126 lines
4.1 KiB
C++
126 lines
4.1 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_flags.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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static char linker_placeholder[sizeof(LoadedModule)] ALIGNED(64);
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static LoadedModule *linker = nullptr;
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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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__attribute__((tls_model("initial-exec")))
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THREADLOCAL int disable_counter;
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bool DisabledInThisThread() { return disable_counter > 0; }
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void DisableInThisThread() { disable_counter++; }
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void EnableInThisThread() {
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if (disable_counter == 0) {
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DisableCounterUnderflow();
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}
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disable_counter--;
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}
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void InitializePlatformSpecificModules() {
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ListOfModules modules;
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modules.init();
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for (LoadedModule &module : modules) {
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if (!IsLinker(module.full_name())) continue;
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if (linker == nullptr) {
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linker = reinterpret_cast<LoadedModule *>(linker_placeholder);
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*linker = module;
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module = LoadedModule();
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} else {
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VReport(1, "LeakSanitizer: Multiple modules match \"%s\". "
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"TLS will not be handled correctly.\n", kLinkerName);
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linker->clear();
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linker = nullptr;
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return;
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}
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}
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if (linker == nullptr) {
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VReport(1, "LeakSanitizer: Dynamic linker not found. "
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"TLS will not be handled correctly.\n");
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}
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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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ScanGlobalRange(begin, end, frontier);
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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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if (!flags()->use_globals) return;
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dl_iterate_phdr(ProcessGlobalRegionsCallback, frontier);
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}
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LoadedModule *GetLinker() { return linker; }
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void ProcessPlatformSpecificAllocations(Frontier *frontier) {}
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struct DoStopTheWorldParam {
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StopTheWorldCallback callback;
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void *argument;
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};
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static int DoStopTheWorldCallback(struct dl_phdr_info *info, size_t size,
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void *data) {
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DoStopTheWorldParam *param = reinterpret_cast<DoStopTheWorldParam *>(data);
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StopTheWorld(param->callback, param->argument);
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return 1;
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}
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// LSan calls dl_iterate_phdr() from the tracer task. This may deadlock: if one
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// of the threads is frozen while holding the libdl lock, the tracer will hang
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// in dl_iterate_phdr() forever.
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// Luckily, (a) the lock is reentrant and (b) libc can't distinguish between the
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// tracer task and the thread that spawned it. Thus, if we run the tracer task
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// while holding the libdl lock in the parent thread, we can safely reenter it
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// in the tracer. The solution is to run stoptheworld from a dl_iterate_phdr()
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// callback in the parent thread.
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void DoStopTheWorld(StopTheWorldCallback callback, void *argument) {
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DoStopTheWorldParam param = {callback, argument};
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dl_iterate_phdr(DoStopTheWorldCallback, ¶m);
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}
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} // namespace __lsan
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#endif // CAN_SANITIZE_LEAKS && SANITIZER_LINUX
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