/*
* Copyright (c) 1997, 2013, 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.
*
*/
#include "precompiled.hpp"
#include "classfile/javaClasses.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/vmSymbols.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.inline.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/method.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "prims/jvm_misc.hpp"
#include "prims/nativeLookup.hpp"
#include "runtime/arguments.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/signature.hpp"
#include "utilities/macros.hpp"
#ifdef TARGET_OS_FAMILY_linux
# include "os_linux.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_solaris
# include "os_solaris.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_windows
# include "os_windows.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_aix
# include "os_aix.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_bsd
# include "os_bsd.inline.hpp"
#endif
static void mangle_name_on(outputStream* st, Symbol* name, int begin, int end) {
char* bytes = (char*)name->bytes() + begin;
char* end_bytes = (char*)name->bytes() + end;
while (bytes < end_bytes) {
jchar c;
bytes = UTF8::next(bytes, &c);
if (c <= 0x7f && isalnum(c)) {
st->put((char) c);
} else {
if (c == '_') st->print("_1");
else if (c == '/') st->print("_");
else if (c == ';') st->print("_2");
else if (c == '[') st->print("_3");
else st->print("_%.5x", c);
}
}
}
static void mangle_name_on(outputStream* st, Symbol* name) {
mangle_name_on(st, name, 0, name->utf8_length());
}
char* NativeLookup::pure_jni_name(methodHandle method) {
stringStream st;
// Prefix
st.print("Java_");
// Klass name
mangle_name_on(&st, method->klass_name());
st.print("_");
// Method name
mangle_name_on(&st, method->name());
return st.as_string();
}
char* NativeLookup::critical_jni_name(methodHandle method) {
stringStream st;
// Prefix
st.print("JavaCritical_");
// Klass name
mangle_name_on(&st, method->klass_name());
st.print("_");
// Method name
mangle_name_on(&st, method->name());
return st.as_string();
}
char* NativeLookup::long_jni_name(methodHandle method) {
// Signature ignore the wrapping parenteses and the trailing return type
stringStream st;
Symbol* signature = method->signature();
st.print("__");
// find ')'
int end;
for (end = 0; end < signature->utf8_length() && signature->byte_at(end) != ')'; end++);
// skip first '('
mangle_name_on(&st, signature, 1, end);
return st.as_string();
}
extern "C" {
void JNICALL JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls);
void JNICALL JVM_RegisterMethodHandleMethods(JNIEnv *env, jclass unsafecls);
void JNICALL JVM_RegisterPerfMethods(JNIEnv *env, jclass perfclass);
void JNICALL JVM_RegisterWhiteBoxMethods(JNIEnv *env, jclass wbclass);
}
#define CC (char*) /* cast a literal from (const char*) */
#define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
static JNINativeMethod lookup_special_native_methods[] = {
{ CC"Java_sun_misc_Unsafe_registerNatives", NULL, FN_PTR(JVM_RegisterUnsafeMethods) },
{ CC"Java_java_lang_invoke_MethodHandleNatives_registerNatives", NULL, FN_PTR(JVM_RegisterMethodHandleMethods) },
{ CC"Java_sun_misc_Perf_registerNatives", NULL, FN_PTR(JVM_RegisterPerfMethods) },
{ CC"Java_sun_hotspot_WhiteBox_registerNatives", NULL, FN_PTR(JVM_RegisterWhiteBoxMethods) },
};
static address lookup_special_native(char* jni_name) {
int count = sizeof(lookup_special_native_methods) / sizeof(JNINativeMethod);
for (int i = 0; i < count; i++) {
// NB: To ignore the jni prefix and jni postfix strstr is used matching.
if (strstr(jni_name, lookup_special_native_methods[i].name) != NULL) {
return CAST_FROM_FN_PTR(address, lookup_special_native_methods[i].fnPtr);
}
}
return NULL;
}
address NativeLookup::lookup_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style, bool& in_base_library, TRAPS) {
address entry;
// Compute complete JNI name for style
stringStream st;
if (os_style) os::print_jni_name_prefix_on(&st, args_size);
st.print_raw(pure_name);
st.print_raw(long_name);
if (os_style) os::print_jni_name_suffix_on(&st, args_size);
char* jni_name = st.as_string();
// If the loader is null we have a system class, so we attempt a lookup in
// the native Java library. This takes care of any bootstrapping problems.
// Note: It is critical for bootstrapping that Java_java_lang_ClassLoader_00024NativeLibrary_find
// gets found the first time around - otherwise an infinite loop can occure. This is
// another VM/library dependency
Handle loader(THREAD, method->method_holder()->class_loader());
if (loader.is_null()) {
entry = lookup_special_native(jni_name);
if (entry == NULL) {
entry = (address) os::dll_lookup(os::native_java_library(), jni_name);
}
if (entry != NULL) {
in_base_library = true;
return entry;
}
}
// Otherwise call static method findNative in ClassLoader
KlassHandle klass (THREAD, SystemDictionary::ClassLoader_klass());
Handle name_arg = java_lang_String::create_from_str(jni_name, CHECK_NULL);
JavaValue result(T_LONG);
JavaCalls::call_static(&result,
klass,
vmSymbols::findNative_name(),
vmSymbols::classloader_string_long_signature(),
// Arguments
loader,
name_arg,
CHECK_NULL);
entry = (address) (intptr_t) result.get_jlong();
if (entry == NULL) {
// findNative didn't find it, if there are any agent libraries look in them
AgentLibrary* agent;
for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
entry = (address) os::dll_lookup(agent->os_lib(), jni_name);
if (entry != NULL) {
return entry;
}
}
}
return entry;
}
address NativeLookup::lookup_critical_style(methodHandle method, char* pure_name, const char* long_name, int args_size, bool os_style) {
if (!method->has_native_function()) {
return NULL;
}
address current_entry = method->native_function();
char dll_name[JVM_MAXPATHLEN];
int offset;
if (os::dll_address_to_library_name(current_entry, dll_name, sizeof(dll_name), &offset)) {
char ebuf[32];
void* dll = os::dll_load(dll_name, ebuf, sizeof(ebuf));
if (dll != NULL) {
// Compute complete JNI name for style
stringStream st;
if (os_style) os::print_jni_name_prefix_on(&st, args_size);
st.print_raw(pure_name);
st.print_raw(long_name);
if (os_style) os::print_jni_name_suffix_on(&st, args_size);
char* jni_name = st.as_string();
return (address)os::dll_lookup(dll, jni_name);
}
}
return NULL;
}
// Check all the formats of native implementation name to see if there is one
// for the specified method.
address NativeLookup::lookup_entry(methodHandle method, bool& in_base_library, TRAPS) {
address entry = NULL;
in_base_library = false;
// Compute pure name
char* pure_name = pure_jni_name(method);
// Compute argument size
int args_size = 1 // JNIEnv
+ (method->is_static() ? 1 : 0) // class for static methods
+ method->size_of_parameters(); // actual parameters
// 1) Try JNI short style
entry = lookup_style(method, pure_name, "", args_size, true, in_base_library, CHECK_NULL);
if (entry != NULL) return entry;
// Compute long name
char* long_name = long_jni_name(method);
// 2) Try JNI long style
entry = lookup_style(method, pure_name, long_name, args_size, true, in_base_library, CHECK_NULL);
if (entry != NULL) return entry;
// 3) Try JNI short style without os prefix/suffix
entry = lookup_style(method, pure_name, "", args_size, false, in_base_library, CHECK_NULL);
if (entry != NULL) return entry;
// 4) Try JNI long style without os prefix/suffix
entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL);
return entry; // NULL indicates not found
}
// Check all the formats of native implementation name to see if there is one
// for the specified method.
address NativeLookup::lookup_critical_entry(methodHandle method) {
if (!CriticalJNINatives) return NULL;
if (method->is_synchronized() ||
!method->is_static()) {
// Only static non-synchronized methods are allowed
return NULL;
}
ResourceMark rm;
address entry = NULL;
Symbol* signature = method->signature();
for (int end = 0; end < signature->utf8_length(); end++) {
if (signature->byte_at(end) == 'L') {
// Don't allow object types
return NULL;
}
}
// Compute critical name
char* critical_name = critical_jni_name(method);
// Compute argument size
int args_size = 1 // JNIEnv
+ (method->is_static() ? 1 : 0) // class for static methods
+ method->size_of_parameters(); // actual parameters
// 1) Try JNI short style
entry = lookup_critical_style(method, critical_name, "", args_size, true);
if (entry != NULL) return entry;
// Compute long name
char* long_name = long_jni_name(method);
// 2) Try JNI long style
entry = lookup_critical_style(method, critical_name, long_name, args_size, true);
if (entry != NULL) return entry;
// 3) Try JNI short style without os prefix/suffix
entry = lookup_critical_style(method, critical_name, "", args_size, false);
if (entry != NULL) return entry;
// 4) Try JNI long style without os prefix/suffix
entry = lookup_critical_style(method, critical_name, long_name, args_size, false);
return entry; // NULL indicates not found
}
// Check if there are any JVM TI prefixes which have been applied to the native method name.
// If any are found, remove them before attemping the look up of the
// native implementation again.
// See SetNativeMethodPrefix in the JVM TI Spec for more details.
address NativeLookup::lookup_entry_prefixed(methodHandle method, bool& in_base_library, TRAPS) {
#if INCLUDE_JVMTI
ResourceMark rm(THREAD);
int prefix_count;
char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
char* in_name = method->name()->as_C_string();
char* wrapper_name = in_name;
// last applied prefix will be first -- go backwards
for (int i = prefix_count-1; i >= 0; i--) {
char* prefix = prefixes[i];
size_t prefix_len = strlen(prefix);
if (strncmp(prefix, wrapper_name, prefix_len) == 0) {
// has this prefix remove it
wrapper_name += prefix_len;
}
}
if (wrapper_name != in_name) {
// we have a name for a wrapping method
int wrapper_name_len = (int)strlen(wrapper_name);
TempNewSymbol wrapper_symbol = SymbolTable::probe(wrapper_name, wrapper_name_len);
if (wrapper_symbol != NULL) {
KlassHandle kh(method->method_holder());
Method* wrapper_method = kh()->lookup_method(wrapper_symbol,
method->signature());
if (wrapper_method != NULL && !wrapper_method->is_native()) {
// we found a wrapper method, use its native entry
method->set_is_prefixed_native();
return lookup_entry(wrapper_method, in_base_library, THREAD);
}
}
}
#endif // INCLUDE_JVMTI
return NULL;
}
address NativeLookup::lookup_base(methodHandle method, bool& in_base_library, TRAPS) {
address entry = NULL;
ResourceMark rm(THREAD);
entry = lookup_entry(method, in_base_library, THREAD);
if (entry != NULL) return entry;
// standard native method resolution has failed. Check if there are any
// JVM TI prefixes which have been applied to the native method name.
entry = lookup_entry_prefixed(method, in_base_library, THREAD);
if (entry != NULL) return entry;
// Native function not found, throw UnsatisfiedLinkError
THROW_MSG_0(vmSymbols::java_lang_UnsatisfiedLinkError(),
method->name_and_sig_as_C_string());
}
address NativeLookup::lookup(methodHandle method, bool& in_base_library, TRAPS) {
if (!method->has_native_function()) {
address entry = lookup_base(method, in_base_library, CHECK_NULL);
method->set_native_function(entry,
Method::native_bind_event_is_interesting);
// -verbose:jni printing
if (PrintJNIResolving) {
ResourceMark rm(THREAD);
tty->print_cr("[Dynamic-linking native method %s.%s ... JNI]",
method->method_holder()->external_name(),
method->name()->as_C_string());
}
}
return method->native_function();
}
address NativeLookup::base_library_lookup(const char* class_name, const char* method_name, const char* signature) {
EXCEPTION_MARK;
bool in_base_library = true; // SharedRuntime inits some math methods.
TempNewSymbol c_name = SymbolTable::new_symbol(class_name, CATCH);
TempNewSymbol m_name = SymbolTable::new_symbol(method_name, CATCH);
TempNewSymbol s_name = SymbolTable::new_symbol(signature, CATCH);
// Find the class
Klass* k = SystemDictionary::resolve_or_fail(c_name, true, CATCH);
instanceKlassHandle klass (THREAD, k);
// Find method and invoke standard lookup
methodHandle method (THREAD,
klass->uncached_lookup_method(m_name, s_name));
address result = lookup(method, in_base_library, CATCH);
assert(in_base_library, "must be in basic library");
guarantee(result != NULL, "must be non NULL");
return result;
}