forked from OSchip/llvm-project
127 lines
4.6 KiB
C++
127 lines
4.6 KiB
C++
//=-- lsan_common_linux.cc ------------------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is a part of LeakSanitizer.
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// Implementation of common leak checking functionality. Linux-specific code.
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//
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//===----------------------------------------------------------------------===//
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#include "sanitizer_common/sanitizer_platform.h"
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#include "lsan_common.h"
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#if CAN_SANITIZE_LEAKS && SANITIZER_LINUX
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#include <link.h>
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#include "sanitizer_common/sanitizer_common.h"
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#include "sanitizer_common/sanitizer_linux.h"
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#include "sanitizer_common/sanitizer_stackdepot.h"
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namespace __lsan {
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static const char kLinkerName[] = "ld";
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// We request 2 modules matching "ld", so we can print a warning if there's more
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// than one match. But only the first one is actually used.
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static char linker_placeholder[2 * sizeof(LoadedModule)] ALIGNED(64);
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static LoadedModule *linker = 0;
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static bool IsLinker(const char* full_name) {
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return LibraryNameIs(full_name, kLinkerName);
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}
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void InitializePlatformSpecificModules() {
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internal_memset(linker_placeholder, 0, sizeof(linker_placeholder));
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uptr num_matches = GetListOfModules(
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reinterpret_cast<LoadedModule *>(linker_placeholder), 2, IsLinker);
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if (num_matches == 1) {
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linker = reinterpret_cast<LoadedModule *>(linker_placeholder);
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return;
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}
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if (num_matches == 0)
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Report("LeakSanitizer: Dynamic linker not found. "
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"TLS will not be handled correctly.\n");
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else if (num_matches > 1)
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Report("LeakSanitizer: Multiple modules match \"%s\". "
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"TLS will not be handled correctly.\n", kLinkerName);
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linker = 0;
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}
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static int ProcessGlobalRegionsCallback(struct dl_phdr_info *info, size_t size,
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void *data) {
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Frontier *frontier = reinterpret_cast<Frontier *>(data);
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for (uptr j = 0; j < info->dlpi_phnum; j++) {
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const ElfW(Phdr) *phdr = &(info->dlpi_phdr[j]);
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// We're looking for .data and .bss sections, which reside in writeable,
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// loadable segments.
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if (!(phdr->p_flags & PF_W) || (phdr->p_type != PT_LOAD) ||
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(phdr->p_memsz == 0))
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continue;
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uptr begin = info->dlpi_addr + phdr->p_vaddr;
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uptr end = begin + phdr->p_memsz;
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uptr allocator_begin = 0, allocator_end = 0;
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GetAllocatorGlobalRange(&allocator_begin, &allocator_end);
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if (begin <= allocator_begin && allocator_begin < end) {
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CHECK_LE(allocator_begin, allocator_end);
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CHECK_LT(allocator_end, end);
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if (begin < allocator_begin)
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ScanRangeForPointers(begin, allocator_begin, frontier, "GLOBAL",
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kReachable);
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if (allocator_end < end)
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ScanRangeForPointers(allocator_end, end, frontier, "GLOBAL",
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kReachable);
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} else {
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ScanRangeForPointers(begin, end, frontier, "GLOBAL", kReachable);
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}
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}
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return 0;
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}
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// Scans global variables for heap pointers.
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void ProcessGlobalRegions(Frontier *frontier) {
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// FIXME: dl_iterate_phdr acquires a linker lock, so we run a risk of
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// deadlocking by running this under StopTheWorld. However, the lock is
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// reentrant, so we should be able to fix this by acquiring the lock before
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// suspending threads.
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dl_iterate_phdr(ProcessGlobalRegionsCallback, frontier);
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}
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static uptr GetCallerPC(u32 stack_id) {
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CHECK(stack_id);
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uptr size = 0;
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const uptr *trace = StackDepotGet(stack_id, &size);
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// The top frame is our malloc/calloc/etc. The next frame is the caller.
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if (size >= 2)
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return trace[1];
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return 0;
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}
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// ForEachChunk callback. Identifies unreachable chunks which must be treated as
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// reachable. Marks them as reachable and adds them to the frontier.
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static void ProcessPlatformSpecificAllocationsCb(uptr chunk, void *arg) {
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CHECK(arg);
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chunk = GetUserBegin(chunk);
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LsanMetadata m(chunk);
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if (m.allocated() && m.tag() != kReachable) {
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if (linker->containsAddress(GetCallerPC(m.stack_trace_id()))) {
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m.set_tag(kReachable);
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reinterpret_cast<Frontier *>(arg)->push_back(chunk);
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}
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}
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}
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// Handles dynamically allocated TLS blocks by treating all chunks allocated
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// from ld-linux.so as reachable.
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void ProcessPlatformSpecificAllocations(Frontier *frontier) {
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if (!flags()->use_tls) return;
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if (!linker) return;
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ForEachChunk(ProcessPlatformSpecificAllocationsCb, frontier);
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}
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} // namespace __lsan
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#endif // CAN_SANITIZE_LEAKS && SANITIZER_LINUX
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