llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_allocator.cc

85 lines
2.5 KiB
C++

//===-- sanitizer_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 shared between AddressSanitizer and ThreadSanitizer
// run-time libraries.
// This allocator that is used inside run-times.
//===----------------------------------------------------------------------===//
#include "sanitizer_common.h"
// FIXME: We should probably use more low-level allocator that would
// mmap some pages and split them into chunks to fulfill requests.
#if SANITIZER_LINUX && !SANITIZER_ANDROID
extern "C" void *__libc_malloc(__sanitizer::uptr size);
extern "C" void __libc_free(void *ptr);
# define LIBC_MALLOC __libc_malloc
# define LIBC_FREE __libc_free
#else // SANITIZER_LINUX && !SANITIZER_ANDROID
# include <stdlib.h>
# define LIBC_MALLOC malloc
# define LIBC_FREE free
#endif // SANITIZER_LINUX && !SANITIZER_ANDROID
namespace __sanitizer {
const u64 kBlockMagic = 0x6A6CB03ABCEBC041ull;
void *InternalAlloc(uptr size) {
if (size + sizeof(u64) < size)
return 0;
void *p = LIBC_MALLOC(size + sizeof(u64));
if (p == 0)
return 0;
((u64*)p)[0] = kBlockMagic;
return (char*)p + sizeof(u64);
}
void InternalFree(void *addr) {
if (addr == 0)
return;
addr = (char*)addr - sizeof(u64);
CHECK_EQ(((u64*)addr)[0], kBlockMagic);
((u64*)addr)[0] = 0;
LIBC_FREE(addr);
}
// LowLevelAllocator
static LowLevelAllocateCallback low_level_alloc_callback;
void *LowLevelAllocator::Allocate(uptr size) {
// Align allocation size.
size = RoundUpTo(size, 8);
if (allocated_end_ - allocated_current_ < (sptr)size) {
uptr size_to_allocate = Max(size, GetPageSizeCached());
allocated_current_ =
(char*)MmapOrDie(size_to_allocate, __FUNCTION__);
allocated_end_ = allocated_current_ + size_to_allocate;
if (low_level_alloc_callback) {
low_level_alloc_callback((uptr)allocated_current_,
size_to_allocate);
}
}
CHECK(allocated_end_ - allocated_current_ >= (sptr)size);
void *res = allocated_current_;
allocated_current_ += size;
return res;
}
void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback) {
low_level_alloc_callback = callback;
}
bool CallocShouldReturnNullDueToOverflow(uptr size, uptr n) {
if (!size) return false;
uptr max = (uptr)-1L;
return (max / size) < n;
}
} // namespace __sanitizer