1 /*
2 * Copyright (c) 2008, 2018, 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 "gc/shared/barrierSet.hpp"
27 #include "gc/shared/cardTable.hpp"
28 #include "gc/shared/cardTableBarrierSet.inline.hpp"
29 #include "gc/shared/collectedHeap.hpp"
30 #include "memory/metaspaceShared.hpp"
31 #include "runtime/frame.inline.hpp"
32
33 frame JavaThread::pd_last_frame() {
34 assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
35 if (_anchor.last_Java_pc() != NULL) {
36 return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
37 } else {
38 // This will pick up pc from sp
39 return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp());
40 }
41 }
42
43 void JavaThread::cache_global_variables() {
44 BarrierSet* bs = BarrierSet::barrier_set();
45
46 const bool allow_shared_alloc =
47 Universe::heap()->supports_inline_contig_alloc();
48
49 if (allow_shared_alloc) {
50 _heap_top_addr = (address) Universe::heap()->top_addr();
51 } else {
52 _heap_top_addr = NULL;
53 }
54
55 if (bs->is_a(BarrierSet::CardTableBarrierSet)) {
56 _card_table_base = (address) (barrier_set_cast<CardTableBarrierSet>(bs)->card_table()->byte_map_base());
57 } else {
58 _card_table_base = NULL;
59 }
60
61 }
62
63 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
64 // currently interrupted by SIGPROF
65 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
66 void* ucontext, bool isInJava) {
67 assert(Thread::current() == this, "caller must be current thread");
68 return pd_get_top_frame(fr_addr, ucontext, isInJava);
69 }
70
71 bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
72 return pd_get_top_frame(fr_addr, ucontext, isInJava);
73 }
74
75 bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) {
76 assert(this->is_Java_thread(), "must be JavaThread");
77
78 JavaThread* jt = (JavaThread *)this;
79
80 // If we have a last_Java_frame, then we should use it even if
81 // isInJava == true. It should be more reliable than ucontext info.
82 if (jt->has_last_Java_frame()) {
83 *fr_addr = jt->pd_last_frame();
84 return true;
85 }
86
87 // Could be in a code section that plays with the stack, like
88 // MacroAssembler::verify_heapbase()
89 if (jt->in_top_frame_unsafe_section()) {
90 return false;
91 }
92
93 // At this point, we don't have a last_Java_frame, so
94 // we try to glean some information out of the ucontext
95 // if we were running Java code when SIGPROF came in.
96 if (isInJava) {
97 ucontext_t* uc = (ucontext_t*) ucontext;
98
99 intptr_t* ret_fp;
100 intptr_t* ret_sp;
101 ExtendedPC addr = os::Linux::fetch_frame_from_ucontext(this, uc,
102 &ret_sp, &ret_fp);
103 if (addr.pc() == NULL || ret_sp == NULL ) {
104 // ucontext wasn't useful
105 return false;
106 }
107
108 if (MetaspaceShared::is_in_trampoline_frame(addr.pc())) {
109 // In the middle of a trampoline call. Bail out for safety.
110 // This happens rarely so shouldn't affect profiling.
111 return false;
112 }
113
114 frame ret_frame(ret_sp, ret_fp, addr.pc());
115 if (!ret_frame.safe_for_sender(jt)) {
116 #ifdef COMPILER2
117 // C2 uses ebp as a general register see if NULL fp helps
118 frame ret_frame2(ret_sp, NULL, addr.pc());
119 if (!ret_frame2.safe_for_sender(jt)) {
120 // nothing else to try if the frame isn't good
121 return false;
122 }
123 ret_frame = ret_frame2;
124 #else
125 // nothing else to try if the frame isn't good
126 return false;
127 #endif /* COMPILER2 */
128 }
129 *fr_addr = ret_frame;
130 return true;
131 }
132
133 // nothing else to try
134 return false;
135 }