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-c/Core.h> 34 #include <llvm-c/Disassembler.h> 35 #include <llvm/Support/raw_ostream.h> 36 #include <llvm/Support/Format.h> 37 #include <llvm/Support/Host.h> 38 #include <llvm/IR/Module.h> 39 40 #include "util/u_math.h" 41 #include "util/u_debug.h" 42 43 #include "lp_bld_debug.h" 44 45 #ifdef __linux__ 46 #include <sys/stat.h> 47 #include <fcntl.h> 48 #endif 49 50 51 52 /** 53 * Check alignment. 54 * 55 * It is important that this check is not implemented as a macro or inlined 56 * function, as the compiler assumptions in respect to alignment of global 57 * and stack variables would often make the check a no op, defeating the 58 * whole purpose of the exercise. 59 */ 60 extern "C" boolean 61 lp_check_alignment(const void *ptr, unsigned alignment) 62 { 63 assert(util_is_power_of_two(alignment)); 64 return ((uintptr_t)ptr & (alignment - 1)) == 0; 65 } 66 67 68 /** 69 * Same as LLVMDumpValue, but through our debugging channels. 70 */ 71 extern "C" void 72 lp_debug_dump_value(LLVMValueRef value) 73 { 74 #if HAVE_LLVM >= 0x0304 75 char *str = LLVMPrintValueToString(value); 76 if (str) { 77 os_log_message(str); 78 LLVMDisposeMessage(str); 79 } 80 #elif defined(PIPE_OS_WINDOWS) || defined(PIPE_OS_EMBEDDED) 81 std::string str; 82 llvm::raw_string_ostream os(str); 83 llvm::unwrap(value)->print(os); 84 os_log_message(str.c_str()); 85 #else 86 LLVMDumpValue(value); 87 #endif 88 } 89 90 91 /* 92 * Disassemble a function, using the LLVM MC disassembler. 93 * 94 * See also: 95 * - http://blog.llvm.org/2010/01/x86-disassembler.html 96 * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html 97 */ 98 static size_t 99 disassemble(const void* func, std::ostream &buffer) 100 { 101 const uint8_t *bytes = (const uint8_t *)func; 102 103 /* 104 * Limit disassembly to this extent 105 */ 106 const uint64_t extent = 96 * 1024; 107 108 /* 109 * Initialize all used objects. 110 */ 111 112 const char *triple = LLVM_HOST_TRIPLE; 113 LLVMDisasmContextRef D = LLVMCreateDisasm(triple, NULL, 0, NULL, NULL); 114 char outline[1024]; 115 116 if (!D) { 117 buffer << "error: could not create disassembler for triple " 118 << triple << '\n'; 119 return 0; 120 } 121 122 uint64_t pc; 123 pc = 0; 124 while (pc < extent) { 125 size_t Size; 126 127 /* 128 * Print address. We use addresses relative to the start of the function, 129 * so that between runs. 130 */ 131 132 buffer << std::setw(6) << (unsigned long)pc << ":\t"; 133 134 Size = LLVMDisasmInstruction(D, (uint8_t *)bytes + pc, extent - pc, 0, outline, 135 sizeof outline); 136 137 if (!Size) { 138 buffer << "invalid\n"; 139 pc += 1; 140 break; 141 } 142 143 /* 144 * Output the bytes in hexidecimal format. 145 */ 146 147 if (0) { 148 unsigned i; 149 for (i = 0; i < Size; ++i) { 150 buffer << std::hex << std::setfill('0') << std::setw(2) 151 << static_cast<int> (bytes[pc + i]); 152 } 153 for (; i < 16; ++i) { 154 buffer << std::dec << " "; 155 } 156 } 157 158 /* 159 * Print the instruction. 160 */ 161 162 buffer << std::setw(Size) << outline << '\n'; 163 164 /* 165 * Stop disassembling on return statements, if there is no record of a 166 * jump to a successive address. 167 * 168 * XXX: This currently assumes x86 169 */ 170 171 #if defined(PIPE_ARCH_X86) || defined(PIPE_ARCH_X86_64) 172 if (Size == 1 && bytes[pc] == 0xc3) { 173 break; 174 } 175 #endif 176 177 /* 178 * Advance. 179 */ 180 181 pc += Size; 182 183 if (pc >= extent) { 184 buffer << "disassembly larger than " << extent << " bytes, aborting\n"; 185 break; 186 } 187 } 188 189 buffer << '\n'; 190 191 LLVMDisasmDispose(D); 192 193 /* 194 * Print GDB command, useful to verify output. 195 */ 196 if (0) { 197 buffer << "disassemble " << static_cast<const void*>(bytes) << ' ' 198 << static_cast<const void*>(bytes + pc) << '\n'; 199 } 200 201 return pc; 202 } 203 204 205 extern "C" void 206 lp_disassemble(LLVMValueRef func, const void *code) 207 { 208 std::ostringstream buffer; 209 std::string s; 210 211 buffer << LLVMGetValueName(func) << ":\n"; 212 disassemble(code, buffer); 213 s = buffer.str(); 214 os_log_message(s.c_str()); 215 os_log_message("\n"); 216 } 217 218 219 /* 220 * Linux perf profiler integration. 221 * 222 * See also: 223 * - http://penberg.blogspot.co.uk/2009/06/jato-has-profiler.html 224 * - https://github.com/penberg/jato/commit/73ad86847329d99d51b386f5aba692580d1f8fdc 225 * - http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=80d496be89ed7dede5abee5c057634e80a31c82d 226 */ 227 extern "C" void 228 lp_profile(LLVMValueRef func, const void *code) 229 { 230 #if defined(__linux__) && defined(PROFILE) 231 static std::ofstream perf_asm_file; 232 static boolean first_time = TRUE; 233 static FILE *perf_map_file = NULL; 234 if (first_time) { 235 /* 236 * We rely on the disassembler for determining a function's size, but 237 * the disassembly is a leaky and slow operation, so avoid running 238 * this except when running inside linux perf, which can be inferred 239 * by the PERF_BUILDID_DIR environment variable. 240 */ 241 if (getenv("PERF_BUILDID_DIR")) { 242 pid_t pid = getpid(); 243 char filename[256]; 244 util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map", (unsigned long long)pid); 245 perf_map_file = fopen(filename, "wt"); 246 util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map.asm", (unsigned long long)pid); 247 perf_asm_file.open(filename); 248 } 249 first_time = FALSE; 250 } 251 if (perf_map_file) { 252 const char *symbol = LLVMGetValueName(func); 253 unsigned long addr = (uintptr_t)code; 254 perf_asm_file << symbol << ":\n"; 255 unsigned long size = disassemble(code, perf_asm_file); 256 perf_asm_file.flush(); 257 fprintf(perf_map_file, "%lx %lx %s\n", addr, size, symbol); 258 fflush(perf_map_file); 259 } 260 #else 261 (void)func; 262 (void)code; 263 #endif 264 } 265 266 267
