1 /*
   2  * Copyright (c) 2003, 2016, 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   if (JvmtiEnv::get_phase() != JVMTI_PHASE_ONLOAD) {
  61     recompute_always_capabilities();
  62   }
  63   onload_capabilities = init_onload_capabilities();
  64   always_solo_capabilities = init_always_solo_capabilities();
  65   onload_solo_capabilities = init_onload_solo_capabilities();
  66   always_solo_remaining_capabilities = init_always_solo_capabilities();
  67   onload_solo_remaining_capabilities = init_onload_solo_capabilities();
  68   memset(&acquired_capabilities, 0, sizeof(acquired_capabilities));
  69 }
  70 
  71 // if the capability sets are initialized in the onload phase then
  72 // it happens before class data sharing (CDS) is initialized. If it
  73 // turns out that CDS gets disabled then we must adjust the always
  74 // capabilities. To ensure a consistent view of the capabililties
  75 // anything we add here should already be in the onload set.
  76 void JvmtiManageCapabilities::recompute_always_capabilities() {
  77   if (!UseSharedSpaces) {
  78     jvmtiCapabilities jc = always_capabilities;
  79     jc.can_generate_all_class_hook_events = 1;
  80     always_capabilities = jc;
  81   }
  82 }
  83 
  84 
  85 // corresponding init functions
  86 jvmtiCapabilities JvmtiManageCapabilities::init_always_capabilities() {
  87   jvmtiCapabilities jc;
  88 
  89   memset(&jc, 0, sizeof(jc));
  90   jc.can_get_bytecodes = 1;
  91   jc.can_signal_thread = 1;
  92   jc.can_get_source_file_name = 1;
  93   jc.can_get_line_numbers = 1;
  94   jc.can_get_synthetic_attribute = 1;
  95   jc.can_get_monitor_info = 1;
  96   jc.can_get_constant_pool = 1;
  97   jc.can_generate_monitor_events = 1;
  98   jc.can_generate_garbage_collection_events = 1;
  99   jc.can_generate_compiled_method_load_events = 1;
 100   jc.can_generate_native_method_bind_events = 1;
 101   jc.can_generate_vm_object_alloc_events = 1;
 102   if (os::is_thread_cpu_time_supported()) {
 103     jc.can_get_current_thread_cpu_time = 1;
 104     jc.can_get_thread_cpu_time = 1;
 105   }
 106   jc.can_redefine_classes = 1;
 107   jc.can_redefine_any_class = 1;
 108   jc.can_retransform_classes = 1;
 109   jc.can_retransform_any_class = 1;
 110   jc.can_set_native_method_prefix = 1;
 111   jc.can_tag_objects = 1;
 112   jc.can_generate_object_free_events = 1;
 113   jc.can_generate_resource_exhaustion_heap_events = 1;
 114   jc.can_generate_resource_exhaustion_threads_events = 1;
 115   return jc;
 116 }
 117 
 118 jvmtiCapabilities JvmtiManageCapabilities::init_onload_capabilities() {
 119   jvmtiCapabilities jc;
 120 
 121   memset(&jc, 0, sizeof(jc));
 122 #ifndef ZERO
 123   jc.can_pop_frame = 1;
 124   jc.can_force_early_return = 1;
 125 #endif // !ZERO
 126   jc.can_get_source_debug_extension = 1;
 127   jc.can_access_local_variables = 1;
 128   jc.can_maintain_original_method_order = 1;
 129   jc.can_generate_all_class_hook_events = 1;
 130   jc.can_generate_single_step_events = 1;
 131   jc.can_generate_exception_events = 1;
 132   jc.can_generate_frame_pop_events = 1;
 133   jc.can_generate_method_entry_events = 1;
 134   jc.can_generate_method_exit_events = 1;
 135   jc.can_get_owned_monitor_info = 1;
 136   jc.can_get_owned_monitor_stack_depth_info = 1;
 137   jc.can_get_current_contended_monitor = 1;
 138   jc.can_generate_early_vmstart = 1;
 139   jc.can_generate_early_class_hook_events = 1;
 140   return jc;
 141 }
 142 
 143 
 144 jvmtiCapabilities JvmtiManageCapabilities::init_always_solo_capabilities() {
 145   jvmtiCapabilities jc;
 146 
 147   memset(&jc, 0, sizeof(jc));
 148   jc.can_suspend = 1;
 149   return jc;
 150 }
 151 
 152 
 153 jvmtiCapabilities JvmtiManageCapabilities::init_onload_solo_capabilities() {
 154   jvmtiCapabilities jc;
 155 
 156   memset(&jc, 0, sizeof(jc));
 157   jc.can_generate_field_modification_events = 1;
 158   jc.can_generate_field_access_events = 1;
 159   jc.can_generate_breakpoint_events = 1;
 160   return jc;
 161 }
 162 
 163 
 164 jvmtiCapabilities *JvmtiManageCapabilities::either(const jvmtiCapabilities *a, const jvmtiCapabilities *b,
 165                                                    jvmtiCapabilities *result) {
 166   char *ap = (char *)a;
 167   char *bp = (char *)b;
 168   char *resultp = (char *)result;
 169 
 170   for (int i = 0; i < CAPA_SIZE; ++i) {
 171     *resultp++ = *ap++ | *bp++;
 172   }
 173 
 174   return result;
 175 }
 176 
 177 
 178 jvmtiCapabilities *JvmtiManageCapabilities::both(const jvmtiCapabilities *a, const jvmtiCapabilities *b,
 179                                                     jvmtiCapabilities *result) {
 180   char *ap = (char *)a;
 181   char *bp = (char *)b;
 182   char *resultp = (char *)result;
 183 
 184   for (int i = 0; i < CAPA_SIZE; ++i) {
 185     *resultp++ = *ap++ & *bp++;
 186   }
 187 
 188   return result;
 189 }
 190 
 191 
 192 jvmtiCapabilities *JvmtiManageCapabilities::exclude(const jvmtiCapabilities *a, const jvmtiCapabilities *b,
 193                                                     jvmtiCapabilities *result) {
 194   char *ap = (char *)a;
 195   char *bp = (char *)b;
 196   char *resultp = (char *)result;
 197 
 198   for (int i = 0; i < CAPA_SIZE; ++i) {
 199     *resultp++ = *ap++ & ~*bp++;
 200   }
 201 
 202   return result;
 203 }
 204 
 205 
 206 bool JvmtiManageCapabilities::has_some(const jvmtiCapabilities *a) {
 207   char *ap = (char *)a;
 208 
 209   for (int i = 0; i < CAPA_SIZE; ++i) {
 210     if (*ap++ != 0) {
 211       return true;
 212     }
 213   }
 214 
 215   return false;
 216 }
 217 
 218 
 219 void JvmtiManageCapabilities::copy_capabilities(const jvmtiCapabilities *from, jvmtiCapabilities *to) {
 220   char *ap = (char *)from;
 221   char *resultp = (char *)to;
 222 
 223   for (int i = 0; i < CAPA_SIZE; ++i) {
 224     *resultp++ = *ap++;
 225   }
 226 }
 227 
 228 
 229 void JvmtiManageCapabilities::get_potential_capabilities(const jvmtiCapabilities *current,
 230                                                          const jvmtiCapabilities *prohibited,
 231                                                          jvmtiCapabilities *result) {
 232   // exclude prohibited capabilities, must be before adding current
 233   exclude(&always_capabilities, prohibited, result);
 234 
 235   // must include current since it may possess solo capabilities and now prohibited
 236   either(result, current, result);
 237 
 238   // add other remaining
 239   either(result, &always_solo_remaining_capabilities, result);
 240 
 241   // if this is during OnLoad more capabilities are available
 242   if (JvmtiEnv::get_phase() == JVMTI_PHASE_ONLOAD) {
 243     either(result, &onload_capabilities, result);
 244     either(result, &onload_solo_remaining_capabilities, result);
 245   }
 246 }
 247 
 248 jvmtiError JvmtiManageCapabilities::add_capabilities(const jvmtiCapabilities *current,
 249                                                      const jvmtiCapabilities *prohibited,
 250                                                      const jvmtiCapabilities *desired,
 251                                                      jvmtiCapabilities *result) {
 252   // check that the capabilities being added are potential capabilities
 253   jvmtiCapabilities temp;
 254   get_potential_capabilities(current, prohibited, &temp);
 255   if (has_some(exclude(desired, &temp, &temp))) {
 256     return JVMTI_ERROR_NOT_AVAILABLE;
 257   }
 258 
 259   // add to the set of ever acquired capabilities
 260   either(&acquired_capabilities, desired, &acquired_capabilities);
 261 
 262   // onload capabilities that got added are now permanent - so, also remove from onload
 263   both(&onload_capabilities, desired, &temp);
 264   either(&always_capabilities, &temp, &always_capabilities);
 265   exclude(&onload_capabilities, &temp, &onload_capabilities);
 266 
 267   // same for solo capabilities (transferred capabilities in the remaining sets handled as part of standard grab - below)
 268   both(&onload_solo_capabilities, desired, &temp);
 269   either(&always_solo_capabilities, &temp, &always_solo_capabilities);
 270   exclude(&onload_solo_capabilities, &temp, &onload_solo_capabilities);
 271 
 272   // remove solo capabilities that are now taken
 273   exclude(&always_solo_remaining_capabilities, desired, &always_solo_remaining_capabilities);
 274   exclude(&onload_solo_remaining_capabilities, desired, &onload_solo_remaining_capabilities);
 275 
 276   // return the result
 277   either(current, desired, result);
 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     RewriteFrequentPairs = false;
 333   }
 334 
 335   // If can_redefine_classes is enabled in the onload phase then we know that the
 336   // dependency information recorded by the compiler is complete.
 337   if ((avail.can_redefine_classes || avail.can_retransform_classes) &&
 338       JvmtiEnv::get_phase() == JVMTI_PHASE_ONLOAD) {
 339     JvmtiExport::set_all_dependencies_are_recorded(true);
 340   }
 341 
 342   JvmtiExport::set_can_get_source_debug_extension(avail.can_get_source_debug_extension);
 343   JvmtiExport::set_can_maintain_original_method_order(avail.can_maintain_original_method_order);
 344   JvmtiExport::set_can_post_interpreter_events(interp_events);
 345   JvmtiExport::set_can_hotswap_or_post_breakpoint(
 346     avail.can_generate_breakpoint_events ||
 347     avail.can_redefine_classes ||
 348     avail.can_retransform_classes);
 349   JvmtiExport::set_can_modify_any_class(
 350     avail.can_generate_breakpoint_events ||
 351     avail.can_generate_all_class_hook_events);
 352   JvmtiExport::set_can_walk_any_space(
 353     avail.can_tag_objects);   // disable sharing in onload phase
 354   // This controls whether the compilers keep extra locals live to
 355   // improve the debugging experience so only set them if the selected
 356   // capabilities look like a debugger.
 357   JvmtiExport::set_can_access_local_variables(
 358     avail.can_access_local_variables ||
 359     avail.can_generate_breakpoint_events ||
 360     avail.can_generate_frame_pop_events);
 361   JvmtiExport::set_can_post_on_exceptions(
 362     avail.can_generate_exception_events ||
 363     avail.can_generate_frame_pop_events ||
 364     avail.can_generate_method_exit_events);
 365   JvmtiExport::set_can_post_breakpoint(avail.can_generate_breakpoint_events);
 366   JvmtiExport::set_can_post_field_access(avail.can_generate_field_access_events);
 367   JvmtiExport::set_can_post_field_modification(avail.can_generate_field_modification_events);
 368   JvmtiExport::set_can_post_method_entry(avail.can_generate_method_entry_events);
 369   JvmtiExport::set_can_post_method_exit(avail.can_generate_method_exit_events ||
 370                                         avail.can_generate_frame_pop_events);
 371   JvmtiExport::set_can_pop_frame(avail.can_pop_frame);
 372   JvmtiExport::set_can_force_early_return(avail.can_force_early_return);
 373   JvmtiExport::set_should_clean_up_heap_objects(avail.can_generate_breakpoint_events);
 374 }
 375 
 376 #ifndef PRODUCT
 377 
 378 void JvmtiManageCapabilities:: print(const jvmtiCapabilities* cap) {
 379   log_trace(jvmti)("----- capabilities -----");
 380   if (cap->can_tag_objects)
 381     log_trace(jvmti)("can_tag_objects");
 382   if (cap->can_generate_field_modification_events)
 383     log_trace(jvmti)("can_generate_field_modification_events");
 384   if (cap->can_generate_field_access_events)
 385     log_trace(jvmti)("can_generate_field_access_events");
 386   if (cap->can_get_bytecodes)
 387     log_trace(jvmti)("can_get_bytecodes");
 388   if (cap->can_get_synthetic_attribute)
 389     log_trace(jvmti)("can_get_synthetic_attribute");
 390   if (cap->can_get_owned_monitor_info)
 391     log_trace(jvmti)("can_get_owned_monitor_info");
 392   if (cap->can_get_current_contended_monitor)
 393     log_trace(jvmti)("can_get_current_contended_monitor");
 394   if (cap->can_get_monitor_info)
 395     log_trace(jvmti)("can_get_monitor_info");
 396   if (cap->can_get_constant_pool)
 397     log_trace(jvmti)("can_get_constant_pool");
 398   if (cap->can_pop_frame)
 399     log_trace(jvmti)("can_pop_frame");
 400   if (cap->can_force_early_return)
 401     log_trace(jvmti)("can_force_early_return");
 402   if (cap->can_redefine_classes)
 403     log_trace(jvmti)("can_redefine_classes");
 404   if (cap->can_retransform_classes)
 405     log_trace(jvmti)("can_retransform_classes");
 406   if (cap->can_signal_thread)
 407     log_trace(jvmti)("can_signal_thread");
 408   if (cap->can_get_source_file_name)
 409     log_trace(jvmti)("can_get_source_file_name");
 410   if (cap->can_get_line_numbers)
 411     log_trace(jvmti)("can_get_line_numbers");
 412   if (cap->can_get_source_debug_extension)
 413     log_trace(jvmti)("can_get_source_debug_extension");
 414   if (cap->can_access_local_variables)
 415     log_trace(jvmti)("can_access_local_variables");
 416   if (cap->can_maintain_original_method_order)
 417     log_trace(jvmti)("can_maintain_original_method_order");
 418   if (cap->can_generate_single_step_events)
 419     log_trace(jvmti)("can_generate_single_step_events");
 420   if (cap->can_generate_exception_events)
 421     log_trace(jvmti)("can_generate_exception_events");
 422   if (cap->can_generate_frame_pop_events)
 423     log_trace(jvmti)("can_generate_frame_pop_events");
 424   if (cap->can_generate_breakpoint_events)
 425     log_trace(jvmti)("can_generate_breakpoint_events");
 426   if (cap->can_suspend)
 427     log_trace(jvmti)("can_suspend");
 428   if (cap->can_redefine_any_class )
 429     log_trace(jvmti)("can_redefine_any_class");
 430   if (cap->can_retransform_any_class )
 431     log_trace(jvmti)("can_retransform_any_class");
 432   if (cap->can_get_current_thread_cpu_time)
 433     log_trace(jvmti)("can_get_current_thread_cpu_time");
 434   if (cap->can_get_thread_cpu_time)
 435     log_trace(jvmti)("can_get_thread_cpu_time");
 436   if (cap->can_generate_method_entry_events)
 437     log_trace(jvmti)("can_generate_method_entry_events");
 438   if (cap->can_generate_method_exit_events)
 439     log_trace(jvmti)("can_generate_method_exit_events");
 440   if (cap->can_generate_all_class_hook_events)
 441     log_trace(jvmti)("can_generate_all_class_hook_events");
 442   if (cap->can_generate_compiled_method_load_events)
 443     log_trace(jvmti)("can_generate_compiled_method_load_events");
 444   if (cap->can_generate_monitor_events)
 445     log_trace(jvmti)("can_generate_monitor_events");
 446   if (cap->can_generate_vm_object_alloc_events)
 447     log_trace(jvmti)("can_generate_vm_object_alloc_events");
 448   if (cap->can_generate_native_method_bind_events)
 449     log_trace(jvmti)("can_generate_native_method_bind_events");
 450   if (cap->can_generate_garbage_collection_events)
 451     log_trace(jvmti)("can_generate_garbage_collection_events");
 452   if (cap->can_generate_object_free_events)
 453     log_trace(jvmti)("can_generate_object_free_events");
 454   if (cap->can_generate_resource_exhaustion_heap_events)
 455     log_trace(jvmti)("can_generate_resource_exhaustion_heap_events");
 456   if (cap->can_generate_resource_exhaustion_threads_events)
 457     log_trace(jvmti)("can_generate_resource_exhaustion_threads_events");
 458   if (cap->can_generate_early_vmstart)
 459     log_trace(jvmti)("can_generate_early_vmstart");
 460   if (cap->can_generate_early_class_hook_events)
 461     log_trace(jvmti)("can_generate_early_class_hook_events");
 462 }
 463 
 464 #endif