1 /*
2 * Copyright (c) 1998, 2010, 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 #ifdef COMPILER2
27 #include "asm/assembler.hpp"
28 #include "assembler_x86.inline.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "code/vmreg.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "nativeInst_x86.hpp"
33 #include "opto/runtime.hpp"
34 #include "runtime/interfaceSupport.hpp"
35 #include "runtime/sharedRuntime.hpp"
36 #include "runtime/stubRoutines.hpp"
37 #include "runtime/vframeArray.hpp"
38 #include "utilities/globalDefinitions.hpp"
39 #include "vmreg_x86.inline.hpp"
40 #endif
41
42
43 #define __ masm->
44
45 ExceptionBlob* OptoRuntime::_exception_blob;
46
47 //------------------------------generate_exception_blob---------------------------
48 // creates exception blob at the end
49 // Using exception blob, this code is jumped from a compiled method.
50 //
51 // Given an exception pc at a call we call into the runtime for the
52 // handler in this method. This handler might merely restore state
53 // (i.e. callee save registers) unwind the frame and jump to the
54 // exception handler for the nmethod if there is no Java level handler
55 // for the nmethod.
56 //
57 // This code is entered with a jmp.
58 //
59 // Arguments:
60 // rax: exception oop
61 // rdx: exception pc
62 //
63 // Results:
64 // rax: exception oop
65 // rdx: exception pc in caller or ???
66 // destination: exception handler of caller
67 //
68 // Note: the exception pc MUST be at a call (precise debug information)
69 // Only register rax, rdx, rcx are not callee saved.
70 //
71
72 void OptoRuntime::generate_exception_blob() {
73
74 // Capture info about frame layout
75 enum layout {
76 thread_off, // last_java_sp
77 // The frame sender code expects that rbp will be in the "natural" place and
78 // will override any oopMap setting for it. We must therefore force the layout
79 // so that it agrees with the frame sender code.
80 rbp_off,
81 return_off, // slot for return address
82 framesize
83 };
84
85 // allocate space for the code
86 ResourceMark rm;
87 // setup code generation tools
88 CodeBuffer buffer("exception_blob", 512, 512);
89 MacroAssembler* masm = new MacroAssembler(&buffer);
90
91 OopMapSet *oop_maps = new OopMapSet();
92
93 address start = __ pc();
94
95 __ push(rdx);
96 __ subptr(rsp, return_off * wordSize); // Prolog!
97
98 // rbp, location is implicitly known
99 __ movptr(Address(rsp,rbp_off *wordSize), rbp);
100
101 // Store exception in Thread object. We cannot pass any arguments to the
102 // handle_exception call, since we do not want to make any assumption
103 // about the size of the frame where the exception happened in.
104 __ get_thread(rcx);
105 __ movptr(Address(rcx, JavaThread::exception_oop_offset()), rax);
106 __ movptr(Address(rcx, JavaThread::exception_pc_offset()), rdx);
107
108 // This call does all the hard work. It checks if an exception handler
109 // exists in the method.
110 // If so, it returns the handler address.
111 // If not, it prepares for stack-unwinding, restoring the callee-save
112 // registers of the frame being removed.
113 //
114 __ movptr(Address(rsp, thread_off * wordSize), rcx); // Thread is first argument
115 __ set_last_Java_frame(rcx, noreg, noreg, NULL);
116
117 __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C)));
118
119 // No registers to map, rbp is known implicitly
120 oop_maps->add_gc_map( __ pc() - start, new OopMap( framesize, 0 ));
121 __ get_thread(rcx);
122 __ reset_last_Java_frame(rcx, false, false);
123
124 // Restore callee-saved registers
125 __ movptr(rbp, Address(rsp, rbp_off * wordSize));
126
127 __ addptr(rsp, return_off * wordSize); // Epilog!
128 __ pop(rdx); // Exception pc
129
130 // rax: exception handler for given <exception oop/exception pc>
131
132 // Restore SP from BP if the exception PC is a MethodHandle call site.
133 __ cmpl(Address(rcx, JavaThread::is_method_handle_return_offset()), 0);
134 __ cmovptr(Assembler::notEqual, rsp, rbp_mh_SP_save);
135
136 // We have a handler in rax, (could be deopt blob)
137 // rdx - throwing pc, deopt blob will need it.
138
139 __ push(rax);
140
141 // Get the exception
142 __ movptr(rax, Address(rcx, JavaThread::exception_oop_offset()));
143 // Get the exception pc in case we are deoptimized
144 __ movptr(rdx, Address(rcx, JavaThread::exception_pc_offset()));
145 #ifdef ASSERT
146 __ movptr(Address(rcx, JavaThread::exception_handler_pc_offset()), NULL_WORD);
147 __ movptr(Address(rcx, JavaThread::exception_pc_offset()), NULL_WORD);
148 #endif
149 // Clear the exception oop so GC no longer processes it as a root.
150 __ movptr(Address(rcx, JavaThread::exception_oop_offset()), NULL_WORD);
151
152 __ pop(rcx);
153
154 // rax: exception oop
155 // rcx: exception handler
156 // rdx: exception pc
157 __ jmp (rcx);
158
159 // -------------
160 // make sure all code is generated
161 masm->flush();
162
163 _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize);
164 }