1 /*
2 * Copyright (c) 2003, 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 "memory/metaspaceShared.hpp"
27 #include "runtime/frame.inline.hpp"
28 #include "runtime/thread.inline.hpp"
29
30 frame JavaThread::pd_last_frame() {
31 assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
32 assert(_anchor.walkable(), "thread has not dumped its register windows yet");
33
34 assert(_anchor.last_Java_pc() != NULL, "Ack no pc!");
35 return frame(last_Java_sp(), frame::unpatchable, _anchor.last_Java_pc());
36 }
37
38 bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
39 ucontext_t* uc = (ucontext_t*) ucontext;
40 *fr_addr = frame((intptr_t*)uc->uc_mcontext.mc_i7, frame::unpatchable,
41 (address)uc->uc_mcontext.mc_gregs[MC_PC]);
42 return true;
43 }
44
45 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
46 // currently interrupted by SIGPROF
47 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
48 void* ucontext,
49 bool isInJava) {
50 assert(Thread::current() == this, "caller must be current thread");
51 assert(this->is_Java_thread(), "must be JavaThread");
52
53 JavaThread* jt = (JavaThread *)this;
54
55 if (!isInJava) {
56 // make_walkable flushes register windows and grabs last_Java_pc
57 // which can not be done if the ucontext sp matches last_Java_sp
58 // stack walking utilities assume last_Java_pc set if marked flushed
59 jt->frame_anchor()->make_walkable(jt);
60 }
61
62 // If we have a walkable last_Java_frame, then we should use it
63 // even if isInJava == true. It should be more reliable than
64 // ucontext info.
65 if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) {
66 *fr_addr = jt->pd_last_frame();
67 return true;
68 }
69
70 ucontext_t* uc = (ucontext_t*) ucontext;
71
72 // At this point, we don't have a walkable last_Java_frame, so
73 // we try to glean some information out of the ucontext.
74 intptr_t* ret_sp;
75 ExtendedPC addr =
76 os::fetch_frame_from_context(uc, &ret_sp,
77 NULL /* ret_fp only used on X86 */);
78 if (addr.pc() == NULL || ret_sp == NULL) {
79 // ucontext wasn't useful
80 return false;
81 }
82
83 if (MetaspaceShared::is_in_trampoline_frame(addr.pc())) {
84 // In the middle of a trampoline call. Bail out for safety.
85 // This happens rarely so shouldn't affect profiling.
86 return false;
87 }
88
89 // we were running Java code when SIGPROF came in
90 if (isInJava) {
91 // If we have a last_Java_sp, then the SIGPROF signal caught us
92 // right when we were transitioning from _thread_in_Java to a new
93 // JavaThreadState. We use last_Java_sp instead of the sp from
94 // the ucontext since it should be more reliable.
95 if (jt->has_last_Java_frame()) {
96 ret_sp = jt->last_Java_sp();
97 }
98 // Implied else: we don't have a last_Java_sp so we use what we
99 // got from the ucontext.
100
101 frame ret_frame(ret_sp, frame::unpatchable, addr.pc());
102 if (!ret_frame.safe_for_sender(jt)) {
103 // nothing else to try if the frame isn't good
104 return false;
105 }
106 *fr_addr = ret_frame;
107 return true;
108 }
109
110 // At this point, we know we weren't running Java code. We might
111 // have a last_Java_sp, but we don't have a walkable frame.
112 // However, we might still be able to construct something useful
113 // if the thread was running native code.
114 if (jt->has_last_Java_frame()) {
115 assert(!jt->frame_anchor()->walkable(), "case covered above");
116
117 if (jt->thread_state() == _thread_in_native) {
118 frame ret_frame(jt->last_Java_sp(), frame::unpatchable, addr.pc());
119 if (!ret_frame.safe_for_sender(jt)) {
120 // nothing else to try if the frame isn't good
121 return false;
122 }
123 *fr_addr = ret_frame;
124 return true;
125 }
126 }
127
128 // nothing else to try
129 return false;
130 }
131
132 void JavaThread::cache_global_variables() { }
133