Files
snmalloc/src/pal/pal_open_enclave.h
2021-04-06 14:09:18 +01:00

84 lines
2.1 KiB
C++

#pragma once
#include "ds/address.h"
#include "ds/flaglock.h"
#include "pal_plain.h"
#include <array>
#ifdef OPEN_ENCLAVE
extern "C" void* oe_memset_s(void* p, size_t p_size, int c, size_t size);
extern "C" int oe_random(void* data, size_t size);
extern "C" [[noreturn]] void oe_abort();
namespace snmalloc
{
class PALOpenEnclave
{
/// Base of OE heap
static inline void* heap_base = nullptr;
/// Size of OE heap
static inline size_t heap_size;
// This is infrequently used code, a spin lock simplifies the code
// considerably, and should never be on the fast path.
static inline std::atomic_flag spin_lock;
public:
/**
* This will be called by oe_allocator_init to set up enclave heap bounds.
*/
static void setup_initial_range(void* base, void* end)
{
heap_size = pointer_diff(base, end);
heap_base = base;
}
/**
* Bitmap of PalFeatures flags indicating the optional features that this
* PAL supports.
*/
static constexpr uint64_t pal_features = Entropy;
static constexpr size_t page_size = Aal::smallest_page_size;
[[noreturn]] static void error(const char* const str)
{
UNUSED(str);
oe_abort();
}
static std::pair<void*, size_t>
reserve_at_least(size_t request_size) noexcept
{
// First call returns the entire address space
// subsequent calls return {nullptr, 0}
FlagLock lock(spin_lock);
if (request_size > heap_size)
return {nullptr, 0};
auto result = std::make_pair(heap_base, heap_size);
heap_size = 0;
return result;
}
template<bool page_aligned = false>
static void zero(void* p, size_t size) noexcept
{
oe_memset_s(p, size, 0, size);
}
/**
* Source of Entropy
*/
static uint64_t get_entropy64()
{
uint64_t result = 0;
if (oe_random(&result, sizeof(result)) != 0)
error("Failed to get system randomness");
return result;
}
};
}
#endif