1 /*
2 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2019 SAP SE. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "asm/assembler.inline.hpp"
27 #include "asm/macroAssembler.hpp"
28 #include "code/codeCache.hpp"
29 #include "compiler/disassembler.hpp"
30 #include "depChecker_s390.hpp"
31 #include "gc/cms/concurrentMarkSweepGeneration.inline.hpp"
32 #include "gc/cms/parOopClosures.inline.hpp"
33 #include "gc/shared/collectedHeap.hpp"
34 #include "gc/shared/cardTableBarrierSet.hpp"
35 #include "gc/shared/genOopClosures.inline.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "runtime/handles.inline.hpp"
38 #include "runtime/stubCodeGenerator.hpp"
39 #include "runtime/stubRoutines.hpp"
40 #include "utilities/align.hpp"
41
42 // List of all major opcodes, as of
43 // Principles of Operation, Eleventh Edition, March 2015
44 bool Disassembler::valid_opcodes[] =
45 { true, true, false, false, true, true, true, true, // 0x00..07
46 false, false, true, true, true, true, true, true, // 0x08..0f
47 true, true, true, true, true, true, true, true, // 0x10..17
48 true, true, true, true, true, true, true, true, // 0x18..1f
49 true, true, true, true, true, true, true, true, // 0x20..27
50 true, true, true, true, true, true, true, true, // 0x28..2f
51 true, true, true, true, true, true, true, true, // 0x30..37
52 true, true, true, true, true, true, true, true, // 0x38..3f
53 true, true, true, true, true, true, true, true, // 0x40..47
54 true, true, true, true, true, true, true, true, // 0x48..4f
55 true, true, false, false, true, true, true, true, // 0x50..57
56 true, true, true, true, true, true, true, true, // 0x58..5f
57 true, false, false, false, false, false, false, true, // 0x60..67
58 true, true, true, true, true, true, true, true, // 0x68..6f
59 true, true, false, false, false, false, false, false, // 0x70..77
60 true, true, true, true, true, true, true, true, // 0x78..7f
61 true, false, true, true, true, true, true, true, // 0x80..87
62 true, true, true, true, true, true, true, true, // 0x88..8f
63 true, true, true, true, true, true, true, true, // 0x90..97
64 true, true, true, true, false, false, false, false, // 0x98..9f
65 false, false, false, false, false, true, false, true, // 0xa0..a7
66 true, true, false, false, true, true, true, true, // 0xa8..af
67 false, true, true, true, false, false, true, true, // 0xb0..b7
68 false, true, true, true, false, true, true, true, // 0xb8..bf
69 true, false, true, false, true, false, true, false, // 0xc0..c7
70 true, false, false, false, true, false, false, false, // 0xc8..cf
71 true, true, true, true, true, true, true, true, // 0xd0..d7
72 false, true, true, true, true, true, true, true, // 0xd8..df
73 false, true, true, true, false, true, false, true, // 0xe0..e7
74 true, true, true, true, true, true, true, true, // 0xe8..ef
75 true, true, true, true, false, false, false, false, // 0xf0..f7
76 true, true, true, true, true, true, false, false, // 0xf8..ff
77 };
78 // Check for valid opcodes.
79 //
80 // The major opcode (one byte) at the passed location is inspected.
81 // If the opcode found is assigned, the function returns true, false otherwise.
82 // The true indication is not reliable. It may well be that the major opcode is
83 // assigned, but there exists a minor opcode field in the instruction which
84 // which has unassigned values.
85 bool Disassembler::is_valid_opcode_at(address here) {
86 return valid_opcodes[*here];
87 }
88
89 // This method does plain instruction decoding, no frills.
90 // It may be called before the binutils disassembler kicks in
91 // to handle special cases the binutils disassembler does not.
92 // Instruction address, comments, and the like have to be output by caller.
93 address Disassembler::decode_instruction0(address here, outputStream * st, address virtual_begin) {
94 if (is_abstract()) {
95 // The disassembler library was not loaded (yet),
96 // use AbstractDisassembler's decode-method.
97 return decode_instruction_abstract(here, st, Assembler::instr_len(here), Assembler::instr_maxlen());
98 }
99
100 // Currently, "special decoding" doesn't work when decoding error files.
101 // When decoding an instruction from a hs_err file, the given
102 // instruction address 'start' points to the instruction's virtual address
103 // which is not equal to the address where the instruction is located.
104 // Therefore, we will either crash or decode garbage.
105 if (is_decode_error_file()) {
106 return here;
107 }
108
109 //---< Decode some well-known "instructions" >---
110
111 address next;
112 uint16_t instruction_2bytes = *(uint16_t*)here;
113
114 if (Assembler::is_z_nop((long)instruction_2bytes)) {
115 #if 1
116 st->print("nop "); // fill up to operand column, leads to better code comment alignment
117 next = here + 2;
118 #else
119 // Compact disassembler output. Does not work the easy way.
120 // Currently unusable, search does not terminate, risk of crash.
121 // TODO: rework required.
122 // Terminate search loop when reaching CodeEntryAlignment-aligned offset
123 // or, at the latest, when reaching the next page boundary.
124 int n_nops = 0;
125 while(is_same_page(here, here+2*n_nops) && Assembler::is_z_nop((long)instruction_2bytes)) {
126 n_nops++;
127 instruction_2bytes = *(uint16_t*)(here+2*n_nops);
128 }
129 if (n_nops <= 4) { // do not group few subsequent nops
130 st->print("nop "); // fill up to operand column, leads to better code comment alignment
131 next = here + 2;
132 } else {
133 st->print("nop count=%d", n_nops);
134 next = here + 2*n_nops;
135 }
136 #endif
137 } else if (Assembler::is_z_sync((long)instruction_2bytes)) {
138 // Specific names. Make use of lightweight sync.
139 st->print("sync ");
140 if (Assembler::is_z_sync_full((long)instruction_2bytes) ) st->print("heavyweight");
141 if (Assembler::is_z_sync_light((long)instruction_2bytes)) st->print("lightweight");
142 next = here + 2;
143 } else if (instruction_2bytes == 0x0000) {
144 #if 1
145 st->print("illtrap .nodata");
146 next = here + 2;
147 #else
148 // Compact disassembler output. Does not work the easy way.
149 // Currently unusable, search does not terminate, risk of crash.
150 // TODO: rework required.
151 // Terminate search loop when reaching CodeEntryAlignment-aligned offset
152 // or, at the latest, when reaching the next page boundary.
153 int n_traps = 0;
154 while(is_same_page(here, here+2*n_nops) && (instruction_2bytes == 0x0000)) {
155 n_traps++;
156 instruction_2bytes = *(uint16_t*)(here+2*n_traps);
157 }
158 if (n_traps <= 4) { // do not group few subsequent illtraps
159 st->print("illtrap .nodata");
160 next = here + 2;
161 } else {
162 st->print("illtrap .nodata count=%d", n_traps);
163 next = here + 2*n_traps;
164 }
165 #endif
166 } else if ((instruction_2bytes & 0xff00) == 0x0000) {
167 st->print("illtrap .data 0x%2.2x", instruction_2bytes & 0x00ff);
168 next = here + 2;
169 } else {
170 next = here;
171 }
172 return next;
173 }
174
175 // Count the instructions contained in the range [begin..end).
176 // The range must exactly contain the instructions, i.e.
177 // - the first instruction starts @begin
178 // - the last instruction ends @(end-1)
179 // The caller has to make sure that the given range is readable.
180 // This function performs no safety checks!
181 // Return value:
182 // - The number of instructions, if there was exact containment.
183 // - If there is no exact containment, a negative value is returned.
184 // Its absolute value is the number of instructions from begin to end,
185 // where the last instruction counted runs over the range end.
186 // - 0 (zero) is returned if there was a parameter error
187 // (inverted range, bad starting point).
188 int Disassembler::count_instr(address begin, address end) {
189 if (end < begin+2) return 0; // no instructions in range
190 if (!Disassembler::is_valid_opcode_at(begin)) return 0; // bad starting point
191
192 address p = begin;
193 int n = 0;
194 while(p < end) {
195 p += Assembler::instr_len(p);
196 n++;
197 }
198 return (p == end) ? n : -n;
199 }
200
201 // Find preceding instruction.
202 //
203 // Starting at the passed location, the n-th preceding (towards lower addresses)
204 // instruction is searched. With variable length instructions, there may be
205 // more than one solution, or no solution at all (if the passed location
206 // does not point to the start of an instruction or if the storage area
207 // does not contain instructions at all).
208 // instructions - has the passed location as n-th successor.
209 // - If multiple such locations exist between (here-n*instr_maxlen()) and here,
210 // the most distant location is selected.
211 // - If no such location exists, NULL is returned. The caller should then
212 // terminate its search and react properly.
213 // Must be placed here in disassembler_s390.cpp. It does not compile
214 // in the header. There the class 'Assembler' is not available.
215 address Disassembler::find_prev_instr(address here, int n_instr) {
216 if (!os::is_readable_pointer(here)) return NULL; // obviously a bad location to decode
217
218 // Find most distant possible starting point.
219 // Narrow down because we don't want to SEGV while printing.
220 address start = here - n_instr*Assembler::instr_maxlen(); // starting point can't be further away.
221 while ((start < here) && !os::is_readable_range(start, here)) {
222 start = align_down(start, os::min_page_size()) + os::min_page_size();
223 }
224 if (start >= here) {
225 // Strange. Can only happen with here on page boundary.
226 return NULL;
227 }
228
229 //---< Find a starting point >---
230 int i_count = 0;
231 while ((start < here) && ((i_count = count_instr(start, here)) <= 0)) start += 2;
232 if (i_count == 0) return NULL; // There is something seriously wrong
233
234 //---< Narrow down distance (estimate was too large) >---
235 while(i_count-- > n_instr) {
236 start += Assembler::instr_len(start);
237 }
238 assert(n_instr >= count_instr(start, here), "just checking");
239 return start;
240 }
241
242
243 // Print annotations (value of loaded constant)
244 void Disassembler::annotate(address here, outputStream* st) {
245 // Currently, annotation doesn't work when decoding error files.
246 // When decoding an instruction from a hs_err file, the given
247 // instruction address 'start' points to the instruction's virtual address
248 // which is not equal to the address where the instruction is located.
249 // Therefore, we will either crash or decode garbage.
250 if (is_decode_error_file()) {
251 return;
252 }
253
254 if (MacroAssembler::is_load_const(here)) {
255 long value = MacroAssembler::get_const(here);
256 const int tsize = 8;
257
258 st->fill_to(60);
259 st->print(";const %p | %ld | %23.15e", (void *)value, value, (double)value);
260 }
261 }