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
45 static oop oop_from_oop_location(stackChunkOop chunk, void* addr) {
46 if (addr == nullptr) {
47 return nullptr;
48 }
49
50 if (UseCompressedOops) {
51 // When compressed oops is enabled, an oop location may
52 // contain narrow oop values - we deal with that here
53
54 if (chunk != nullptr && chunk->has_bitmap()) {
55 // Transformed stack chunk with narrow oops
56 return chunk->load_oop((narrowOop*)addr);
57 }
58
59 #ifdef _LP64
60 if (CompressedOops::is_base(*(void**)addr)) {
61 // Compiled code may produce decoded oop = narrow_oop_base
62 // when a narrow oop implicit null check is used.
63 // The narrow_oop_base could be null or be the address
64 // of the page below heap. Use null value for both cases.
65 return nullptr;
66 }
67 #endif
68 }
69
70 if (chunk != nullptr) {
71 // Load oop from chunk
72 return chunk->load_oop((oop*)addr);
73 }
74
75 // Load oop from stack
76 oop val = *(oop*)addr;
77
78 #if INCLUDE_SHENANDOAHGC
79 if (UseShenandoahGC) {
80 // Pass the value through the barrier to avoid capturing bad oops as
81 // stack values. Note: do not heal the location, to avoid accidentally
82 // corrupting the stack. Stack watermark barriers are supposed to handle
83 // the healing.
84 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
85 }
86 #endif
87
88 return val;
89 }
90
91 static oop oop_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) {
92 assert(UseCompressedOops, "Narrow oops should not exist");
93 assert(addr != nullptr, "Not expecting null address");
94 narrowOop* narrow_addr;
95 if (is_register) {
96 // The callee has no clue whether the register holds an int,
97 // long or is unused. He always saves a long. Here we know
98 // a long was saved, but we only want an int back. Narrow the
99 // saved long to the int that the JVM wants. We can't just
100 // use narrow_oop_cast directly, because we don't know what
101 // the high bits of the value might be.
102 narrow_addr = ((narrowOop*)addr) BIG_ENDIAN_ONLY(+ 1);
103 } else {
104 narrow_addr = (narrowOop*)addr;
105 }
106
107 if (chunk != nullptr) {
108 // Load oop from chunk
109 return chunk->load_oop(narrow_addr);
110 }
111
112 // Load oop from stack
113 oop val = CompressedOops::decode(*narrow_addr);
114
115 #if INCLUDE_SHENANDOAHGC
116 if (UseShenandoahGC) {
117 // Pass the value through the barrier to avoid capturing bad oops as
118 // stack values. Note: do not heal the location, to avoid accidentally
119 // corrupting the stack. Stack watermark barriers are supposed to handle
120 // the healing.
121 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val);
122 }
123 #endif
124
125 return val;
126 }
127
128 StackValue* StackValue::create_stack_value_from_oop_location(stackChunkOop chunk, void* addr) {
129 oop val = oop_from_oop_location(chunk, addr);
130 assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
131 p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
132 Handle h(Thread::current(), val); // Wrap a handle around the oop
133 return new StackValue(h);
134 }
135
136 StackValue* StackValue::create_stack_value_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) {
137 oop val = oop_from_narrowOop_location(chunk, addr, is_register);
138 assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d",
139 p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops);
140 Handle h(Thread::current(), val); // Wrap a handle around the oop
141 return new StackValue(h);
142 }
143
144
145 template StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
146 template StackValue* StackValue::create_stack_value(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv);
147
148 template<typename RegisterMapT>
149 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
150 address value_addr = stack_value_address(fr, reg_map, sv);
151 stackChunkOop chunk = reg_map->stack_chunk()();
152 if (sv->is_location()) {
153 // Stack or register value
154 Location loc = ((LocationValue *)sv)->location();
155
156 // Then package it right depending on type
157 // Note: the transfer of the data is thru a union that contains
158 // an intptr_t. This is because an interpreter stack slot is
159 // really an intptr_t. The use of a union containing an intptr_t
160 // ensures that on a 64 bit platform we have proper alignment
161 // and that we store the value where the interpreter will expect
162 // to find it (i.e. proper endian). Similarly on a 32bit platform
163 // using the intptr_t ensures that when a value is larger than
164 // a stack slot (jlong/jdouble) that we capture the proper part
165 // of the value for the stack slot in question.
166 //
167 switch( loc.type() ) {
168 case Location::float_in_dbl: { // Holds a float in a double register?
169 // The callee has no clue whether the register holds a float,
170 // double or is unused. He always saves a double. Here we know
171 // a double was saved, but we only want a float back. Narrow the
172 // saved double to the float that the JVM wants.
173 assert( loc.is_register(), "floats always saved to stack in 1 word" );
174 union { intptr_t p; jfloat jf; } value;
175 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
176 value.jf = (jfloat) *(jdouble*) value_addr;
177 return new StackValue(value.p); // 64-bit high half is stack junk
178 }
179 case Location::int_in_long: { // Holds an int in a long register?
180 // The callee has no clue whether the register holds an int,
181 // long or is unused. He always saves a long. Here we know
182 // a long was saved, but we only want an int back. Narrow the
183 // saved long to the int that the JVM wants.
184 assert( loc.is_register(), "ints always saved to stack in 1 word" );
185 union { intptr_t p; jint ji;} value;
186 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
187 value.ji = (jint) *(jlong*) value_addr;
188 return new StackValue(value.p); // 64-bit high half is stack junk
189 }
190 #ifdef _LP64
191 case Location::dbl:
192 // Double value in an aligned adjacent pair
193 return new StackValue(*(intptr_t*)value_addr);
194 case Location::lng:
195 // Long value in an aligned adjacent pair
196 return new StackValue(*(intptr_t*)value_addr);
197 case Location::narrowoop:
198 return create_stack_value_from_narrowOop_location(reg_map->stack_chunk()(), (void*)value_addr, loc.is_register());
199 #endif
200 case Location::oop:
201 return create_stack_value_from_oop_location(reg_map->stack_chunk()(), (void*)value_addr);
202 case Location::addr: {
203 loc.print_on(tty);
204 ShouldNotReachHere(); // both C1 and C2 now inline jsrs
205 }
206 case Location::normal: {
207 // Just copy all other bits straight through
208 union { intptr_t p; jint ji;} value;
209 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
210 value.ji = *(jint*)value_addr;
211 return new StackValue(value.p);
212 }
213 case Location::invalid: {
214 return new StackValue();
215 }
216 case Location::vector: {
217 loc.print_on(tty);
218 ShouldNotReachHere(); // should be handled by VectorSupport::allocate_vector()
219 }
220 default:
221 loc.print_on(tty);
222 ShouldNotReachHere();
223 }
224
225 } else if (sv->is_constant_int()) {
226 // Constant int: treat same as register int.
227 union { intptr_t p; jint ji;} value;
228 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
229 value.ji = (jint)((ConstantIntValue*)sv)->value();
230 return new StackValue(value.p);
231 } else if (sv->is_constant_oop()) {
232 // constant oop
233 return new StackValue(sv->as_ConstantOopReadValue()->value());
234 #ifdef _LP64
235 } else if (sv->is_constant_double()) {
236 // Constant double in a single stack slot
237 union { intptr_t p; double d; } value;
238 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
239 value.d = ((ConstantDoubleValue *)sv)->value();
240 return new StackValue(value.p);
241 } else if (sv->is_constant_long()) {
242 // Constant long in a single stack slot
243 union { intptr_t p; jlong jl; } value;
244 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF);
245 value.jl = ((ConstantLongValue *)sv)->value();
246 return new StackValue(value.p);
247 #endif
248 } else if (sv->is_object()) { // Scalar replaced object in compiled frame
249 ObjectValue* ov = ((ObjectValue *)sv);
250 bool scalar_replaced = ov->value().is_null();
251 if (ov->maybe_null()) {
252 // Don't treat inline type as scalar replaced if it is null
253 jint is_init = StackValue::create_stack_value(fr, reg_map, ov->is_init())->get_jint();
254 scalar_replaced &= (is_init != 0);
255 }
256 return new StackValue(ov->value(), scalar_replaced ? 1 : 0);
257 } else if (sv->is_marker()) {
258 // Should never need to directly construct a marker.
259 ShouldNotReachHere();
260 }
261 // Unknown ScopeValue type
262 ShouldNotReachHere();
263 return new StackValue((intptr_t) 0); // dummy
264 }
265
266 template address StackValue::stack_value_address(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
267 template address StackValue::stack_value_address(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv);
268
269 template<typename RegisterMapT>
270 address StackValue::stack_value_address(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) {
271 if (!sv->is_location()) {
272 return nullptr;
273 }
274 Location loc = ((LocationValue *)sv)->location();
275 if (loc.type() == Location::invalid) {
276 return nullptr;
277 }
278
279 if (!reg_map->in_cont()) {
280 address value_addr = loc.is_register()
281 // Value was in a callee-save register
282 ? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()), fr->sp())
283 // Else value was directly saved on the stack. The frame's original stack pointer,
284 // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used.
285 : ((address)fr->unextended_sp()) + loc.stack_offset();
286
287 assert(value_addr == nullptr || reg_map->thread() == nullptr || reg_map->thread()->is_in_usable_stack(value_addr), INTPTR_FORMAT, p2i(value_addr));
288 return value_addr;
289 }
290
291 address value_addr = loc.is_register()
292 ? reg_map->as_RegisterMap()->stack_chunk()->reg_to_location(*fr, reg_map->as_RegisterMap(), VMRegImpl::as_VMReg(loc.register_number()))
293 : reg_map->as_RegisterMap()->stack_chunk()->usp_offset_to_location(*fr, loc.stack_offset());
294
295 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));
296 return value_addr;
297 }
298
299 BasicLock* StackValue::resolve_monitor_lock(const frame* fr, Location location) {
300 assert(location.is_stack(), "for now we only look at the stack");
301 int word_offset = location.stack_offset() / wordSize;
302 // (stack picture)
303 // high: [ ] word_offset + 1
304 // low [ ] word_offset
305 //
306 // sp-> [ ] 0
307 // the word_offset is the distance from the stack pointer to the lowest address
308 // The frame's original stack pointer, before any extension by its callee
309 // (due to Compiler1 linkage on SPARC), must be used.
310 return (BasicLock*) (fr->unextended_sp() + word_offset);
311 }
312
313
314 #ifndef PRODUCT
315
316 void StackValue::print_on(outputStream* st) const {
317 switch(_type) {
318 case T_INT:
319 st->print("%d (int) %f (float) %x (hex)", *(int *)&_integer_value, *(float *)&_integer_value, *(int *)&_integer_value);
320 break;
321
322 case T_OBJECT:
323 if (_handle_value() != nullptr) {
324 _handle_value()->print_value_on(st);
325 } else {
326 st->print("null");
327 }
328 st->print(" <" INTPTR_FORMAT ">", p2i(_handle_value()));
329 break;
330
331 case T_CONFLICT:
332 st->print("conflict");
333 break;
334
335 default:
336 ShouldNotReachHere();
337 }
338 }
339
340 #endif