Patch: FYI: fix PR 29812

Tom Tromey tromey@redhat.com
Mon Jan 22 22:58:00 GMT 2007


I'm checking this in on the trunk, the 4.2 branch, and the RH 4.1
branch.

This fixes PR java/29812.  This is a JNI bug that occurs because we
don't properly track the class during JNI calls.  This occurs not just
for ordinary methods but also for calls to JNI_OnLoad.  There's a test
case included.

Tom


Index: ChangeLog
from  Tom Tromey  <tromey@redhat.com>
	PR java/29812:
	* testsuite/libjava.jni/pr29812.java: New file.
	* testsuite/libjava.jni/pr29812_injar.java: New file.
	* testsuite/libjava.jni/pr29812_injar.jar: New file.
	* testsuite/libjava.jni/pr29812.out: New file.
	* testsuite/libjava.jni/pr29812_injar.c: New file.
	* testsuite/libjava.jni/pr29812_injar.h: New file.
	* testsuite/libjava.jni/pr29812.jar: New file.
	* testsuite/libjava.jni/pr29812.c: New file.
	* testsuite/libjava.jni/pr29812.h: New file.
	* testsuite/libjava.jni/jni.exp (gcj_jni_get_cxxflags_invocation):
	New proc.
	(gcj_jni_invocation_test_one): Use it.
	(gcj_jni_pr29812): New proc.
	(gcj_jni_run): Use it.
	* java/lang/natRuntime.cc (_load): Push a new system frame before
	calling JNI_OnLoad.
	* include/jvm.h (_Jv_JNI_PopSystemFrame): Declare.
	(_Jv_GetJNIEnvNewFrameWithLoader): Likewise.
	* jni.cc (struct _Jv_JNI_LocalFrame) <marker>: Now unsigned char.
	<allocated_p>: Now bool.
	<loader>: New field.
	(_Jv_JNI_EnsureLocalCapacity): Updated.
	(_Jv_JNI_NewLocalRef): Likewise.
	(_Jv_JNI_NewLocalRef): Likewise.
	(_Jv_JNI_PopLocalFrame): Likewise.
	(_Jv_JNI_FindClass): Likewise.
	(_Jv_GetJNIEnvNewFrame): Likewise.
	(_Jv_JNI_AttachCurrentThread): Likewise.
	(_Jv_GetJNIEnvNewFrameWithLoader): New function.
	(_Jv_GetJNIEnvNewFrame): Use it.
	* include/jni_md.h (_CLASSPATH_JNIENV_CONTENTS): Removed 'klass'.

Index: include/jni_md.h
===================================================================
--- include/jni_md.h	(revision 121057)
+++ include/jni_md.h	(working copy)
@@ -1,5 +1,5 @@
 /* jni_md.h
-   Copyright (C) 2001, 2005 Free Software Foundation, Inc.
+   Copyright (C) 2001, 2005, 2007 Free Software Foundation, Inc.
 
 This file is part of GNU Classpath.
 
@@ -58,9 +58,6 @@
   /* The current exception.  */						\
   jthrowable ex;							\
 									\
-  /* The class of the current native method.  */			\
-  jclass klass;								\
-									\
   /* The chain of local frames.  */					\
   struct _Jv_JNI_LocalFrame *locals;					\
 									\
Index: include/jvm.h
===================================================================
--- include/jvm.h	(revision 121057)
+++ include/jvm.h	(working copy)
@@ -592,8 +592,8 @@
 /* Free a JNIEnv. */
 void _Jv_FreeJNIEnv (_Jv_JNIEnv *);
 
-/* Free a JNIEnv. */
-void _Jv_FreeJNIEnv (_Jv_JNIEnv *);
+extern "C" void _Jv_JNI_PopSystemFrame (_Jv_JNIEnv *);
+_Jv_JNIEnv *_Jv_GetJNIEnvNewFrameWithLoader (::java::lang::ClassLoader *);
 
 struct _Jv_JavaVM;
 _Jv_JavaVM *_Jv_GetJavaVM (); 
Index: testsuite/libjava.jni/pr29812.java
===================================================================
--- testsuite/libjava.jni/pr29812.java	(revision 0)
+++ testsuite/libjava.jni/pr29812.java	(revision 0)
@@ -0,0 +1,25 @@
+import java.io.File;
+import java.net.*;
+import java.lang.reflect.Method;
+
+public class pr29812
+{
+  static {
+    System.loadLibrary("pr29812");
+  }
+
+  public static native void baseN();
+
+  public static void main(String[] args) throws Throwable
+  {
+    // Make sure JNI environment is initialized.
+    baseN();
+
+    File jar = new File(args[0]);
+    URL u = jar.toURL();
+    URLClassLoader uc = new URLClassLoader(new URL[] { u });
+    Class k = uc.loadClass("pr29812_injar");
+    Method m = k.getMethod("doit", (Class[]) null);
+    m.invoke(null, (Object[]) null);
+  }
+}
Index: testsuite/libjava.jni/pr29812_injar.java
===================================================================
--- testsuite/libjava.jni/pr29812_injar.java	(revision 0)
+++ testsuite/libjava.jni/pr29812_injar.java	(revision 0)
@@ -0,0 +1,12 @@
+public class pr29812_injar
+{
+  public class inner
+  {
+  }
+
+  static {
+    System.loadLibrary("pr29812_injar");
+  }
+
+  public static native void doit();
+}
Index: testsuite/libjava.jni/pr29812_injar.jar
===================================================================
Cannot display: file marked as a binary type.
svn:mime-type = application/octet-stream

Property changes on: testsuite/libjava.jni/pr29812_injar.jar
___________________________________________________________________
Name: svn:mime-type
   + application/octet-stream

Index: testsuite/libjava.jni/pr29812.out
===================================================================
Index: testsuite/libjava.jni/pr29812_injar.c
===================================================================
--- testsuite/libjava.jni/pr29812_injar.c	(revision 0)
+++ testsuite/libjava.jni/pr29812_injar.c	(revision 0)
@@ -0,0 +1,26 @@
+
+#include <stdlib.h>
+#include <assert.h>
+#include <pr29812_injar.h>
+
+JNIEXPORT jint JNICALL
+JNI_OnLoad (JavaVM *vm, void *nothing)
+{
+  JNIEnv *env;
+  jint r;
+  jclass k;
+
+  r = (*vm)->GetEnv (vm, (void **) &env, JNI_VERSION_1_2);
+  assert (r == JNI_OK);
+  k = (*env)->FindClass (env, "pr29812_injar$inner");
+  assert (k != NULL);
+
+  return JNI_VERSION_1_2;
+}
+
+void
+Java_pr29812_1injar_doit (JNIEnv *env, jclass b)
+{
+  jclass k = (*env)->FindClass(env, "pr29812_injar$inner");
+  assert (k != NULL);
+}
Index: testsuite/libjava.jni/pr29812_injar.h
===================================================================
--- testsuite/libjava.jni/pr29812_injar.h	(revision 0)
+++ testsuite/libjava.jni/pr29812_injar.h	(revision 0)
@@ -0,0 +1,19 @@
+/* DO NOT EDIT THIS FILE - it is machine generated */
+
+#include <jni.h>
+
+#ifndef __pr29812_1injar__
+#define __pr29812_1injar__
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+JNIEXPORT void JNICALL Java_pr29812_1injar_doit (JNIEnv *env, jclass);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __pr29812_1injar__ */
Index: testsuite/libjava.jni/pr29812.jar
===================================================================
Cannot display: file marked as a binary type.
svn:mime-type = application/octet-stream

Property changes on: testsuite/libjava.jni/pr29812.jar
___________________________________________________________________
Name: svn:mime-type
   + application/octet-stream

Index: testsuite/libjava.jni/pr29812.c
===================================================================
--- testsuite/libjava.jni/pr29812.c	(revision 0)
+++ testsuite/libjava.jni/pr29812.c	(revision 0)
@@ -0,0 +1,7 @@
+#include <pr29812.h>
+
+void
+Java_pr29812_baseN (JNIEnv *env, jclass barf)
+{
+  /* nothing */
+}
Index: testsuite/libjava.jni/jni.exp
===================================================================
--- testsuite/libjava.jni/jni.exp	(revision 121057)
+++ testsuite/libjava.jni/jni.exp	(working copy)
@@ -101,7 +101,7 @@
 
   # The base name.  We use it for several purposes.
   set main [file rootname [file tail $file]]
-  if {! [runtest_file_p $runtests $main]} {
+  if {! [runtest_file_p $runtests $main] || $main == "pr29812"} {
     # Simply skip it.
     return 1
   }
@@ -235,6 +235,33 @@
   return 1
 }
 
+proc gcj_jni_get_cxxflags_invocation {} {
+  # Darwin needs -liconv linked, otherwise we get some unresolved.
+  # If you're building the compiler with --prefix set to a place
+  # where it's not yet installed, then the linker won't be able to
+  # find the libgcc used by libffi.dylib.  We could pass the
+  # -dylib_file option, but that's complicated, and it's much easier
+  # to just make the linker find libgcc using -L options.
+  # Similar logic applies to libgcj.
+  if { [istarget "*-*-darwin*"] } {
+      set cxxflags "-L../.libs -shared-libgcc -ljvm -lgcj -liconv"
+  } else {
+      global LIBJAVA
+      if [info exists LIBJAVA] {
+	  set libjava $LIBJAVA;
+      } else {
+	  set libjava [libjava_find_lib libjava gcj]
+      }
+      set cxxflags "$libjava -ljvm"
+  }
+
+  if { [istarget "*-*-solaris*"] } {
+    lappend cxxflags "-lsocket"
+  }
+
+  return $cxxflags
+}
+
 # Do all the work for a single invocation API test.  Return 0 on
 # failure.
 proc gcj_jni_invocation_test_one {file} {
@@ -259,29 +286,8 @@
 #   pass "bytecompile $file"
 
   set cfile [file rootname $file].c
-  # Darwin needs -liconv linked, otherwise we get some unresolved.
-  # If you're building the compiler with --prefix set to a place
-  # where it's not yet installed, then the linker won't be able to
-  # find the libgcc used by libffi.dylib.  We could pass the
-  # -dylib_file option, but that's complicated, and it's much easier
-  # to just make the linker find libgcc using -L options.
-  # Similar logic applies to libgcj.
-  if { [istarget "*-*-darwin*"] } {
-      set cxxflags "-L../.libs -shared-libgcc -ljvm -lgcj -liconv"
-  } else {
-      global LIBJAVA
-      if [info exists LIBJAVA] {
-	  set libjava $LIBJAVA;
-      } else {
-	  set libjava [libjava_find_lib libjava gcj]
-      }
-      set cxxflags "$libjava -ljvm"
-  }
 
-  if { [istarget "*-*-solaris*"] } {
-    lappend cxxflags "-lsocket"
-  }
-
+  set cxxflags [gcj_jni_get_cxxflags_invocation]
   if {! [gcj_jni_invocation_compile_c_to_binary $cfile $cxxflags]} {
     # FIXME
     return 0
@@ -309,6 +315,40 @@
   return 1
 }
 
+proc gcj_jni_pr29812 {} {
+  global srcdir subdir
+  global INTERPRETER runtests
+
+  # Set up a global we need.
+  libjava_arguments
+
+  set b ${srcdir}/${subdir}
+
+  if {! [runtest_file_p $runtests pr29812]} {
+    # Simply skip it.
+    return 1
+  }
+
+  if {! [gcj_jni_compile_c_to_so $b/pr29812.c ""]} {
+    return 0
+  }
+  if {! [gcj_jni_compile_c_to_so $b/pr29812_injar.c ""]} {
+    return 0
+  }
+
+  set gij [libjava_find_gij]
+  if {$INTERPRETER == "yes" && $gij != ""} {
+    if {! [libjava_invoke pr29812 "gij test" opts $gij \
+	     "" $b/pr29812.out "" \
+	     -classpath $b/pr29812.jar pr29812 $b/pr29812_injar.jar]} {
+      return 0
+    }
+  }
+
+  # When we succeed we remove all our clutter.
+  eval gcj_cleanup [glob -nocomplain -- *pr29812*]
+}
+
 # Run the JNI tests.
 proc gcj_jni_run {} {
   global srcdir subdir
@@ -328,6 +368,8 @@
     foreach x $srcfiles {
       gcj_jni_invocation_test_one $x
     }
+
+    gcj_jni_pr29812
   } else {
     verbose "JNI tests not run in cross-compilation environment"
   }
Index: testsuite/libjava.jni/pr29812.h
===================================================================
--- testsuite/libjava.jni/pr29812.h	(revision 0)
+++ testsuite/libjava.jni/pr29812.h	(revision 0)
@@ -0,0 +1,19 @@
+/* DO NOT EDIT THIS FILE - it is machine generated */
+
+#include <jni.h>
+
+#ifndef __pr29812__
+#define __pr29812__
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+JNIEXPORT void JNICALL Java_pr29812_baseN (JNIEnv *env, jclass);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __pr29812__ */
Index: jni.cc
===================================================================
--- jni.cc	(revision 121057)
+++ jni.cc	(working copy)
@@ -85,16 +85,18 @@
 // This structure is used to keep track of local references.
 struct _Jv_JNI_LocalFrame
 {
-  // This is true if this frame object represents a pushed frame (eg
-  // from PushLocalFrame).
-  int marker;
+  // This is one of the MARK_ constants.
+  unsigned char marker;
 
   // Flag to indicate some locals were allocated.
-  int allocated_p;
+  bool allocated_p;
 
   // Number of elements in frame.
   int size;
 
+  // The class loader of the JNI method that allocated this frame.
+  ::java::lang::ClassLoader *loader;
+
   // Next frame in chain.
   _Jv_JNI_LocalFrame *next;
 
@@ -311,8 +313,9 @@
 
   frame->marker = MARK_NONE;
   frame->size = size;
-  frame->allocated_p = 0;
+  frame->allocated_p = false;
   memset (&frame->vec[0], 0, size * sizeof (jobject));
+  frame->loader = env->locals->loader;
   frame->next = env->locals;
   env->locals = frame;
 
@@ -350,7 +353,7 @@
 	      set = true;
 	      done = true;
 	      frame->vec[i] = obj;
-	      frame->allocated_p = 1;
+	      frame->allocated_p = true;
 	      break;
 	    }
 	}
@@ -368,7 +371,7 @@
       _Jv_JNI_EnsureLocalCapacity (env, 16);
       // We know the first element of the new frame will be ok.
       env->locals->vec[0] = obj;
-      env->locals->allocated_p = 1;
+      env->locals->allocated_p = true;
     }
 
   mark_for_gc (obj, local_ref_table);
@@ -397,7 +400,7 @@
 	{
 	  if (rf->allocated_p)
 	    memset (&rf->vec[0], 0, rf->size * sizeof (jobject));
-	  rf->allocated_p = 0;
+	  rf->allocated_p = false;
 	  rf = NULL;
 	  break;
 	}
@@ -541,8 +544,8 @@
       jstring n = JvNewStringUTF (s);
 
       java::lang::ClassLoader *loader = NULL;
-      if (env->klass != NULL)
-	loader = env->klass->getClassLoaderInternal ();
+      if (env->locals->loader != NULL)
+	loader = env->locals->loader;
 
       if (loader == NULL)
 	{
@@ -2087,18 +2090,14 @@
   buf[here] = '\0';
 }
 
-// Return the current thread's JNIEnv; if one does not exist, create
-// it.  Also create a new system frame for use.  This is `extern "C"'
-// because the compiler calls it.
-extern "C" JNIEnv *
-_Jv_GetJNIEnvNewFrame (jclass klass)
+JNIEnv *
+_Jv_GetJNIEnvNewFrameWithLoader (::java::lang::ClassLoader *loader)
 {
   JNIEnv *env = _Jv_GetCurrentJNIEnv ();
   if (__builtin_expect (env == NULL, false))
     {
       env = (JNIEnv *) _Jv_MallocUnchecked (sizeof (JNIEnv));
       env->p = &_Jv_JNIFunctions;
-      env->klass = klass;
       env->locals = NULL;
       // We set env->ex below.
 
@@ -2107,11 +2106,12 @@
 	_Jv_MallocUnchecked (sizeof (_Jv_JNI_LocalFrame)
 			     + (FRAME_SIZE
 				* sizeof (jobject)));
-      
+
       env->bottom_locals->marker = MARK_SYSTEM;
       env->bottom_locals->size = FRAME_SIZE;
       env->bottom_locals->next = NULL;
-      env->bottom_locals->allocated_p = 0;
+      env->bottom_locals->allocated_p = false;
+      // We set the klass field below.
       memset (&env->bottom_locals->vec[0], 0, 
 	      env->bottom_locals->size * sizeof (jobject));
 
@@ -2123,23 +2123,25 @@
   // built, above.
 
   if (__builtin_expect (env->locals == NULL, true))
-    env->locals = env->bottom_locals;
-
+    {
+      env->locals = env->bottom_locals;
+      env->locals->loader = loader;
+    }
   else
     {
       // Alternatively, we might be re-entering JNI, in which case we can't
       // reuse the bottom_locals frame, because it is already underneath
       // us. So we need to make a new one.
-
       _Jv_JNI_LocalFrame *frame
 	= (_Jv_JNI_LocalFrame *) _Jv_MallocUnchecked (sizeof (_Jv_JNI_LocalFrame)
 						      + (FRAME_SIZE
 							 * sizeof (jobject)));
-      
+
       frame->marker = MARK_SYSTEM;
       frame->size = FRAME_SIZE;
-      frame->allocated_p = 0;
+      frame->allocated_p = false;
       frame->next = env->locals;
+      frame->loader = loader;
 
       memset (&frame->vec[0], 0, 
 	      frame->size * sizeof (jobject));
@@ -2152,6 +2154,15 @@
   return env;
 }
 
+// Return the current thread's JNIEnv; if one does not exist, create
+// it.  Also create a new system frame for use.  This is `extern "C"'
+// because the compiler calls it.
+extern "C" JNIEnv *
+_Jv_GetJNIEnvNewFrame (jclass klass)
+{
+  return _Jv_GetJNIEnvNewFrameWithLoader (klass->getClassLoaderInternal());
+}
+
 // Destroy the env's reusable resources. This is called from the thread
 // destructor "finalize_native" in natThread.cc
 void 
@@ -2392,7 +2403,6 @@
     return JNI_ERR;
   env->p = &_Jv_JNIFunctions;
   env->ex = NULL;
-  env->klass = NULL;
   env->bottom_locals
     = (_Jv_JNI_LocalFrame *) _Jv_MallocUnchecked (sizeof (_Jv_JNI_LocalFrame)
 						  + (FRAME_SIZE
@@ -2404,9 +2414,10 @@
       return JNI_ERR;
     }
 
-  env->locals->allocated_p = 0;
+  env->locals->allocated_p = false;
   env->locals->marker = MARK_SYSTEM;
   env->locals->size = FRAME_SIZE;
+  env->locals->loader = NULL;
   env->locals->next = NULL;
 
   for (int i = 0; i < env->locals->size; ++i)
Index: java/lang/natRuntime.cc
===================================================================
--- java/lang/natRuntime.cc	(revision 121057)
+++ java/lang/natRuntime.cc	(working copy)
@@ -207,7 +207,14 @@
 	  // FIXME: what?
 	  return;
 	}
+
+      // Push a new frame so that JNI_OnLoad will get the right class
+      // loader if it calls FindClass.
+      ::java::lang::ClassLoader *loader
+	  = _Jv_StackTrace::GetFirstNonSystemClassLoader();
+      JNIEnv *env = _Jv_GetJNIEnvNewFrameWithLoader (loader);
       jint vers = ((jint (JNICALL *) (JavaVM *, void *)) onload) (vm, NULL);
+      _Jv_JNI_PopSystemFrame (env);
       if (vers != JNI_VERSION_1_1 && vers != JNI_VERSION_1_2
 	  && vers != JNI_VERSION_1_4)
 	{



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