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_range.h"
22#include "sanitizer_common/sanitizer_stackdepot.h"
23#include "sanitizer_common/sanitizer_stoptheworld.h"
24#include "sanitizer_common/sanitizer_symbolizer.h"
25#include "sanitizer_common/sanitizer_thread_registry.h"
26
27// LeakSanitizer relies on some Glibc's internals (e.g. TLS machinery) on Linux.
28// Also, LSan doesn't like 32 bit architectures
29// because of "small" (4 bytes) pointer size that leads to high false negative
30// ratio on large leaks. But we still want to have it for some 32 bit arches
31// (e.g. x86), see https://github.com/google/sanitizers/issues/403.
32// To enable LeakSanitizer on a new architecture, one needs to implement the
33// internal_clone function as well as (probably) adjust the TLS machinery for
34// the new architecture inside the sanitizer library.
35// Exclude leak-detection on arm32 for Android because `__aeabi_read_tp`
36// is missing. This caused a link error.
37#if SANITIZER_ANDROID && (__ANDROID_API__ < 28 || defined(__arm__))
38# define CAN_SANITIZE_LEAKS 0
39#elif (SANITIZER_LINUX || SANITIZER_APPLE) && (SANITIZER_WORDSIZE == 64) && \
40 (defined(__x86_64__) || defined(__mips64) || defined(__aarch64__) || \
41 defined(__powerpc64__) || defined(__s390x__))
42# define CAN_SANITIZE_LEAKS 1
43#elif defined(__i386__) && (SANITIZER_LINUX || SANITIZER_APPLE)
44# define CAN_SANITIZE_LEAKS 1
45#elif defined(__arm__) && SANITIZER_LINUX
46# define CAN_SANITIZE_LEAKS 1
47#elif SANITIZER_LOONGARCH64 && SANITIZER_LINUX
48# define CAN_SANITIZE_LEAKS 1
49#elif SANITIZER_RISCV64 && SANITIZER_LINUX
50# define CAN_SANITIZE_LEAKS 1
51#elif SANITIZER_NETBSD || SANITIZER_FUCHSIA
52# define CAN_SANITIZE_LEAKS 1
53#else
54# define CAN_SANITIZE_LEAKS 0
55#endif
56
57namespace __sanitizer {
58class FlagParser;
59class ThreadRegistry;
60class ThreadContextBase;
61struct DTLS;
62}
63
64// This section defines function and class prototypes which must be implemented
65// by the parent tool linking in LSan. There are implementations provided by the
66// LSan library which will be linked in when LSan is used as a standalone tool.
67namespace __lsan {
68
69// Chunk tags.
70enum ChunkTag {
71 kDirectlyLeaked = 0, // default
72 kIndirectlyLeaked = 1,
73 kReachable = 2,
74 kIgnored = 3
75};
76
77enum IgnoreObjectResult {
78 kIgnoreObjectSuccess,
79 kIgnoreObjectAlreadyIgnored,
80 kIgnoreObjectInvalid
81};
82
83//// --------------------------------------------------------------------------
84//// Poisoning prototypes.
85//// --------------------------------------------------------------------------
86
87// Returns true if [addr, addr + sizeof(void *)) is poisoned.
88bool WordIsPoisoned(uptr addr);
89
90//// --------------------------------------------------------------------------
91//// Thread prototypes.
92//// --------------------------------------------------------------------------
93
94// Wrappers for ThreadRegistry access.
95void LockThreads() SANITIZER_NO_THREAD_SAFETY_ANALYSIS;
96void UnlockThreads() SANITIZER_NO_THREAD_SAFETY_ANALYSIS;
97// If called from the main thread, updates the main thread's TID in the thread
98// registry. We need this to handle processes that fork() without a subsequent
99// exec(), which invalidates the recorded TID. To update it, we must call
100// gettid() from the main thread. Our solution is to call this function before
101// leak checking and also before every call to pthread_create() (to handle cases
102// where leak checking is initiated from a non-main thread).
103void EnsureMainThreadIDIsCorrect();
104
105bool GetThreadRangesLocked(tid_t os_id, uptr *stack_begin, uptr *stack_end,
106 uptr *tls_begin, uptr *tls_end, uptr *cache_begin,
107 uptr *cache_end, DTLS **dtls);
108void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches);
109void GetThreadExtraStackRangesLocked(InternalMmapVector<Range> *ranges);
110void GetThreadExtraStackRangesLocked(tid_t os_id,
111 InternalMmapVector<Range> *ranges);
112void GetAdditionalThreadContextPtrsLocked(InternalMmapVector<uptr> *ptrs);
113void GetRunningThreadsLocked(InternalMmapVector<tid_t> *threads);
114
115//// --------------------------------------------------------------------------
116//// Allocator prototypes.
117//// --------------------------------------------------------------------------
118
119// Wrappers for allocator's ForceLock()/ForceUnlock().
120void LockAllocator();
121void UnlockAllocator();
122
123// Lock/unlock global mutext.
124void LockGlobal();
125void UnlockGlobal();
126
127// Returns the address range occupied by the global allocator object.
128void GetAllocatorGlobalRange(uptr *begin, uptr *end);
129// If p points into a chunk that has been allocated to the user, returns its
130// user-visible address. Otherwise, returns 0.
131uptr PointsIntoChunk(void *p);
132// Returns address of user-visible chunk contained in this allocator chunk.
133uptr GetUserBegin(uptr chunk);
134// Returns user-visible address for chunk. If memory tagging is used this
135// function will return the tagged address.
136uptr GetUserAddr(uptr chunk);
137
138// Wrapper for chunk metadata operations.
139class LsanMetadata {
140 public:
141 // Constructor accepts address of user-visible chunk.
142 explicit LsanMetadata(uptr chunk);
143 bool allocated() const;
144 ChunkTag tag() const;
145 void set_tag(ChunkTag value);
146 uptr requested_size() const;
147 u32 stack_trace_id() const;
148
149 private:
150 void *metadata_;
151};
152
153// Iterate over all existing chunks. Allocator must be locked.
154void ForEachChunk(ForEachChunkCallback callback, void *arg);
155
156// Helper for __lsan_ignore_object().
157IgnoreObjectResult IgnoreObject(const void *p);
158
159// The rest of the LSan interface which is implemented by library.
160
161struct ScopedStopTheWorldLock {
162 ScopedStopTheWorldLock() {
163 LockThreads();
164 LockAllocator();
165 }
166
167 ~ScopedStopTheWorldLock() {
168 UnlockAllocator();
169 UnlockThreads();
170 }
171
172 ScopedStopTheWorldLock &operator=(const ScopedStopTheWorldLock &) = delete;
173 ScopedStopTheWorldLock(const ScopedStopTheWorldLock &) = delete;
174};
175
176struct Flags {
177#define LSAN_FLAG(Type, Name, DefaultValue, Description) Type Name;
178#include "lsan_flags.inc"
179#undef LSAN_FLAG
180
181 void SetDefaults();
182 uptr pointer_alignment() const {
183 return use_unaligned ? 1 : sizeof(uptr);
184 }
185};
186
187extern Flags lsan_flags;
188inline Flags *flags() { return &lsan_flags; }
189void RegisterLsanFlags(FlagParser *parser, Flags *f);
190
191struct LeakedChunk {
192 uptr chunk;
193 u32 stack_trace_id;
194 uptr leaked_size;
195 ChunkTag tag;
196};
197
198using LeakedChunks = InternalMmapVector<LeakedChunk>;
199
200struct Leak {
201 u32 id;
202 uptr hit_count;
203 uptr total_size;
204 u32 stack_trace_id;
205 bool is_directly_leaked;
206 bool is_suppressed;
207};
208
209struct LeakedObject {
210 u32 leak_id;
211 uptr addr;
212 uptr size;
213};
214
215// Aggregates leaks by stack trace prefix.
216class LeakReport {
217 public:
218 LeakReport() {}
219 void AddLeakedChunks(const LeakedChunks &chunks);
220 void ReportTopLeaks(uptr max_leaks);
221 void PrintSummary();
222 uptr ApplySuppressions();
223 uptr UnsuppressedLeakCount();
224 uptr IndirectUnsuppressedLeakCount();
225
226 private:
227 void PrintReportForLeak(uptr index);
228 void PrintLeakedObjectsForLeak(uptr index);
229
230 u32 next_id_ = 0;
231 InternalMmapVector<Leak> leaks_;
232 InternalMmapVector<LeakedObject> leaked_objects_;
233};
234
235typedef InternalMmapVector<uptr> Frontier;
236
237// Platform-specific functions.
238void InitializePlatformSpecificModules();
239void ProcessGlobalRegions(Frontier *frontier);
240void ProcessPlatformSpecificAllocations(Frontier *frontier);
241
242// LockStuffAndStopTheWorld can start to use Scan* calls to collect into
243// this Frontier vector before the StopTheWorldCallback actually runs.
244// This is used when the OS has a unified callback API for suspending
245// threads and enumerating roots.
246struct CheckForLeaksParam {
247 Frontier frontier;
248 LeakedChunks leaks;
249 tid_t caller_tid;
250 uptr caller_sp;
251 bool success = false;
252};
253
254using Region = Range;
255
256bool HasRootRegions();
257void ScanRootRegions(Frontier *frontier,
258 const InternalMmapVectorNoCtor<Region> &region);
259// Run stoptheworld while holding any platform-specific locks, as well as the
260// allocator and thread registry locks.
261void LockStuffAndStopTheWorld(StopTheWorldCallback callback,
262 CheckForLeaksParam* argument);
263
264void ScanRangeForPointers(uptr begin, uptr end,
265 Frontier *frontier,
266 const char *region_type, ChunkTag tag);
267void ScanGlobalRange(uptr begin, uptr end, Frontier *frontier);
268void ScanExtraStackRanges(const InternalMmapVector<Range> &ranges,
269 Frontier *frontier);
270
271// Functions called from the parent tool.
272const char *MaybeCallLsanDefaultOptions();
273void InitCommonLsan();
274void DoLeakCheck();
275void DoRecoverableLeakCheckVoid();
276void DisableCounterUnderflow();
277bool DisabledInThisThread();
278
279// Used to implement __lsan::ScopedDisabler.
280void DisableInThisThread();
281void EnableInThisThread();
282// Can be used to ignore memory allocated by an intercepted
283// function.
284struct ScopedInterceptorDisabler {
285 ScopedInterceptorDisabler() { DisableInThisThread(); }
286 ~ScopedInterceptorDisabler() { EnableInThisThread(); }
287};
288
289// According to Itanium C++ ABI array cookie is a one word containing
290// size of allocated array.
291static inline bool IsItaniumABIArrayCookie(uptr chunk_beg, uptr chunk_size,
292 uptr addr) {
293 return chunk_size == sizeof(uptr) && chunk_beg + chunk_size == addr &&
294 *reinterpret_cast<uptr *>(chunk_beg) == 0;
295}
296
297// According to ARM C++ ABI array cookie consists of two words:
298// struct array_cookie {
299// std::size_t element_size; // element_size != 0
300// std::size_t element_count;
301// };
302static inline bool IsARMABIArrayCookie(uptr chunk_beg, uptr chunk_size,
303 uptr addr) {
304 return chunk_size == 2 * sizeof(uptr) && chunk_beg + chunk_size == addr &&
305 *reinterpret_cast<uptr *>(chunk_beg + sizeof(uptr)) == 0;
306}
307
308// Special case for "new T[0]" where T is a type with DTOR.
309// new T[0] will allocate a cookie (one or two words) for the array size (0)
310// and store a pointer to the end of allocated chunk. The actual cookie layout
311// varies between platforms according to their C++ ABI implementation.
312inline bool IsSpecialCaseOfOperatorNew0(uptr chunk_beg, uptr chunk_size,
313 uptr addr) {
314#if defined(__arm__)
315 return IsARMABIArrayCookie(chunk_beg, chunk_size, addr);
316#else
317 return IsItaniumABIArrayCookie(chunk_beg, chunk_size, addr);
318#endif
319}
320
321// Return the linker module, if valid for the platform.
322LoadedModule *GetLinker();
323
324// Return true if LSan has finished leak checking and reported leaks.
325bool HasReportedLeaks();
326
327// Run platform-specific leak handlers.
328void HandleLeaks();
329
330} // namespace __lsan
331
332extern "C" {
333SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
334const char *__lsan_default_options();
335
336SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
337int __lsan_is_turned_off();
338
339SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
340const char *__lsan_default_suppressions();
341
342SANITIZER_INTERFACE_ATTRIBUTE
343void __lsan_register_root_region(const void *p, __lsan::uptr size);
344
345SANITIZER_INTERFACE_ATTRIBUTE
346void __lsan_unregister_root_region(const void *p, __lsan::uptr size);
347
348} // extern "C"
349
350#endif // LSAN_COMMON_H
351