1 /*
   2  * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvmtifiles/jvmtiEnv.hpp"
  27 #include "logging/log.hpp"
  28 #include "prims/jvmtiExport.hpp"
  29 #include "prims/jvmtiManageCapabilities.hpp"
  30 
  31 static const jint CAPA_SIZE = (JVMTI_INTERNAL_CAPABILITY_COUNT + 7) / 8;
  32 
  33   // capabilities which are always potentially available
  34 jvmtiCapabilities JvmtiManageCapabilities::always_capabilities;
  35 
  36   // capabilities which are potentially available during OnLoad
  37 jvmtiCapabilities JvmtiManageCapabilities::onload_capabilities;
  38 
  39   // capabilities which are always potentially available
  40   // but to only one environment
  41 jvmtiCapabilities JvmtiManageCapabilities::always_solo_capabilities;
  42 
  43   // capabilities which are potentially available during OnLoad
  44   // but to only one environment
  45 jvmtiCapabilities JvmtiManageCapabilities::onload_solo_capabilities;
  46 
  47   // remaining capabilities which are always potentially available
  48   // but to only one environment
  49 jvmtiCapabilities JvmtiManageCapabilities::always_solo_remaining_capabilities;
  50 
  51   // remaining capabilities which are potentially available during OnLoad
  52   // but to only one environment
  53 jvmtiCapabilities JvmtiManageCapabilities::onload_solo_remaining_capabilities;
  54 
  55   // all capabilities ever acquired
  56 jvmtiCapabilities JvmtiManageCapabilities::acquired_capabilities;
  57 
  58 void JvmtiManageCapabilities::initialize() {
  59   always_capabilities = init_always_capabilities();
  60   onload_capabilities = init_onload_capabilities();
  61   always_solo_capabilities = init_always_solo_capabilities();
  62   onload_solo_capabilities = init_onload_solo_capabilities();
  63   always_solo_remaining_capabilities = init_always_solo_capabilities();
  64   onload_solo_remaining_capabilities = init_onload_solo_capabilities();
  65   memset(&acquired_capabilities, 0, sizeof(acquired_capabilities));
  66 }
  67 
  68 
  69 // corresponding init functions
  70 jvmtiCapabilities JvmtiManageCapabilities::init_always_capabilities() {
  71   jvmtiCapabilities jc;
  72 
  73   memset(&jc, 0, sizeof(jc));
  74   jc.can_get_bytecodes = 1;
  75   jc.can_signal_thread = 1;
  76   jc.can_get_source_file_name = 1;
  77   jc.can_get_line_numbers = 1;
  78   jc.can_get_synthetic_attribute = 1;
  79   jc.can_get_monitor_info = 1;
  80   jc.can_get_constant_pool = 1;
  81   jc.can_generate_all_class_hook_events = 1;
  82   jc.can_generate_monitor_events = 1;
  83   jc.can_generate_garbage_collection_events = 1;
  84   jc.can_generate_compiled_method_load_events = 1;
  85   jc.can_generate_native_method_bind_events = 1;
  86   jc.can_generate_vm_object_alloc_events = 1;
  87   if (os::is_thread_cpu_time_supported()) {
  88     jc.can_get_current_thread_cpu_time = 1;
  89     jc.can_get_thread_cpu_time = 1;
  90   }
  91   jc.can_redefine_classes = 1;
  92   jc.can_redefine_any_class = 1;
  93   jc.can_retransform_classes = 1;
  94   jc.can_retransform_any_class = 1;
  95   jc.can_set_native_method_prefix = 1;
  96   jc.can_tag_objects = 1;
  97   jc.can_generate_object_free_events = 1;
  98   jc.can_generate_resource_exhaustion_heap_events = 1;
  99   jc.can_generate_resource_exhaustion_threads_events = 1;
 100   return jc;
 101 }
 102 
 103 jvmtiCapabilities JvmtiManageCapabilities::init_onload_capabilities() {
 104   jvmtiCapabilities jc;
 105 
 106   memset(&jc, 0, sizeof(jc));
 107 #ifndef ZERO
 108   jc.can_pop_frame = 1;
 109   jc.can_force_early_return = 1;
 110   // Workaround for 8195635:
 111   // disable pop_frame and force_early_return capabilities with Graal
 112 #if INCLUDE_JVMCI
 113   if (UseJVMCICompiler) {
 114     jc.can_pop_frame = 0;
 115     jc.can_force_early_return = 0;
 116   }
 117 #endif // INCLUDE_JVMCI
 118 #endif // !ZERO
 119   jc.can_get_source_debug_extension = 1;
 120   jc.can_access_local_variables = 1;
 121   jc.can_maintain_original_method_order = 1;
 122   jc.can_generate_single_step_events = 1;
 123   jc.can_generate_exception_events = 1;
 124   jc.can_generate_frame_pop_events = 1;
 125   jc.can_generate_method_entry_events = 1;
 126   jc.can_generate_method_exit_events = 1;
 127   jc.can_get_owned_monitor_info = 1;
 128   jc.can_get_owned_monitor_stack_depth_info = 1;
 129   jc.can_get_current_contended_monitor = 1;
 130   jc.can_generate_early_vmstart = 1;
 131   jc.can_generate_early_class_hook_events = 1;
 132   jc.can_support_fibers = 1;
 133   jc.can_support_continuations = 1;
 134   return jc;
 135 }
 136 
 137 
 138 jvmtiCapabilities JvmtiManageCapabilities::init_always_solo_capabilities() {
 139   jvmtiCapabilities jc;
 140 
 141   memset(&jc, 0, sizeof(jc));
 142   jc.can_suspend = 1;
 143   jc.can_generate_sampled_object_alloc_events = 1;
 144   return jc;
 145 }
 146 
 147 
 148 jvmtiCapabilities JvmtiManageCapabilities::init_onload_solo_capabilities() {
 149   jvmtiCapabilities jc;
 150 
 151   memset(&jc, 0, sizeof(jc));
 152   jc.can_generate_field_modification_events = 1;
 153   jc.can_generate_field_access_events = 1;
 154   jc.can_generate_breakpoint_events = 1;
 155   return jc;
 156 }
 157 
 158 
 159 jvmtiCapabilities *JvmtiManageCapabilities::either(const jvmtiCapabilities *a, const jvmtiCapabilities *b,
 160                                                    jvmtiCapabilities *result) {
 161   char *ap = (char *)a;
 162   char *bp = (char *)b;
 163   char *resultp = (char *)result;
 164 
 165   for (int i = 0; i < CAPA_SIZE; ++i) {
 166     *resultp++ = *ap++ | *bp++;
 167   }
 168 
 169   return result;
 170 }
 171 
 172 
 173 jvmtiCapabilities *JvmtiManageCapabilities::both(const jvmtiCapabilities *a, const jvmtiCapabilities *b,
 174                                                     jvmtiCapabilities *result) {
 175   char *ap = (char *)a;
 176   char *bp = (char *)b;
 177   char *resultp = (char *)result;
 178 
 179   for (int i = 0; i < CAPA_SIZE; ++i) {
 180     *resultp++ = *ap++ & *bp++;
 181   }
 182 
 183   return result;
 184 }
 185 
 186 
 187 jvmtiCapabilities *JvmtiManageCapabilities::exclude(const jvmtiCapabilities *a, const jvmtiCapabilities *b,
 188                                                     jvmtiCapabilities *result) {
 189   char *ap = (char *)a;
 190   char *bp = (char *)b;
 191   char *resultp = (char *)result;
 192 
 193   for (int i = 0; i < CAPA_SIZE; ++i) {
 194     *resultp++ = *ap++ & ~*bp++;
 195   }
 196 
 197   return result;
 198 }
 199 
 200 
 201 bool JvmtiManageCapabilities::has_some(const jvmtiCapabilities *a) {
 202   char *ap = (char *)a;
 203 
 204   for (int i = 0; i < CAPA_SIZE; ++i) {
 205     if (*ap++ != 0) {
 206       return true;
 207     }
 208   }
 209 
 210   return false;
 211 }
 212 
 213 
 214 void JvmtiManageCapabilities::copy_capabilities(const jvmtiCapabilities *from, jvmtiCapabilities *to) {
 215   char *ap = (char *)from;
 216   char *resultp = (char *)to;
 217 
 218   for (int i = 0; i < CAPA_SIZE; ++i) {
 219     *resultp++ = *ap++;
 220   }
 221 }
 222 
 223 
 224 void JvmtiManageCapabilities::get_potential_capabilities(const jvmtiCapabilities *current,
 225                                                          const jvmtiCapabilities *prohibited,
 226                                                          jvmtiCapabilities *result) {
 227   // exclude prohibited capabilities, must be before adding current
 228   exclude(&always_capabilities, prohibited, result);
 229 
 230   // must include current since it may possess solo capabilities and now prohibited
 231   either(result, current, result);
 232 
 233   // add other remaining
 234   either(result, &always_solo_remaining_capabilities, result);
 235 
 236   // if this is during OnLoad more capabilities are available
 237   if (JvmtiEnv::get_phase() == JVMTI_PHASE_ONLOAD) {
 238     either(result, &onload_capabilities, result);
 239     either(result, &onload_solo_remaining_capabilities, result);
 240   }
 241 }
 242 
 243 jvmtiError JvmtiManageCapabilities::add_capabilities(const jvmtiCapabilities *current,
 244                                                      const jvmtiCapabilities *prohibited,
 245                                                      const jvmtiCapabilities *desired,
 246                                                      jvmtiCapabilities *result) {
 247   // check that the capabilities being added are potential capabilities
 248   jvmtiCapabilities temp;
 249   get_potential_capabilities(current, prohibited, &temp);
 250   if (has_some(exclude(desired, &temp, &temp))) {
 251     return JVMTI_ERROR_NOT_AVAILABLE;
 252   }
 253 
 254   // add to the set of ever acquired capabilities
 255   either(&acquired_capabilities, desired, &acquired_capabilities);
 256 
 257   // onload capabilities that got added are now permanent - so, also remove from onload
 258   both(&onload_capabilities, desired, &temp);
 259   either(&always_capabilities, &temp, &always_capabilities);
 260   exclude(&onload_capabilities, &temp, &onload_capabilities);
 261 
 262   // same for solo capabilities (transferred capabilities in the remaining sets handled as part of standard grab - below)
 263   both(&onload_solo_capabilities, desired, &temp);
 264   either(&always_solo_capabilities, &temp, &always_solo_capabilities);
 265   exclude(&onload_solo_capabilities, &temp, &onload_solo_capabilities);
 266 
 267   // remove solo capabilities that are now taken
 268   exclude(&always_solo_remaining_capabilities, desired, &always_solo_remaining_capabilities);
 269   exclude(&onload_solo_remaining_capabilities, desired, &onload_solo_remaining_capabilities);
 270 
 271   // return the result
 272   either(current, desired, result);
 273 
 274   // special case for Fiber events
 275   if (result->can_support_fibers == 1) {
 276     java_lang_Fiber::set_notify_jvmti_events(true);
 277   }
 278 
 279   update();
 280 
 281   return JVMTI_ERROR_NONE;
 282 }
 283 
 284 
 285 void JvmtiManageCapabilities::relinquish_capabilities(const jvmtiCapabilities *current,
 286                                                       const jvmtiCapabilities *unwanted,
 287                                                       jvmtiCapabilities *result) {
 288   jvmtiCapabilities to_trash;
 289   jvmtiCapabilities temp;
 290 
 291   // can't give up what you don't have
 292   both(current, unwanted, &to_trash);
 293 
 294   // restore solo capabilities but only those that belong
 295   either(&always_solo_remaining_capabilities, both(&always_solo_capabilities, &to_trash, &temp),
 296          &always_solo_remaining_capabilities);
 297   either(&onload_solo_remaining_capabilities, both(&onload_solo_capabilities, &to_trash, &temp),
 298          &onload_solo_remaining_capabilities);
 299 
 300   update();
 301 
 302   // return the result
 303   exclude(current, unwanted, result);
 304 }
 305 
 306 
 307 void JvmtiManageCapabilities::update() {
 308   jvmtiCapabilities avail;
 309 
 310   // all capabilities
 311   either(&always_capabilities, &always_solo_capabilities, &avail);
 312 
 313   bool interp_events =
 314     avail.can_generate_field_access_events ||
 315     avail.can_generate_field_modification_events ||
 316     avail.can_generate_single_step_events ||
 317     avail.can_generate_frame_pop_events ||
 318     avail.can_generate_method_entry_events ||
 319     avail.can_generate_method_exit_events;
 320 #ifdef ZERO
 321   bool enter_all_methods =
 322     interp_events ||
 323     avail.can_generate_breakpoint_events;
 324   if (enter_all_methods) {
 325     // Disable these when tracking the bytecodes
 326     UseFastEmptyMethods = false;
 327     UseFastAccessorMethods = false;
 328   }
 329 #endif // ZERO
 330 
 331   if (avail.can_generate_breakpoint_events
 332        || avail.can_generate_field_access_events
 333        || avail.can_generate_field_modification_events)
 334   {
 335     RewriteFrequentPairs = false;
 336   }
 337 
 338   // If can_redefine_classes is enabled in the onload phase then we know that the
 339   // dependency information recorded by the compiler is complete.
 340   if ((avail.can_redefine_classes || avail.can_retransform_classes) &&
 341       JvmtiEnv::get_phase() == JVMTI_PHASE_ONLOAD) {
 342     JvmtiExport::set_all_dependencies_are_recorded(true);
 343   }
 344 
 345   JvmtiExport::set_can_get_source_debug_extension(avail.can_get_source_debug_extension);
 346   JvmtiExport::set_can_maintain_original_method_order(avail.can_maintain_original_method_order);
 347   JvmtiExport::set_can_post_interpreter_events(interp_events);
 348   JvmtiExport::set_can_hotswap_or_post_breakpoint(
 349     avail.can_generate_breakpoint_events ||
 350     avail.can_redefine_classes ||
 351     avail.can_retransform_classes);
 352   JvmtiExport::set_can_modify_any_class(
 353     avail.can_generate_breakpoint_events ||
 354     avail.can_generate_all_class_hook_events);
 355   JvmtiExport::set_can_walk_any_space(
 356     avail.can_tag_objects);   // disable sharing in onload phase
 357   // This controls whether the compilers keep extra locals live to
 358   // improve the debugging experience so only set them if the selected
 359   // capabilities look like a debugger.
 360   JvmtiExport::set_can_access_local_variables(
 361     avail.can_access_local_variables ||
 362     avail.can_generate_breakpoint_events ||
 363     avail.can_generate_frame_pop_events);
 364   JvmtiExport::set_can_post_on_exceptions(
 365     avail.can_generate_exception_events ||
 366     avail.can_generate_frame_pop_events ||
 367     avail.can_generate_method_exit_events);
 368   JvmtiExport::set_can_post_breakpoint(avail.can_generate_breakpoint_events);
 369   JvmtiExport::set_can_post_field_access(avail.can_generate_field_access_events);
 370   JvmtiExport::set_can_post_field_modification(avail.can_generate_field_modification_events);
 371   JvmtiExport::set_can_post_method_entry(avail.can_generate_method_entry_events);
 372   JvmtiExport::set_can_post_method_exit(avail.can_generate_method_exit_events ||
 373                                         avail.can_generate_frame_pop_events);
 374   JvmtiExport::set_can_post_frame_pop(avail.can_generate_frame_pop_events);
 375   JvmtiExport::set_can_pop_frame(avail.can_pop_frame);
 376   JvmtiExport::set_can_force_early_return(avail.can_force_early_return);
 377   JvmtiExport::set_can_support_fibers(avail.can_support_fibers);
 378   JvmtiExport::set_can_support_continuations(avail.can_support_continuations);
 379   JvmtiExport::set_should_clean_up_heap_objects(avail.can_generate_breakpoint_events);
 380 }
 381 
 382 #ifndef PRODUCT
 383 
 384 void JvmtiManageCapabilities:: print(const jvmtiCapabilities* cap) {
 385   log_trace(jvmti)("----- capabilities -----");
 386   if (cap->can_tag_objects)
 387     log_trace(jvmti)("can_tag_objects");
 388   if (cap->can_generate_field_modification_events)
 389     log_trace(jvmti)("can_generate_field_modification_events");
 390   if (cap->can_generate_field_access_events)
 391     log_trace(jvmti)("can_generate_field_access_events");
 392   if (cap->can_get_bytecodes)
 393     log_trace(jvmti)("can_get_bytecodes");
 394   if (cap->can_get_synthetic_attribute)
 395     log_trace(jvmti)("can_get_synthetic_attribute");
 396   if (cap->can_get_owned_monitor_info)
 397     log_trace(jvmti)("can_get_owned_monitor_info");
 398   if (cap->can_get_current_contended_monitor)
 399     log_trace(jvmti)("can_get_current_contended_monitor");
 400   if (cap->can_get_monitor_info)
 401     log_trace(jvmti)("can_get_monitor_info");
 402   if (cap->can_get_constant_pool)
 403     log_trace(jvmti)("can_get_constant_pool");
 404   if (cap->can_pop_frame)
 405     log_trace(jvmti)("can_pop_frame");
 406   if (cap->can_force_early_return)
 407     log_trace(jvmti)("can_force_early_return");
 408   if (cap->can_redefine_classes)
 409     log_trace(jvmti)("can_redefine_classes");
 410   if (cap->can_retransform_classes)
 411     log_trace(jvmti)("can_retransform_classes");
 412   if (cap->can_signal_thread)
 413     log_trace(jvmti)("can_signal_thread");
 414   if (cap->can_get_source_file_name)
 415     log_trace(jvmti)("can_get_source_file_name");
 416   if (cap->can_get_line_numbers)
 417     log_trace(jvmti)("can_get_line_numbers");
 418   if (cap->can_get_source_debug_extension)
 419     log_trace(jvmti)("can_get_source_debug_extension");
 420   if (cap->can_access_local_variables)
 421     log_trace(jvmti)("can_access_local_variables");
 422   if (cap->can_maintain_original_method_order)
 423     log_trace(jvmti)("can_maintain_original_method_order");
 424   if (cap->can_generate_single_step_events)
 425     log_trace(jvmti)("can_generate_single_step_events");
 426   if (cap->can_generate_exception_events)
 427     log_trace(jvmti)("can_generate_exception_events");
 428   if (cap->can_generate_frame_pop_events)
 429     log_trace(jvmti)("can_generate_frame_pop_events");
 430   if (cap->can_generate_breakpoint_events)
 431     log_trace(jvmti)("can_generate_breakpoint_events");
 432   if (cap->can_generate_sampled_object_alloc_events)
 433     log_trace(jvmti)("can_generate_sampled_object_alloc_events");
 434   if (cap->can_suspend)
 435     log_trace(jvmti)("can_suspend");
 436   if (cap->can_redefine_any_class )
 437     log_trace(jvmti)("can_redefine_any_class");
 438   if (cap->can_retransform_any_class )
 439     log_trace(jvmti)("can_retransform_any_class");
 440   if (cap->can_get_current_thread_cpu_time)
 441     log_trace(jvmti)("can_get_current_thread_cpu_time");
 442   if (cap->can_get_thread_cpu_time)
 443     log_trace(jvmti)("can_get_thread_cpu_time");
 444   if (cap->can_generate_method_entry_events)
 445     log_trace(jvmti)("can_generate_method_entry_events");
 446   if (cap->can_generate_method_exit_events)
 447     log_trace(jvmti)("can_generate_method_exit_events");
 448   if (cap->can_generate_all_class_hook_events)
 449     log_trace(jvmti)("can_generate_all_class_hook_events");
 450   if (cap->can_generate_compiled_method_load_events)
 451     log_trace(jvmti)("can_generate_compiled_method_load_events");
 452   if (cap->can_generate_monitor_events)
 453     log_trace(jvmti)("can_generate_monitor_events");
 454   if (cap->can_generate_vm_object_alloc_events)
 455     log_trace(jvmti)("can_generate_vm_object_alloc_events");
 456   if (cap->can_generate_native_method_bind_events)
 457     log_trace(jvmti)("can_generate_native_method_bind_events");
 458   if (cap->can_generate_garbage_collection_events)
 459     log_trace(jvmti)("can_generate_garbage_collection_events");
 460   if (cap->can_generate_object_free_events)
 461     log_trace(jvmti)("can_generate_object_free_events");
 462   if (cap->can_generate_resource_exhaustion_heap_events)
 463     log_trace(jvmti)("can_generate_resource_exhaustion_heap_events");
 464   if (cap->can_generate_resource_exhaustion_threads_events)
 465     log_trace(jvmti)("can_generate_resource_exhaustion_threads_events");
 466   if (cap->can_generate_early_vmstart)
 467     log_trace(jvmti)("can_generate_early_vmstart");
 468   if (cap->can_generate_early_class_hook_events)
 469     log_trace(jvmti)("can_generate_early_class_hook_events");
 470   if (cap->can_support_fibers)
 471     log_trace(jvmti)("can_support_fibers");
 472   if (cap->can_support_continuations)
 473     log_trace(jvmti)("can_support_continuations");
 474 }
 475 
 476 #endif