gcc/libsanitizer/lsan/lsan_common_fuchsia.cpp
2020-11-13 17:28:49 +01:00

168 lines
6.2 KiB
C++

//=-- lsan_common_fuchsia.cpp --------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===---------------------------------------------------------------------===//
//
// This file is a part of LeakSanitizer.
// Implementation of common leak checking functionality. Fuchsia-specific code.
//
//===---------------------------------------------------------------------===//
#include "lsan_common.h"
#include "sanitizer_common/sanitizer_platform.h"
#if CAN_SANITIZE_LEAKS && SANITIZER_FUCHSIA
#include <zircon/sanitizer.h>
#include "lsan_allocator.h"
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_stoptheworld_fuchsia.h"
#include "sanitizer_common/sanitizer_thread_registry.h"
// Ensure that the Zircon system ABI is linked in.
#pragma comment(lib, "zircon")
namespace __lsan {
void InitializePlatformSpecificModules() {}
LoadedModule *GetLinker() { return nullptr; }
__attribute__((tls_model("initial-exec"))) THREADLOCAL int disable_counter;
bool DisabledInThisThread() { return disable_counter > 0; }
void DisableInThisThread() { disable_counter++; }
void EnableInThisThread() {
if (disable_counter == 0) {
DisableCounterUnderflow();
}
disable_counter--;
}
// There is nothing left to do after the globals callbacks.
void ProcessGlobalRegions(Frontier *frontier) {}
// Nothing to do here.
void ProcessPlatformSpecificAllocations(Frontier *frontier) {}
// On Fuchsia, we can intercept _Exit gracefully, and return a failing exit
// code if required at that point. Calling Die() here is undefined
// behavior and causes rare race conditions.
void HandleLeaks() {}
int ExitHook(int status) {
return status == 0 && HasReportedLeaks() ? common_flags()->exitcode : status;
}
void LockStuffAndStopTheWorld(StopTheWorldCallback callback,
CheckForLeaksParam *argument) {
LockThreadRegistry();
LockAllocator();
struct Params {
InternalMmapVector<uptr> allocator_caches;
StopTheWorldCallback callback;
CheckForLeaksParam *argument;
} params = {{}, callback, argument};
// Callback from libc for globals (data/bss modulo relro), when enabled.
auto globals = +[](void *chunk, size_t size, void *data) {
auto params = static_cast<const Params *>(data);
uptr begin = reinterpret_cast<uptr>(chunk);
uptr end = begin + size;
ScanGlobalRange(begin, end, &params->argument->frontier);
};
// Callback from libc for thread stacks.
auto stacks = +[](void *chunk, size_t size, void *data) {
auto params = static_cast<const Params *>(data);
uptr begin = reinterpret_cast<uptr>(chunk);
uptr end = begin + size;
ScanRangeForPointers(begin, end, &params->argument->frontier, "STACK",
kReachable);
};
// Callback from libc for thread registers.
auto registers = +[](void *chunk, size_t size, void *data) {
auto params = static_cast<const Params *>(data);
uptr begin = reinterpret_cast<uptr>(chunk);
uptr end = begin + size;
ScanRangeForPointers(begin, end, &params->argument->frontier, "REGISTERS",
kReachable);
};
if (flags()->use_tls) {
// Collect the allocator cache range from each thread so these
// can all be excluded from the reported TLS ranges.
GetAllThreadAllocatorCachesLocked(&params.allocator_caches);
__sanitizer::Sort(params.allocator_caches.data(),
params.allocator_caches.size());
}
// Callback from libc for TLS regions. This includes thread_local
// variables as well as C11 tss_set and POSIX pthread_setspecific.
auto tls = +[](void *chunk, size_t size, void *data) {
auto params = static_cast<const Params *>(data);
uptr begin = reinterpret_cast<uptr>(chunk);
uptr end = begin + size;
auto i = __sanitizer::InternalLowerBound(params->allocator_caches, 0,
params->allocator_caches.size(),
begin, CompareLess<uptr>());
if (i < params->allocator_caches.size() &&
params->allocator_caches[i] >= begin &&
end - params->allocator_caches[i] <= sizeof(AllocatorCache)) {
// Split the range in two and omit the allocator cache within.
ScanRangeForPointers(begin, params->allocator_caches[i],
&params->argument->frontier, "TLS", kReachable);
uptr begin2 = params->allocator_caches[i] + sizeof(AllocatorCache);
ScanRangeForPointers(begin2, end, &params->argument->frontier, "TLS",
kReachable);
} else {
ScanRangeForPointers(begin, end, &params->argument->frontier, "TLS",
kReachable);
}
};
// This stops the world and then makes callbacks for various memory regions.
// The final callback is the last thing before the world starts up again.
__sanitizer_memory_snapshot(
flags()->use_globals ? globals : nullptr,
flags()->use_stacks ? stacks : nullptr,
flags()->use_registers ? registers : nullptr,
flags()->use_tls ? tls : nullptr,
[](zx_status_t, void *data) {
auto params = static_cast<const Params *>(data);
// We don't use the thread registry at all for enumerating the threads
// and their stacks, registers, and TLS regions. So use it separately
// just for the allocator cache, and to call ForEachExtraStackRange,
// which ASan needs.
if (flags()->use_stacks) {
GetThreadRegistryLocked()->RunCallbackForEachThreadLocked(
[](ThreadContextBase *tctx, void *arg) {
ForEachExtraStackRange(tctx->os_id, ForEachExtraStackRangeCb,
arg);
},
&params->argument->frontier);
}
params->callback(SuspendedThreadsListFuchsia(), params->argument);
},
&params);
UnlockAllocator();
UnlockThreadRegistry();
}
} // namespace __lsan
// This is declared (in extern "C") by <zircon/sanitizer.h>.
// _Exit calls this directly to intercept and change the status value.
int __sanitizer_process_exit_hook(int status) {
return __lsan::ExitHook(status);
}
#endif