llvm-project/compiler-rt/lib/lsan/lsan_common_linux.cc

124 lines
4.4 KiB
C++

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