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
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.
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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
69 // Repair the sender sp if the frame has been extended
70 if (sender_cb->is_nmethod()) {
71 sender_sp = f.repair_sender_sp(sender_sp, link_addr);
72 }
73
74 return sender_cb != nullptr
75 ? frame(sender_sp, sender_sp, *link_addr, sender_pc, sender_cb,
76 slot == -1 ? nullptr : sender_cb->oop_map_for_slot(slot, sender_pc), false)
77 : frame(sender_sp, sender_sp, *link_addr, sender_pc);
78 }
79
80 template<typename FKind>
81 frame FreezeBase::new_heap_frame(frame& f, frame& caller, int size_adjust) {
82 assert(FKind::is_instance(f), "");
83 assert(!caller.is_interpreted_frame()
84 || caller.unextended_sp() == (intptr_t*)caller.at(frame::interpreter_frame_last_sp_offset), "");
85
86 intptr_t *sp, *fp; // sp is really our unextended_sp
87 if (FKind::interpreted) {
88 assert((intptr_t*)f.at_relative_or_null(frame::interpreter_frame_last_sp_offset) == nullptr
89 || f.unextended_sp() == (intptr_t*)f.at_relative(frame::interpreter_frame_last_sp_offset), "");
90 intptr_t locals_offset = *f.addr_at(frame::interpreter_frame_locals_offset);
91 // If the caller.is_empty(), i.e. we're freezing into an empty chunk, then we set
92 // the chunk's argsize in finalize_freeze and make room for it above the unextended_sp
93 bool overlap_caller = caller.is_interpreted_frame() || caller.is_empty();
94 fp = caller.unextended_sp() - 1 - locals_offset + (overlap_caller ? ContinuationHelper::InterpretedFrame::stack_argsize(f) : 0);
95 sp = fp - (f.fp() - f.unextended_sp());
96 assert(sp <= fp, "");
97 assert(fp <= caller.unextended_sp(), "");
98 caller.set_sp(fp + frame::sender_sp_offset);
99
100 assert(_cont.tail()->is_in_chunk(sp), "");
101
102 frame hf(sp, sp, fp, f.pc(), nullptr, nullptr, true /* on_heap */);
103 // copy relativized locals from the stack frame
104 *hf.addr_at(frame::interpreter_frame_locals_offset) = locals_offset;
105 return hf;
106 } else {
107 // For a compiled frame we need to re-read fp out of the frame because it may be an
108 // oop and we might have had a safepoint in finalize_freeze, after constructing f.
109 // For stub/native frames the value is not used while frozen, and will be constructed again
110 // when thawing the frame (see ThawBase::new_stack_frame). We use a special bad address to
111 // help with debugging, particularly when inspecting frames and identifying invalid accesses.
112 fp = FKind::compiled ? *(intptr_t**)(f.sp() - frame::sender_sp_offset) : (intptr_t*)badAddressVal;
113
114 int fsize = FKind::size(f);
115 sp = caller.unextended_sp() - fsize - size_adjust;
116 if (caller.is_interpreted_frame() && size_adjust == 0) {
117 // If the caller is interpreted, our stackargs are not supposed to overlap with it
118 // so we make more room by moving sp down by argsize
119 int argsize = FKind::stack_argsize(f);
120 sp -= argsize;
121 }
122 caller.set_sp(sp + fsize);
123
124 assert(_cont.tail()->is_in_chunk(sp), "");
125
126 return frame(sp, sp, fp, f.pc(), nullptr, nullptr, true /* on_heap */);
127 }
128 }
129
130 void FreezeBase::adjust_interpreted_frame_unextended_sp(frame& f) {
131 assert((f.at(frame::interpreter_frame_last_sp_offset) != 0) || (f.unextended_sp() == f.sp()), "");
132 intptr_t* real_unextended_sp = (intptr_t*)f.at_relative_or_null(frame::interpreter_frame_last_sp_offset);
133 if (real_unextended_sp != nullptr) {
134 f.set_unextended_sp(real_unextended_sp); // can be null at a safepoint
135 }
136 }
137
138 inline void FreezeBase::prepare_freeze_interpreted_top_frame(frame& f) {
139 assert(f.interpreter_frame_last_sp() == nullptr, "should be null for top frame");
140 f.interpreter_frame_set_last_sp(f.unextended_sp());
141 }
142
143 inline void FreezeBase::relativize_interpreted_frame_metadata(const frame& f, const frame& hf) {
144 assert(hf.fp() == hf.unextended_sp() + (f.fp() - f.unextended_sp()), "");
145 assert((f.at(frame::interpreter_frame_last_sp_offset) != 0)
146 || (f.unextended_sp() == f.sp()), "");
147 assert(f.fp() > (intptr_t*)f.at_relative(frame::interpreter_frame_initial_sp_offset), "");
148
149 // Make sure that last_sp is already relativized.
150 assert((intptr_t*)hf.at_relative(frame::interpreter_frame_last_sp_offset) == hf.unextended_sp(), "");
151
152 // Make sure that locals is already relativized.
153 DEBUG_ONLY(Method* m = f.interpreter_frame_method();)
154 // Frames for native methods have 2 extra words (temp oop/result handler) before fixed part of frame.
155 DEBUG_ONLY(int max_locals = !m->is_native() ? m->max_locals() : m->size_of_parameters() + 2;)
156 assert((*hf.addr_at(frame::interpreter_frame_locals_offset) == frame::sender_sp_offset + max_locals - 1), "");
157
158 // Make sure that monitor_block_top is already relativized.
159 assert(hf.at_absolute(frame::interpreter_frame_monitor_block_top_offset) <= frame::interpreter_frame_initial_sp_offset, "");
160
161 assert((hf.fp() - hf.unextended_sp()) == (f.fp() - f.unextended_sp()), "");
162 assert(hf.unextended_sp() == (intptr_t*)hf.at(frame::interpreter_frame_last_sp_offset), "");
163 assert(hf.unextended_sp() <= (intptr_t*)hf.at(frame::interpreter_frame_initial_sp_offset), "");
164 assert(hf.fp() > (intptr_t*)hf.at(frame::interpreter_frame_initial_sp_offset), "");
165 assert(hf.fp() <= (intptr_t*)hf.at(frame::interpreter_frame_locals_offset), "");
166 }
167
168 inline void FreezeBase::set_top_frame_metadata_pd(const frame& hf) {
169 stackChunkOop chunk = _cont.tail();
170 assert(chunk->is_in_chunk(hf.sp() - 1), "");
171 assert(chunk->is_in_chunk(hf.sp() - frame::sender_sp_offset), "");
172
173 address frame_pc = hf.pc();
174
175 *(hf.sp() - 1) = (intptr_t)hf.pc();
176
177 intptr_t* fp_addr = hf.sp() - frame::sender_sp_offset;
178 *fp_addr = hf.is_interpreted_frame() ? (intptr_t)(hf.fp() - fp_addr)
179 : (intptr_t)hf.fp();
180 assert(frame_pc == ContinuationHelper::Frame::real_pc(hf), "");
181 }
182
183 inline void FreezeBase::patch_pd(frame& hf, const frame& caller, bool is_bottom_frame) {
184 if (caller.is_interpreted_frame()) {
185 assert(!caller.is_empty(), "");
186 patch_callee_link_relative(caller, caller.fp());
187 } else if (is_bottom_frame && caller.pc() != nullptr) {
188 assert(caller.is_compiled_frame(), "");
189 // If we're the bottom-most frame frozen in this freeze, the caller might have stayed frozen in the chunk,
190 // and its oop-containing fp fixed. We've now just overwritten it, so we must patch it back to its value
191 // as read from the chunk.
192 patch_callee_link(caller, caller.fp());
193 }
194 }
195
196 inline void FreezeBase::patch_pd_unused(intptr_t* sp) {
197 intptr_t* fp_addr = sp - frame::sender_sp_offset;
198 *fp_addr = badAddressVal;
199 }
200
201 //////// Thaw
202
203 // Fast path
204
205 inline void ThawBase::prefetch_chunk_pd(void* start, int size) {
206 size <<= LogBytesPerWord;
207 Prefetch::read(start, size);
208 Prefetch::read(start, size - 64);
209 }
210
211 template <typename ConfigT>
212 inline void Thaw<ConfigT>::patch_caller_links(intptr_t* sp, intptr_t* bottom) {
213 // Fast path depends on !PreserveFramePointer. See can_thaw_fast().
214 assert(!PreserveFramePointer, "Frame pointers need to be fixed");
215 }
216
217 // Slow path
218
219 inline frame ThawBase::new_entry_frame() {
220 intptr_t* sp = _cont.entrySP();
221 return frame(sp, sp, _cont.entryFP(), _cont.entryPC()); // TODO PERF: This finds code blob and computes deopt state
222 }
223
224 template<typename FKind> frame ThawBase::new_stack_frame(const frame& hf, frame& caller, bool bottom, int size_adjust) {
225 assert(FKind::is_instance(hf), "");
226 // The values in the returned frame object will be written into the callee's stack in patch.
227
228 if (FKind::interpreted) {
229 intptr_t* heap_sp = hf.unextended_sp();
230 // If caller is interpreted it already made room for the callee arguments
231 int overlap = caller.is_interpreted_frame() ? ContinuationHelper::InterpretedFrame::stack_argsize(hf) : 0;
232 const int fsize = (int)(ContinuationHelper::InterpretedFrame::frame_bottom(hf) - hf.unextended_sp() - overlap);
233 intptr_t* frame_sp = caller.unextended_sp() - fsize;
234 intptr_t* fp = frame_sp + (hf.fp() - heap_sp);
235 DEBUG_ONLY(intptr_t* unextended_sp = fp + *hf.addr_at(frame::interpreter_frame_last_sp_offset);)
236 assert(frame_sp == unextended_sp, "");
237 caller.set_sp(fp + frame::sender_sp_offset);
238 frame f(frame_sp, frame_sp, fp, hf.pc());
239 // we need to set the locals so that the caller of new_stack_frame() can call
240 // ContinuationHelper::InterpretedFrame::frame_bottom
241 intptr_t locals_offset = *hf.addr_at(frame::interpreter_frame_locals_offset);
242 DEBUG_ONLY(Method* m = hf.interpreter_frame_method();)
243 // Frames for native methods have 2 extra words (temp oop/result handler) before fixed part of frame.
244 DEBUG_ONLY(const int max_locals = !m->is_native() ? m->max_locals() : m->size_of_parameters() + 2;)
245 assert((int)locals_offset == frame::sender_sp_offset + max_locals - 1, "");
246 // copy relativized locals from the heap frame
247 *f.addr_at(frame::interpreter_frame_locals_offset) = locals_offset;
248 return f;
249 } else {
250 int fsize = FKind::size(hf);
251 intptr_t* frame_sp = caller.unextended_sp() - fsize - size_adjust;
252 if (bottom || caller.is_interpreted_frame()) {
253 if (size_adjust == 0) {
254 int argsize = FKind::stack_argsize(hf);
255 frame_sp -= argsize;
256 }
257 frame_sp = align(hf, frame_sp, caller, bottom);
258 }
259 caller.set_sp(frame_sp + fsize);
260 assert(is_aligned(frame_sp, frame::frame_alignment), "");
261
262 assert(hf.cb() != nullptr, "");
263 assert(hf.oop_map() != nullptr, "");
264 intptr_t* fp;
265 if (PreserveFramePointer) {
266 // we need to recreate a "real" frame pointer, pointing into the stack
267 fp = frame_sp + fsize - frame::sender_sp_offset;
268 } else {
269 fp = FKind::stub || FKind::native
270 ? frame_sp + fsize - frame::sender_sp_offset // fp always points to the address below the pushed return pc. We need correct address.
271 : *(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.
272 }
273 return frame(frame_sp, frame_sp, fp, hf.pc(), hf.cb(), hf.oop_map(), false); // TODO PERF : this computes deopt state; is it necessary?
274 }
275 }
276
277 inline intptr_t* ThawBase::align(const frame& hf, intptr_t* frame_sp, frame& caller, bool bottom) {
278 if (((intptr_t)frame_sp & 0xf) != 0) {
279 assert(caller.is_interpreted_frame() || (bottom && hf.compiled_frame_stack_argsize() % 2 != 0), "");
280 frame_sp--;
281 }
282 assert(is_aligned(frame_sp, frame::frame_alignment), "");
283 return frame_sp;
284 }
285
286 inline void ThawBase::patch_pd(frame& f, const frame& caller) {
287 if (caller.is_interpreted_frame() || PreserveFramePointer) {
288 patch_callee_link(caller, caller.fp());
289 }
290 }
291
292 inline void ThawBase::patch_pd(frame& f, intptr_t* caller_sp) {
293 intptr_t* fp = caller_sp - frame::sender_sp_offset;
294 patch_callee_link(f, fp);
295 }
296
297 inline intptr_t* ThawBase::push_cleanup_continuation() {
298 frame enterSpecial = new_entry_frame();
299 intptr_t* sp = enterSpecial.sp();
300
301 sp[-1] = (intptr_t)ContinuationEntry::cleanup_pc();
302 sp[-2] = (intptr_t)enterSpecial.fp();
303
304 log_develop_trace(continuations, preempt)("push_cleanup_continuation initial sp: " INTPTR_FORMAT " final sp: " INTPTR_FORMAT, p2i(sp + 2 * frame::metadata_words), p2i(sp));
305 return sp;
306 }
307
308 inline void ThawBase::derelativize_interpreted_frame_metadata(const frame& hf, const frame& f) {
309 // Make sure that last_sp is kept relativized.
310 assert((intptr_t*)f.at_relative(frame::interpreter_frame_last_sp_offset) == f.unextended_sp(), "");
311
312 // Make sure that monitor_block_top is still relativized.
313 assert(f.at_absolute(frame::interpreter_frame_monitor_block_top_offset) <= frame::interpreter_frame_initial_sp_offset, "");
314 }
315
316 #endif // CPU_X86_CONTINUATIONFREEZE_THAW_X86_INLINE_HPP