1//===-- memprof_rtl.cpp --------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file is a part of MemProfiler, a memory profiler.
10//
11// Main file of the MemProf run-time library.
12//===----------------------------------------------------------------------===//
13
14#include "memprof_allocator.h"
15#include "memprof_interceptors.h"
16#include "memprof_interface_internal.h"
17#include "memprof_internal.h"
18#include "memprof_mapping.h"
19#include "memprof_stack.h"
20#include "memprof_stats.h"
21#include "memprof_thread.h"
22#include "sanitizer_common/sanitizer_atomic.h"
23#include "sanitizer_common/sanitizer_flags.h"
24#include "sanitizer_common/sanitizer_interface_internal.h"
25#include "sanitizer_common/sanitizer_libc.h"
26#include "sanitizer_common/sanitizer_symbolizer.h"
27
28#include <time.h>
29
30SANITIZER_WEAK_ATTRIBUTE char __memprof_default_options_str[1];
31
32uptr __memprof_shadow_memory_dynamic_address; // Global interface symbol.
33
34// Allow the user to specify a profile output file via the binary.
35SANITIZER_WEAK_ATTRIBUTE char __memprof_profile_filename[1];
36
37// Share ClHistogram compiler flag with runtime.
38SANITIZER_WEAK_ATTRIBUTE bool __memprof_histogram;
39
40namespace __memprof {
41
42static void MemprofDie() {
43 static atomic_uint32_t num_calls;
44 if (atomic_fetch_add(a: &num_calls, v: 1, mo: memory_order_relaxed) != 0) {
45 // Don't die twice - run a busy loop.
46 while (1) {
47 internal_sched_yield();
48 }
49 }
50 if (common_flags()->print_module_map >= 1)
51 DumpProcessMap();
52 if (flags()->unmap_shadow_on_exit) {
53 if (kHighShadowEnd)
54 UnmapOrDie(addr: (void *)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
55 }
56}
57
58static void MemprofOnDeadlySignal(int signo, void *siginfo, void *context) {
59 // We call StartReportDeadlySignal not HandleDeadlySignal so we get the
60 // deadly signal message to stderr but no writing to the profile output file
61 StartReportDeadlySignal();
62 __memprof_profile_dump();
63 Die();
64}
65
66static void CheckUnwind() {
67 GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_check);
68 stack.Print();
69}
70
71// -------------------------- Globals --------------------- {{{1
72int memprof_inited;
73bool memprof_init_is_running;
74int memprof_timestamp_inited;
75long memprof_init_timestamp_s;
76
77uptr kHighMemEnd;
78
79// -------------------------- Run-time entry ------------------- {{{1
80// exported functions
81
82#define MEMPROF_MEMORY_ACCESS_CALLBACK_BODY() __memprof::RecordAccess(addr);
83#define MEMPROF_MEMORY_ACCESS_CALLBACK_BODY_HIST() \
84 __memprof::RecordAccessHistogram(addr);
85
86#define MEMPROF_MEMORY_ACCESS_CALLBACK(type) \
87 extern "C" NOINLINE INTERFACE_ATTRIBUTE void __memprof_##type(uptr addr) { \
88 MEMPROF_MEMORY_ACCESS_CALLBACK_BODY() \
89 }
90
91#define MEMPROF_MEMORY_ACCESS_CALLBACK_HIST(type) \
92 extern "C" NOINLINE INTERFACE_ATTRIBUTE void __memprof_hist_##type( \
93 uptr addr) { \
94 MEMPROF_MEMORY_ACCESS_CALLBACK_BODY_HIST() \
95 }
96
97MEMPROF_MEMORY_ACCESS_CALLBACK_HIST(load)
98MEMPROF_MEMORY_ACCESS_CALLBACK_HIST(store)
99
100MEMPROF_MEMORY_ACCESS_CALLBACK(load)
101MEMPROF_MEMORY_ACCESS_CALLBACK(store)
102
103// Force the linker to keep the symbols for various MemProf interface
104// functions. We want to keep those in the executable in order to let the
105// instrumented dynamic libraries access the symbol even if it is not used by
106// the executable itself. This should help if the build system is removing dead
107// code at link time.
108static NOINLINE void force_interface_symbols() {
109 volatile int fake_condition = 0; // prevent dead condition elimination.
110 // clang-format off
111 switch (fake_condition) {
112 case 1: __memprof_record_access(addr: nullptr); break;
113 case 2: __memprof_record_access_range(addr: nullptr, size: 0); break;
114 }
115 // clang-format on
116}
117
118static void memprof_atexit() {
119 Printf(format: "MemProfiler exit stats:\n");
120 __memprof_print_accumulated_stats();
121}
122
123static void InitializeHighMemEnd() {
124 kHighMemEnd = GetMaxUserVirtualAddress();
125 // Increase kHighMemEnd to make sure it's properly
126 // aligned together with kHighMemBeg:
127 kHighMemEnd |= (GetMmapGranularity() << SHADOW_SCALE) - 1;
128}
129
130void PrintAddressSpaceLayout() {
131 if (kHighMemBeg) {
132 Printf(format: "|| `[%p, %p]` || HighMem ||\n", (void *)kHighMemBeg,
133 (void *)kHighMemEnd);
134 Printf(format: "|| `[%p, %p]` || HighShadow ||\n", (void *)kHighShadowBeg,
135 (void *)kHighShadowEnd);
136 }
137 Printf(format: "|| `[%p, %p]` || ShadowGap ||\n", (void *)kShadowGapBeg,
138 (void *)kShadowGapEnd);
139 if (kLowShadowBeg) {
140 Printf(format: "|| `[%p, %p]` || LowShadow ||\n", (void *)kLowShadowBeg,
141 (void *)kLowShadowEnd);
142 Printf(format: "|| `[%p, %p]` || LowMem ||\n", (void *)kLowMemBeg,
143 (void *)kLowMemEnd);
144 }
145 Printf(format: "MemToShadow(shadow): %p %p", (void *)MEM_TO_SHADOW(kLowShadowBeg),
146 (void *)MEM_TO_SHADOW(kLowShadowEnd));
147 if (kHighMemBeg) {
148 Printf(format: " %p %p", (void *)MEM_TO_SHADOW(kHighShadowBeg),
149 (void *)MEM_TO_SHADOW(kHighShadowEnd));
150 }
151 Printf(format: "\n");
152 Printf(format: "malloc_context_size=%zu\n",
153 (uptr)common_flags()->malloc_context_size);
154
155 Printf(format: "SHADOW_SCALE: %d\n", (int)SHADOW_SCALE);
156 Printf(format: "SHADOW_GRANULARITY: %d\n", (int)SHADOW_GRANULARITY);
157 Printf(format: "SHADOW_OFFSET: %p\n", (void *)SHADOW_OFFSET);
158 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
159}
160
161static void MemprofInitInternal() {
162 if (LIKELY(memprof_inited))
163 return;
164 SanitizerToolName = "MemProfiler";
165 CHECK(!memprof_init_is_running && "MemProf init calls itself!");
166 memprof_init_is_running = true;
167
168 CacheBinaryName();
169
170 // Initialize flags. This must be done early, because most of the
171 // initialization steps look at flags().
172 InitializeFlags();
173
174 AvoidCVE_2016_2143();
175
176 SetMallocContextSize(common_flags()->malloc_context_size);
177
178 InitializeHighMemEnd();
179
180 // Make sure we are not statically linked.
181 __interception::DoesNotSupportStaticLinking();
182
183 // Install tool-specific callbacks in sanitizer_common.
184 AddDieCallback(callback: MemprofDie);
185 SetCheckUnwindCallback(CheckUnwind);
186
187 // Use profile name specified via the binary itself if it exists, and hasn't
188 // been overrriden by a flag at runtime.
189 if (__memprof_profile_filename[0] != 0 && !common_flags()->log_path)
190 __sanitizer_set_report_path(path: __memprof_profile_filename);
191 else
192 __sanitizer_set_report_path(path: common_flags()->log_path);
193
194 __sanitizer::InitializePlatformEarly();
195
196 // Setup internal allocator callback.
197 SetLowLevelAllocateMinAlignment(SHADOW_GRANULARITY);
198
199 InitializeMemprofInterceptors();
200 CheckASLR();
201
202 ReplaceSystemMalloc();
203
204 DisableCoreDumperIfNecessary();
205
206 InitializeShadowMemory();
207
208 TSDInit(destructor: PlatformTSDDtor);
209 InstallDeadlySignalHandlers(handler: MemprofOnDeadlySignal);
210
211 InitializeAllocator();
212
213 if (flags()->atexit)
214 Atexit(function: memprof_atexit);
215
216 InitializeCoverage(enabled: common_flags()->coverage, coverage_dir: common_flags()->coverage_dir);
217
218 // Create main thread.
219 MemprofThread *main_thread = CreateMainThread();
220 CHECK_EQ(0, main_thread->tid());
221 force_interface_symbols(); // no-op.
222 SanitizerInitializeUnwinder();
223
224 Symbolizer::LateInitialize();
225
226 VReport(1, "MemProfiler Init done\n");
227
228 memprof_init_is_running = false;
229 memprof_inited = 1;
230}
231
232void MemprofInitTime() {
233 if (LIKELY(memprof_timestamp_inited))
234 return;
235 timespec ts;
236 clock_gettime(CLOCK_REALTIME, tp: &ts);
237 memprof_init_timestamp_s = ts.tv_sec;
238 memprof_timestamp_inited = 1;
239}
240
241// Initialize as requested from some part of MemProf runtime library
242// (interceptors, allocator, etc).
243void MemprofInitFromRtl() { MemprofInitInternal(); }
244
245#if MEMPROF_DYNAMIC
246// Initialize runtime in case it's LD_PRELOAD-ed into uninstrumented executable
247// (and thus normal initializers from .preinit_array or modules haven't run).
248
249class MemprofInitializer {
250public:
251 MemprofInitializer() { MemprofInitFromRtl(); }
252};
253
254static MemprofInitializer memprof_initializer;
255#endif // MEMPROF_DYNAMIC
256
257} // namespace __memprof
258
259// ---------------------- Interface ---------------- {{{1
260using namespace __memprof;
261
262// Initialize as requested from instrumented application code.
263void __memprof_init() {
264 MemprofInitTime();
265 MemprofInitInternal();
266}
267
268void __memprof_preinit() { MemprofInitInternal(); }
269
270void __memprof_version_mismatch_check_v1() {}
271
272void __memprof_record_access(void const volatile *addr) {
273 __memprof::RecordAccess(a: (uptr)addr);
274}
275
276void __memprof_record_access_hist(void const volatile *addr) {
277 __memprof::RecordAccessHistogram(a: (uptr)addr);
278}
279
280void __memprof_record_access_range(void const volatile *addr, uptr size) {
281 for (uptr a = (uptr)addr; a < (uptr)addr + size; a += kWordSize)
282 __memprof::RecordAccess(a);
283}
284
285void __memprof_record_access_range_hist(void const volatile *addr, uptr size) {
286 for (uptr a = (uptr)addr; a < (uptr)addr + size; a += kWordSize)
287 __memprof::RecordAccessHistogram(a);
288}
289
290extern "C" SANITIZER_INTERFACE_ATTRIBUTE u16
291__sanitizer_unaligned_load16(const uu16 *p) {
292 __memprof_record_access(addr: p);
293 return *p;
294}
295
296extern "C" SANITIZER_INTERFACE_ATTRIBUTE u32
297__sanitizer_unaligned_load32(const uu32 *p) {
298 __memprof_record_access(addr: p);
299 return *p;
300}
301
302extern "C" SANITIZER_INTERFACE_ATTRIBUTE u64
303__sanitizer_unaligned_load64(const uu64 *p) {
304 __memprof_record_access(addr: p);
305 return *p;
306}
307
308extern "C" SANITIZER_INTERFACE_ATTRIBUTE void
309__sanitizer_unaligned_store16(uu16 *p, u16 x) {
310 __memprof_record_access(addr: p);
311 *p = x;
312}
313
314extern "C" SANITIZER_INTERFACE_ATTRIBUTE void
315__sanitizer_unaligned_store32(uu32 *p, u32 x) {
316 __memprof_record_access(addr: p);
317 *p = x;
318}
319
320extern "C" SANITIZER_INTERFACE_ATTRIBUTE void
321__sanitizer_unaligned_store64(uu64 *p, u64 x) {
322 __memprof_record_access(addr: p);
323 *p = x;
324}
325