1 /*
2 * Copyright (c) 2019, 2025, 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
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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,
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23 */
24
25 #ifndef CPU_X86_CONTINUATIONFREEZETHAW_X86_INLINE_HPP
26 #define CPU_X86_CONTINUATIONFREEZETHAW_X86_INLINE_HPP
27
28 #include "code/codeBlob.inline.hpp"
29 #include "oops/stackChunkOop.inline.hpp"
30 #include "runtime/frame.hpp"
31 #include "runtime/frame.inline.hpp"
32
33 inline void patch_callee_link(const frame& f, intptr_t* fp) {
34 *ContinuationHelper::Frame::callee_link_address(f) = fp;
35 }
36
37 inline void patch_callee_link_relative(const frame& f, intptr_t* fp) {
38 intptr_t* la = (intptr_t*)ContinuationHelper::Frame::callee_link_address(f);
39 intptr_t new_value = fp - la;
40 *la = new_value;
41 }
42
43 ////// Freeze
44
45 // Fast path
46
47 inline void FreezeBase::patch_stack_pd(intptr_t* frame_sp, intptr_t* heap_sp) {
48 // copy the spilled rbp from the heap to the stack
49 *(frame_sp - frame::sender_sp_offset) = *(heap_sp - frame::sender_sp_offset);
50 }
51
52 // Slow path
53
54 template<typename FKind>
55 inline frame FreezeBase::sender(const frame& f) {
56 assert(FKind::is_instance(f), "");
57 if (FKind::interpreted) {
58 return frame(f.sender_sp(), f.interpreter_frame_sender_sp(), f.link(), f.sender_pc());
59 }
60 intptr_t** link_addr = link_address<FKind>(f);
61
62 intptr_t* sender_sp = (intptr_t*)(link_addr + frame::sender_sp_offset); // f.unextended_sp() + (fsize/wordSize); //
63 address sender_pc = (address) *(sender_sp-1);
64 assert(sender_sp != f.sp(), "must have changed");
65
66 int slot = 0;
67 CodeBlob* sender_cb = CodeCache::find_blob_and_oopmap(sender_pc, slot);
68 return sender_cb != nullptr
69 ? frame(sender_sp, sender_sp, *link_addr, sender_pc, sender_cb,
70 slot == -1 ? nullptr : sender_cb->oop_map_for_slot(slot, sender_pc), false)
71 : frame(sender_sp, sender_sp, *link_addr, sender_pc);
72 }
73
74 template<typename FKind>
75 frame FreezeBase::new_heap_frame(frame& f, frame& caller) {
76 assert(FKind::is_instance(f), "");
77 assert(!caller.is_interpreted_frame()
78 || caller.unextended_sp() == (intptr_t*)caller.at(frame::interpreter_frame_last_sp_offset), "");
79
80 intptr_t *sp, *fp; // sp is really our unextended_sp
81 if (FKind::interpreted) {
82 assert((intptr_t*)f.at_relative_or_null(frame::interpreter_frame_last_sp_offset) == nullptr
83 || f.unextended_sp() == (intptr_t*)f.at_relative(frame::interpreter_frame_last_sp_offset), "");
84 intptr_t locals_offset = *f.addr_at(frame::interpreter_frame_locals_offset);
85 // If the caller.is_empty(), i.e. we're freezing into an empty chunk, then we set
86 // the chunk's argsize in finalize_freeze and make room for it above the unextended_sp
87 bool overlap_caller = caller.is_interpreted_frame() || caller.is_empty();
88 fp = caller.unextended_sp() - 1 - locals_offset + (overlap_caller ? ContinuationHelper::InterpretedFrame::stack_argsize(f) : 0);
89 sp = fp - (f.fp() - f.unextended_sp());
90 assert(sp <= fp, "");
91 assert(fp <= caller.unextended_sp(), "");
92 caller.set_sp(fp + frame::sender_sp_offset);
93
94 assert(_cont.tail()->is_in_chunk(sp), "");
95
96 frame hf(sp, sp, fp, f.pc(), nullptr, nullptr, true /* on_heap */);
97 // copy relativized locals from the stack frame
98 *hf.addr_at(frame::interpreter_frame_locals_offset) = locals_offset;
99 return hf;
100 } else {
101 // For a compiled frame we need to re-read fp out of the frame because it may be an
102 // oop and we might have had a safepoint in finalize_freeze, after constructing f.
103 // For stub/native frames the value is not used while frozen, and will be constructed again
104 // when thawing the frame (see ThawBase::new_stack_frame). We use a special bad address to
105 // help with debugging, particularly when inspecting frames and identifying invalid accesses.
106 fp = FKind::compiled ? *(intptr_t**)(f.sp() - frame::sender_sp_offset) : (intptr_t*)badAddressVal;
107
108 int fsize = FKind::size(f);
109 sp = caller.unextended_sp() - fsize;
110 if (caller.is_interpreted_frame()) {
111 // If the caller is interpreted, our stackargs are not supposed to overlap with it
112 // so we make more room by moving sp down by argsize
113 int argsize = FKind::stack_argsize(f);
114 sp -= argsize;
115 }
116 caller.set_sp(sp + fsize);
117
118 assert(_cont.tail()->is_in_chunk(sp), "");
119
120 return frame(sp, sp, fp, f.pc(), nullptr, nullptr, true /* on_heap */);
121 }
122 }
123
124 void FreezeBase::adjust_interpreted_frame_unextended_sp(frame& f) {
125 assert((f.at(frame::interpreter_frame_last_sp_offset) != 0) || (f.unextended_sp() == f.sp()), "");
126 intptr_t* real_unextended_sp = (intptr_t*)f.at_relative_or_null(frame::interpreter_frame_last_sp_offset);
127 if (real_unextended_sp != nullptr) {
128 f.set_unextended_sp(real_unextended_sp); // can be null at a safepoint
129 }
130 }
131
132 inline void FreezeBase::prepare_freeze_interpreted_top_frame(frame& f) {
133 assert(f.interpreter_frame_last_sp() == nullptr, "should be null for top frame");
134 f.interpreter_frame_set_last_sp(f.unextended_sp());
135 }
136
137 inline void FreezeBase::relativize_interpreted_frame_metadata(const frame& f, const frame& hf) {
138 assert(hf.fp() == hf.unextended_sp() + (f.fp() - f.unextended_sp()), "");
139 assert((f.at(frame::interpreter_frame_last_sp_offset) != 0)
140 || (f.unextended_sp() == f.sp()), "");
141 assert(f.fp() > (intptr_t*)f.at_relative(frame::interpreter_frame_initial_sp_offset), "");
142
143 // Make sure that last_sp is already relativized.
144 assert((intptr_t*)hf.at_relative(frame::interpreter_frame_last_sp_offset) == hf.unextended_sp(), "");
145
146 // Make sure that locals is already relativized.
147 DEBUG_ONLY(Method* m = f.interpreter_frame_method();)
148 // Frames for native methods have 2 extra words (temp oop/result handler) before fixed part of frame.
149 DEBUG_ONLY(int max_locals = !m->is_native() ? m->max_locals() : m->size_of_parameters() + 2;)
150 assert((*hf.addr_at(frame::interpreter_frame_locals_offset) == frame::sender_sp_offset + max_locals - 1), "");
151
152 // Make sure that monitor_block_top is already relativized.
153 assert(hf.at_absolute(frame::interpreter_frame_monitor_block_top_offset) <= frame::interpreter_frame_initial_sp_offset, "");
154
155 assert((hf.fp() - hf.unextended_sp()) == (f.fp() - f.unextended_sp()), "");
156 assert(hf.unextended_sp() == (intptr_t*)hf.at(frame::interpreter_frame_last_sp_offset), "");
157 assert(hf.unextended_sp() <= (intptr_t*)hf.at(frame::interpreter_frame_initial_sp_offset), "");
158 assert(hf.fp() > (intptr_t*)hf.at(frame::interpreter_frame_initial_sp_offset), "");
159 assert(hf.fp() <= (intptr_t*)hf.at(frame::interpreter_frame_locals_offset), "");
160 }
161
162 inline void FreezeBase::set_top_frame_metadata_pd(const frame& hf) {
163 stackChunkOop chunk = _cont.tail();
164 assert(chunk->is_in_chunk(hf.sp() - 1), "");
165 assert(chunk->is_in_chunk(hf.sp() - frame::sender_sp_offset), "");
166
167 address frame_pc = hf.pc();
168
169 *(hf.sp() - 1) = (intptr_t)hf.pc();
170
171 intptr_t* fp_addr = hf.sp() - frame::sender_sp_offset;
172 *fp_addr = hf.is_interpreted_frame() ? (intptr_t)(hf.fp() - fp_addr)
173 : (intptr_t)hf.fp();
174 assert(frame_pc == ContinuationHelper::Frame::real_pc(hf), "");
175 }
176
177 inline void FreezeBase::patch_pd(frame& hf, const frame& caller) {
178 if (caller.is_interpreted_frame()) {
179 assert(!caller.is_empty(), "");
180 patch_callee_link_relative(caller, caller.fp());
181 } else {
182 // If we're the bottom-most frame frozen in this freeze, the caller might have stayed frozen in the chunk,
183 // and its oop-containing fp fixed. We've now just overwritten it, so we must patch it back to its value
184 // as read from the chunk.
185 patch_callee_link(caller, caller.fp());
186 }
187 }
188
189 inline void FreezeBase::patch_pd_unused(intptr_t* sp) {
190 intptr_t* fp_addr = sp - frame::sender_sp_offset;
191 *fp_addr = badAddressVal;
192 }
193
194 inline intptr_t* AnchorMark::anchor_mark_set_pd() {
195 intptr_t* sp = _top_frame.sp();
196 if (_top_frame.is_interpreted_frame()) {
197 // In case the top frame is interpreted we need to set up the anchor using
198 // the last_sp saved in the frame (remove possible alignment added while
199 // thawing, see ThawBase::finish_thaw()). We also need to clear the last_sp
200 // saved in the frame as it is not expected to be set in case we preempt again.
201 _last_sp_from_frame = _top_frame.interpreter_frame_last_sp();
202 assert(_last_sp_from_frame != nullptr, "");
203 _top_frame.interpreter_frame_set_last_sp(nullptr);
204 if (sp != _last_sp_from_frame) {
205 _last_sp_from_frame[-1] = (intptr_t)_top_frame.pc();
206 _last_sp_from_frame[-2] = (intptr_t)_top_frame.fp();
207 }
208 _is_interpreted = true;
209 sp = _last_sp_from_frame;
210 }
211 return sp;
212 }
213
214 inline void AnchorMark::anchor_mark_clear_pd() {
215 if (_is_interpreted) {
216 // Restore last_sp_from_frame and possibly overwritten pc.
217 _top_frame.interpreter_frame_set_last_sp(_last_sp_from_frame);
218 intptr_t* sp = _top_frame.sp();
219 if (sp != _last_sp_from_frame) {
220 sp[-1] = (intptr_t)_top_frame.pc();
221 }
222 }
223 }
224
225 //////// Thaw
226
227 // Fast path
228
229 inline void ThawBase::prefetch_chunk_pd(void* start, int size) {
230 size <<= LogBytesPerWord;
231 Prefetch::read(start, size);
232 Prefetch::read(start, size - 64);
233 }
234
235 template <typename ConfigT>
236 inline void Thaw<ConfigT>::patch_caller_links(intptr_t* sp, intptr_t* bottom) {
237 // Fast path depends on !PreserveFramePointer. See can_thaw_fast().
238 assert(!PreserveFramePointer, "Frame pointers need to be fixed");
239 }
240
241 // Slow path
242
243 inline frame ThawBase::new_entry_frame() {
244 intptr_t* sp = _cont.entrySP();
245 return frame(sp, sp, _cont.entryFP(), _cont.entryPC()); // TODO PERF: This finds code blob and computes deopt state
246 }
247
248 template<typename FKind> frame ThawBase::new_stack_frame(const frame& hf, frame& caller, bool bottom) {
249 assert(FKind::is_instance(hf), "");
250 // The values in the returned frame object will be written into the callee's stack in patch.
251
252 if (FKind::interpreted) {
253 intptr_t* heap_sp = hf.unextended_sp();
254 // If caller is interpreted it already made room for the callee arguments
255 int overlap = caller.is_interpreted_frame() ? ContinuationHelper::InterpretedFrame::stack_argsize(hf) : 0;
256 const int fsize = (int)(ContinuationHelper::InterpretedFrame::frame_bottom(hf) - hf.unextended_sp() - overlap);
257 intptr_t* frame_sp = caller.unextended_sp() - fsize;
258 intptr_t* fp = frame_sp + (hf.fp() - heap_sp);
259 DEBUG_ONLY(intptr_t* unextended_sp = fp + *hf.addr_at(frame::interpreter_frame_last_sp_offset);)
260 assert(frame_sp == unextended_sp, "");
261 caller.set_sp(fp + frame::sender_sp_offset);
262 frame f(frame_sp, frame_sp, fp, hf.pc());
263 // we need to set the locals so that the caller of new_stack_frame() can call
264 // ContinuationHelper::InterpretedFrame::frame_bottom
265 intptr_t locals_offset = *hf.addr_at(frame::interpreter_frame_locals_offset);
266 DEBUG_ONLY(Method* m = hf.interpreter_frame_method();)
267 // Frames for native methods have 2 extra words (temp oop/result handler) before fixed part of frame.
268 DEBUG_ONLY(const int max_locals = !m->is_native() ? m->max_locals() : m->size_of_parameters() + 2;)
269 assert((int)locals_offset == frame::sender_sp_offset + max_locals - 1, "");
270 // copy relativized locals from the heap frame
271 *f.addr_at(frame::interpreter_frame_locals_offset) = locals_offset;
272 return f;
273 } else {
274 int fsize = FKind::size(hf);
275 intptr_t* frame_sp = caller.unextended_sp() - fsize;
276 if (bottom || caller.is_interpreted_frame()) {
277 int argsize = FKind::stack_argsize(hf);
278
279 fsize += argsize;
280 frame_sp -= argsize;
281 caller.set_sp(caller.sp() - argsize);
282 assert(caller.sp() == frame_sp + (fsize-argsize), "");
283
284 frame_sp = align(hf, frame_sp, caller, bottom);
285 }
286
287 assert(hf.cb() != nullptr, "");
288 assert(hf.oop_map() != nullptr, "");
289 intptr_t* fp;
290 if (PreserveFramePointer) {
291 // we need to recreate a "real" frame pointer, pointing into the stack
292 fp = frame_sp + FKind::size(hf) - frame::sender_sp_offset;
293 } else {
294 fp = FKind::stub || FKind::native
295 ? frame_sp + fsize - frame::sender_sp_offset // fp always points to the address below the pushed return pc. We need correct address.
296 : *(intptr_t**)(hf.sp() - frame::sender_sp_offset); // we need to re-read fp because it may be an oop and we might have fixed the frame.
297 }
298 return frame(frame_sp, frame_sp, fp, hf.pc(), hf.cb(), hf.oop_map(), false); // TODO PERF : this computes deopt state; is it necessary?
299 }
300 }
301
302 inline intptr_t* ThawBase::align(const frame& hf, intptr_t* frame_sp, frame& caller, bool bottom) {
303 if (((intptr_t)frame_sp & 0xf) != 0) {
304 assert(caller.is_interpreted_frame() || (bottom && hf.compiled_frame_stack_argsize() % 2 != 0), "");
305 frame_sp--;
306 caller.set_sp(caller.sp() - 1);
307 }
308 assert(is_aligned(frame_sp, frame::frame_alignment), "");
309 return frame_sp;
310 }
311
312 inline void ThawBase::patch_pd(frame& f, const frame& caller) {
313 patch_callee_link(caller, caller.fp());
314 }
315
316 inline void ThawBase::patch_pd(frame& f, intptr_t* caller_sp) {
317 intptr_t* fp = caller_sp - frame::sender_sp_offset;
318 patch_callee_link(f, fp);
319 }
320
321 inline intptr_t* ThawBase::push_cleanup_continuation() {
322 frame enterSpecial = new_entry_frame();
323 intptr_t* sp = enterSpecial.sp();
324
325 sp[-1] = (intptr_t)ContinuationEntry::cleanup_pc();
326 sp[-2] = (intptr_t)enterSpecial.fp();
327
328 log_develop_trace(continuations, preempt)("push_cleanup_continuation initial sp: " INTPTR_FORMAT " final sp: " INTPTR_FORMAT, p2i(sp + 2 * frame::metadata_words), p2i(sp));
329 return sp;
330 }
331
332 inline intptr_t* ThawBase::push_preempt_adapter() {
333 frame enterSpecial = new_entry_frame();
334 intptr_t* sp = enterSpecial.sp();
335
336 sp[-1] = (intptr_t)StubRoutines::cont_preempt_stub();
337
338 log_develop_trace(continuations, preempt)("push_preempt_adapter initial sp: " INTPTR_FORMAT " final sp: " INTPTR_FORMAT, p2i(sp + 2 * frame::metadata_words), p2i(sp));
339 return sp;
340 }
341
342 inline void ThawBase::derelativize_interpreted_frame_metadata(const frame& hf, const frame& f) {
343 // Make sure that last_sp is kept relativized.
344 assert((intptr_t*)f.at_relative(frame::interpreter_frame_last_sp_offset) == f.unextended_sp(), "");
345
346 // Make sure that monitor_block_top is still relativized.
347 assert(f.at_absolute(frame::interpreter_frame_monitor_block_top_offset) <= frame::interpreter_frame_initial_sp_offset, "");
348 }
349
350 #endif // CPU_X86_CONTINUATIONFREEZE_THAW_X86_INLINE_HPP