77 lines
1.5 KiB
C++
77 lines
1.5 KiB
C++
// adapted from https://github.com/mifki/df-sizecheck/blob/master/b.cpp
|
|
// usage:
|
|
// linux: PRELOAD_LIB=hack/libsizecheck.so ./dfhack
|
|
|
|
#include <cstdint>
|
|
#include <cstdio>
|
|
#include <cstdlib>
|
|
#include <cstring>
|
|
#include <memory>
|
|
|
|
using namespace std;
|
|
|
|
const uint32_t MAGIC = 0xdfdf4ac8;
|
|
bool initialized = false;
|
|
int perturb = -1;
|
|
|
|
void init() {
|
|
#ifndef _LINUX
|
|
if (getenv("MALLOC_PERTURB_")) {
|
|
perturb = atoi(getenv("MALLOC_PERTURB_"));
|
|
}
|
|
#endif
|
|
initialized = true;
|
|
}
|
|
|
|
#ifdef _WIN32
|
|
static int posix_memalign(void **ptr, size_t alignment, size_t size)
|
|
{
|
|
if ((*ptr = _aligned_malloc(size, alignment)))
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
return errno;
|
|
}
|
|
#endif
|
|
|
|
void* alloc(size_t n) {
|
|
if (!initialized) {
|
|
init();
|
|
}
|
|
void* addr;
|
|
if (posix_memalign(&addr, 32, n + 16) != 0) {
|
|
return addr;
|
|
}
|
|
memset(addr, 0, 16);
|
|
*(size_t*)addr = n;
|
|
*(uint32_t*)((uint8_t*)addr + 8) = MAGIC;
|
|
if (perturb > 0) {
|
|
memset((uint8_t*)addr + 16, ~(perturb & 0xff), n);
|
|
}
|
|
return (uint8_t*)addr + 16;
|
|
}
|
|
|
|
void dealloc(void* addr) {
|
|
if (!initialized) {
|
|
init();
|
|
}
|
|
if (uintptr_t(addr) % 32 == 16 && *(uint32_t*)((uint8_t*)addr - 8) == MAGIC) {
|
|
addr = (void*)((uint8_t*)addr - 16);
|
|
memset((uint8_t*)addr + 16, perturb & 0xff, *(size_t*)addr);
|
|
}
|
|
free(addr);
|
|
}
|
|
|
|
void* operator new (size_t n, const nothrow_t& tag) {
|
|
return alloc(n);
|
|
}
|
|
|
|
void* operator new (size_t n) {
|
|
return alloc(n);
|
|
}
|
|
|
|
void operator delete (void* addr) {
|
|
return dealloc(addr);
|
|
}
|