1//=-- lsan_common.h -------------------------------------------------------===//
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 LeakSanitizer.
10// Private LSan header.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LSAN_COMMON_H
15#define LSAN_COMMON_H
16
17#include "sanitizer_common/sanitizer_allocator.h"
18#include "sanitizer_common/sanitizer_common.h"
19#include "sanitizer_common/sanitizer_internal_defs.h"
20#include "sanitizer_common/sanitizer_platform.h"
21#include "sanitizer_common/sanitizer_stoptheworld.h"
22#include "sanitizer_common/sanitizer_symbolizer.h"
23
24// LeakSanitizer relies on some Glibc's internals (e.g. TLS machinery) on Linux.
25// Also, LSan doesn't like 32 bit architectures
26// because of "small" (4 bytes) pointer size that leads to high false negative
27// ratio on large leaks. But we still want to have it for some 32 bit arches
28// (e.g. x86), see https://github.com/google/sanitizers/issues/403.
29// To enable LeakSanitizer on a new architecture, one needs to implement the
30// internal_clone function as well as (probably) adjust the TLS machinery for
31// the new architecture inside the sanitizer library.
32#if (SANITIZER_LINUX && !SANITIZER_ANDROID || SANITIZER_MAC) &&          \
33    (SANITIZER_WORDSIZE == 64) &&                                        \
34    (defined(__x86_64__) || defined(__mips64) || defined(__aarch64__) || \
35     defined(__powerpc64__) || defined(__s390x__))
36#define CAN_SANITIZE_LEAKS 1
37#elif defined(__i386__) && \
38    (SANITIZER_LINUX && !SANITIZER_ANDROID || SANITIZER_MAC)
39#define CAN_SANITIZE_LEAKS 1
40#elif defined(__arm__) && \
41    SANITIZER_LINUX && !SANITIZER_ANDROID
42#define CAN_SANITIZE_LEAKS 1
43#elif SANITIZER_NETBSD || SANITIZER_FUCHSIA
44#define CAN_SANITIZE_LEAKS 1
45#else
46#define CAN_SANITIZE_LEAKS 0
47#endif
48
49namespace __sanitizer {
50class FlagParser;
51class ThreadRegistry;
52struct DTLS;
53}
54
55namespace __lsan {
56
57// Chunk tags.
58enum ChunkTag {
59  kDirectlyLeaked = 0,  // default
60  kIndirectlyLeaked = 1,
61  kReachable = 2,
62  kIgnored = 3
63};
64
65const u32 kInvalidTid = (u32) -1;
66
67struct Flags {
68#define LSAN_FLAG(Type, Name, DefaultValue, Description) Type Name;
69#include "lsan_flags.inc"
70#undef LSAN_FLAG
71
72  void SetDefaults();
73  uptr pointer_alignment() const {
74    return use_unaligned ? 1 : sizeof(uptr);
75  }
76};
77
78extern Flags lsan_flags;
79inline Flags *flags() { return &lsan_flags; }
80void RegisterLsanFlags(FlagParser *parser, Flags *f);
81
82struct Leak {
83  u32 id;
84  uptr hit_count;
85  uptr total_size;
86  u32 stack_trace_id;
87  bool is_directly_leaked;
88  bool is_suppressed;
89};
90
91struct LeakedObject {
92  u32 leak_id;
93  uptr addr;
94  uptr size;
95};
96
97// Aggregates leaks by stack trace prefix.
98class LeakReport {
99 public:
100  LeakReport() {}
101  void AddLeakedChunk(uptr chunk, u32 stack_trace_id, uptr leaked_size,
102                      ChunkTag tag);
103  void ReportTopLeaks(uptr max_leaks);
104  void PrintSummary();
105  void ApplySuppressions();
106  uptr UnsuppressedLeakCount();
107
108 private:
109  void PrintReportForLeak(uptr index);
110  void PrintLeakedObjectsForLeak(uptr index);
111
112  u32 next_id_ = 0;
113  InternalMmapVector<Leak> leaks_;
114  InternalMmapVector<LeakedObject> leaked_objects_;
115};
116
117typedef InternalMmapVector<uptr> Frontier;
118
119// Platform-specific functions.
120void InitializePlatformSpecificModules();
121void ProcessGlobalRegions(Frontier *frontier);
122void ProcessPlatformSpecificAllocations(Frontier *frontier);
123
124struct RootRegion {
125  uptr begin;
126  uptr size;
127};
128
129// LockStuffAndStopTheWorld can start to use Scan* calls to collect into
130// this Frontier vector before the StopTheWorldCallback actually runs.
131// This is used when the OS has a unified callback API for suspending
132// threads and enumerating roots.
133struct CheckForLeaksParam {
134  Frontier frontier;
135  LeakReport leak_report;
136  bool success = false;
137};
138
139InternalMmapVector<RootRegion> const *GetRootRegions();
140void ScanRootRegion(Frontier *frontier, RootRegion const &region,
141                    uptr region_begin, uptr region_end, bool is_readable);
142void ForEachExtraStackRangeCb(uptr begin, uptr end, void* arg);
143// Run stoptheworld while holding any platform-specific locks, as well as the
144// allocator and thread registry locks.
145void LockStuffAndStopTheWorld(StopTheWorldCallback callback,
146                              CheckForLeaksParam* argument);
147
148void ScanRangeForPointers(uptr begin, uptr end,
149                          Frontier *frontier,
150                          const char *region_type, ChunkTag tag);
151void ScanGlobalRange(uptr begin, uptr end, Frontier *frontier);
152
153enum IgnoreObjectResult {
154  kIgnoreObjectSuccess,
155  kIgnoreObjectAlreadyIgnored,
156  kIgnoreObjectInvalid
157};
158
159// Functions called from the parent tool.
160const char *MaybeCallLsanDefaultOptions();
161void InitCommonLsan();
162void DoLeakCheck();
163void DoRecoverableLeakCheckVoid();
164void DisableCounterUnderflow();
165bool DisabledInThisThread();
166
167// Used to implement __lsan::ScopedDisabler.
168void DisableInThisThread();
169void EnableInThisThread();
170// Can be used to ignore memory allocated by an intercepted
171// function.
172struct ScopedInterceptorDisabler {
173  ScopedInterceptorDisabler() { DisableInThisThread(); }
174  ~ScopedInterceptorDisabler() { EnableInThisThread(); }
175};
176
177// According to Itanium C++ ABI array cookie is a one word containing
178// size of allocated array.
179static inline bool IsItaniumABIArrayCookie(uptr chunk_beg, uptr chunk_size,
180                                           uptr addr) {
181  return chunk_size == sizeof(uptr) && chunk_beg + chunk_size == addr &&
182         *reinterpret_cast<uptr *>(chunk_beg) == 0;
183}
184
185// According to ARM C++ ABI array cookie consists of two words:
186// struct array_cookie {
187//   std::size_t element_size; // element_size != 0
188//   std::size_t element_count;
189// };
190static inline bool IsARMABIArrayCookie(uptr chunk_beg, uptr chunk_size,
191                                       uptr addr) {
192  return chunk_size == 2 * sizeof(uptr) && chunk_beg + chunk_size == addr &&
193         *reinterpret_cast<uptr *>(chunk_beg + sizeof(uptr)) == 0;
194}
195
196// Special case for "new T[0]" where T is a type with DTOR.
197// new T[0] will allocate a cookie (one or two words) for the array size (0)
198// and store a pointer to the end of allocated chunk. The actual cookie layout
199// varies between platforms according to their C++ ABI implementation.
200inline bool IsSpecialCaseOfOperatorNew0(uptr chunk_beg, uptr chunk_size,
201                                        uptr addr) {
202#if defined(__arm__)
203  return IsARMABIArrayCookie(chunk_beg, chunk_size, addr);
204#else
205  return IsItaniumABIArrayCookie(chunk_beg, chunk_size, addr);
206#endif
207}
208
209// The following must be implemented in the parent tool.
210
211void ForEachChunk(ForEachChunkCallback callback, void *arg);
212// Returns the address range occupied by the global allocator object.
213void GetAllocatorGlobalRange(uptr *begin, uptr *end);
214// Wrappers for allocator's ForceLock()/ForceUnlock().
215void LockAllocator();
216void UnlockAllocator();
217// Returns true if [addr, addr + sizeof(void *)) is poisoned.
218bool WordIsPoisoned(uptr addr);
219// Wrappers for ThreadRegistry access.
220void LockThreadRegistry();
221void UnlockThreadRegistry();
222ThreadRegistry *GetThreadRegistryLocked();
223bool GetThreadRangesLocked(tid_t os_id, uptr *stack_begin, uptr *stack_end,
224                           uptr *tls_begin, uptr *tls_end, uptr *cache_begin,
225                           uptr *cache_end, DTLS **dtls);
226void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches);
227void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
228                            void *arg);
229// If called from the main thread, updates the main thread's TID in the thread
230// registry. We need this to handle processes that fork() without a subsequent
231// exec(), which invalidates the recorded TID. To update it, we must call
232// gettid() from the main thread. Our solution is to call this function before
233// leak checking and also before every call to pthread_create() (to handle cases
234// where leak checking is initiated from a non-main thread).
235void EnsureMainThreadIDIsCorrect();
236// If p points into a chunk that has been allocated to the user, returns its
237// user-visible address. Otherwise, returns 0.
238uptr PointsIntoChunk(void *p);
239// Returns address of user-visible chunk contained in this allocator chunk.
240uptr GetUserBegin(uptr chunk);
241// Helper for __lsan_ignore_object().
242IgnoreObjectResult IgnoreObjectLocked(const void *p);
243
244// Return the linker module, if valid for the platform.
245LoadedModule *GetLinker();
246
247// Return true if LSan has finished leak checking and reported leaks.
248bool HasReportedLeaks();
249
250// Run platform-specific leak handlers.
251void HandleLeaks();
252
253// Wrapper for chunk metadata operations.
254class LsanMetadata {
255 public:
256  // Constructor accepts address of user-visible chunk.
257  explicit LsanMetadata(uptr chunk);
258  bool allocated() const;
259  ChunkTag tag() const;
260  void set_tag(ChunkTag value);
261  uptr requested_size() const;
262  u32 stack_trace_id() const;
263 private:
264  void *metadata_;
265};
266
267}  // namespace __lsan
268
269extern "C" {
270SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
271const char *__lsan_default_options();
272
273SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
274int __lsan_is_turned_off();
275
276SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
277const char *__lsan_default_suppressions();
278}  // extern "C"
279
280#endif  // LSAN_COMMON_H
281