Bug Summary

File:jdk/src/hotspot/share/code/compiledMethod.cpp
Warning:line 447, column 5
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name compiledMethod.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -mthread-model posix -fno-delete-null-pointer-checks -mframe-pointer=all -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/libjvm/objs/precompiled -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D _GNU_SOURCE -D _REENTRANT -D LIBC=gnu -D LINUX -D VM_LITTLE_ENDIAN -D _LP64=1 -D ASSERT -D CHECK_UNHANDLED_OOPS -D TARGET_ARCH_x86 -D INCLUDE_SUFFIX_OS=_linux -D INCLUDE_SUFFIX_CPU=_x86 -D INCLUDE_SUFFIX_COMPILER=_gcc -D TARGET_COMPILER_gcc -D AMD64 -D HOTSPOT_LIB_ARCH="amd64" -D COMPILER1 -D COMPILER2 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc/adfiles -I /home/daniel/Projects/java/jdk/src/hotspot/share -I /home/daniel/Projects/java/jdk/src/hotspot/os/linux -I /home/daniel/Projects/java/jdk/src/hotspot/os/posix -I /home/daniel/Projects/java/jdk/src/hotspot/cpu/x86 -I /home/daniel/Projects/java/jdk/src/hotspot/os_cpu/linux_x86 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc -I /home/daniel/Projects/java/jdk/src/hotspot/share/precompiled -I /home/daniel/Projects/java/jdk/src/hotspot/share/include -I /home/daniel/Projects/java/jdk/src/hotspot/os/posix/include -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/support/modules_include/java.base -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/support/modules_include/java.base/linux -I /home/daniel/Projects/java/jdk/src/java.base/share/native/libjimage -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc/adfiles -I /home/daniel/Projects/java/jdk/src/hotspot/share -I /home/daniel/Projects/java/jdk/src/hotspot/os/linux -I /home/daniel/Projects/java/jdk/src/hotspot/os/posix -I /home/daniel/Projects/java/jdk/src/hotspot/cpu/x86 -I /home/daniel/Projects/java/jdk/src/hotspot/os_cpu/linux_x86 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc -D _FORTIFY_SOURCE=2 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/c++/7.5.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/x86_64-linux-gnu/c++/7.5.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/x86_64-linux-gnu/c++/7.5.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/c++/7.5.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O3 -Wno-format-zero-length -Wno-unused-parameter -Wno-unused -Wno-parentheses -Wno-comment -Wno-unknown-pragmas -Wno-address -Wno-delete-non-virtual-dtor -Wno-char-subscripts -Wno-array-bounds -Wno-int-in-bool-context -Wno-ignored-qualifiers -Wno-missing-field-initializers -Wno-implicit-fallthrough -Wno-empty-body -Wno-strict-overflow -Wno-sequence-point -Wno-maybe-uninitialized -Wno-misleading-indentation -Wno-cast-function-type -Wno-shift-negative-value -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /home/daniel/Projects/java/jdk/make/hotspot -ferror-limit 19 -fmessage-length 0 -fvisibility hidden -stack-protector 1 -fno-rtti -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -faddrsig -o /home/daniel/Projects/java/scan/2021-12-21-193737-8510-1 -x c++ /home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp
1/*
2 * Copyright (c) 2015, 2021, 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 "code/compiledIC.hpp"
27#include "code/compiledMethod.inline.hpp"
28#include "code/exceptionHandlerTable.hpp"
29#include "code/scopeDesc.hpp"
30#include "code/codeCache.hpp"
31#include "code/icBuffer.hpp"
32#include "gc/shared/barrierSet.hpp"
33#include "gc/shared/barrierSetNMethod.hpp"
34#include "gc/shared/gcBehaviours.hpp"
35#include "interpreter/bytecode.inline.hpp"
36#include "logging/log.hpp"
37#include "logging/logTag.hpp"
38#include "memory/resourceArea.hpp"
39#include "oops/compiledICHolder.inline.hpp"
40#include "oops/klass.inline.hpp"
41#include "oops/methodData.hpp"
42#include "oops/method.inline.hpp"
43#include "prims/methodHandles.hpp"
44#include "runtime/atomic.hpp"
45#include "runtime/deoptimization.hpp"
46#include "runtime/handles.inline.hpp"
47#include "runtime/mutexLocker.hpp"
48#include "runtime/sharedRuntime.hpp"
49
50CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, const CodeBlobLayout& layout,
51 int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps,
52 bool caller_must_gc_arguments)
53 : CodeBlob(name, type, layout, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
54 _mark_for_deoptimization_status(not_marked),
55 _method(method),
56 _gc_data(NULL__null)
57{
58 init_defaults();
59}
60
61CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, int size,
62 int header_size, CodeBuffer* cb, int frame_complete_offset, int frame_size,
63 OopMapSet* oop_maps, bool caller_must_gc_arguments)
64 : CodeBlob(name, type, CodeBlobLayout((address) this, size, header_size, cb), cb,
65 frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments),
66 _mark_for_deoptimization_status(not_marked),
67 _method(method),
68 _gc_data(NULL__null)
69{
70 init_defaults();
71}
72
73void CompiledMethod::init_defaults() {
74 { // avoid uninitialized fields, even for short time periods
75 _scopes_data_begin = NULL__null;
76 _deopt_handler_begin = NULL__null;
77 _deopt_mh_handler_begin = NULL__null;
78 _exception_cache = NULL__null;
79 }
80 _has_unsafe_access = 0;
81 _has_method_handle_invokes = 0;
82 _has_wide_vectors = 0;
83}
84
85bool CompiledMethod::is_method_handle_return(address return_pc) {
86 if (!has_method_handle_invokes()) return false;
87 PcDesc* pd = pc_desc_at(return_pc);
88 if (pd == NULL__null)
89 return false;
90 return pd->is_method_handle_invoke();
91}
92
93// Returns a string version of the method state.
94const char* CompiledMethod::state() const {
95 int state = get_state();
96 switch (state) {
97 case not_installed:
98 return "not installed";
99 case in_use:
100 return "in use";
101 case not_used:
102 return "not_used";
103 case not_entrant:
104 return "not_entrant";
105 case zombie:
106 return "zombie";
107 case unloaded:
108 return "unloaded";
109 default:
110 fatal("unexpected method state: %d", state)do { (*g_assert_poison) = 'X';; report_fatal(INTERNAL_ERROR, "/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 110, "unexpected method state: %d", state); ::breakpoint();
} while (0);
111 return NULL__null;
112 }
113}
114
115//-----------------------------------------------------------------------------
116void CompiledMethod::mark_for_deoptimization(bool inc_recompile_counts) {
117 MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL__null : CompiledMethod_lock,
118 Mutex::_no_safepoint_check_flag);
119 _mark_for_deoptimization_status = (inc_recompile_counts ? deoptimize : deoptimize_noupdate);
120}
121
122//-----------------------------------------------------------------------------
123
124ExceptionCache* CompiledMethod::exception_cache_acquire() const {
125 return Atomic::load_acquire(&_exception_cache);
126}
127
128void CompiledMethod::add_exception_cache_entry(ExceptionCache* new_entry) {
129 assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock")do { if (!(ExceptionCache_lock->owned_by_self())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 129, "assert(" "ExceptionCache_lock->owned_by_self()" ") failed"
, "Must hold the ExceptionCache_lock"); ::breakpoint(); } } while
(0);
130 assert(new_entry != NULL,"Must be non null")do { if (!(new_entry != __null)) { (*g_assert_poison) = 'X';;
report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 130, "assert(" "new_entry != __null" ") failed", "Must be non null"
); ::breakpoint(); } } while (0);
131 assert(new_entry->next() == NULL, "Must be null")do { if (!(new_entry->next() == __null)) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 131, "assert(" "new_entry->next() == __null" ") failed",
"Must be null"); ::breakpoint(); } } while (0);
132
133 for (;;) {
134 ExceptionCache *ec = exception_cache();
135 if (ec != NULL__null) {
136 Klass* ex_klass = ec->exception_type();
137 if (!ex_klass->is_loader_alive()) {
138 // We must guarantee that entries are not inserted with new next pointer
139 // edges to ExceptionCache entries with dead klasses, due to bad interactions
140 // with concurrent ExceptionCache cleanup. Therefore, the inserts roll
141 // the head pointer forward to the first live ExceptionCache, so that the new
142 // next pointers always point at live ExceptionCaches, that are not removed due
143 // to concurrent ExceptionCache cleanup.
144 ExceptionCache* next = ec->next();
145 if (Atomic::cmpxchg(&_exception_cache, ec, next) == ec) {
146 CodeCache::release_exception_cache(ec);
147 }
148 continue;
149 }
150 ec = exception_cache();
151 if (ec != NULL__null) {
152 new_entry->set_next(ec);
153 }
154 }
155 if (Atomic::cmpxchg(&_exception_cache, ec, new_entry) == ec) {
156 return;
157 }
158 }
159}
160
161void CompiledMethod::clean_exception_cache() {
162 // For each nmethod, only a single thread may call this cleanup function
163 // at the same time, whether called in STW cleanup or concurrent cleanup.
164 // Note that if the GC is processing exception cache cleaning in a concurrent phase,
165 // then a single writer may contend with cleaning up the head pointer to the
166 // first ExceptionCache node that has a Klass* that is alive. That is fine,
167 // as long as there is no concurrent cleanup of next pointers from concurrent writers.
168 // And the concurrent writers do not clean up next pointers, only the head.
169 // Also note that concurent readers will walk through Klass* pointers that are not
170 // alive. That does not cause ABA problems, because Klass* is deleted after
171 // a handshake with all threads, after all stale ExceptionCaches have been
172 // unlinked. That is also when the CodeCache::exception_cache_purge_list()
173 // is deleted, with all ExceptionCache entries that were cleaned concurrently.
174 // That similarly implies that CAS operations on ExceptionCache entries do not
175 // suffer from ABA problems as unlinking and deletion is separated by a global
176 // handshake operation.
177 ExceptionCache* prev = NULL__null;
178 ExceptionCache* curr = exception_cache_acquire();
179
180 while (curr != NULL__null) {
181 ExceptionCache* next = curr->next();
182
183 if (!curr->exception_type()->is_loader_alive()) {
184 if (prev == NULL__null) {
185 // Try to clean head; this is contended by concurrent inserts, that
186 // both lazily clean the head, and insert entries at the head. If
187 // the CAS fails, the operation is restarted.
188 if (Atomic::cmpxchg(&_exception_cache, curr, next) != curr) {
189 prev = NULL__null;
190 curr = exception_cache_acquire();
191 continue;
192 }
193 } else {
194 // It is impossible to during cleanup connect the next pointer to
195 // an ExceptionCache that has not been published before a safepoint
196 // prior to the cleanup. Therefore, release is not required.
197 prev->set_next(next);
198 }
199 // prev stays the same.
200
201 CodeCache::release_exception_cache(curr);
202 } else {
203 prev = curr;
204 }
205
206 curr = next;
207 }
208}
209
210// public method for accessing the exception cache
211// These are the public access methods.
212address CompiledMethod::handler_for_exception_and_pc(Handle exception, address pc) {
213 // We never grab a lock to read the exception cache, so we may
214 // have false negatives. This is okay, as it can only happen during
215 // the first few exception lookups for a given nmethod.
216 ExceptionCache* ec = exception_cache_acquire();
217 while (ec != NULL__null) {
218 address ret_val;
219 if ((ret_val = ec->match(exception,pc)) != NULL__null) {
220 return ret_val;
221 }
222 ec = ec->next();
223 }
224 return NULL__null;
225}
226
227void CompiledMethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
228 // There are potential race conditions during exception cache updates, so we
229 // must own the ExceptionCache_lock before doing ANY modifications. Because
230 // we don't lock during reads, it is possible to have several threads attempt
231 // to update the cache with the same data. We need to check for already inserted
232 // copies of the current data before adding it.
233
234 MutexLocker ml(ExceptionCache_lock);
235 ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
236
237 if (target_entry == NULL__null || !target_entry->add_address_and_handler(pc,handler)) {
238 target_entry = new ExceptionCache(exception,pc,handler);
239 add_exception_cache_entry(target_entry);
240 }
241}
242
243// private method for handling exception cache
244// These methods are private, and used to manipulate the exception cache
245// directly.
246ExceptionCache* CompiledMethod::exception_cache_entry_for_exception(Handle exception) {
247 ExceptionCache* ec = exception_cache_acquire();
248 while (ec != NULL__null) {
249 if (ec->match_exception_with_space(exception)) {
250 return ec;
251 }
252 ec = ec->next();
253 }
254 return NULL__null;
255}
256
257//-------------end of code for ExceptionCache--------------
258
259bool CompiledMethod::is_at_poll_return(address pc) {
260 RelocIterator iter(this, pc, pc+1);
261 while (iter.next()) {
262 if (iter.type() == relocInfo::poll_return_type)
263 return true;
264 }
265 return false;
266}
267
268
269bool CompiledMethod::is_at_poll_or_poll_return(address pc) {
270 RelocIterator iter(this, pc, pc+1);
271 while (iter.next()) {
272 relocInfo::relocType t = iter.type();
273 if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
274 return true;
275 }
276 return false;
277}
278
279void CompiledMethod::verify_oop_relocations() {
280 // Ensure sure that the code matches the current oop values
281 RelocIterator iter(this, NULL__null, NULL__null);
282 while (iter.next()) {
283 if (iter.type() == relocInfo::oop_type) {
284 oop_Relocation* reloc = iter.oop_reloc();
285 if (!reloc->oop_is_immediate()) {
286 reloc->verify_oop_relocation();
287 }
288 }
289 }
290}
291
292
293ScopeDesc* CompiledMethod::scope_desc_at(address pc) {
294 PcDesc* pd = pc_desc_at(pc);
295 guarantee(pd != NULL, "scope must be present")do { if (!(pd != __null)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 295, "guarantee(" "pd != NULL" ") failed", "scope must be present"
); ::breakpoint(); } } while (0);
296 return new ScopeDesc(this, pd);
297}
298
299ScopeDesc* CompiledMethod::scope_desc_near(address pc) {
300 PcDesc* pd = pc_desc_near(pc);
301 guarantee(pd != NULL, "scope must be present")do { if (!(pd != __null)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 301, "guarantee(" "pd != NULL" ") failed", "scope must be present"
); ::breakpoint(); } } while (0);
302 return new ScopeDesc(this, pd);
303}
304
305address CompiledMethod::oops_reloc_begin() const {
306 // If the method is not entrant or zombie then a JMP is plastered over the
307 // first few bytes. If an oop in the old code was there, that oop
308 // should not get GC'd. Skip the first few bytes of oops on
309 // not-entrant methods.
310 if (frame_complete_offset() != CodeOffsets::frame_never_safe &&
311 code_begin() + frame_complete_offset() >
312 verified_entry_point() + NativeJump::instruction_size)
313 {
314 // If we have a frame_complete_offset after the native jump, then there
315 // is no point trying to look for oops before that. This is a requirement
316 // for being allowed to scan oops concurrently.
317 return code_begin() + frame_complete_offset();
318 }
319
320 // It is not safe to read oops concurrently using entry barriers, if their
321 // location depend on whether the nmethod is entrant or not.
322 assert(BarrierSet::barrier_set()->barrier_set_nmethod() == NULL, "Not safe oop scan")do { if (!(BarrierSet::barrier_set()->barrier_set_nmethod(
) == __null)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 322, "assert(" "BarrierSet::barrier_set()->barrier_set_nmethod() == __null"
") failed", "Not safe oop scan"); ::breakpoint(); } } while (
0);
323
324 address low_boundary = verified_entry_point();
325 if (!is_in_use() && is_nmethod()) {
326 low_boundary += NativeJump::instruction_size;
327 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
328 // This means that the low_boundary is going to be a little too high.
329 // This shouldn't matter, since oops of non-entrant methods are never used.
330 // In fact, why are we bothering to look at oops in a non-entrant method??
331 }
332 return low_boundary;
333}
334
335int CompiledMethod::verify_icholder_relocations() {
336 ResourceMark rm;
337 int count = 0;
338
339 RelocIterator iter(this);
340 while(iter.next()) {
341 if (iter.type() == relocInfo::virtual_call_type) {
342 if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc(), this)) {
343 CompiledIC *ic = CompiledIC_at(&iter);
344 if (TraceCompiledIC) {
345 tty->print("noticed icholder " INTPTR_FORMAT"0x%016" "l" "x" " ", p2i(ic->cached_icholder()));
346 ic->print();
347 }
348 assert(ic->cached_icholder() != NULL, "must be non-NULL")do { if (!(ic->cached_icholder() != __null)) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 348, "assert(" "ic->cached_icholder() != __null" ") failed"
, "must be non-NULL"); ::breakpoint(); } } while (0);
349 count++;
350 }
351 }
352 }
353
354 return count;
355}
356
357// Method that knows how to preserve outgoing arguments at call. This method must be
358// called with a frame corresponding to a Java invoke
359void CompiledMethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
360 if (method() != NULL__null && !method()->is_native()) {
361 address pc = fr.pc();
362 SimpleScopeDesc ssd(this, pc);
363 if (ssd.is_optimized_linkToNative()) return; // call was replaced
364 Bytecode_invoke call(methodHandle(Thread::current(), ssd.method()), ssd.bci());
365 bool has_receiver = call.has_receiver();
366 bool has_appendix = call.has_appendix();
367 Symbol* signature = call.signature();
368
369 // The method attached by JIT-compilers should be used, if present.
370 // Bytecode can be inaccurate in such case.
371 Method* callee = attached_method_before_pc(pc);
372 if (callee != NULL__null) {
373 has_receiver = !(callee->access_flags().is_static());
374 has_appendix = false;
375 signature = callee->signature();
376 }
377
378 fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f);
379 }
380}
381
382Method* CompiledMethod::attached_method(address call_instr) {
383 assert(code_contains(call_instr), "not part of the nmethod")do { if (!(code_contains(call_instr))) { (*g_assert_poison) =
'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 383, "assert(" "code_contains(call_instr)" ") failed", "not part of the nmethod"
); ::breakpoint(); } } while (0);
384 RelocIterator iter(this, call_instr, call_instr + 1);
385 while (iter.next()) {
386 if (iter.addr() == call_instr) {
387 switch(iter.type()) {
388 case relocInfo::static_call_type: return iter.static_call_reloc()->method_value();
389 case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value();
390 case relocInfo::virtual_call_type: return iter.virtual_call_reloc()->method_value();
391 default: break;
392 }
393 }
394 }
395 return NULL__null; // not found
396}
397
398Method* CompiledMethod::attached_method_before_pc(address pc) {
399 if (NativeCall::is_call_before(pc)) {
400 NativeCall* ncall = nativeCall_before(pc);
401 return attached_method(ncall->instruction_address());
402 }
403 return NULL__null; // not a call
404}
405
406void CompiledMethod::clear_inline_caches() {
407 assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint")do { if (!(SafepointSynchronize::is_at_safepoint())) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 407, "assert(" "SafepointSynchronize::is_at_safepoint()" ") failed"
, "cleaning of IC's only allowed at safepoint"); ::breakpoint
(); } } while (0);
408 if (is_zombie()) {
409 return;
410 }
411
412 RelocIterator iter(this);
413 while (iter.next()) {
414 iter.reloc()->clear_inline_cache();
415 }
416}
417
418// Clear IC callsites, releasing ICStubs of all compiled ICs
419// as well as any associated CompiledICHolders.
420void CompiledMethod::clear_ic_callsites() {
421 assert(CompiledICLocker::is_safe(this), "mt unsafe call")do { if (!(CompiledICLocker::is_safe(this))) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 421, "assert(" "CompiledICLocker::is_safe(this)" ") failed"
, "mt unsafe call"); ::breakpoint(); } } while (0);
422 ResourceMark rm;
423 RelocIterator iter(this);
424 while(iter.next()) {
425 if (iter.type() == relocInfo::virtual_call_type) {
426 CompiledIC* ic = CompiledIC_at(&iter);
427 ic->set_to_clean(false);
428 }
429 }
430}
431
432#ifdef ASSERT1
433// Check class_loader is alive for this bit of metadata.
434class CheckClass : public MetadataClosure {
435 void do_metadata(Metadata* md) {
436 Klass* klass = NULL__null;
1
'klass' initialized to a null pointer value
→
437 if (md->is_klass()) {
2
←
Assuming the condition is false
→
3
←
Taking false branch
→
438 klass = ((Klass*)md);
439 } else if (md->is_method()) {
4
←
Assuming the condition is false
→
5
←
Taking false branch
→
440 klass = ((Method*)md)->method_holder();
441 } else if (md->is_methodData()) {
6
←
Assuming the condition is false
→
7
←
Taking false branch
→
442 klass = ((MethodData*)md)->method()->method_holder();
443 } else {
444 md->print();
445 ShouldNotReachHere()do { (*g_assert_poison) = 'X';; report_should_not_reach_here(
"/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 445); ::breakpoint(); } while (0);
8
←
Loop condition is false. Exiting loop
→
446 }
447 assert(klass->is_loader_alive(), "must be alive")do { if (!(klass->is_loader_alive())) { (*g_assert_poison)
= 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 447, "assert(" "klass->is_loader_alive()" ") failed", "must be alive"
); ::breakpoint(); } } while (0);
9
←
Called C++ object pointer is null
448 }
449};
450#endif // ASSERT
451
452
453bool CompiledMethod::clean_ic_if_metadata_is_dead(CompiledIC *ic) {
454 if (ic->is_clean()) {
455 return true;
456 }
457 if (ic->is_icholder_call()) {
458 // The only exception is compiledICHolder metdata which may
459 // yet be marked below. (We check this further below).
460 CompiledICHolder* cichk_metdata = ic->cached_icholder();
461
462 if (cichk_metdata->is_loader_alive()) {
463 return true;
464 }
465 } else {
466 Metadata* ic_metdata = ic->cached_metadata();
467 if (ic_metdata != NULL__null) {
468 if (ic_metdata->is_klass()) {
469 if (((Klass*)ic_metdata)->is_loader_alive()) {
470 return true;
471 }
472 } else if (ic_metdata->is_method()) {
473 Method* method = (Method*)ic_metdata;
474 assert(!method->is_old(), "old method should have been cleaned")do { if (!(!method->is_old())) { (*g_assert_poison) = 'X';
; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 474, "assert(" "!method->is_old()" ") failed", "old method should have been cleaned"
); ::breakpoint(); } } while (0);
475 if (method->method_holder()->is_loader_alive()) {
476 return true;
477 }
478 } else {
479 ShouldNotReachHere()do { (*g_assert_poison) = 'X';; report_should_not_reach_here(
"/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 479); ::breakpoint(); } while (0);
480 }
481 } else {
482 // This inline cache is a megamorphic vtable call. Those ICs never hold
483 // any Metadata and should therefore never be cleaned by this function.
484 return true;
485 }
486 }
487
488 return ic->set_to_clean();
489}
490
491// Clean references to unloaded nmethods at addr from this one, which is not unloaded.
492template <class CompiledICorStaticCall>
493static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, CompiledMethod* from,
494 bool clean_all) {
495 // Ok, to lookup references to zombies here
496 CodeBlob *cb = CodeCache::find_blob_unsafe(addr);
497 CompiledMethod* nm = (cb != NULL__null) ? cb->as_compiled_method_or_null() : NULL__null;
498 if (nm != NULL__null) {
499 // Clean inline caches pointing to both zombie and not_entrant methods
500 if (clean_all || !nm->is_in_use() || nm->is_unloading() || (nm->method()->code() != nm)) {
501 // Inline cache cleaning should only be initiated on CompiledMethods that have been
502 // observed to be is_alive(). However, with concurrent code cache unloading, it is
503 // possible that by now, the state has become !is_alive. This can happen in two ways:
504 // 1) It can be racingly flipped to unloaded if the nmethod // being cleaned (from the
505 // sweeper) is_unloading(). This is fine, because if that happens, then the inline
506 // caches have already been cleaned under the same CompiledICLocker that we now hold during
507 // inline cache cleaning, and we will simply walk the inline caches again, and likely not
508 // find much of interest to clean. However, this race prevents us from asserting that the
509 // nmethod is_alive(). The is_unloading() function is completely monotonic; once set due
510 // to an oop dying, it remains set forever until freed. Because of that, all unloaded
511 // nmethods are is_unloading(), but notably, an unloaded nmethod may also subsequently
512 // become zombie (when the sweeper converts it to zombie).
513 // 2) It can be racingly flipped to zombie if the nmethod being cleaned (by the concurrent
514 // GC) cleans a zombie nmethod that is concurrently made zombie by the sweeper. In this
515 // scenario, the sweeper will first transition the nmethod to zombie, and then when
516 // unregistering from the GC, it will wait until the GC is done. The GC will then clean
517 // the inline caches *with IC stubs*, even though no IC stubs are needed. This is fine,
518 // as long as the IC stubs are guaranteed to be released until the next safepoint, where
519 // IC finalization requires live IC stubs to not be associated with zombie nmethods.
520 // This is guaranteed, because the sweeper does not have a single safepoint check until
521 // after it completes the whole transition function; it will wake up after the GC is
522 // done with concurrent code cache cleaning (which blocks out safepoints using the
523 // suspendible threads set), and then call clear_ic_callsites, which will release the
524 // associated IC stubs, before a subsequent safepoint poll can be reached. This
525 // guarantees that the spuriously created IC stubs are released appropriately before
526 // IC finalization in a safepoint gets to run. Therefore, this race is fine. This is also
527 // valid in a scenario where an inline cache of a zombie nmethod gets a spurious IC stub,
528 // and then when cleaning another inline cache, fails to request an IC stub because we
529 // exhausted the IC stub buffer. In this scenario, the GC will request a safepoint after
530 // yielding the suspendible therad set, effectively unblocking safepoints. Before such
531 // a safepoint can be reached, the sweeper similarly has to wake up, clear the IC stubs,
532 // and reach the next safepoint poll, after the whole transition function has completed.
533 // Due to the various races that can cause an nmethod to first be is_alive() and then
534 // racingly become !is_alive(), it is unfortunately not possible to assert the nmethod
535 // is_alive(), !is_unloaded() or !is_zombie() here.
536 if (!ic->set_to_clean(!from->is_unloading())) {
537 return false;
538 }
539 assert(ic->is_clean(), "nmethod " PTR_FORMAT "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string())do { if (!(ic->is_clean())) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 539, "assert(" "ic->is_clean()" ") failed", "nmethod " "0x%016"
"l" "x" "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string
()); ::breakpoint(); } } while (0);
540 }
541 }
542 return true;
543}
544
545static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, CompiledMethod* from,
546 bool clean_all) {
547 return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), from, clean_all);
548}
549
550static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, CompiledMethod* from,
551 bool clean_all) {
552 return clean_if_nmethod_is_unloaded(csc, csc->destination(), from, clean_all);
553}
554
555// Cleans caches in nmethods that point to either classes that are unloaded
556// or nmethods that are unloaded.
557//
558// Can be called either in parallel by G1 currently or after all
559// nmethods are unloaded. Return postponed=true in the parallel case for
560// inline caches found that point to nmethods that are not yet visited during
561// the do_unloading walk.
562bool CompiledMethod::unload_nmethod_caches(bool unloading_occurred) {
563 ResourceMark rm;
564
565 // Exception cache only needs to be called if unloading occurred
566 if (unloading_occurred) {
567 clean_exception_cache();
568 }
569
570 if (!cleanup_inline_caches_impl(unloading_occurred, false)) {
571 return false;
572 }
573
574#ifdef ASSERT1
575 // Check that the metadata embedded in the nmethod is alive
576 CheckClass check_class;
577 metadata_do(&check_class);
578#endif
579 return true;
580}
581
582void CompiledMethod::run_nmethod_entry_barrier() {
583 BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
584 if (bs_nm != NULL__null) {
585 // We want to keep an invariant that nmethods found through iterations of a Thread's
586 // nmethods found in safepoints have gone through an entry barrier and are not armed.
587 // By calling this nmethod entry barrier, it plays along and acts
588 // like any other nmethod found on the stack of a thread (fewer surprises).
589 nmethod* nm = as_nmethod_or_null();
590 if (nm != NULL__null) {
591 bool alive = bs_nm->nmethod_entry_barrier(nm);
592 assert(alive, "should be alive")do { if (!(alive)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 592, "assert(" "alive" ") failed", "should be alive"); ::breakpoint
(); } } while (0);
593 }
594 }
595}
596
597void CompiledMethod::cleanup_inline_caches(bool clean_all) {
598 for (;;) {
599 ICRefillVerifier ic_refill_verifier;
600 { CompiledICLocker ic_locker(this);
601 if (cleanup_inline_caches_impl(false, clean_all)) {
602 return;
603 }
604 }
605 // Call this nmethod entry barrier from the sweeper.
606 run_nmethod_entry_barrier();
607 InlineCacheBuffer::refill_ic_stubs();
608 }
609}
610
611// Called to clean up after class unloading for live nmethods and from the sweeper
612// for all methods.
613bool CompiledMethod::cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all) {
614 assert(CompiledICLocker::is_safe(this), "mt unsafe call")do { if (!(CompiledICLocker::is_safe(this))) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 614, "assert(" "CompiledICLocker::is_safe(this)" ") failed"
, "mt unsafe call"); ::breakpoint(); } } while (0);
615 ResourceMark rm;
616
617 // Find all calls in an nmethod and clear the ones that point to non-entrant,
618 // zombie and unloaded nmethods.
619 RelocIterator iter(this, oops_reloc_begin());
620 bool is_in_static_stub = false;
621 while(iter.next()) {
622
623 switch (iter.type()) {
624
625 case relocInfo::virtual_call_type:
626 if (unloading_occurred) {
627 // If class unloading occurred we first clear ICs where the cached metadata
628 // is referring to an unloaded klass or method.
629 if (!clean_ic_if_metadata_is_dead(CompiledIC_at(&iter))) {
630 return false;
631 }
632 }
633
634 if (!clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, clean_all)) {
635 return false;
636 }
637 break;
638
639 case relocInfo::opt_virtual_call_type:
640 if (!clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), this, clean_all)) {
641 return false;
642 }
643 break;
644
645 case relocInfo::static_call_type:
646 if (!clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), this, clean_all)) {
647 return false;
648 }
649 break;
650
651 case relocInfo::static_stub_type: {
652 is_in_static_stub = true;
653 break;
654 }
655
656 case relocInfo::metadata_type: {
657 // Only the metadata relocations contained in static/opt virtual call stubs
658 // contains the Method* passed to c2i adapters. It is the only metadata
659 // relocation that needs to be walked, as it is the one metadata relocation
660 // that violates the invariant that all metadata relocations have an oop
661 // in the compiled method (due to deferred resolution and code patching).
662
663 // This causes dead metadata to remain in compiled methods that are not
664 // unloading. Unless these slippery metadata relocations of the static
665 // stubs are at least cleared, subsequent class redefinition operations
666 // will access potentially free memory, and JavaThread execution
667 // concurrent to class unloading may call c2i adapters with dead methods.
668 if (!is_in_static_stub) {
669 // The first metadata relocation after a static stub relocation is the
670 // metadata relocation of the static stub used to pass the Method* to
671 // c2i adapters.
672 continue;
673 }
674 is_in_static_stub = false;
675 if (is_unloading()) {
676 // If the nmethod itself is dying, then it may point at dead metadata.
677 // Nobody should follow that metadata; it is strictly unsafe.
678 continue;
679 }
680 metadata_Relocation* r = iter.metadata_reloc();
681 Metadata* md = r->metadata_value();
682 if (md != NULL__null && md->is_method()) {
683 Method* method = static_cast<Method*>(md);
684 if (!method->method_holder()->is_loader_alive()) {
685 Atomic::store(r->metadata_addr(), (Method*)NULL__null);
686
687 if (!r->metadata_is_immediate()) {
688 r->fix_metadata_relocation();
689 }
690 }
691 }
692 break;
693 }
694
695 default:
696 break;
697 }
698 }
699
700 return true;
701}
702
703address CompiledMethod::continuation_for_implicit_exception(address pc, bool for_div0_check) {
704 // Exception happened outside inline-cache check code => we are inside
705 // an active nmethod => use cpc to determine a return address
706 int exception_offset = pc - code_begin();
707 int cont_offset = ImplicitExceptionTable(this).continuation_offset( exception_offset );
708#ifdef ASSERT1
709 if (cont_offset == 0) {
710 Thread* thread = Thread::current();
711 ResourceMark rm(thread);
712 CodeBlob* cb = CodeCache::find_blob(pc);
713 assert(cb != NULL && cb == this, "")do { if (!(cb != __null && cb == this)) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 713, "assert(" "cb != __null && cb == this" ") failed"
, ""); ::breakpoint(); } } while (0);
714 ttyLocker ttyl;
715 tty->print_cr("implicit exception happened at " INTPTR_FORMAT"0x%016" "l" "x", p2i(pc));
716 print();
717 method()->print_codes();
718 print_code();
719 print_pcs();
720 }
721#endif
722 if (cont_offset == 0) {
723 // Let the normal error handling report the exception
724 return NULL__null;
725 }
726 if (cont_offset == exception_offset) {
727#if INCLUDE_JVMCI1
728 Deoptimization::DeoptReason deopt_reason = for_div0_check ? Deoptimization::Reason_div0_check : Deoptimization::Reason_null_check;
729 JavaThread *thread = JavaThread::current();
730 thread->set_jvmci_implicit_exception_pc(pc);
731 thread->set_pending_deoptimization(Deoptimization::make_trap_request(deopt_reason,
732 Deoptimization::Action_reinterpret));
733 return (SharedRuntime::deopt_blob()->implicit_exception_uncommon_trap());
734#else
735 ShouldNotReachHere()do { (*g_assert_poison) = 'X';; report_should_not_reach_here(
"/home/daniel/Projects/java/jdk/src/hotspot/share/code/compiledMethod.cpp"
, 735); ::breakpoint(); } while (0);
736#endif
737 }
738 return code_begin() + cont_offset;
739}
740
741class HasEvolDependency : public MetadataClosure {
742 bool _has_evol_dependency;
743 public:
744 HasEvolDependency() : _has_evol_dependency(false) {}
745 void do_metadata(Metadata* md) {
746 if (md->is_method()) {
747 Method* method = (Method*)md;
748 if (method->is_old()) {
749 _has_evol_dependency = true;
750 }
751 }
752 }
753 bool has_evol_dependency() const { return _has_evol_dependency; }
754};
755
756bool CompiledMethod::has_evol_metadata() {
757 // Check the metadata in relocIter and CompiledIC and also deoptimize
758 // any nmethod that has reference to old methods.
759 HasEvolDependency check_evol;
760 metadata_do(&check_evol);
761 if (check_evol.has_evol_dependency() && log_is_enabled(Debug, redefine, class, nmethod)(LogImpl<(LogTag::_redefine), (LogTag::_class), (LogTag::_nmethod
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::is_level(LogLevel::Debug))) {
762 ResourceMark rm;
763 log_debug(redefine, class, nmethod)(!(LogImpl<(LogTag::_redefine), (LogTag::_class), (LogTag::
_nmethod), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG
)>::is_level(LogLevel::Debug))) ? (void)0 : LogImpl<(LogTag
::_redefine), (LogTag::_class), (LogTag::_nmethod), (LogTag::
__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)>::write<
LogLevel::Debug>
764 ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on in nmethod metadata",
765 _method->method_holder()->external_name(),
766 _method->name()->as_C_string(),
767 _method->signature()->as_C_string(),
768 compile_id());
769 }
770 return check_evol.has_evol_dependency();
771}