1 /* 2 * Copyright (c) 2003, 2008, 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 "incls/_precompiled.incl" 26 #include "incls/_thread_solaris_sparc.cpp.incl" 27 28 // For Forte Analyzer AsyncGetCallTrace profiling support - thread is 29 // currently interrupted by SIGPROF 30 // 31 // NOTE: On Solaris, register windows are flushed in the signal handler 32 // except for possibly the top frame. 33 // 34 bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr, 35 void* ucontext, bool isInJava) { 36 37 assert(Thread::current() == this, "caller must be current thread"); 38 assert(this->is_Java_thread(), "must be JavaThread"); 39 40 JavaThread* jt = (JavaThread *)this; 41 42 if (!isInJava) { 43 // make_walkable flushes register windows and grabs last_Java_pc 44 // which can not be done if the ucontext sp matches last_Java_sp 45 // stack walking utilities assume last_Java_pc set if marked flushed 46 jt->frame_anchor()->make_walkable(jt); 47 } 48 49 // If we have a walkable last_Java_frame, then we should use it 50 // even if isInJava == true. It should be more reliable than 51 // ucontext info. 52 if (jt->has_last_Java_frame() && jt->frame_anchor()->walkable()) { 53 *fr_addr = jt->pd_last_frame(); 54 return true; 55 } 56 57 ucontext_t* uc = (ucontext_t*) ucontext; 58 59 // At this point, we don't have a walkable last_Java_frame, so 60 // we try to glean some information out of the ucontext. 61 intptr_t* ret_sp; 62 ExtendedPC addr = os::Solaris::fetch_frame_from_ucontext(this, uc, 63 &ret_sp, NULL /* ret_fp only used on Solaris X86 */); 64 if (addr.pc() == NULL || ret_sp == NULL) { 65 // ucontext wasn't useful 66 return false; 67 } 68 69 frame ret_frame(ret_sp, frame::unpatchable, addr.pc()); 70 71 // we were running Java code when SIGPROF came in 72 if (isInJava) { 73 74 75 // If the frame we got is safe then it is most certainly valid 76 if (ret_frame.safe_for_sender(jt)) { 77 *fr_addr = ret_frame; 78 return true; 79 } 80 81 // If it isn't safe then we can try several things to try and get 82 // a good starting point. 83 // 84 // On sparc the frames are almost certainly walkable in the sense 85 // of sp/fp linkages. However because of recycling of windows if 86 // a piece of code does multiple save's where the initial save creates 87 // a real frame with a return pc and the succeeding save's are used to 88 // simply get free registers and have no real pc then the pc linkage on these 89 // "inner" temporary frames will be bogus. 90 // Since there is in general only a nesting level like 91 // this one deep in general we'll try and unwind such an "inner" frame 92 // here ourselves and see if it makes sense 93 94 frame unwind_frame(ret_frame.fp(), frame::unpatchable, addr.pc()); 95 96 if (unwind_frame.safe_for_sender(jt)) { 97 *fr_addr = unwind_frame; 98 return true; 99 } 100 101 // Well that didn't work. Most likely we're toast on this tick 102 // The previous code would try this. I think it is dubious in light 103 // of changes to safe_for_sender and the unwind trick above but 104 // if it gets us a safe frame who wants to argue. 105 106 // If we have a last_Java_sp, then the SIGPROF signal caught us 107 // right when we were transitioning from _thread_in_Java to a new 108 // JavaThreadState. We use last_Java_sp instead of the sp from 109 // the ucontext since it should be more reliable. 110 111 if (jt->has_last_Java_frame()) { 112 ret_sp = jt->last_Java_sp(); 113 frame ret_frame2(ret_sp, frame::unpatchable, addr.pc()); 114 if (ret_frame2.safe_for_sender(jt)) { 115 *fr_addr = ret_frame2; 116 return true; 117 } 118 } 119 120 // This is the best we can do. We will only be able to decode the top frame 121 122 *fr_addr = ret_frame; 123 return true; 124 } 125 126 // At this point, we know we weren't running Java code. We might 127 // have a last_Java_sp, but we don't have a walkable frame. 128 // However, we might still be able to construct something useful 129 // if the thread was running native code. 130 if (jt->has_last_Java_frame()) { 131 assert(!jt->frame_anchor()->walkable(), "case covered above"); 132 133 frame ret_frame(jt->last_Java_sp(), frame::unpatchable, addr.pc()); 134 *fr_addr = ret_frame; 135 return true; 136 } 137 138 // nothing else to try but what we found initially 139 140 *fr_addr = ret_frame; 141 return true; 142 } 143 144 void JavaThread::cache_global_variables() { } 145