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
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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
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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 
pd_last_frame()33 frame JavaThread::pd_last_frame() {
34   assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
35 #ifdef AARCH64
36   assert (_anchor.last_Java_pc() != NULL, "pc should be stored");
37   return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
38 #else
39   if (_anchor.last_Java_pc() != NULL) {
40     return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
41   } else {
42     // This will pick up pc from sp
43     return frame(_anchor.last_Java_sp(), _anchor.last_Java_fp());
44   }
45 #endif // AARCH64
46 }
47 
cache_global_variables()48 void JavaThread::cache_global_variables() {
49   BarrierSet* bs = BarrierSet::barrier_set();
50 
51   const bool allow_shared_alloc =
52     Universe::heap()->supports_inline_contig_alloc();
53 
54   if (allow_shared_alloc) {
55     _heap_top_addr = (address) Universe::heap()->top_addr();
56   } else {
57     _heap_top_addr = NULL;
58   }
59 
60   if (bs->is_a(BarrierSet::CardTableBarrierSet)) {
61     _card_table_base = (address) (barrier_set_cast<CardTableBarrierSet>(bs)->card_table()->byte_map_base());
62   } else {
63     _card_table_base = NULL;
64   }
65 
66 }
67 
68 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is
69 // currently interrupted by SIGPROF
pd_get_top_frame_for_signal_handler(frame * fr_addr,void * ucontext,bool isInJava)70 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr,
71   void* ucontext, bool isInJava) {
72   assert(Thread::current() == this, "caller must be current thread");
73   return pd_get_top_frame(fr_addr, ucontext, isInJava);
74 }
75 
pd_get_top_frame_for_profiling(frame * fr_addr,void * ucontext,bool isInJava)76 bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) {
77   return pd_get_top_frame(fr_addr, ucontext, isInJava);
78 }
79 
pd_get_top_frame(frame * fr_addr,void * ucontext,bool isInJava)80 bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) {
81   assert(this->is_Java_thread(), "must be JavaThread");
82 
83   JavaThread* jt = (JavaThread *)this;
84 
85   // If we have a last_Java_frame, then we should use it even if
86   // isInJava == true.  It should be more reliable than ucontext info.
87   if (jt->has_last_Java_frame() AARCH64_ONLY(&& jt->last_Java_pc() != NULL)) {
88     *fr_addr = jt->pd_last_frame();
89     return true;
90   }
91 
92   // Could be in a code section that plays with the stack, like
93   // MacroAssembler::verify_heapbase()
94   if (jt->in_top_frame_unsafe_section()) {
95     return false;
96   }
97 
98   // At this point, we don't have a last_Java_frame, so
99   // we try to glean some information out of the ucontext
100   // if we were running Java code when SIGPROF came in.
101   if (isInJava) {
102     ucontext_t* uc = (ucontext_t*) ucontext;
103 
104     intptr_t* ret_fp;
105     intptr_t* ret_sp;
106     ExtendedPC addr = os::Linux::fetch_frame_from_ucontext(this, uc,
107       &ret_sp, &ret_fp);
108     if (addr.pc() == NULL || ret_sp == NULL ) {
109       // ucontext wasn't useful
110       return false;
111     }
112 
113     if (MetaspaceShared::is_in_trampoline_frame(addr.pc())) {
114       // In the middle of a trampoline call. Bail out for safety.
115       // This happens rarely so shouldn't affect profiling.
116       return false;
117     }
118 
119     frame ret_frame(ret_sp, ret_fp, addr.pc());
120     if (!ret_frame.safe_for_sender(jt)) {
121 #ifdef COMPILER2
122       // C2 uses ebp as a general register see if NULL fp helps
123       frame ret_frame2(ret_sp, NULL, addr.pc());
124       if (!ret_frame2.safe_for_sender(jt)) {
125         // nothing else to try if the frame isn't good
126         return false;
127       }
128       ret_frame = ret_frame2;
129 #else
130       // nothing else to try if the frame isn't good
131       return false;
132 #endif /* COMPILER2 */
133     }
134     *fr_addr = ret_frame;
135     return true;
136   }
137 
138   // nothing else to try
139   return false;
140 }
141