1 //===-- memprof_interceptors.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 // Intercept various libc functions.
12 //===----------------------------------------------------------------------===//
13 
14 #include "memprof_interceptors.h"
15 #include "memprof_allocator.h"
16 #include "memprof_internal.h"
17 #include "memprof_mapping.h"
18 #include "memprof_stack.h"
19 #include "memprof_stats.h"
20 #include "sanitizer_common/sanitizer_libc.h"
21 #include "sanitizer_common/sanitizer_posix.h"
22 
23 namespace __memprof {
24 
25 #define MEMPROF_READ_STRING(s, n) MEMPROF_READ_RANGE((s), (n))
26 
27 static inline uptr MaybeRealStrnlen(const char *s, uptr maxlen) {
28 #if SANITIZER_INTERCEPT_STRNLEN
29   if (REAL(strnlen)) {
30     return REAL(strnlen)(s, maxlen);
31   }
32 #endif
33   return internal_strnlen(s, maxlen);
34 }
35 
36 void SetThreadName(const char *name) {
37   MemprofThread *t = GetCurrentThread();
38   if (t)
39     memprofThreadRegistry().SetThreadName(t->tid(), name);
40 }
41 
42 int OnExit() {
43   // FIXME: ask frontend whether we need to return failure.
44   return 0;
45 }
46 
47 } // namespace __memprof
48 
49 // ---------------------- Wrappers ---------------- {{{1
50 using namespace __memprof;
51 
52 DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr)
53 DECLARE_REAL_AND_INTERCEPTOR(void, free, void *)
54 
55 #define MEMPROF_INTERCEPTOR_ENTER(ctx, func)                                   \
56   ctx = 0;                                                                     \
57   (void)ctx;
58 
59 #define COMMON_INTERCEPT_FUNCTION(name) MEMPROF_INTERCEPT_FUNC(name)
60 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver)                               \
61   MEMPROF_INTERCEPT_FUNC_VER(name, ver)
62 #define COMMON_INTERCEPT_FUNCTION_VER_UNVERSIONED_FALLBACK(name, ver)          \
63   MEMPROF_INTERCEPT_FUNC_VER_UNVERSIONED_FALLBACK(name, ver)
64 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size)                         \
65   MEMPROF_WRITE_RANGE(ptr, size)
66 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size)                          \
67   MEMPROF_READ_RANGE(ptr, size)
68 #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)                               \
69   MEMPROF_INTERCEPTOR_ENTER(ctx, func);                                        \
70   do {                                                                         \
71     if (memprof_init_is_running)                                               \
72       return REAL(func)(__VA_ARGS__);                                          \
73     ENSURE_MEMPROF_INITED();                                                   \
74   } while (false)
75 #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path)                              \
76   do {                                                                         \
77   } while (false)
78 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd)                                 \
79   do {                                                                         \
80   } while (false)
81 #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd)                                 \
82   do {                                                                         \
83   } while (false)
84 #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd)                    \
85   do {                                                                         \
86   } while (false)
87 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) SetThreadName(name)
88 // Should be memprofThreadRegistry().SetThreadNameByUserId(thread, name)
89 // But memprof does not remember UserId's for threads (pthread_t);
90 // and remembers all ever existed threads, so the linear search by UserId
91 // can be slow.
92 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name)                 \
93   do {                                                                         \
94   } while (false)
95 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
96 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
97 #define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle)
98 #define COMMON_INTERCEPTOR_LIBRARY_UNLOADED()
99 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!memprof_inited)
100 #define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end)                           \
101   if (MemprofThread *t = GetCurrentThread()) {                                 \
102     *begin = t->tls_begin();                                                   \
103     *end = t->tls_end();                                                       \
104   } else {                                                                     \
105     *begin = *end = 0;                                                         \
106   }
107 
108 #define COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size)                   \
109   do {                                                                         \
110     MEMPROF_INTERCEPTOR_ENTER(ctx, memmove);                                   \
111     MEMPROF_MEMMOVE_IMPL(to, from, size);                                      \
112   } while (false)
113 
114 #define COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size)                    \
115   do {                                                                         \
116     MEMPROF_INTERCEPTOR_ENTER(ctx, memcpy);                                    \
117     MEMPROF_MEMCPY_IMPL(to, from, size);                                       \
118   } while (false)
119 
120 #define COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size)                    \
121   do {                                                                         \
122     MEMPROF_INTERCEPTOR_ENTER(ctx, memset);                                    \
123     MEMPROF_MEMSET_IMPL(block, c, size);                                       \
124   } while (false)
125 
126 #include "sanitizer_common/sanitizer_common_interceptors.inc"
127 
128 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) MEMPROF_READ_RANGE(p, s)
129 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) MEMPROF_WRITE_RANGE(p, s)
130 #define COMMON_SYSCALL_POST_READ_RANGE(p, s)                                   \
131   do {                                                                         \
132     (void)(p);                                                                 \
133     (void)(s);                                                                 \
134   } while (false)
135 #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s)                                  \
136   do {                                                                         \
137     (void)(p);                                                                 \
138     (void)(s);                                                                 \
139   } while (false)
140 #include "sanitizer_common/sanitizer_common_syscalls.inc"
141 
142 struct ThreadStartParam {
143   atomic_uintptr_t t;
144   atomic_uintptr_t is_registered;
145 };
146 
147 static thread_return_t THREAD_CALLING_CONV memprof_thread_start(void *arg) {
148   ThreadStartParam *param = reinterpret_cast<ThreadStartParam *>(arg);
149   MemprofThread *t = nullptr;
150   while ((t = reinterpret_cast<MemprofThread *>(
151               atomic_load(&param->t, memory_order_acquire))) == nullptr)
152     internal_sched_yield();
153   SetCurrentThread(t);
154   return t->ThreadStart(GetTid(), &param->is_registered);
155 }
156 
157 INTERCEPTOR(int, pthread_create, void *thread, void *attr,
158             void *(*start_routine)(void *), void *arg) {
159   EnsureMainThreadIDIsCorrect();
160   GET_STACK_TRACE_THREAD;
161   int detached = 0;
162   if (attr)
163     REAL(pthread_attr_getdetachstate)(attr, &detached);
164   ThreadStartParam param;
165   atomic_store(&param.t, 0, memory_order_relaxed);
166   atomic_store(&param.is_registered, 0, memory_order_relaxed);
167   int result;
168   {
169     // Ignore all allocations made by pthread_create: thread stack/TLS may be
170     // stored by pthread for future reuse even after thread destruction, and
171     // the linked list it's stored in doesn't even hold valid pointers to the
172     // objects, the latter are calculated by obscure pointer arithmetic.
173     result = REAL(pthread_create)(thread, attr, memprof_thread_start, &param);
174   }
175   if (result == 0) {
176     u32 current_tid = GetCurrentTidOrInvalid();
177     MemprofThread *t = MemprofThread::Create(start_routine, arg, current_tid,
178                                              &stack, detached);
179     atomic_store(&param.t, reinterpret_cast<uptr>(t), memory_order_release);
180     // Wait until the MemprofThread object is initialized and the
181     // ThreadRegistry entry is in "started" state.
182     while (atomic_load(&param.is_registered, memory_order_acquire) == 0)
183       internal_sched_yield();
184   }
185   return result;
186 }
187 
188 INTERCEPTOR(int, pthread_join, void *t, void **arg) {
189   return real_pthread_join(t, arg);
190 }
191 
192 DEFINE_REAL_PTHREAD_FUNCTIONS
193 
194 INTERCEPTOR(char *, index, const char *string, int c)
195 ALIAS(WRAPPER_NAME(strchr));
196 
197 // For both strcat() and strncat() we need to check the validity of |to|
198 // argument irrespective of the |from| length.
199 INTERCEPTOR(char *, strcat, char *to, const char *from) {
200   void *ctx;
201   MEMPROF_INTERCEPTOR_ENTER(ctx, strcat);
202   ENSURE_MEMPROF_INITED();
203   uptr from_length = internal_strlen(from);
204   MEMPROF_READ_RANGE(from, from_length + 1);
205   uptr to_length = internal_strlen(to);
206   MEMPROF_READ_STRING(to, to_length);
207   MEMPROF_WRITE_RANGE(to + to_length, from_length + 1);
208   return REAL(strcat)(to, from);
209 }
210 
211 INTERCEPTOR(char *, strncat, char *to, const char *from, uptr size) {
212   void *ctx;
213   MEMPROF_INTERCEPTOR_ENTER(ctx, strncat);
214   ENSURE_MEMPROF_INITED();
215   uptr from_length = MaybeRealStrnlen(from, size);
216   uptr copy_length = Min(size, from_length + 1);
217   MEMPROF_READ_RANGE(from, copy_length);
218   uptr to_length = internal_strlen(to);
219   MEMPROF_READ_STRING(to, to_length);
220   MEMPROF_WRITE_RANGE(to + to_length, from_length + 1);
221   return REAL(strncat)(to, from, size);
222 }
223 
224 INTERCEPTOR(char *, strcpy, char *to, const char *from) {
225   void *ctx;
226   MEMPROF_INTERCEPTOR_ENTER(ctx, strcpy);
227   if (memprof_init_is_running) {
228     return REAL(strcpy)(to, from);
229   }
230   ENSURE_MEMPROF_INITED();
231   uptr from_size = internal_strlen(from) + 1;
232   MEMPROF_READ_RANGE(from, from_size);
233   MEMPROF_WRITE_RANGE(to, from_size);
234   return REAL(strcpy)(to, from);
235 }
236 
237 INTERCEPTOR(char *, strdup, const char *s) {
238   void *ctx;
239   MEMPROF_INTERCEPTOR_ENTER(ctx, strdup);
240   if (UNLIKELY(!memprof_inited))
241     return internal_strdup(s);
242   ENSURE_MEMPROF_INITED();
243   uptr length = internal_strlen(s);
244   MEMPROF_READ_RANGE(s, length + 1);
245   GET_STACK_TRACE_MALLOC;
246   void *new_mem = memprof_malloc(length + 1, &stack);
247   REAL(memcpy)(new_mem, s, length + 1);
248   return reinterpret_cast<char *>(new_mem);
249 }
250 
251 INTERCEPTOR(char *, __strdup, const char *s) {
252   void *ctx;
253   MEMPROF_INTERCEPTOR_ENTER(ctx, strdup);
254   if (UNLIKELY(!memprof_inited))
255     return internal_strdup(s);
256   ENSURE_MEMPROF_INITED();
257   uptr length = internal_strlen(s);
258   MEMPROF_READ_RANGE(s, length + 1);
259   GET_STACK_TRACE_MALLOC;
260   void *new_mem = memprof_malloc(length + 1, &stack);
261   REAL(memcpy)(new_mem, s, length + 1);
262   return reinterpret_cast<char *>(new_mem);
263 }
264 
265 INTERCEPTOR(char *, strncpy, char *to, const char *from, uptr size) {
266   void *ctx;
267   MEMPROF_INTERCEPTOR_ENTER(ctx, strncpy);
268   ENSURE_MEMPROF_INITED();
269   uptr from_size = Min(size, MaybeRealStrnlen(from, size) + 1);
270   MEMPROF_READ_RANGE(from, from_size);
271   MEMPROF_WRITE_RANGE(to, size);
272   return REAL(strncpy)(to, from, size);
273 }
274 
275 INTERCEPTOR(long, strtol, const char *nptr, char **endptr, int base) {
276   void *ctx;
277   MEMPROF_INTERCEPTOR_ENTER(ctx, strtol);
278   ENSURE_MEMPROF_INITED();
279   char *real_endptr;
280   long result = REAL(strtol)(nptr, &real_endptr, base);
281   StrtolFixAndCheck(ctx, nptr, endptr, real_endptr, base);
282   return result;
283 }
284 
285 INTERCEPTOR(int, atoi, const char *nptr) {
286   void *ctx;
287   MEMPROF_INTERCEPTOR_ENTER(ctx, atoi);
288   ENSURE_MEMPROF_INITED();
289   char *real_endptr;
290   // "man atoi" tells that behavior of atoi(nptr) is the same as
291   // strtol(nptr, 0, 10), i.e. it sets errno to ERANGE if the
292   // parsed integer can't be stored in *long* type (even if it's
293   // different from int). So, we just imitate this behavior.
294   int result = REAL(strtol)(nptr, &real_endptr, 10);
295   FixRealStrtolEndptr(nptr, &real_endptr);
296   MEMPROF_READ_STRING(nptr, (real_endptr - nptr) + 1);
297   return result;
298 }
299 
300 INTERCEPTOR(long, atol, const char *nptr) {
301   void *ctx;
302   MEMPROF_INTERCEPTOR_ENTER(ctx, atol);
303   ENSURE_MEMPROF_INITED();
304   char *real_endptr;
305   long result = REAL(strtol)(nptr, &real_endptr, 10);
306   FixRealStrtolEndptr(nptr, &real_endptr);
307   MEMPROF_READ_STRING(nptr, (real_endptr - nptr) + 1);
308   return result;
309 }
310 
311 INTERCEPTOR(long long, strtoll, const char *nptr, char **endptr, int base) {
312   void *ctx;
313   MEMPROF_INTERCEPTOR_ENTER(ctx, strtoll);
314   ENSURE_MEMPROF_INITED();
315   char *real_endptr;
316   long long result = REAL(strtoll)(nptr, &real_endptr, base);
317   StrtolFixAndCheck(ctx, nptr, endptr, real_endptr, base);
318   return result;
319 }
320 
321 INTERCEPTOR(long long, atoll, const char *nptr) {
322   void *ctx;
323   MEMPROF_INTERCEPTOR_ENTER(ctx, atoll);
324   ENSURE_MEMPROF_INITED();
325   char *real_endptr;
326   long long result = REAL(strtoll)(nptr, &real_endptr, 10);
327   FixRealStrtolEndptr(nptr, &real_endptr);
328   MEMPROF_READ_STRING(nptr, (real_endptr - nptr) + 1);
329   return result;
330 }
331 
332 // ---------------------- InitializeMemprofInterceptors ---------------- {{{1
333 namespace __memprof {
334 void InitializeMemprofInterceptors() {
335   static bool was_called_once;
336   CHECK(!was_called_once);
337   was_called_once = true;
338   InitializeCommonInterceptors();
339 
340   // Intercept str* functions.
341   MEMPROF_INTERCEPT_FUNC(strcat);
342   MEMPROF_INTERCEPT_FUNC(strcpy);
343   MEMPROF_INTERCEPT_FUNC(strncat);
344   MEMPROF_INTERCEPT_FUNC(strncpy);
345   MEMPROF_INTERCEPT_FUNC(strdup);
346   MEMPROF_INTERCEPT_FUNC(__strdup);
347   MEMPROF_INTERCEPT_FUNC(index);
348 
349   MEMPROF_INTERCEPT_FUNC(atoi);
350   MEMPROF_INTERCEPT_FUNC(atol);
351   MEMPROF_INTERCEPT_FUNC(strtol);
352   MEMPROF_INTERCEPT_FUNC(atoll);
353   MEMPROF_INTERCEPT_FUNC(strtoll);
354 
355   // Intercept threading-related functions
356   MEMPROF_INTERCEPT_FUNC(pthread_create);
357   MEMPROF_INTERCEPT_FUNC(pthread_join);
358 
359   InitializePlatformInterceptors();
360 
361   VReport(1, "MemProfiler: libc interceptors initialized\n");
362 }
363 
364 } // namespace __memprof
365