1 /* 2 * Copyright (c) 2003, 2017, 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 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is 31 // currently interrupted by SIGPROF 32 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr, 33 void* ucontext, 34 bool isInJava) { 35 assert(Thread::current() == this, "caller must be current thread"); 36 assert(this->is_Java_thread(), "must be JavaThread"); 37 38 JavaThread* jt = (JavaThread *)this; 39 40 if (!isInJava) { 41 // make_walkable flushes register windows and grabs last_Java_pc 42 // which can not be done if the ucontext sp matches last_Java_sp 43 // stack walking utilities assume last_Java_pc set if marked flushed 44 jt->frame_anchor()->make_walkable(jt); 45 } 46 47 // If we have a walkable last_Java_frame, then we should use it 48 // even if isInJava == true. It should be more reliable than 49 // ucontext info. 50 if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) { 51 *fr_addr = jt->pd_last_frame(); 52 return true; 53 } 54 55 ucontext_t* uc = (ucontext_t*) ucontext; 56 57 // At this point, we don't have a walkable last_Java_frame, so 58 // we try to glean some information out of the ucontext. 59 intptr_t* ret_sp; 60 ExtendedPC addr = 61 os::fetch_frame_from_context(uc, &ret_sp, 62 NULL /* ret_fp only used on X86 */); 63 if (addr.pc() == NULL || ret_sp == NULL) { 64 // ucontext wasn't useful 65 return false; 66 } 67 68 if (MetaspaceShared::is_in_trampoline_frame(addr.pc())) { 69 // In the middle of a trampoline call. Bail out for safety. 70 // This happens rarely so shouldn't affect profiling. 71 return false; 72 } 73 74 // we were running Java code when SIGPROF came in 75 if (isInJava) { 76 // If we have a last_Java_sp, then the SIGPROF signal caught us 77 // right when we were transitioning from _thread_in_Java to a new 78 // JavaThreadState. We use last_Java_sp instead of the sp from 79 // the ucontext since it should be more reliable. 80 if (jt->has_last_Java_frame()) { 81 ret_sp = jt->last_Java_sp(); 82 } 83 // Implied else: we don't have a last_Java_sp so we use what we 84 // got from the ucontext. 85 86 frame ret_frame(ret_sp, frame::unpatchable, addr.pc()); 87 if (!ret_frame.safe_for_sender(jt)) { 88 // nothing else to try if the frame isn't good 89 return false; 90 } 91 *fr_addr = ret_frame; 92 return true; 93 } 94 95 // At this point, we know we weren't running Java code. We might 96 // have a last_Java_sp, but we don't have a walkable frame. 97 // However, we might still be able to construct something useful 98 // if the thread was running native code. 99 if (jt->has_last_Java_frame()) { 100 assert(!jt->frame_anchor()->walkable(), "case covered above"); 101 102 if (jt->thread_state() == _thread_in_native) { 103 frame ret_frame(jt->last_Java_sp(), frame::unpatchable, addr.pc()); 104 if (!ret_frame.safe_for_sender(jt)) { 105 // nothing else to try if the frame isn't good 106 return false; 107 } 108 *fr_addr = ret_frame; 109 return true; 110 } 111 } 112 113 // nothing else to try 114 return false; 115 } 116 117 void JavaThread::cache_global_variables() { } 118