Bug Summary

File:jdk/src/hotspot/share/prims/stackwalk.cpp
Warning:line 260, column 18
Value stored to 'ret' during its initialization is never read

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 stackwalk.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/prims/stackwalk.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 "classfile/javaClasses.hpp"
27#include "classfile/javaClasses.inline.hpp"
28#include "classfile/vmClasses.hpp"
29#include "classfile/vmSymbols.hpp"
30#include "logging/log.hpp"
31#include "logging/logStream.hpp"
32#include "memory/oopFactory.hpp"
33#include "memory/universe.hpp"
34#include "oops/klass.inline.hpp"
35#include "oops/oop.inline.hpp"
36#include "oops/objArrayOop.inline.hpp"
37#include "prims/stackwalk.hpp"
38#include "runtime/globals.hpp"
39#include "runtime/handles.inline.hpp"
40#include "runtime/javaCalls.hpp"
41#include "runtime/keepStackGCProcessed.hpp"
42#include "runtime/stackWatermarkSet.hpp"
43#include "runtime/thread.inline.hpp"
44#include "runtime/vframe.inline.hpp"
45#include "utilities/formatBuffer.hpp"
46#include "utilities/globalDefinitions.hpp"
47
48// setup and cleanup actions
49void BaseFrameStream::setup_magic_on_entry(objArrayHandle frames_array) {
50 frames_array->obj_at_put(magic_pos, _thread->threadObj());
51 _anchor = address_value();
52 assert(check_magic(frames_array), "invalid magic")do { if (!(check_magic(frames_array))) { (*g_assert_poison) =
'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 52, "assert(" "check_magic(frames_array)" ") failed", "invalid magic"
); ::breakpoint(); } } while (0);
53}
54
55bool BaseFrameStream::check_magic(objArrayHandle frames_array) {
56 oop m1 = frames_array->obj_at(magic_pos);
57 jlong m2 = _anchor;
58 if (m1 == _thread->threadObj() && m2 == address_value()) return true;
59 return false;
60}
61
62bool BaseFrameStream::cleanup_magic_on_exit(objArrayHandle frames_array) {
63 bool ok = check_magic(frames_array);
64 frames_array->obj_at_put(magic_pos, NULL__null);
65 _anchor = 0L;
66 return ok;
67}
68
69JavaFrameStream::JavaFrameStream(JavaThread* thread, int mode)
70 : BaseFrameStream(thread), _vfst(thread) {
71 _need_method_info = StackWalk::need_method_info(mode);
72}
73
74void JavaFrameStream::next() { _vfst.next();}
75
76// Returns the BaseFrameStream for the current stack being traversed.
77//
78// Parameters:
79// thread Current Java thread.
80// magic Magic value used for each stack walking
81// frames_array User-supplied buffers. The 0th element is reserved
82// for this BaseFrameStream to use
83//
84BaseFrameStream* BaseFrameStream::from_current(JavaThread* thread, jlong magic,
85 objArrayHandle frames_array)
86{
87 oop m1 = frames_array->obj_at(magic_pos);
88 if (m1 != thread->threadObj()) return NULL__null;
89 if (magic == 0L) return NULL__null;
90 BaseFrameStream* stream = (BaseFrameStream*) (intptr_t) magic;
91 if (!stream->is_valid_in(thread, frames_array)) return NULL__null;
92 return stream;
93}
94
95// Unpacks one or more frames into user-supplied buffers.
96// Updates the end index, and returns the number of unpacked frames.
97// Always start with the existing vfst.method and bci.
98// Do not call vfst.next to advance over the last returned value.
99// In other words, do not leave any stale data in the vfst.
100//
101// Parameters:
102// mode Restrict which frames to be decoded.
103// BaseFrameStream stream of frames
104// max_nframes Maximum number of frames to be filled.
105// start_index Start index to the user-supplied buffers.
106// frames_array Buffer to store Class or StackFrame in, starting at start_index.
107// frames array is a Class<?>[] array when only getting caller
108// reference, and a StackFrameInfo[] array (or derivative)
109// otherwise. It should never be null.
110// end_index End index to the user-supplied buffers with unpacked frames.
111//
112// Returns the number of frames whose information was transferred into the buffers.
113//
114int StackWalk::fill_in_frames(jlong mode, BaseFrameStream& stream,
115 int max_nframes, int start_index,
116 objArrayHandle frames_array,
117 int& end_index, TRAPSJavaThread* __the_thread__) {
118 log_debug(stackwalk)(!(LogImpl<(LogTag::_stackwalk), (LogTag::__NO_TAG), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Debug))) ? (void)0 : LogImpl
<(LogTag::_stackwalk), (LogTag::__NO_TAG), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Debug>("fill_in_frames limit=%d start=%d frames length=%d",
119 max_nframes, start_index, frames_array->length());
120 assert(max_nframes > 0, "invalid max_nframes")do { if (!(max_nframes > 0)) { (*g_assert_poison) = 'X';; report_vm_error
("/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 120, "assert(" "max_nframes > 0" ") failed", "invalid max_nframes"
); ::breakpoint(); } } while (0);
121 assert(start_index + max_nframes <= frames_array->length(), "oob")do { if (!(start_index + max_nframes <= frames_array->length
())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 121, "assert(" "start_index + max_nframes <= frames_array->length()"
") failed", "oob"); ::breakpoint(); } } while (0);
122
123 int frames_decoded = 0;
124 for (; !stream.at_end(); stream.next()) {
125 Method* method = stream.method();
126
127 if (method == NULL__null) continue;
128
129 // skip hidden frames for default StackWalker option (i.e. SHOW_HIDDEN_FRAMES
130 // not set) and when StackWalker::getCallerClass is called
131 if (!ShowHiddenFrames && (skip_hidden_frames(mode) || get_caller_class(mode))) {
132 if (method->is_hidden()) {
133 LogTarget(Debug, stackwalk)LogTargetImpl<LogLevel::Debug, (LogTag::_stackwalk), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG), (LogTag::__NO_TAG)> lt;
134 if (lt.is_enabled()) {
135 ResourceMark rm(THREAD__the_thread__);
136 LogStream ls(lt);
137 ls.print(" hidden method: ");
138 method->print_short_name(&ls);
139 ls.cr();
140 }
141 continue;
142 }
143 }
144
145 int index = end_index++;
146 LogTarget(Debug, stackwalk)LogTargetImpl<LogLevel::Debug, (LogTag::_stackwalk), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG), (LogTag::__NO_TAG)> lt;
147 if (lt.is_enabled()) {
148 ResourceMark rm(THREAD__the_thread__);
149 LogStream ls(lt);
150 ls.print(" %d: frame method: ", index);
151 method->print_short_name(&ls);
152 ls.print_cr(" bci=%d", stream.bci());
153 }
154
155 if (!need_method_info(mode) && get_caller_class(mode) &&
156 index == start_index && method->caller_sensitive()) {
157 ResourceMark rm(THREAD__the_thread__);
158 THROW_MSG_0(vmSymbols::java_lang_UnsupportedOperationException(),{ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 160, vmSymbols::java_lang_UnsupportedOperationException(), err_msg
("StackWalker::getCallerClass called from @CallerSensitive '%s' method"
, method->external_name())); return 0; }
159 err_msg("StackWalker::getCallerClass called from @CallerSensitive '%s' method",{ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 160, vmSymbols::java_lang_UnsupportedOperationException(), err_msg
("StackWalker::getCallerClass called from @CallerSensitive '%s' method"
, method->external_name())); return 0; }
160 method->external_name())){ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 160, vmSymbols::java_lang_UnsupportedOperationException(), err_msg
("StackWalker::getCallerClass called from @CallerSensitive '%s' method"
, method->external_name())); return 0; };
161 }
162 // fill in StackFrameInfo and initialize MemberName
163 stream.fill_frame(index, frames_array, methodHandle(THREAD__the_thread__, method), CHECK_0__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return 0; (void)(0);
164 if (++frames_decoded >= max_nframes) break;
165 }
166 return frames_decoded;
167}
168
169// Fill in the LiveStackFrameInfo at the given index in frames_array
170void LiveFrameStream::fill_frame(int index, objArrayHandle frames_array,
171 const methodHandle& method, TRAPSJavaThread* __the_thread__) {
172 HandleMark hm(THREAD__the_thread__);
173 Handle stackFrame(THREAD__the_thread__, frames_array->obj_at(index));
174 fill_live_stackframe(stackFrame, method, CHECK__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return ; (void)(0);
175}
176
177// Fill in the StackFrameInfo at the given index in frames_array
178void JavaFrameStream::fill_frame(int index, objArrayHandle frames_array,
179 const methodHandle& method, TRAPSJavaThread* __the_thread__) {
180 if (_need_method_info) {
181 HandleMark hm(THREAD__the_thread__);
182 Handle stackFrame(THREAD__the_thread__, frames_array->obj_at(index));
183 fill_stackframe(stackFrame, method, CHECK__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return ; (void)(0);
184 } else {
185 frames_array->obj_at_put(index, method->method_holder()->java_mirror());
186 }
187}
188
189// Create and return a LiveStackFrame.PrimitiveSlot (if needed) for the
190// StackValue at the given index. 'type' is expected to be T_INT, T_LONG,
191// T_OBJECT, or T_CONFLICT.
192oop LiveFrameStream::create_primitive_slot_instance(StackValueCollection* values,
193 int i, BasicType type, TRAPSJavaThread* __the_thread__) {
194 Klass* k = vmClasses::LiveStackFrameInfo_klass();
195 InstanceKlass* ik = InstanceKlass::cast(k);
196
197 JavaValue result(T_OBJECT);
198 JavaCallArguments args;
199 Symbol* signature = NULL__null;
200
201 // ## TODO: type is only available in LocalVariable table, if present.
202 // ## StackValue type is T_INT or T_OBJECT (or converted to T_LONG on 64-bit)
203 switch (type) {
204 case T_INT:
205 args.push_int(values->int_at(i));
206 signature = vmSymbols::asPrimitive_int_signature();
207 break;
208
209 case T_LONG:
210 args.push_long(values->long_at(i));
211 signature = vmSymbols::asPrimitive_long_signature();
212 break;
213
214 case T_FLOAT:
215 case T_DOUBLE:
216 case T_BYTE:
217 case T_SHORT:
218 case T_CHAR:
219 case T_BOOLEAN:
220 THROW_MSG_(vmSymbols::java_lang_InternalError(), "Unexpected StackValue type", NULL){ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 220, vmSymbols::java_lang_InternalError(), "Unexpected StackValue type"
); return __null; };
221
222 case T_OBJECT:
223 return values->obj_at(i)();
224
225 case T_CONFLICT:
226 // put a non-null slot
227 #ifdef _LP641
228 args.push_long(0);
229 signature = vmSymbols::asPrimitive_long_signature();
230 #else
231 args.push_int(0);
232 signature = vmSymbols::asPrimitive_int_signature();
233 #endif
234
235 break;
236
237 default: ShouldNotReachHere()do { (*g_assert_poison) = 'X';; report_should_not_reach_here(
"/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 237); ::breakpoint(); } while (0);
238 }
239 JavaCalls::call_static(&result,
240 ik,
241 vmSymbols::asPrimitive_name(),
242 signature,
243 &args,
244 CHECK_NULL__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return __null; (void)(0);
245 return (instanceOop) result.get_oop();
246}
247
248objArrayHandle LiveFrameStream::values_to_object_array(StackValueCollection* values, TRAPSJavaThread* __the_thread__) {
249 objArrayHandle empty;
250 int length = values->size();
251 objArrayOop array_oop = oopFactory::new_objArray(vmClasses::Object_klass(),
252 length, CHECK_(empty)__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return empty; (void)(0);
253 objArrayHandle array_h(THREAD__the_thread__, array_oop);
254 for (int i = 0; i < values->size(); i++) {
255 StackValue* st = values->at(i);
256 BasicType type = st->type();
257 int index = i;
258#ifdef _LP641
259 if (type != T_OBJECT && type != T_CONFLICT) {
260 intptr_t ret = st->get_int(); // read full 64-bit slot
Value stored to 'ret' during its initialization is never read
261 type = T_LONG; // treat as long
262 index--; // undo +1 in StackValueCollection::long_at
263 }
264#endif
265 oop obj = create_primitive_slot_instance(values, index, type, CHECK_(empty)__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return empty; (void)(0);
266 if (obj != NULL__null) {
267 array_h->obj_at_put(i, obj);
268 }
269 }
270 return array_h;
271}
272
273objArrayHandle LiveFrameStream::monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors, TRAPSJavaThread* __the_thread__) {
274 int length = monitors->length();
275 objArrayOop array_oop = oopFactory::new_objArray(vmClasses::Object_klass(),
276 length, CHECK_(objArrayHandle())__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return objArrayHandle(); (void)(0);
277 objArrayHandle array_h(THREAD__the_thread__, array_oop);
278 for (int i = 0; i < length; i++) {
279 MonitorInfo* monitor = monitors->at(i);
280 array_h->obj_at_put(i, monitor->owner());
281 }
282 return array_h;
283}
284
285// Fill StackFrameInfo with bci and initialize memberName
286void BaseFrameStream::fill_stackframe(Handle stackFrame, const methodHandle& method, TRAPSJavaThread* __the_thread__) {
287 java_lang_StackFrameInfo::set_method_and_bci(stackFrame, method, bci(), THREAD__the_thread__);
288}
289
290// Fill LiveStackFrameInfo with locals, monitors, and expressions
291void LiveFrameStream::fill_live_stackframe(Handle stackFrame,
292 const methodHandle& method, TRAPSJavaThread* __the_thread__) {
293 fill_stackframe(stackFrame, method, CHECK__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return ; (void)(0);
294 if (_jvf != NULL__null) {
295 ResourceMark rm(THREAD__the_thread__);
296 HandleMark hm(THREAD__the_thread__);
297
298 StackValueCollection* locals = _jvf->locals();
299 StackValueCollection* expressions = _jvf->expressions();
300 GrowableArray<MonitorInfo*>* monitors = _jvf->monitors();
301
302 int mode = 0;
303 if (_jvf->is_interpreted_frame()) {
304 mode = MODE_INTERPRETED;
305 } else if (_jvf->is_compiled_frame()) {
306 mode = MODE_COMPILED;
307 }
308
309 if (!locals->is_empty()) {
310 objArrayHandle locals_h = values_to_object_array(locals, CHECK__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return ; (void)(0);
311 java_lang_LiveStackFrameInfo::set_locals(stackFrame(), locals_h());
312 }
313 if (!expressions->is_empty()) {
314 objArrayHandle expressions_h = values_to_object_array(expressions, CHECK__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return ; (void)(0);
315 java_lang_LiveStackFrameInfo::set_operands(stackFrame(), expressions_h());
316 }
317 if (monitors->length() > 0) {
318 objArrayHandle monitors_h = monitors_to_object_array(monitors, CHECK__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return ; (void)(0);
319 java_lang_LiveStackFrameInfo::set_monitors(stackFrame(), monitors_h());
320 }
321 java_lang_LiveStackFrameInfo::set_mode(stackFrame(), mode);
322 }
323}
324
325// Begins stack walking.
326//
327// Parameters:
328// stackStream StackStream object
329// mode Stack walking mode.
330// skip_frames Number of frames to be skipped.
331// frame_count Number of frames to be traversed.
332// start_index Start index to the user-supplied buffers.
333// frames_array Buffer to store StackFrame in, starting at start_index.
334// frames array is a Class<?>[] array when only getting caller
335// reference, and a StackFrameInfo[] array (or derivative)
336// otherwise. It should never be null.
337//
338// Returns Object returned from AbstractStackWalker::doStackWalk call.
339//
340oop StackWalk::walk(Handle stackStream, jlong mode,
341 int skip_frames, int frame_count, int start_index,
342 objArrayHandle frames_array,
343 TRAPSJavaThread* __the_thread__) {
344 ResourceMark rm(THREAD__the_thread__);
345 JavaThread* jt = THREAD__the_thread__;
346 log_debug(stackwalk)(!(LogImpl<(LogTag::_stackwalk), (LogTag::__NO_TAG), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Debug))) ? (void)0 : LogImpl
<(LogTag::_stackwalk), (LogTag::__NO_TAG), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Debug>("Start walking: mode " JLONG_FORMAT"%" "l" "d" " skip %d frames batch size %d",
347 mode, skip_frames, frame_count);
348
349 if (frames_array.is_null()) {
350 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL){ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 350, vmSymbols::java_lang_NullPointerException(), "frames_array is NULL"
); return __null; };
351 }
352
353 // Setup traversal onto my stack.
354 if (live_frame_info(mode)) {
355 assert (use_frames_array(mode), "Bad mode for get live frame")do { if (!(use_frames_array(mode))) { (*g_assert_poison) = 'X'
;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 355, "assert(" "use_frames_array(mode)" ") failed", "Bad mode for get live frame"
); ::breakpoint(); } } while (0);
356 RegisterMap regMap(jt, true);
357 LiveFrameStream stream(jt, &regMap);
358 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
359 start_index, frames_array, THREAD__the_thread__);
360 } else {
361 JavaFrameStream stream(jt, mode);
362 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
363 start_index, frames_array, THREAD__the_thread__);
364 }
365}
366
367oop StackWalk::fetchFirstBatch(BaseFrameStream& stream, Handle stackStream,
368 jlong mode, int skip_frames, int frame_count,
369 int start_index, objArrayHandle frames_array, TRAPSJavaThread* __the_thread__) {
370 methodHandle m_doStackWalk(THREAD__the_thread__, Universe::do_stack_walk_method());
371
372 {
373 Klass* stackWalker_klass = vmClasses::StackWalker_klass();
374 Klass* abstractStackWalker_klass = vmClasses::AbstractStackWalker_klass();
375 while (!stream.at_end()) {
376 InstanceKlass* ik = stream.method()->method_holder();
377 if (ik != stackWalker_klass &&
378 ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass) {
379 break;
380 }
381
382 LogTarget(Debug, stackwalk)LogTargetImpl<LogLevel::Debug, (LogTag::_stackwalk), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG), (LogTag::__NO_TAG)> lt;
383 if (lt.is_enabled()) {
384 ResourceMark rm(THREAD__the_thread__);
385 LogStream ls(lt);
386 ls.print(" skip ");
387 stream.method()->print_short_name(&ls);
388 ls.cr();
389 }
390 stream.next();
391 }
392
393 // stack frame has been traversed individually and resume stack walk
394 // from the stack frame at depth == skip_frames.
395 for (int n=0; n < skip_frames && !stream.at_end(); stream.next(), n++) {
396 LogTarget(Debug, stackwalk)LogTargetImpl<LogLevel::Debug, (LogTag::_stackwalk), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG), (LogTag::__NO_TAG)> lt;
397 if (lt.is_enabled()) {
398 ResourceMark rm(THREAD__the_thread__);
399 LogStream ls(lt);
400 ls.print(" skip ");
401 stream.method()->print_short_name(&ls);
402 ls.cr();
403 }
404 }
405 }
406
407 int end_index = start_index;
408 int numFrames = 0;
409 if (!stream.at_end()) {
410 KeepStackGCProcessedMark keep_stack(THREAD__the_thread__);
411 numFrames = fill_in_frames(mode, stream, frame_count, start_index,
412 frames_array, end_index, CHECK_NULL__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return __null; (void)(0);
413 if (numFrames < 1) {
414 THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL){ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 414, vmSymbols::java_lang_InternalError(), "stack walk: decode failed"
); return __null; };
415 }
416 }
417
418 // JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
419 // Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
420 // which calls the implementation to consume the stack frames.
421 // When JVM_CallStackWalk returns, it invalidates the stack stream.
422 JavaValue result(T_OBJECT);
423 JavaCallArguments args(stackStream);
424 args.push_long(stream.address_value());
425 args.push_int(skip_frames);
426 args.push_int(frame_count);
427 args.push_int(start_index);
428 args.push_int(end_index);
429
430 // Link the thread and vframe stream into the callee-visible object
431 stream.setup_magic_on_entry(frames_array);
432
433 JavaCalls::call(&result, m_doStackWalk, &args, THREAD__the_thread__);
434
435 // Do this before anything else happens, to disable any lingering stream objects
436 bool ok = stream.cleanup_magic_on_exit(frames_array);
437
438 // Throw pending exception if we must
439 (void) (CHECK_NULL__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return __null; (void)(0);
440
441 if (!ok) {
442 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL){ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 442, vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit"
); return __null; };
443 }
444
445 // Return normally
446 return result.get_oop();
447}
448
449// Walk the next batch of stack frames
450//
451// Parameters:
452// stackStream StackStream object
453// mode Stack walking mode.
454// magic Must be valid value to continue the stack walk
455// frame_count Number of frames to be decoded.
456// start_index Start index to the user-supplied buffers.
457// frames_array Buffer to store StackFrame in, starting at start_index.
458//
459// Returns the end index of frame filled in the buffer.
460//
461jint StackWalk::fetchNextBatch(Handle stackStream, jlong mode, jlong magic,
462 int frame_count, int start_index,
463 objArrayHandle frames_array,
464 TRAPSJavaThread* __the_thread__)
465{
466 JavaThread* jt = THREAD__the_thread__;
467 BaseFrameStream* existing_stream = BaseFrameStream::from_current(jt, magic, frames_array);
468 if (existing_stream == NULL__null) {
469 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L){ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 469, vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers"
); return 0L; };
470 }
471
472 if (frames_array.is_null()) {
473 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", 0L){ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 473, vmSymbols::java_lang_NullPointerException(), "frames_array is NULL"
); return 0L; };
474 }
475
476 log_debug(stackwalk)(!(LogImpl<(LogTag::_stackwalk), (LogTag::__NO_TAG), (LogTag
::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::
__NO_TAG)>::is_level(LogLevel::Debug))) ? (void)0 : LogImpl
<(LogTag::_stackwalk), (LogTag::__NO_TAG), (LogTag::__NO_TAG
), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG)
>::write<LogLevel::Debug>("StackWalk::fetchNextBatch frame_count %d existing_stream "
477 PTR_FORMAT"0x%016" "l" "x" " start %d frames %d",
478 frame_count, p2i(existing_stream), start_index, frames_array->length());
479 int end_index = start_index;
480 if (frame_count <= 0) {
481 return end_index; // No operation.
482 }
483
484 int count = frame_count + start_index;
485 assert (frames_array->length() >= count, "not enough space in buffers")do { if (!(frames_array->length() >= count)) { (*g_assert_poison
) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 485, "assert(" "frames_array->length() >= count" ") failed"
, "not enough space in buffers"); ::breakpoint(); } } while (
0);
486
487 BaseFrameStream& stream = (*existing_stream);
488 if (!stream.at_end()) {
489 // If we have to get back here for even more frames, then 1) the user did not supply
490 // an accurate hint suggesting the depth of the stack walk, and 2) we are not just
491 // peeking at a few frames. Take the cost of flushing out any pending deferred GC
492 // processing of the stack.
493 KeepStackGCProcessedMark keep_stack(jt);
494 stream.next(); // advance past the last frame decoded in previous batch
495 if (!stream.at_end()) {
496 int n = fill_in_frames(mode, stream, frame_count, start_index,
497 frames_array, end_index, CHECK_0__the_thread__); if ((((ThreadShadow*)__the_thread__)->has_pending_exception
())) return 0; (void)(0);
498 if (n < 1) {
499 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed", 0L){ Exceptions::_throw_msg(__the_thread__, "/home/daniel/Projects/java/jdk/src/hotspot/share/prims/stackwalk.cpp"
, 499, vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed"
); return 0L; };
500 }
501 return end_index;
502 }
503 }
504 return end_index;
505}