8315706: com/sun/tools/attach/warnings/DynamicLoadWarningTest.java real fix for failure on AIX

Reviewed-by: dholmes, mbaesken

src/hotspot/os/aix/os_aix.cpp

@@ -3043,3 +3043,32 @@ void os::print_memory_mappings(char* addr, size_t bytes, outputStream* st) {}
 void os::jfr_report_memory_info() {}
 
 #endif // INCLUDE_JFR
+
+// Simulate the library search algorithm of dlopen() (in os::dll_load)
+int os::Aix::stat64x_via_LIBPATH(const char* path, struct stat64x* stat) {
+  if (path[0] == '/' ||
+      (path[0] == '.' && (path[1] == '/' ||
+                          (path[1] == '.' && path[2] == '/')))) {
+    return stat64x(path, stat);
+  }
+
+  const char* env = getenv("LIBPATH");
+  if (env == nullptr || *env == 0)
+    return -1;
+
+  int ret = -1;
+  size_t libpathlen = strlen(env);
+  char* libpath = NEW_C_HEAP_ARRAY(char, libpathlen + 1, mtServiceability);
+  char* combined = NEW_C_HEAP_ARRAY(char, libpathlen + strlen(path) + 1, mtServiceability);
+  char *saveptr, *token;
+  strcpy(libpath, env);
+  for (token = strtok_r(libpath, ":", &saveptr); token != nullptr; token = strtok_r(nullptr, ":", &saveptr)) {
+    sprintf(combined, "%s/%s", token, path);
+    if (0 == (ret = stat64x(combined, stat)))
+      break;
+  }
+
+  FREE_C_HEAP_ARRAY(char*, combined);
+  FREE_C_HEAP_ARRAY(char*, libpath);
+  return ret;
+}

src/hotspot/os/aix/os_aix.hpp

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2013, 2016 SAP SE. All rights reserved.
+ * Copyright (c) 2013, 2023 SAP SE. 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
@@ -174,6 +174,9 @@ class os::Aix {
 
   static bool platform_print_native_stack(outputStream* st, const void* context, char *buf, int buf_size, address& lastpc);
   static void* resolve_function_descriptor(void* p);
+
+  // Simulate the library search algorithm of dlopen() (in os::dll_load)
+  static int stat64x_via_LIBPATH(const char* path, struct stat64x* stat);
 };
 
 #endif // OS_AIX_OS_AIX_HPP

src/hotspot/share/prims/jvmtiAgent.cpp

@@ -74,6 +74,10 @@ JvmtiAgent::JvmtiAgent(const char* name, const char* options, bool is_absolute_p
   _options(copy_string(options)),
   _os_lib(nullptr),
   _os_lib_path(nullptr),
+#ifdef AIX
+  _inode(0),
+  _device(0),
+#endif
   _jplis(nullptr),
   _loaded(false),
   _absolute_path(is_absolute_path),
@@ -118,6 +122,24 @@ const char* JvmtiAgent::os_lib_path() const {
   return _os_lib_path;
 }
 
+#ifdef AIX
+void JvmtiAgent::set_inode(ino64_t inode) {
+  _inode = inode;
+}
+
+void JvmtiAgent::set_device(dev64_t device) {
+  _device = device;
+}
+
+ino64_t JvmtiAgent::inode() const {
+  return _inode;
+}
+
+dev64_t JvmtiAgent::device() const {
+  return _device;
+}
+#endif
+
 bool JvmtiAgent::is_loaded() const {
   return _loaded;
 }
@@ -272,6 +294,20 @@ static bool load_agent_from_executable(JvmtiAgent* agent, const char* on_load_sy
   return os::find_builtin_agent(agent, &on_load_symbols[0], num_symbol_entries);
 }
 
+#ifdef AIX
+// save the inode and device of the library's file as a signature. This signature can be used
+// in the same way as the library handle as a signature on other platforms.
+static void save_library_signature(JvmtiAgent* agent, const char* name) {
+  struct stat64x libstat;
+  if (0 == os::Aix::stat64x_via_LIBPATH(name, &libstat)) {
+    agent->set_inode(libstat.st_ino);
+    agent->set_device(libstat.st_dev);
+  } else {
+    assert(false, "stat64x failed");
+  }
+}
+#endif
+
 // Load the library from the absolute path of the agent, if available.
 static void* load_agent_from_absolute_path(JvmtiAgent* agent, bool vm_exit_on_error) {
   DEBUG_ONLY(assert_preload(agent);)
@@ -281,6 +317,7 @@ static void* load_agent_from_absolute_path(JvmtiAgent* agent, bool vm_exit_on_er
   if (library == nullptr && vm_exit_on_error) {
     vm_exit(agent, " in absolute path, with error: ", nullptr);
   }
+  AIX_ONLY(if (library != nullptr) save_library_signature(agent, agent->name());)
   return library;
 }
 
@@ -293,11 +330,13 @@ static void* load_agent_from_relative_path(JvmtiAgent* agent, bool vm_exit_on_er
   // Try to load the agent from the standard dll directory
   if (os::dll_locate_lib(&buffer[0], sizeof buffer, Arguments::get_dll_dir(), name)) {
     library = os::dll_load(&buffer[0], &ebuf[0], sizeof ebuf);
+    AIX_ONLY(if (library != nullptr) save_library_signature(agent, &buffer[0]);)
   }
   if (library == nullptr && os::dll_build_name(&buffer[0], sizeof buffer, name)) {
     // Try the library path directory.
     library = os::dll_load(&buffer[0], &ebuf[0], sizeof ebuf);
     if (library != nullptr) {
+      AIX_ONLY(save_library_signature(agent, &buffer[0]);)
       return library;
     }
     if (vm_exit_on_error) {
@@ -515,7 +554,11 @@ static bool invoke_Agent_OnAttach(JvmtiAgent* agent, outputStream* st) {
     agent->set_os_lib_path(&buffer[0]);
     agent->set_os_lib(library);
     agent->set_loaded();
+  #ifdef AIX
+    previously_loaded = JvmtiAgentList::is_dynamic_lib_loaded(agent->device(), agent->inode());
+  #else
     previously_loaded = JvmtiAgentList::is_dynamic_lib_loaded(library);
+  #endif
   }
 
   // Print warning if agent was not previously loaded and EnableDynamicAgentLoading not enabled on the command line.

src/hotspot/share/prims/jvmtiAgent.hpp

@@ -43,6 +43,10 @@ class JvmtiAgent : public CHeapObj<mtServiceability> {
   const char* _options;
   void* _os_lib;
   const char* _os_lib_path;
+#ifdef AIX
+  ino64_t _inode;
+  dev64_t _device;
+#endif
   const void* _jplis;
   bool _loaded;
   bool _absolute_path;
@@ -80,6 +84,12 @@ class JvmtiAgent : public CHeapObj<mtServiceability> {
   void initialization_end();
   const Ticks& initialization_time() const;
   const Tickspan& initialization_duration() const;
+#ifdef AIX
+  void set_inode(ino64_t inode);
+  void set_device(dev64_t device);
+  unsigned long inode() const;
+  unsigned long device() const;
+#endif
 
   bool load(outputStream* st = nullptr);
   void unload();

src/hotspot/share/prims/jvmtiAgentList.cpp

@@ -243,6 +243,19 @@ bool JvmtiAgentList::is_dynamic_lib_loaded(void* os_lib) {
   }
   return false;
 }
+#ifdef AIX
+bool JvmtiAgentList::is_dynamic_lib_loaded(dev64_t device, ino64_t inode) {
+  JvmtiAgentList::Iterator it = JvmtiAgentList::agents();
+  while (it.has_next()) {
+    JvmtiAgent* const agent = it.next();
+    if (!agent->is_static_lib() && device != 0 && inode != 0 &&
+        agent->device() == device && agent->inode() == inode) {
+      return true;
+    }
+  }
+  return false;
+}
+#endif
 
 static bool match(JvmtiEnv* env, const JvmtiAgent* agent, const void* os_module_address) {
   assert(env != nullptr, "invariant");

src/hotspot/share/prims/jvmtiAgentList.hpp

@@ -78,6 +78,9 @@ class JvmtiAgentList : AllStatic {
 
   static bool is_static_lib_loaded(const char* name);
   static bool is_dynamic_lib_loaded(void* os_lib);
+#ifdef AIX
+  static bool is_dynamic_lib_loaded(dev64_t device, ino64_t inode);
+#endif
 
   static JvmtiAgent* lookup(JvmtiEnv* env, void* f_ptr);
 

test/jdk/com/sun/tools/attach/warnings/DynamicLoadWarningTest.java

@@ -123,18 +123,15 @@ class DynamicLoadWarningTest {
                 .whenRunning(loadJvmtiAgent1)
                 .stderrShouldNotContain(JVMTI_AGENT_WARNING);
 
-        // test behavior on platforms that can detect if an agent library was previously loaded
-        if (!Platform.isAix()) {
-            // start loadJvmtiAgent1 via the command line, then dynamically load loadJvmtiAgent1
-            test().withOpts("-agentpath:" + jvmtiAgentPath1)
-                    .whenRunning(loadJvmtiAgent1)
-                    .stderrShouldNotContain(JVMTI_AGENT_WARNING);
+        // start loadJvmtiAgent1 via the command line, then dynamically load loadJvmtiAgent1
+        test().withOpts("-agentpath:" + jvmtiAgentPath1)
+                .whenRunning(loadJvmtiAgent1)
+                .stderrShouldNotContain(JVMTI_AGENT_WARNING);
 
-            // dynamically load loadJvmtiAgent1 twice, should be one warning
-            test().whenRunning(loadJvmtiAgent1)
-                    .whenRunning(loadJvmtiAgent1)
-                    .stderrShouldContain(JVMTI_AGENT_WARNING, 1);
-        }
+        // dynamically load loadJvmtiAgent1 twice, should be one warning
+        test().whenRunning(loadJvmtiAgent1)
+                .whenRunning(loadJvmtiAgent1)
+                .stderrShouldContain(JVMTI_AGENT_WARNING, 1);
     }
 
     /**