Sergey Matveev | ab0f744 | 2013-05-20 11:06:50 +0000 | [diff] [blame] | 1 | //=-- lsan_common_linux.cc ------------------------------------------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file is a part of LeakSanitizer. |
| 11 | // Implementation of common leak checking functionality. Linux-specific code. |
| 12 | // |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #include "sanitizer_common/sanitizer_platform.h" |
| 16 | #if SANITIZER_LINUX |
| 17 | #include "lsan_common.h" |
| 18 | |
| 19 | #include <link.h> |
| 20 | |
| 21 | #include "sanitizer_common/sanitizer_common.h" |
| 22 | #include "sanitizer_common/sanitizer_linux.h" |
| 23 | #include "sanitizer_common/sanitizer_stackdepot.h" |
| 24 | |
| 25 | namespace __lsan { |
| 26 | |
| 27 | static const char kLinkerName[] = "ld"; |
| 28 | // We request 2 modules matching "ld", so we can print a warning if there's more |
| 29 | // than one match. But only the first one is actually used. |
| 30 | static char linker_placeholder[2 * sizeof(LoadedModule)] ALIGNED(64); |
| 31 | static LoadedModule *linker = 0; |
| 32 | |
| 33 | static bool IsLinker(const char* full_name) { |
| 34 | return LibraryNameIs(full_name, kLinkerName); |
| 35 | } |
| 36 | |
| 37 | void InitializePlatformSpecificModules() { |
| 38 | internal_memset(linker_placeholder, 0, sizeof(linker_placeholder)); |
| 39 | uptr num_matches = GetListOfModules( |
| 40 | reinterpret_cast<LoadedModule *>(linker_placeholder), 2, IsLinker); |
| 41 | if (num_matches == 1) { |
| 42 | linker = reinterpret_cast<LoadedModule *>(linker_placeholder); |
| 43 | return; |
| 44 | } |
| 45 | if (num_matches == 0) |
| 46 | Report("%s: Dynamic linker not found. TLS will not be handled correctly.\n", |
| 47 | SanitizerToolName); |
| 48 | else if (num_matches > 1) |
| 49 | Report("%s: Multiple modules match \"%s\". TLS will not be handled " |
| 50 | "correctly.\n", SanitizerToolName, kLinkerName); |
| 51 | linker = 0; |
| 52 | } |
| 53 | |
| 54 | static int ProcessGlobalRegionsCallback(struct dl_phdr_info *info, size_t size, |
| 55 | void *data) { |
| 56 | InternalVector<uptr> *frontier = |
| 57 | reinterpret_cast<InternalVector<uptr> *>(data); |
| 58 | for (uptr j = 0; j < info->dlpi_phnum; j++) { |
| 59 | const ElfW(Phdr) *phdr = &(info->dlpi_phdr[j]); |
| 60 | // We're looking for .data and .bss sections, which reside in writeable, |
| 61 | // loadable segments. |
| 62 | if (!(phdr->p_flags & PF_W) || (phdr->p_type != PT_LOAD) || |
| 63 | (phdr->p_memsz == 0)) |
| 64 | continue; |
| 65 | uptr begin = info->dlpi_addr + phdr->p_vaddr; |
| 66 | uptr end = begin + phdr->p_memsz; |
| 67 | uptr allocator_begin = 0, allocator_end = 0; |
| 68 | GetAllocatorGlobalRange(&allocator_begin, &allocator_end); |
| 69 | if (begin <= allocator_begin && allocator_begin < end) { |
| 70 | CHECK_LE(allocator_begin, allocator_end); |
| 71 | CHECK_LT(allocator_end, end); |
| 72 | if (begin < allocator_begin) |
| 73 | ScanRangeForPointers(begin, allocator_begin, frontier, "GLOBAL", |
| 74 | kReachable); |
| 75 | if (allocator_end < end) |
| 76 | ScanRangeForPointers(allocator_end, end, frontier, "GLOBAL", |
| 77 | kReachable); |
| 78 | } else { |
| 79 | ScanRangeForPointers(begin, end, frontier, "GLOBAL", kReachable); |
| 80 | } |
| 81 | } |
| 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | // Scan global variables for heap pointers. |
| 86 | void ProcessGlobalRegions(InternalVector<uptr> *frontier) { |
| 87 | // FIXME: dl_iterate_phdr acquires a linker lock, so we run a risk of |
| 88 | // deadlocking by running this under StopTheWorld. However, the lock is |
| 89 | // reentrant, so we should be able to fix this by acquiring the lock before |
| 90 | // suspending threads. |
| 91 | dl_iterate_phdr(ProcessGlobalRegionsCallback, frontier); |
| 92 | } |
| 93 | |
| 94 | static uptr GetCallerPC(u32 stack_id) { |
| 95 | CHECK(stack_id); |
| 96 | uptr size = 0; |
| 97 | const uptr *trace = StackDepotGet(stack_id, &size); |
| 98 | // The top frame is our malloc/calloc/etc. The next frame is the caller. |
| 99 | CHECK_GE(size, 2); |
| 100 | return trace[1]; |
| 101 | } |
| 102 | |
| 103 | void ProcessPlatformSpecificAllocationsCb::operator()(void *p) const { |
Sergey Matveev | b9c9ce7 | 2013-05-20 14:04:56 +0000 | [diff] [blame^] | 104 | p = GetUserBegin(p); |
Sergey Matveev | ab0f744 | 2013-05-20 11:06:50 +0000 | [diff] [blame] | 105 | LsanMetadata m(p); |
| 106 | if (m.allocated() && m.tag() != kReachable) { |
| 107 | if (linker->containsAddress(GetCallerPC(m.stack_trace_id()))) { |
| 108 | m.set_tag(kReachable); |
| 109 | frontier_->push_back(reinterpret_cast<uptr>(p)); |
| 110 | } |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | // Handle dynamically allocated TLS blocks by treating all chunks allocated from |
| 115 | // ld-linux.so as reachable. |
| 116 | void ProcessPlatformSpecificAllocations(InternalVector<uptr> *frontier) { |
| 117 | if (!flags()->use_tls()) return; |
| 118 | if (!linker) return; |
| 119 | ForEachChunk(ProcessPlatformSpecificAllocationsCb(frontier)); |
| 120 | } |
| 121 | |
| 122 | } // namespace __lsan |
| 123 | #endif // SANITIZER_LINUX |