signature()),
+         "Invalid method signature");
 
   // Initial stack map frame: offset is 0, stack is initially empty.
   StackMapFrame current_frame(max_locals, max_stack, this);
@@ -2110,12 +2109,9 @@
         vmSymbols::java_lang_invoke_MethodType()), CHECK_VERIFY(this));
   } else if (tag.is_dynamic_constant()) {
     Symbol* constant_type = cp->uncached_signature_ref_at(index);
-    if (!SignatureVerifier::is_valid_type_signature(constant_type)) {
-      class_format_error(
-        "Invalid type for dynamic constant in class %s referenced "
-        "from constant pool index %d", _klass->external_name(), index);
-      return;
-    }
+    // Field signature was checked in ClassFileParser.
+    assert(SignatureVerifier::is_valid_type_signature(constant_type),
+           "Invalid type for dynamic constant");
     assert(sizeof(VerificationType) == sizeof(uintptr_t),
           "buffer type must match VerificationType size");
     uintptr_t constant_type_buffer[2];
@@ -2235,12 +2231,9 @@
   Symbol* field_name = cp->name_ref_at(index);
   Symbol* field_sig = cp->signature_ref_at(index);
 
-  if (!SignatureVerifier::is_valid_type_signature(field_sig)) {
-    class_format_error(
-      "Invalid signature for field in class %s referenced "
-      "from constant pool index %d", _klass->external_name(), index);
-    return;
-  }
+  // Field signature was checked in ClassFileParser.
+  assert(SignatureVerifier::is_valid_type_signature(field_sig),
+         "Invalid field signature");
 
   // Get referenced class type
   VerificationType ref_class_type = cp_ref_index_to_type(
@@ -2719,12 +2712,9 @@
   Symbol* method_name = cp->name_ref_at(index);
   Symbol* method_sig = cp->signature_ref_at(index);
 
-  if (!SignatureVerifier::is_valid_method_signature(method_sig)) {
-    class_format_error(
-      "Invalid method signature in class %s referenced "
-      "from constant pool index %d", _klass->external_name(), index);
-    return;
-  }
+  // Method signature was checked in ClassFileParser.
+  assert(SignatureVerifier::is_valid_method_signature(method_sig),
+         "Invalid method signature");
 
   // Get referenced class type
   VerificationType ref_class_type;
--- a/src/hotspot/share/runtime/arguments.cpp	Mon Feb 25 15:41:24 2019 +0100
+++ b/src/hotspot/share/runtime/arguments.cpp	Thu Mar 14 09:38:17 2019 -0400
@@ -3918,6 +3918,13 @@
     warning("Setting CompressedClassSpaceSize has no effect when compressed class pointers are not used");
   }
 
+  // Treat the odd case where local verification is enabled but remote
+  // verification is not as if both were enabled.
+  if (BytecodeVerificationLocal && !BytecodeVerificationRemote) {
+    log_info(verification)("Turning on remote verification because local verification is on");
+    FLAG_SET_DEFAULT(BytecodeVerificationRemote, true);
+  }
+
 #ifndef PRODUCT
   if (!LogVMOutput && FLAG_IS_DEFAULT(LogVMOutput)) {
     if (use_vm_log()) {
--- a/src/hotspot/share/runtime/signature.cpp	Mon Feb 25 15:41:24 2019 +0100
+++ b/src/hotspot/share/runtime/signature.cpp	Thu Mar 14 09:38:17 2019 -0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2019, 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
@@ -418,18 +418,7 @@
   return args_count;
 }
 
-bool SignatureVerifier::is_valid_signature(Symbol* sig) {
-  const char* signature = (const char*)sig->bytes();
-  ssize_t len = sig->utf8_length();
-  if (signature == NULL || signature[0] == '\0' || len < 1) {
-    return false;
-  } else if (signature[0] == '(') {
-    return is_valid_method_signature(sig);
-  } else {
-    return is_valid_type_signature(sig);
-  }
-}
-
+#ifdef ASSERT
 bool SignatureVerifier::is_valid_method_signature(Symbol* sig) {
   const char* method_sig = (const char*)sig->bytes();
   ssize_t len = sig->utf8_length();
@@ -499,3 +488,4 @@
       return false;
   }
 }
+#endif // ASSERT
--- a/src/hotspot/share/runtime/signature.hpp	Mon Feb 25 15:41:24 2019 +0100
+++ b/src/hotspot/share/runtime/signature.hpp	Thu Mar 14 09:38:17 2019 -0400
@@ -415,11 +415,9 @@
   int reference_parameter_count();
 };
 
+#ifdef ASSERT
 class SignatureVerifier : public StackObj {
   public:
-    // Returns true if the symbol is valid method or type signature
-    static bool is_valid_signature(Symbol* sig);
-
     static bool is_valid_method_signature(Symbol* sig);
     static bool is_valid_type_signature(Symbol* sig);
   private:
@@ -427,5 +425,5 @@
     static ssize_t is_valid_type(const char*, ssize_t);
     static bool invalid_name_char(char);
 };
-
+#endif
 #endif // SHARE_RUNTIME_SIGNATURE_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/verifier/BadSignatures.jcod	Thu Mar 14 09:38:17 2019 -0400
@@ -0,0 +1,424 @@
+/*
+ * Copyright (c) 2019, 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.
+ */
+
+/*
+ * In this case, the signature for the fieldRef for str is missing its closing ';'.
+ *  public class BadFieldRef {
+ *      static String str = new String("Hi");
+ *      public static void m(String argv[]) {
+ *          System.out.println(str);
+ *      }
+ *  }
+*/
+class BadFieldRef {
+  0xCAFEBABE;
+  0; // minor version
+  57; // version
+  [38] { // Constant Pool
+    ; // first element is empty
+    Method #9 #21; // #1     at 0x0A
+    Field #22 #23; // #2     at 0x0F
+    Field #8 #24; // #3     at 0x14
+    Method #25 #26; // #4     at 0x19
+    class #27; // #5     at 0x1E
+    String #28; // #6     at 0x21
+    Method #5 #29; // #7     at 0x24
+    class #30; // #8     at 0x29
+    class #31; // #9     at 0x2C
+    Utf8 "str"; // #10     at 0x2F
+    Utf8 "Ljava/lang/String"; // #11     at 0x35  // Missing closing ';' !!
+    Utf8 "<init>"; // #12     at 0x4A
+    Utf8 "()V"; // #13     at 0x53
+    Utf8 "Code"; // #14     at 0x59
+    Utf8 "LineNumberTable"; // #15     at 0x60
+    Utf8 "m"; // #16     at 0x72
+    Utf8 "([Ljava/lang/String;)V"; // #17     at 0x76
+    Utf8 "<clinit>"; // #18     at 0x8F
+    Utf8 "SourceFile"; // #19     at 0x9A
+    Utf8 "BadFieldRef.java"; // #20     at 0xA7
+    NameAndType #12 #13; // #21     at 0xBA
+    class #32; // #22     at 0xBF
+    NameAndType #33 #34; // #23     at 0xC2
+    NameAndType #10 #11; // #24     at 0xC7
+    class #35; // #25     at 0xCC
+    NameAndType #36 #37; // #26     at 0xCF
+    Utf8 "java/lang/String"; // #27     at 0xD4
+    Utf8 "Hi"; // #28     at 0xE7
+    NameAndType #12 #37; // #29     at 0xEC
+    Utf8 "BadFieldRef"; // #30     at 0xF1
+    Utf8 "java/lang/Object"; // #31     at 0xFF
+    Utf8 "java/lang/System"; // #32     at 0x0112
+    Utf8 "out"; // #33     at 0x0125
+    Utf8 "Ljava/io/PrintStream;"; // #34     at 0x012B
+    Utf8 "java/io/PrintStream"; // #35     at 0x0143
+    Utf8 "println"; // #36     at 0x0159
+    Utf8 "(Ljava/lang/String;)V"; // #37     at 0x0163
+  } // Constant Pool
+
+  0x0021; // access [ ACC_PUBLIC ACC_SUPER ]
+  #8;// this_cpx
+  #9;// super_cpx
+
+  [0] { // Interfaces
+  } // Interfaces
+
+  [1] { // fields
+    { // Member at 0x0185
+      0x0008; // access
+      #10; // name_cpx
+      #11; // sig_cpx
+      [0] { // Attributes
+      } // Attributes
+    } // Member
+  } // fields
+
+  [3] { // methods
+    { // Member at 0x018F
+      0x0001; // access
+      #12; // name_cpx
+      #13; // sig_cpx
+      [1] { // Attributes
+        Attr(#14, 29) { // Code at 0x0197
+          1; // max_stack
+          1; // max_locals
+          Bytes[5]{
+            0x2AB70001B1;
+          };
+          [0] { // Traps
+          } // end Traps
+          [1] { // Attributes
+            Attr(#15, 6) { // LineNumberTable at 0x01AE
+              [1] { // LineNumberTable
+                0  1; //  at 0x01BA
+              }
+            } // end LineNumberTable
+          } // Attributes
+        } // end Code
+      } // Attributes
+    } // Member
+    ;
+    { // Member at 0x01BA
+      0x0009; // access
+      #16; // name_cpx
+      #17; // sig_cpx
+      [1] { // Attributes
+        Attr(#14, 38) { // Code at 0x01C2
+          2; // max_stack
+          1; // max_locals
+          Bytes[10]{
+            0xB20002B20003B600;
+            0x04B1;
+          };
+          [0] { // Traps
+          } // end Traps
+          [1] { // Attributes
+            Attr(#15, 10) { // LineNumberTable at 0x01DE
+              [2] { // LineNumberTable
+                0  6; //  at 0x01EA
+                9  7; //  at 0x01EE
+              }
+            } // end LineNumberTable
+          } // Attributes
+        } // end Code
+      } // Attributes
+    } // Member
+    ;
+    { // Member at 0x01EE
+      0x0008; // access
+      #18; // name_cpx
+      #13; // sig_cpx
+      [1] { // Attributes
+        Attr(#14, 37) { // Code at 0x01F6
+          3; // max_stack
+          0; // max_locals
+          Bytes[13]{
+            0xBB0005591206B700;
+            0x07B30003B1;
+          };
+          [0] { // Traps
+          } // end Traps
+          [1] { // Attributes
+            Attr(#15, 6) { // LineNumberTable at 0x0215
+              [1] { // LineNumberTable
+                0  3; //  at 0x0221
+              }
+            } // end LineNumberTable
+          } // Attributes
+        } // end Code
+      } // Attributes
+    } // Member
+  } // methods
+
+  [1] { // Attributes
+    Attr(#19, 2) { // SourceFile at 0x0223
+      #20;
+    } // end SourceFile
+  } // Attributes
+} // end class BadFieldRef
+
+
+
+/*
+ * In this case, the signature for the methodRef has an illegal embedded ';'.
+ *  public class BadMethodRef {
+ *      public static void main(java.la;ng.String argv[]) throws Throwable {
+ *          System.out.println(" World");
+ *      }
+ *  }
+*/
+class BadMethodRef {
+  0xCAFEBABE;
+  0; // minor version
+  57; // version
+  [32] { // Constant Pool
+    ; // first element is empty
+    Method #6 #17; // #1     at 0x0A
+    Field #18 #19; // #2     at 0x0F
+    String #20; // #3     at 0x14
+    Method #21 #22; // #4     at 0x17
+    class #23; // #5     at 0x1C
+    class #24; // #6     at 0x1F
+    Utf8 "<init>"; // #7     at 0x22
+    Utf8 "()V"; // #8     at 0x2B
+    Utf8 "Code"; // #9     at 0x31
+    Utf8 "LineNumberTable"; // #10     at 0x38
+    Utf8 "main"; // #11     at 0x4A
+    Utf8 "([Ljava/lang/String;)V"; // #12     at 0x51
+    Utf8 "Exceptions"; // #13     at 0x6A
+    class #25; // #14     at 0x77
+    Utf8 "SourceFile"; // #15     at 0x7A
+    Utf8 "BadMethodRef.java"; // #16     at 0x87
+    NameAndType #7 #8; // #17     at 0x9B
+    class #26; // #18     at 0xA0
+    NameAndType #27 #28; // #19     at 0xA3
+    Utf8 " World"; // #20     at 0xA8
+    class #29; // #21     at 0xB1
+    NameAndType #30 #31; // #22     at 0xB4
+    Utf8 "BadMethodRef"; // #23     at 0xB9
+    Utf8 "java/lang/Object"; // #24     at 0xC8
+    Utf8 "java/lang/Throwable"; // #25     at 0xDB
+    Utf8 "java/lang/System"; // #26     at 0xF1
+    Utf8 "out"; // #27     at 0x0104
+    Utf8 "Ljava/io/PrintStream;"; // #28     at 0x010A
+    Utf8 "java/io/PrintStream"; // #29     at 0x0122
+    Utf8 "println"; // #30     at 0x0138
+    Utf8 "(Ljava/la;ng/String;)V"; // #31     at 0x0142 // Illegal "la;ng"
+  } // Constant Pool
+
+  0x0021; // access [ ACC_PUBLIC ACC_SUPER ]
+  #5;// this_cpx
+  #6;// super_cpx
+
+  [0] { // Interfaces
+  } // Interfaces
+
+  [0] { // fields
+  } // fields
+
+  [2] { // methods
+    { // Member at 0x0166
+      0x0001; // access
+      #7; // name_cpx
+      #8; // sig_cpx
+      [1] { // Attributes
+        Attr(#9, 29) { // Code at 0x016E
+          1; // max_stack
+          1; // max_locals
+          Bytes[5]{
+            0x2AB70001B1;
+          };
+          [0] { // Traps
+          } // end Traps
+          [1] { // Attributes
+            Attr(#10, 6) { // LineNumberTable at 0x0185
+              [1] { // LineNumberTable
+                0  1; //  at 0x0191
+              }
+            } // end LineNumberTable
+          } // Attributes
+        } // end Code
+      } // Attributes
+    } // Member
+    ;
+    { // Member at 0x0191
+      0x0009; // access
+      #11; // name_cpx
+      #12; // sig_cpx
+      [2] { // Attributes
+        Attr(#9, 37) { // Code at 0x0199
+          2; // max_stack
+          1; // max_locals
+          Bytes[9]{
+            0xB200021203B60004;
+            0xB1;
+          };
+          [0] { // Traps
+          } // end Traps
+          [1] { // Attributes
+            Attr(#10, 10) { // LineNumberTable at 0x01B4
+              [2] { // LineNumberTable
+                0  4; //  at 0x01C0
+                8  5; //  at 0x01C4
+              }
+            } // end LineNumberTable
+          } // Attributes
+        } // end Code
+        ;
+        Attr(#13, 4) { // Exceptions at 0x01C4
+          [1] { // Exceptions
+            #14; //  at 0x01CE
+          }
+        } // end Exceptions
+      } // Attributes
+    } // Member
+  } // methods
+
+  [1] { // Attributes
+    Attr(#15, 2) { // SourceFile at 0x01D0
+      #16;
+    } // end SourceFile
+  } // Attributes
+} // end class BadMethodRef
+
+
+/*
+ * In this case, the signature for myMethod has an illegal embedded '['.
+ *  public class BadMethodSig {
+ *      public static void myMethod(Str[ing argv[]) throws Throwable {
+ *          System.out.println(" World");
+ *      }
+ *  }
+*/
+class BadMethodSig {
+  0xCAFEBABE;
+  0; // minor version
+  57; // version
+  [32] { // Constant Pool
+    ; // first element is empty
+    Method #6 #17; // #1     at 0x0A
+    Field #18 #19; // #2     at 0x0F
+    String #20; // #3     at 0x14
+    Method #21 #22; // #4     at 0x17
+    class #23; // #5     at 0x1C
+    class #24; // #6     at 0x1F
+    Utf8 "<init>"; // #7     at 0x22
+    Utf8 "()V"; // #8     at 0x2B
+    Utf8 "Code"; // #9     at 0x31
+    Utf8 "LineNumberTable"; // #10     at 0x38
+    Utf8 "myMethod"; // #11     at 0x4A
+    Utf8 "([Ljava/lang/Str[ing;)V"; // #12     at 0x55  // Illegal "Str[ing"
+    Utf8 "Exceptions"; // #13     at 0x6E
+    class #25; // #14     at 0x7B
+    Utf8 "SourceFile"; // #15     at 0x7E
+    Utf8 "BadMethodSig.java"; // #16     at 0x8B
+    NameAndType #7 #8; // #17     at 0x9F
+    class #26; // #18     at 0xA4
+    NameAndType #27 #28; // #19     at 0xA7
+    Utf8 " World"; // #20     at 0xAC
+    class #29; // #21     at 0xB5
+    NameAndType #30 #31; // #22     at 0xB8
+    Utf8 "BadMethodSig"; // #23     at 0xBD
+    Utf8 "java/lang/Object"; // #24     at 0xCC
+    Utf8 "java/lang/Throwable"; // #25     at 0xDF
+    Utf8 "java/lang/System"; // #26     at 0xF5
+    Utf8 "out"; // #27     at 0x0108
+    Utf8 "Ljava/io/PrintStream;"; // #28     at 0x010E
+    Utf8 "java/io/PrintStream"; // #29     at 0x0126
+    Utf8 "println"; // #30     at 0x013C
+    Utf8 "(Ljava/lang/String;)V"; // #31     at 0x0146
+  } // Constant Pool
+
+  0x0021; // access [ ACC_PUBLIC ACC_SUPER ]
+  #5;// this_cpx
+  #6;// super_cpx
+
+  [0] { // Interfaces
+  } // Interfaces
+
+  [0] { // fields
+  } // fields
+
+  [2] { // methods
+    { // Member at 0x016A
+      0x0001; // access
+      #7; // name_cpx
+      #8; // sig_cpx
+      [1] { // Attributes
+        Attr(#9, 29) { // Code at 0x0172
+          1; // max_stack
+          1; // max_locals
+          Bytes[5]{
+            0x2AB70001B1;
+          };
+          [0] { // Traps
+          } // end Traps
+          [1] { // Attributes
+            Attr(#10, 6) { // LineNumberTable at 0x0189
+              [1] { // LineNumberTable
+                0  1; //  at 0x0195
+              }
+            } // end LineNumberTable
+          } // Attributes
+        } // end Code
+      } // Attributes
+    } // Member
+    ;
+    { // Member at 0x0195
+      0x0009; // access
+      #11; // name_cpx
+      #12; // sig_cpx
+      [2] { // Attributes
+        Attr(#9, 37) { // Code at 0x019D
+          2; // max_stack
+          1; // max_locals
+          Bytes[9]{
+            0xB200021203B60004;
+            0xB1;
+          };
+          [0] { // Traps
+          } // end Traps
+          [1] { // Attributes
+            Attr(#10, 10) { // LineNumberTable at 0x01B8
+              [2] { // LineNumberTable
+                0  4; //  at 0x01C4
+                8  5; //  at 0x01C8
+              }
+            } // end LineNumberTable
+          } // Attributes
+        } // end Code
+        ;
+        Attr(#13, 4) { // Exceptions at 0x01C8
+          [1] { // Exceptions
+            #14; //  at 0x01D2
+          }
+        } // end Exceptions
+      } // Attributes
+    } // Member
+  } // methods
+
+  [1] { // Attributes
+    Attr(#15, 2) { // SourceFile at 0x01D4
+      #16;
+    } // end SourceFile
+  } // Attributes
+} // end class BadMethodSig
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/verifier/TestSigParse.java	Thu Mar 14 09:38:17 2019 -0400
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2019, 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 8129579
+ * @summary Test that signatures are properly parsed when verification of local
+ *          classes is requested but verification of remote classes is not.
+ * @compile BadSignatures.jcod
+ * @run main/othervm -XX:+BytecodeVerificationLocal -XX:-BytecodeVerificationRemote TestSigParse
+ */
+
+public class TestSigParse {
+
+    public static void main(String args[]) throws Throwable {
+        System.out.println("Regression test for bug 819579");
+
+        // Test a FieldRef with a bad signature.
+        try {
+            Class newClass = Class.forName("BadFieldRef");
+            throw new RuntimeException("Expected ClasFormatError exception not thrown");
+        } catch (java.lang.ClassFormatError e) {
+            String eMsg = e.getMessage();
+            if (!eMsg.contains("Field") || !eMsg.contains("has illegal signature")) {
+                throw new RuntimeException("Unexpected exception: " + eMsg);
+            }
+        }
+
+        // Test a MethodRef with a bad signature.
+        try {
+            Class newClass = Class.forName("BadMethodRef");
+            throw new RuntimeException("Expected ClasFormatError exception not thrown");
+        } catch (java.lang.ClassFormatError e) {
+            String eMsg = e.getMessage();
+            if (!eMsg.contains("Method") || !eMsg.contains("has illegal signature")) {
+                throw new RuntimeException("Unexpected exception: " + eMsg);
+            }
+        }
+
+        // Test a method in a class with a bad signature.
+        try {
+            Class newClass = Class.forName("BadMethodSig");
+            throw new RuntimeException("Expected ClasFormatError exception not thrown");
+        } catch (java.lang.ClassFormatError e) {
+            String eMsg = e.getMessage();
+            if (!eMsg.contains("Class name contains illegal character")) {
+                throw new RuntimeException("Unexpected exception: " + eMsg);
+            }
+        }
+    }
+
+}