zig/lib/tsan/tsan_mman.cpp
2024-01-10 01:00:37 -07:00

486 lines
15 KiB
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//===-- tsan_mman.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 ThreadSanitizer (TSan), a race detector.
//
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_allocator_checks.h"
#include "sanitizer_common/sanitizer_allocator_interface.h"
#include "sanitizer_common/sanitizer_allocator_report.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_errno.h"
#include "sanitizer_common/sanitizer_placement_new.h"
#include "tsan_interface.h"
#include "tsan_mman.h"
#include "tsan_rtl.h"
#include "tsan_report.h"
#include "tsan_flags.h"
namespace __tsan {
struct MapUnmapCallback {
void OnMap(uptr p, uptr size) const { }
void OnMapSecondary(uptr p, uptr size, uptr user_begin,
uptr user_size) const {};
void OnUnmap(uptr p, uptr size) const {
// We are about to unmap a chunk of user memory.
// Mark the corresponding shadow memory as not needed.
DontNeedShadowFor(p, size);
// Mark the corresponding meta shadow memory as not needed.
// Note the block does not contain any meta info at this point
// (this happens after free).
const uptr kMetaRatio = kMetaShadowCell / kMetaShadowSize;
const uptr kPageSize = GetPageSizeCached() * kMetaRatio;
// Block came from LargeMmapAllocator, so must be large.
// We rely on this in the calculations below.
CHECK_GE(size, 2 * kPageSize);
uptr diff = RoundUp(p, kPageSize) - p;
if (diff != 0) {
p += diff;
size -= diff;
}
diff = p + size - RoundDown(p + size, kPageSize);
if (diff != 0)
size -= diff;
uptr p_meta = (uptr)MemToMeta(p);
ReleaseMemoryPagesToOS(p_meta, p_meta + size / kMetaRatio);
}
};
static char allocator_placeholder[sizeof(Allocator)] ALIGNED(64);
Allocator *allocator() {
return reinterpret_cast<Allocator*>(&allocator_placeholder);
}
struct GlobalProc {
Mutex mtx;
Processor *proc;
// This mutex represents the internal allocator combined for
// the purposes of deadlock detection. The internal allocator
// uses multiple mutexes, moreover they are locked only occasionally
// and they are spin mutexes which don't support deadlock detection.
// So we use this fake mutex to serve as a substitute for these mutexes.
CheckedMutex internal_alloc_mtx;
GlobalProc()
: mtx(MutexTypeGlobalProc),
proc(ProcCreate()),
internal_alloc_mtx(MutexTypeInternalAlloc) {}
};
static char global_proc_placeholder[sizeof(GlobalProc)] ALIGNED(64);
GlobalProc *global_proc() {
return reinterpret_cast<GlobalProc*>(&global_proc_placeholder);
}
static void InternalAllocAccess() {
global_proc()->internal_alloc_mtx.Lock();
global_proc()->internal_alloc_mtx.Unlock();
}
ScopedGlobalProcessor::ScopedGlobalProcessor() {
GlobalProc *gp = global_proc();
ThreadState *thr = cur_thread();
if (thr->proc())
return;
// If we don't have a proc, use the global one.
// There are currently only two known case where this path is triggered:
// __interceptor_free
// __nptl_deallocate_tsd
// start_thread
// clone
// and:
// ResetRange
// __interceptor_munmap
// __deallocate_stack
// start_thread
// clone
// Ideally, we destroy thread state (and unwire proc) when a thread actually
// exits (i.e. when we join/wait it). Then we would not need the global proc
gp->mtx.Lock();
ProcWire(gp->proc, thr);
}
ScopedGlobalProcessor::~ScopedGlobalProcessor() {
GlobalProc *gp = global_proc();
ThreadState *thr = cur_thread();
if (thr->proc() != gp->proc)
return;
ProcUnwire(gp->proc, thr);
gp->mtx.Unlock();
}
void AllocatorLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
global_proc()->internal_alloc_mtx.Lock();
InternalAllocatorLock();
}
void AllocatorUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
InternalAllocatorUnlock();
global_proc()->internal_alloc_mtx.Unlock();
}
void GlobalProcessorLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
global_proc()->mtx.Lock();
}
void GlobalProcessorUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
global_proc()->mtx.Unlock();
}
static constexpr uptr kMaxAllowedMallocSize = 1ull << 40;
static uptr max_user_defined_malloc_size;
void InitializeAllocator() {
SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
allocator()->Init(common_flags()->allocator_release_to_os_interval_ms);
max_user_defined_malloc_size = common_flags()->max_allocation_size_mb
? common_flags()->max_allocation_size_mb
<< 20
: kMaxAllowedMallocSize;
}
void InitializeAllocatorLate() {
new(global_proc()) GlobalProc();
}
void AllocatorProcStart(Processor *proc) {
allocator()->InitCache(&proc->alloc_cache);
internal_allocator()->InitCache(&proc->internal_alloc_cache);
}
void AllocatorProcFinish(Processor *proc) {
allocator()->DestroyCache(&proc->alloc_cache);
internal_allocator()->DestroyCache(&proc->internal_alloc_cache);
}
void AllocatorPrintStats() {
allocator()->PrintStats();
}
static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
if (atomic_load_relaxed(&thr->in_signal_handler) == 0 ||
!ShouldReport(thr, ReportTypeSignalUnsafe))
return;
VarSizeStackTrace stack;
ObtainCurrentStack(thr, pc, &stack);
if (IsFiredSuppression(ctx, ReportTypeSignalUnsafe, stack))
return;
ThreadRegistryLock l(&ctx->thread_registry);
ScopedReport rep(ReportTypeSignalUnsafe);
rep.AddStack(stack, true);
OutputReport(thr, rep);
}
void *user_alloc_internal(ThreadState *thr, uptr pc, uptr sz, uptr align,
bool signal) {
if (sz >= kMaxAllowedMallocSize || align >= kMaxAllowedMallocSize ||
sz > max_user_defined_malloc_size) {
if (AllocatorMayReturnNull())
return nullptr;
uptr malloc_limit =
Min(kMaxAllowedMallocSize, max_user_defined_malloc_size);
GET_STACK_TRACE_FATAL(thr, pc);
ReportAllocationSizeTooBig(sz, malloc_limit, &stack);
}
if (UNLIKELY(IsRssLimitExceeded())) {
if (AllocatorMayReturnNull())
return nullptr;
GET_STACK_TRACE_FATAL(thr, pc);
ReportRssLimitExceeded(&stack);
}
void *p = allocator()->Allocate(&thr->proc()->alloc_cache, sz, align);
if (UNLIKELY(!p)) {
SetAllocatorOutOfMemory();
if (AllocatorMayReturnNull())
return nullptr;
GET_STACK_TRACE_FATAL(thr, pc);
ReportOutOfMemory(sz, &stack);
}
if (ctx && ctx->initialized)
OnUserAlloc(thr, pc, (uptr)p, sz, true);
if (signal)
SignalUnsafeCall(thr, pc);
return p;
}
void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
ScopedGlobalProcessor sgp;
if (ctx && ctx->initialized)
OnUserFree(thr, pc, (uptr)p, true);
allocator()->Deallocate(&thr->proc()->alloc_cache, p);
if (signal)
SignalUnsafeCall(thr, pc);
}
void *user_alloc(ThreadState *thr, uptr pc, uptr sz) {
return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, kDefaultAlignment));
}
void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
if (UNLIKELY(CheckForCallocOverflow(size, n))) {
if (AllocatorMayReturnNull())
return SetErrnoOnNull(nullptr);
GET_STACK_TRACE_FATAL(thr, pc);
ReportCallocOverflow(n, size, &stack);
}
void *p = user_alloc_internal(thr, pc, n * size);
if (p)
internal_memset(p, 0, n * size);
return SetErrnoOnNull(p);
}
void *user_reallocarray(ThreadState *thr, uptr pc, void *p, uptr size, uptr n) {
if (UNLIKELY(CheckForCallocOverflow(size, n))) {
if (AllocatorMayReturnNull())
return SetErrnoOnNull(nullptr);
GET_STACK_TRACE_FATAL(thr, pc);
ReportReallocArrayOverflow(size, n, &stack);
}
return user_realloc(thr, pc, p, size * n);
}
void OnUserAlloc(ThreadState *thr, uptr pc, uptr p, uptr sz, bool write) {
DPrintf("#%d: alloc(%zu) = 0x%zx\n", thr->tid, sz, p);
// Note: this can run before thread initialization/after finalization.
// As a result this is not necessarily synchronized with DoReset,
// which iterates over and resets all sync objects,
// but it is fine to create new MBlocks in this context.
ctx->metamap.AllocBlock(thr, pc, p, sz);
// If this runs before thread initialization/after finalization
// and we don't have trace initialized, we can't imitate writes.
// In such case just reset the shadow range, it is fine since
// it affects only a small fraction of special objects.
if (write && thr->ignore_reads_and_writes == 0 &&
atomic_load_relaxed(&thr->trace_pos))
MemoryRangeImitateWrite(thr, pc, (uptr)p, sz);
else
MemoryResetRange(thr, pc, (uptr)p, sz);
}
void OnUserFree(ThreadState *thr, uptr pc, uptr p, bool write) {
CHECK_NE(p, (void*)0);
if (!thr->slot) {
// Very early/late in thread lifetime, or during fork.
UNUSED uptr sz = ctx->metamap.FreeBlock(thr->proc(), p, false);
DPrintf("#%d: free(0x%zx, %zu) (no slot)\n", thr->tid, p, sz);
return;
}
SlotLocker locker(thr);
uptr sz = ctx->metamap.FreeBlock(thr->proc(), p, true);
DPrintf("#%d: free(0x%zx, %zu)\n", thr->tid, p, sz);
if (write && thr->ignore_reads_and_writes == 0)
MemoryRangeFreed(thr, pc, (uptr)p, sz);
}
void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
// FIXME: Handle "shrinking" more efficiently,
// it seems that some software actually does this.
if (!p)
return SetErrnoOnNull(user_alloc_internal(thr, pc, sz));
if (!sz) {
user_free(thr, pc, p);
return nullptr;
}
void *new_p = user_alloc_internal(thr, pc, sz);
if (new_p) {
uptr old_sz = user_alloc_usable_size(p);
internal_memcpy(new_p, p, min(old_sz, sz));
user_free(thr, pc, p);
}
return SetErrnoOnNull(new_p);
}
void *user_memalign(ThreadState *thr, uptr pc, uptr align, uptr sz) {
if (UNLIKELY(!IsPowerOfTwo(align))) {
errno = errno_EINVAL;
if (AllocatorMayReturnNull())
return nullptr;
GET_STACK_TRACE_FATAL(thr, pc);
ReportInvalidAllocationAlignment(align, &stack);
}
return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
}
int user_posix_memalign(ThreadState *thr, uptr pc, void **memptr, uptr align,
uptr sz) {
if (UNLIKELY(!CheckPosixMemalignAlignment(align))) {
if (AllocatorMayReturnNull())
return errno_EINVAL;
GET_STACK_TRACE_FATAL(thr, pc);
ReportInvalidPosixMemalignAlignment(align, &stack);
}
void *ptr = user_alloc_internal(thr, pc, sz, align);
if (UNLIKELY(!ptr))
// OOM error is already taken care of by user_alloc_internal.
return errno_ENOMEM;
CHECK(IsAligned((uptr)ptr, align));
*memptr = ptr;
return 0;
}
void *user_aligned_alloc(ThreadState *thr, uptr pc, uptr align, uptr sz) {
if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(align, sz))) {
errno = errno_EINVAL;
if (AllocatorMayReturnNull())
return nullptr;
GET_STACK_TRACE_FATAL(thr, pc);
ReportInvalidAlignedAllocAlignment(sz, align, &stack);
}
return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
}
void *user_valloc(ThreadState *thr, uptr pc, uptr sz) {
return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, GetPageSizeCached()));
}
void *user_pvalloc(ThreadState *thr, uptr pc, uptr sz) {
uptr PageSize = GetPageSizeCached();
if (UNLIKELY(CheckForPvallocOverflow(sz, PageSize))) {
errno = errno_ENOMEM;
if (AllocatorMayReturnNull())
return nullptr;
GET_STACK_TRACE_FATAL(thr, pc);
ReportPvallocOverflow(sz, &stack);
}
// pvalloc(0) should allocate one page.
sz = sz ? RoundUpTo(sz, PageSize) : PageSize;
return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, PageSize));
}
static const void *user_alloc_begin(const void *p) {
if (p == nullptr || !IsAppMem((uptr)p))
return nullptr;
void *beg = allocator()->GetBlockBegin(p);
if (!beg)
return nullptr;
MBlock *b = ctx->metamap.GetBlock((uptr)beg);
if (!b)
return nullptr; // Not a valid pointer.
return (const void *)beg;
}
uptr user_alloc_usable_size(const void *p) {
if (p == 0 || !IsAppMem((uptr)p))
return 0;
MBlock *b = ctx->metamap.GetBlock((uptr)p);
if (!b)
return 0; // Not a valid pointer.
if (b->siz == 0)
return 1; // Zero-sized allocations are actually 1 byte.
return b->siz;
}
uptr user_alloc_usable_size_fast(const void *p) {
MBlock *b = ctx->metamap.GetBlock((uptr)p);
// Static objects may have malloc'd before tsan completes
// initialization, and may believe returned ptrs to be valid.
if (!b)
return 0; // Not a valid pointer.
if (b->siz == 0)
return 1; // Zero-sized allocations are actually 1 byte.
return b->siz;
}
void invoke_malloc_hook(void *ptr, uptr size) {
ThreadState *thr = cur_thread();
if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
return;
RunMallocHooks(ptr, size);
}
void invoke_free_hook(void *ptr) {
ThreadState *thr = cur_thread();
if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
return;
RunFreeHooks(ptr);
}
void *Alloc(uptr sz) {
ThreadState *thr = cur_thread();
if (thr->nomalloc) {
thr->nomalloc = 0; // CHECK calls internal_malloc().
CHECK(0);
}
InternalAllocAccess();
return InternalAlloc(sz, &thr->proc()->internal_alloc_cache);
}
void FreeImpl(void *p) {
ThreadState *thr = cur_thread();
if (thr->nomalloc) {
thr->nomalloc = 0; // CHECK calls internal_malloc().
CHECK(0);
}
InternalAllocAccess();
InternalFree(p, &thr->proc()->internal_alloc_cache);
}
} // namespace __tsan
using namespace __tsan;
extern "C" {
uptr __sanitizer_get_current_allocated_bytes() {
uptr stats[AllocatorStatCount];
allocator()->GetStats(stats);
return stats[AllocatorStatAllocated];
}
uptr __sanitizer_get_heap_size() {
uptr stats[AllocatorStatCount];
allocator()->GetStats(stats);
return stats[AllocatorStatMapped];
}
uptr __sanitizer_get_free_bytes() {
return 1;
}
uptr __sanitizer_get_unmapped_bytes() {
return 1;
}
uptr __sanitizer_get_estimated_allocated_size(uptr size) {
return size;
}
int __sanitizer_get_ownership(const void *p) {
return allocator()->GetBlockBegin(p) != 0;
}
const void *__sanitizer_get_allocated_begin(const void *p) {
return user_alloc_begin(p);
}
uptr __sanitizer_get_allocated_size(const void *p) {
return user_alloc_usable_size(p);
}
uptr __sanitizer_get_allocated_size_fast(const void *p) {
DCHECK_EQ(p, __sanitizer_get_allocated_begin(p));
uptr ret = user_alloc_usable_size_fast(p);
DCHECK_EQ(ret, __sanitizer_get_allocated_size(p));
return ret;
}
void __sanitizer_purge_allocator() {
allocator()->ForceReleaseToOS();
}
void __tsan_on_thread_idle() {
ThreadState *thr = cur_thread();
allocator()->SwallowCache(&thr->proc()->alloc_cache);
internal_allocator()->SwallowCache(&thr->proc()->internal_alloc_cache);
ctx->metamap.OnProcIdle(thr->proc());
}
} // extern "C"