1 /**************************************************************************
2 *
3 * Copyright 2009-2011 VMware, Inc.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28 #include <stddef.h>
29 #include <fstream>
30 #include <sstream>
31 #include <iomanip>
32
33 #include <llvm/Config/llvm-config.h>
34 #include <llvm-c/Core.h>
35 #include <llvm-c/Disassembler.h>
36 #include <llvm/Support/raw_ostream.h>
37 #include <llvm/Support/Format.h>
38 #include <llvm/IR/Module.h>
39
40 #if LLVM_VERSION_MAJOR >= 17
41 #include <llvm/TargetParser/Host.h>
42 #else
43 #include <llvm/Support/Host.h>
44 #endif
45
46 #include "util/u_math.h"
47 #include "util/u_debug.h"
48
49 #include "lp_bld_debug.h"
50
51 #ifdef __linux__
52 #include <sys/stat.h>
53 #include <fcntl.h>
54 #endif
55
56
57
58 /**
59 * Check alignment.
60 *
61 * It is important that this check is not implemented as a macro or inlined
62 * function, as the compiler assumptions in respect to alignment of global
63 * and stack variables would often make the check a no op, defeating the
64 * whole purpose of the exercise.
65 */
66 extern "C" bool
lp_check_alignment(const void * ptr,unsigned alignment)67 lp_check_alignment(const void *ptr, unsigned alignment)
68 {
69 assert(util_is_power_of_two_or_zero(alignment));
70 return ((uintptr_t)ptr & (alignment - 1)) == 0;
71 }
72
73
74 /**
75 * Same as LLVMDumpValue, but through our debugging channels.
76 */
77 extern "C" void
lp_debug_dump_value(LLVMValueRef value)78 lp_debug_dump_value(LLVMValueRef value)
79 {
80 char *str = LLVMPrintValueToString(value);
81 if (str) {
82 os_log_message(str);
83 LLVMDisposeMessage(str);
84 }
85 }
86
87
88 /*
89 * Disassemble a function, using the LLVM MC disassembler.
90 *
91 * See also:
92 * - http://blog.llvm.org/2010/01/x86-disassembler.html
93 * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
94 */
95 static size_t
disassemble(const void * func,std::ostream & buffer)96 disassemble(const void* func, std::ostream &buffer)
97 {
98 const uint8_t *bytes = (const uint8_t *)func;
99
100 /*
101 * Limit disassembly to this extent
102 */
103 const uint64_t extent = 96 * 1024;
104
105 /*
106 * Initialize all used objects.
107 */
108
109 const char *triple = LLVM_HOST_TRIPLE;
110 LLVMDisasmContextRef D = LLVMCreateDisasm(triple, NULL, 0, NULL, NULL);
111 char outline[1024];
112
113 if (!D) {
114 buffer << "error: could not create disassembler for triple "
115 << triple << '\n';
116 return 0;
117 }
118
119 uint64_t pc;
120 pc = 0;
121 while (pc < extent) {
122 size_t Size;
123
124 /*
125 * Print address. We use addresses relative to the start of the function,
126 * so that between runs.
127 */
128
129 buffer << std::setw(6) << std::hex << (unsigned long)pc
130 << std::setw(0) << std::dec << ":";
131
132 Size = LLVMDisasmInstruction(D, (uint8_t *)bytes + pc, extent - pc, 0, outline,
133 sizeof(outline));
134
135 if (!Size) {
136 #if DETECT_ARCH_AARCH64
137 uint32_t invalid = bytes[pc + 0] << 0 | bytes[pc + 1] << 8 |
138 bytes[pc + 2] << 16 | bytes[pc + 3] << 24;
139 snprintf(outline, sizeof(outline), "\tinvalid %x", invalid);
140 Size = 4;
141 #else
142 buffer << "\tinvalid\n";
143 break;
144 #endif
145 }
146
147 /*
148 * Output the bytes in hexidecimal format.
149 */
150
151 if (0) {
152 unsigned i;
153 for (i = 0; i < Size; ++i) {
154 buffer << std::hex << std::setfill('0') << std::setw(2)
155 << static_cast<int> (bytes[pc + i])
156 << std::setw(0) << std::dec;
157 }
158 for (; i < 16; ++i) {
159 buffer << " ";
160 }
161 }
162
163 /*
164 * Print the instruction.
165 */
166
167 buffer << outline << '\n';
168
169 /*
170 * Advance.
171 */
172
173 pc += Size;
174
175 /*
176 * Stop disassembling on return statements
177 */
178
179 #if DETECT_ARCH_X86 || DETECT_ARCH_X86_64
180 if (Size == 1 && bytes[pc - 1] == 0xc3) {
181 break;
182 }
183 #elif DETECT_ARCH_AARCH64
184 if (Size == 4 && bytes[pc - 1] == 0xD6 && bytes[pc - 2] == 0x5F &&
185 (bytes[pc - 3] & 0xFC) == 0 && (bytes[pc - 4] & 0x1F) == 0) {
186 break;
187 }
188 #endif
189
190 if (pc >= extent) {
191 buffer << "disassembly larger than " << extent << " bytes, aborting\n";
192 break;
193 }
194 }
195
196 buffer << '\n';
197
198 LLVMDisasmDispose(D);
199
200 /*
201 * Print GDB command, useful to verify output.
202 */
203 if (0) {
204 buffer << "disassemble " << std::hex << static_cast<const void*>(bytes) << ' '
205 << static_cast<const void*>(bytes + pc) << std::dec << '\n';
206 }
207
208 return pc;
209 }
210
211
212 extern "C" void
lp_disassemble(LLVMValueRef func,const void * code)213 lp_disassemble(LLVMValueRef func, const void *code)
214 {
215 std::ostringstream buffer;
216 std::string s;
217
218 buffer << LLVMGetValueName(func) << ":\n";
219 disassemble(code, buffer);
220 s = buffer.str();
221 os_log_message(s.c_str());
222 os_log_message("\n");
223 }
224
225
226 /*
227 * Linux perf profiler integration.
228 *
229 * See also:
230 * - http://penberg.blogspot.co.uk/2009/06/jato-has-profiler.html
231 * - https://github.com/penberg/jato/commit/73ad86847329d99d51b386f5aba692580d1f8fdc
232 * - http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=80d496be89ed7dede5abee5c057634e80a31c82d
233 */
234 extern "C" void
lp_profile(LLVMValueRef func,const void * code)235 lp_profile(LLVMValueRef func, const void *code)
236 {
237 #if defined(PROFILE)
238 static std::ofstream perf_asm_file;
239 static bool first_time = true;
240 static FILE *perf_map_file = NULL;
241 if (first_time) {
242 unsigned long long pid = (unsigned long long)getpid();
243 char filename[1024];
244 #if defined(__linux__)
245 /*
246 * We rely on the disassembler for determining a function's size, but
247 * the disassembly is a leaky and slow operation, so avoid running
248 * this except when running inside linux perf, which can be inferred
249 * by the PERF_BUILDID_DIR environment variable.
250 */
251 if (getenv("PERF_BUILDID_DIR")) {
252 snprintf(filename, sizeof(filename), "/tmp/perf-%llu.map", pid);
253 perf_map_file = fopen(filename, "wt");
254 snprintf(filename, sizeof(filename), "/tmp/perf-%llu.map.asm", pid);
255 perf_asm_file.open(filename);
256 }
257 #else
258 if (const char* output_dir = getenv("JIT_SYMBOL_MAP_DIR")) {
259 snprintf(filename, sizeof(filename), "%s/jit-symbols-%llu.map", output_dir, pid);
260 perf_map_file = fopen(filename, "wt");
261 snprintf(filename, sizeof(filename), "%s/jit-symbols-%llu.map.asm", output_dir, pid);
262 perf_asm_file.open(filename);
263 }
264 #endif
265 first_time = false;
266 }
267 if (perf_map_file) {
268 const char *symbol = LLVMGetValueName(func);
269 unsigned long addr = (uintptr_t)code;
270 perf_asm_file << symbol << " " << std::hex
271 << (uintptr_t)code << std::dec << ":\n";
272 unsigned long size = disassemble(code, perf_asm_file);
273 perf_asm_file.flush();
274 fprintf(perf_map_file, "%lx %lx %s\n", addr, size, symbol);
275 fflush(perf_map_file);
276 }
277 #else
278 (void)func;
279 (void)code;
280 #endif
281 }
282