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
lp_check_alignment(const void * ptr,unsigned alignment)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
lp_debug_dump_value(LLVMValueRef value)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
disassemble(const void * func,std::ostream & buffer)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
lp_disassemble(LLVMValueRef func,const void * code)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
lp_profile(LLVMValueRef func,const void * code)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