llvm-project/compiler-rt/lib/msan/msan_allocator.cc

108 lines
3.5 KiB
C++

//===-- msan_allocator.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 MemorySanitizer.
//
// MemorySanitizer allocator.
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_allocator.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
#include "msan.h"
namespace __msan {
struct Metadata {
uptr requested_size;
};
static const uptr kAllocatorSpace = 0x600000000000ULL;
static const uptr kAllocatorSize = 0x80000000000; // 8T.
static const uptr kMetadataSize = sizeof(Metadata);
typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, kMetadataSize,
DefaultSizeClassMap> PrimaryAllocator;
typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
typedef LargeMmapAllocator<> SecondaryAllocator;
typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
SecondaryAllocator> Allocator;
static THREADLOCAL AllocatorCache cache;
static Allocator allocator;
static int inited = 0;
static inline void Init() {
if (inited) return;
__msan_init();
inited = true; // this must happen before any threads are created.
allocator.Init();
}
static void *MsanAllocate(StackTrace *stack, uptr size,
uptr alignment, bool zeroise) {
Init();
void *res = allocator.Allocate(&cache, size, alignment, false);
Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(res));
meta->requested_size = size;
if (zeroise)
__msan_clear_and_unpoison(res, size);
else if (flags()->poison_in_malloc)
__msan_poison(res, size);
if (__msan_get_track_origins()) {
u32 stack_id = StackDepotPut(stack->trace, stack->size);
CHECK(stack_id);
CHECK_EQ((stack_id >> 31), 0); // Higher bit is occupied by stack origins.
__msan_set_origin(res, size, stack_id);
}
return res;
}
void MsanDeallocate(void *p) {
CHECK(p);
Init();
Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(p));
uptr size = meta->requested_size;
// This memory will not be reused by anyone else, so we are free to keep it
// poisoned.
__msan_poison(p, size);
if (__msan_get_track_origins())
__msan_set_origin(p, size, -1);
allocator.Deallocate(&cache, p);
}
void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,
uptr alignment, bool zeroise) {
if (!old_p)
return MsanAllocate(stack, new_size, alignment, zeroise);
if (!new_size) {
MsanDeallocate(old_p);
return 0;
}
Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(old_p));
uptr old_size = meta->requested_size;
uptr actually_allocated_size = allocator.GetActuallyAllocatedSize(old_p);
if (new_size <= actually_allocated_size) {
// We are not reallocating here.
meta->requested_size = new_size;
if (new_size > old_size)
__msan_poison((char*)old_p + old_size, new_size - old_size);
return old_p;
}
uptr memcpy_size = Min(new_size, old_size);
void *new_p = MsanAllocate(stack, new_size, alignment, zeroise);
// Printf("realloc: old_size %zd new_size %zd\n", old_size, new_size);
if (new_p)
__msan_memcpy(new_p, old_p, memcpy_size);
MsanDeallocate(old_p);
return new_p;
}
} // namespace __msan