1 /*
2 * Copyright (c) 1997, 2023, 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/debugInfo.hpp"
27 #include "oops/access.hpp"
28 #include "oops/compressedOops.inline.hpp"
29 #include "oops/oop.hpp"
30 #include "runtime/frame.inline.hpp"
31 #include "runtime/globals.hpp"
32 #include "runtime/handles.inline.hpp"
33 #include "runtime/stackValue.hpp"
34 #if INCLUDE_ZGC
35 #include "gc/z/zBarrier.inline.hpp"
36 #endif
37 #if INCLUDE_SHENANDOAHGC
38 #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp"
39 #endif
40
41 class RegisterMap;
42 class SmallRegisterMap;
43
44 template StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
45 template StackValue* StackValue::create_stack_value(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv);
46
47 template<typename RegisterMapT>
48 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
49 return create_stack_value(sv, stack_value_address(fr, reg_map, sv), reg_map);
50 }
51
52 static oop oop_from_oop_location(stackChunkOop chunk, void* addr) {
53 if (addr == nullptr) {
54 return nullptr;
55 }
56
57 if (UseCompressedOops) {
58 // When compressed oops is enabled, an oop location may
59 // contain narrow oop values - we deal with that here
60
61 if (chunk != nullptr && chunk->has_bitmap()) {
62 // Transformed stack chunk with narrow oops
63 return chunk->load_oop((narrowOop*)addr);
64 }
65
66 #ifdef _LP64
67 if (CompressedOops::is_base(*(void**)addr)) {
68 // Compiled code may produce decoded oop = narrow_oop_base
69 // when a narrow oop implicit null check is used.
70 // The narrow_oop_base could be null or be the address
71 // of the page below heap. Use null value for both cases.
72 return nullptr;
73 }
74 #endif
75 }
76
77 if (chunk != nullptr) {
78 // Load oop from chunk
79 return chunk->load_oop((oop*)addr);
80 }
81
82 // Load oop from stack
83 oop val = *(oop*)addr;
84
85 #if INCLUDE_SHENANDOAHGC
86 if (UseShenandoahGC) {
87 // Pass the value through the barrier to avoid capturing bad oops as
88 // stack values. Note: do not heal the location, to avoid accidentally
89 // corrupting the stack. Stack watermark barriers are supposed to handle
90 // the healing.
91 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
92 }
93 #endif
94
95 return val;
96 }
97
98 static oop oop_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) {
99 assert(UseCompressedOops, "Narrow oops should not exist");
100 assert(addr != nullptr, "Not expecting null address");
101 narrowOop* narrow_addr;
102 if (is_register) {
103 // The callee has no clue whether the register holds an int,
104 // long or is unused. He always saves a long. Here we know
105 // a long was saved, but we only want an int back. Narrow the
106 // saved long to the int that the JVM wants. We can't just
107 // use narrow_oop_cast directly, because we don't know what
108 // the high bits of the value might be.
109 narrow_addr = ((narrowOop*)addr) BIG_ENDIAN_ONLY(+ 1);
110 } else {
111 narrow_addr = (narrowOop*)addr;
112 }
113
114 if (chunk != nullptr) {
115 // Load oop from chunk
116 return chunk->load_oop(narrow_addr);
117 }
118
119 // Load oop from stack
120 oop val = CompressedOops::decode(*narrow_addr);
121
122 #if INCLUDE_SHENANDOAHGC
123 if (UseShenandoahGC) {
124 // Pass the value through the barrier to avoid capturing bad oops as
125 // stack values. Note: do not heal the location, to avoid accidentally
126 // corrupting the stack. Stack watermark barriers are supposed to handle
127 // the healing.
128 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
129 }
130 #endif
131
132 return val;
133 }
134
135 StackValue* StackValue::create_stack_value_from_oop_location(stackChunkOop chunk, void* addr) {
136 oop val = oop_from_oop_location(chunk, addr);
137 assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
138 p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
139 Handle h(Thread::current(), val); // Wrap a handle around the oop
140 return new StackValue(h);
141 }
142
143 StackValue* StackValue::create_stack_value_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) {
144 oop val = oop_from_narrowOop_location(chunk, addr, is_register);
145 assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
146 p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
147 Handle h(Thread::current(), val); // Wrap a handle around the oop
148 return new StackValue(h);
149 }
150
151 template<typename RegisterMapT>
152 StackValue* StackValue::create_stack_value(ScopeValue* sv, address value_addr, const RegisterMapT* reg_map) {
153 stackChunkOop chunk = reg_map->stack_chunk()();
154 if (sv->is_location()) {
155 // Stack or register value
156 Location loc = ((LocationValue *)sv)->location();
157
158 // Then package it right depending on type
159 // Note: the transfer of the data is thru a union that contains
160 // an intptr_t. This is because an interpreter stack slot is
161 // really an intptr_t. The use of a union containing an intptr_t
162 // ensures that on a 64 bit platform we have proper alignment
163 // and that we store the value where the interpreter will expect
164 // to find it (i.e. proper endian). Similarly on a 32bit platform
165 // using the intptr_t ensures that when a value is larger than
166 // a stack slot (jlong/jdouble) that we capture the proper part
167 // of the value for the stack slot in question.
168 //
169 switch( loc.type() ) {
170 case Location::float_in_dbl: { // Holds a float in a double register?
171 // The callee has no clue whether the register holds a float,
172 // double or is unused. He always saves a double. Here we know
173 // a double was saved, but we only want a float back. Narrow the
174 // saved double to the float that the JVM wants.
175 assert( loc.is_register(), "floats always saved to stack in 1 word" );
176 union { intptr_t p; jfloat jf; } value;
177 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
178 value.jf = (jfloat) *(jdouble*) value_addr;
179 return new StackValue(value.p); // 64-bit high half is stack junk
180 }
181 case Location::int_in_long: { // Holds an int in a long register?
182 // The callee has no clue whether the register holds an int,
183 // long or is unused. He always saves a long. Here we know
184 // a long was saved, but we only want an int back. Narrow the
185 // saved long to the int that the JVM wants.
186 assert( loc.is_register(), "ints always saved to stack in 1 word" );
187 union { intptr_t p; jint ji;} value;
188 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
189 value.ji = (jint) *(jlong*) value_addr;
190 return new StackValue(value.p); // 64-bit high half is stack junk
191 }
192 #ifdef _LP64
193 case Location::dbl:
194 // Double value in an aligned adjacent pair
195 return new StackValue(*(intptr_t*)value_addr);
196 case Location::lng:
197 // Long value in an aligned adjacent pair
198 return new StackValue(*(intptr_t*)value_addr);
199 case Location::narrowoop:
200 return create_stack_value_from_narrowOop_location(reg_map->stack_chunk()(), (void*)value_addr, loc.is_register());
201 #endif
202 case Location::oop:
203 return create_stack_value_from_oop_location(reg_map->stack_chunk()(), (void*)value_addr);
204 case Location::addr: {
205 loc.print_on(tty);
206 ShouldNotReachHere(); // both C1 and C2 now inline jsrs
207 }
208 case Location::normal: {
209 // Just copy all other bits straight through
210 union { intptr_t p; jint ji;} value;
211 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
212 value.ji = *(jint*)value_addr;
213 return new StackValue(value.p);
214 }
215 case Location::invalid: {
216 return new StackValue();
217 }
218 case Location::vector: {
219 loc.print_on(tty);
220 ShouldNotReachHere(); // should be handled by VectorSupport::allocate_vector()
221 }
222 default:
223 loc.print_on(tty);
224 ShouldNotReachHere();
225 }
226
227 } else if (sv->is_constant_int()) {
228 // Constant int: treat same as register int.
229 union { intptr_t p; jint ji;} value;
230 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
231 value.ji = (jint)((ConstantIntValue*)sv)->value();
232 return new StackValue(value.p);
233 } else if (sv->is_constant_oop()) {
234 // constant oop
235 return new StackValue(sv->as_ConstantOopReadValue()->value());
236 #ifdef _LP64
237 } else if (sv->is_constant_double()) {
238 // Constant double in a single stack slot
239 union { intptr_t p; double d; } value;
240 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
241 value.d = ((ConstantDoubleValue *)sv)->value();
242 return new StackValue(value.p);
243 } else if (sv->is_constant_long()) {
244 // Constant long in a single stack slot
245 union { intptr_t p; jlong jl; } value;
246 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
247 value.jl = ((ConstantLongValue *)sv)->value();
248 return new StackValue(value.p);
249 #endif
250 } else if (sv->is_object()) { // Scalar replaced object in compiled frame
251 ObjectValue* ov = (ObjectValue *)sv;
252 Handle hdl = ov->value();
253 return new StackValue(hdl, hdl.is_null() && ov->is_scalar_replaced() ? 1 : 0);
254 } else if (sv->is_marker()) {
255 // Should never need to directly construct a marker.
256 ShouldNotReachHere();
257 }
258 // Unknown ScopeValue type
259 ShouldNotReachHere();
260 return new StackValue((intptr_t) 0); // dummy
261 }
262
263 template address StackValue::stack_value_address(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
264 template address StackValue::stack_value_address(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv);
265
266 template<typename RegisterMapT>
267 address StackValue::stack_value_address(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
268 if (!sv->is_location()) {
269 return nullptr;
270 }
271 Location loc = ((LocationValue *)sv)->location();
272 if (loc.type() == Location::invalid) {
273 return nullptr;
274 }
275
276 if (!reg_map->in_cont()) {
277 address value_addr = loc.is_register()
278 // Value was in a callee-save register
279 ? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()), fr->sp())
280 // Else value was directly saved on the stack. The frame's original stack pointer,
281 // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used.
282 : ((address)fr->unextended_sp()) + loc.stack_offset();
283
284 assert(value_addr == nullptr || reg_map->thread() == nullptr || reg_map->thread()->is_in_usable_stack(value_addr), INTPTR_FORMAT, p2i(value_addr));
285 return value_addr;
286 }
287
288 address value_addr = loc.is_register()
289 ? reg_map->as_RegisterMap()->stack_chunk()->reg_to_location(*fr, reg_map->as_RegisterMap(), VMRegImpl::as_VMReg(loc.register_number()))
290 : reg_map->as_RegisterMap()->stack_chunk()->usp_offset_to_location(*fr, loc.stack_offset());
291
292 assert(value_addr == nullptr || Continuation::is_in_usable_stack(value_addr, reg_map->as_RegisterMap()) || (reg_map->thread() != nullptr && reg_map->thread()->is_in_usable_stack(value_addr)), INTPTR_FORMAT, p2i(value_addr));
293 return value_addr;
294 }
295
296 BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {
297 assert(location.is_stack(), "for now we only look at the stack");
298 int word_offset = location.stack_offset() / wordSize;
299 // (stack picture)
300 // high: [ ] word_offset + 1
301 // low [ ] word_offset
302 //
303 // sp-> [ ] 0
304 // the word_offset is the distance from the stack pointer to the lowest address
305 // The frame's original stack pointer, before any extension by its callee
306 // (due to Compiler1 linkage on SPARC), must be used.
307 return (BasicLock*) (fr->unextended_sp() + word_offset);
308 }
309
310
311 #ifndef PRODUCT
312
313 void StackValue::print_on(outputStream* st) const {
314 switch(_type) {
315 case T_INT:
316 st->print("%d (int) %f (float) %x (hex)", *(int *)&_integer_value, *(float *)&_integer_value, *(int *)&_integer_value);
317 break;
318
319 case T_OBJECT:
320 if (_handle_value() != nullptr) {
321 _handle_value()->print_value_on(st);
322 } else {
323 st->print("null");
324 }
325 st->print(" <" INTPTR_FORMAT ">", p2i(_handle_value()));
326 break;
327
328 case T_CONFLICT:
329 st->print("conflict");
330 break;
331
332 default:
333 ShouldNotReachHere();
334 }
335 }
336
337 #endif