diff options
Diffstat (limited to 'thirdparty/tourist/foundation/src/malloc.cpp')
| -rw-r--r-- | thirdparty/tourist/foundation/src/malloc.cpp | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/thirdparty/tourist/foundation/src/malloc.cpp b/thirdparty/tourist/foundation/src/malloc.cpp new file mode 100644 index 000000000..c8d4c5d66 --- /dev/null +++ b/thirdparty/tourist/foundation/src/malloc.cpp @@ -0,0 +1,211 @@ +#include <foundation/types.h> +#include <foundation/malloc.h> +#include <foundation/platform.h> + +//------------------------------------------------------------------------------ +struct Header +{ + enum : uint32 { Magic = 0xaa55aa55 }; + size_t size; + uint32 bias; + uint32 canary; + uint8 ptr[]; +}; +static bool g_add_canaries = false; + +//------------------------------------------------------------------------------ +#ifdef _WIN32 + +template <typename T=uint8> +static T* tt_malloc_norm(size_t size, size_t alignment) +{ + alignment = uint32(std::max(alignment, alignof(std::max_align_t))); + if (!g_add_canaries) + return (T*)_aligned_malloc(size, alignment); + + uint32 lead_size = uint32(sizeof(Header) + alignment - 1) & ~uint32(alignment - 1); + size_t alloc_size = lead_size + size + sizeof(uint32); + auto* alloc_ptr = (uint8*)_aligned_malloc(alloc_size, alignment); + + auto* header = (Header*)(alloc_ptr + lead_size - sizeof(Header)); + header->bias = lead_size; + header->size = size; + header->canary = Header::Magic; + + std::memcpy(header->ptr + size, &header->canary, sizeof(uint32)); + + return header->ptr; +} + +static void tt_free_norm(void* address) +{ + if (address == nullptr) + return; + + if (!g_add_canaries) + return _aligned_free(address); + + auto* header = (Header*)address - 1; + + auto is_canary = [] (void* ptr) { + uint32 canary = Header::Magic; + return !std::memcmp(ptr, &canary, sizeof(uint32)); + }; + if (!is_canary(&header->canary)) __debugbreak(); + if (!is_canary(header->ptr + header->size)) __debugbreak(); + + _aligned_free(header->ptr - header->bias); +} + +#else // POSIX + +template <typename T=uint8> +static T* tt_malloc_norm(size_t size, size_t alignment) +{ + alignment = std::max(alignment, alignof(std::max_align_t)); + // std::aligned_alloc requires size to be a multiple of alignment + size_t aligned_size = (size + alignment - 1) & ~(alignment - 1); + if (aligned_size == 0) + aligned_size = alignment; + + if (!g_add_canaries) + return (T*)std::aligned_alloc(alignment, aligned_size); + + uint32 lead_size = uint32(sizeof(Header) + alignment - 1) & ~uint32(alignment - 1); + size_t alloc_size = lead_size + size + sizeof(uint32); + size_t alloc_aligned = (alloc_size + alignment - 1) & ~(alignment - 1); + auto* alloc_ptr = (uint8*)std::aligned_alloc(alignment, alloc_aligned); + + auto* header = (Header*)(alloc_ptr + lead_size - sizeof(Header)); + header->bias = lead_size; + header->size = size; + header->canary = Header::Magic; + + std::memcpy(header->ptr + size, &header->canary, sizeof(uint32)); + + return header->ptr; +} + +static void tt_free_norm(void* address) +{ + if (address == nullptr) + return; + + if (!g_add_canaries) + return std::free(address); + + auto* header = (Header*)address - 1; + + auto is_canary = [] (void* ptr) { + uint32 canary = Header::Magic; + return !std::memcmp(ptr, &canary, sizeof(uint32)); + }; + if (!is_canary(&header->canary)) __builtin_trap(); + if (!is_canary(header->ptr + header->size)) __builtin_trap(); + + std::free(header->ptr - header->bias); +} + +#endif + +//------------------------------------------------------------------------------ +void tt_memory_canaries_on() +{ + g_add_canaries = true; +} + + +//------------------------------------------------------------------------------ +void* (*tt_malloc_impl)(size_t, size_t) = tt_malloc_norm; +void (*tt_free)(void*) = tt_free_norm; + + + +//------------------------------------------------------------------------------ +#ifdef _WIN32 + +template <typename T=uint8> +static T* tt_malloc_stomp(size_t size, size_t alignment) +{ + enum { PAGE_SIZE = 64 << 10 }; + size = (size + (alignment - 1)) & ~(alignment - 1); + size_t alloc_size = (size + (2 * PAGE_SIZE)) & ~(PAGE_SIZE - 1); + auto* ptr = (uint8*)VirtualAlloc(nullptr, alloc_size, MEM_COMMIT, PAGE_READWRITE); + ptr += alloc_size - PAGE_SIZE; + DWORD unused; + VirtualProtect(ptr, PAGE_SIZE, PAGE_NOACCESS, &unused); + + return (T*)(ptr - size); +} + +static void tt_free_stomp(void* address) +{ + if (address == nullptr) + return; + + *(uint32*)address = 0x30493049; + + MEMORY_BASIC_INFORMATION info; + VirtualQuery(address, &info, sizeof(info)); + DWORD unused; + VirtualProtect(info.AllocationBase, info.RegionSize, PAGE_NOACCESS, &unused); +} + +#else // POSIX + +static size_t tt_get_page_size() +{ + static size_t page_size = size_t(sysconf(_SC_PAGESIZE)); + return page_size; +} + +struct StompHeader +{ + void* base; + size_t total_size; +}; + +template <typename T=uint8> +static T* tt_malloc_stomp(size_t size, size_t alignment) +{ + size_t page_size = tt_get_page_size(); + size = (size + (alignment - 1)) & ~(alignment - 1); + size_t needed = sizeof(StompHeader) + size + page_size; + size_t alloc_size = (needed + (page_size - 1)) & ~(page_size - 1); + auto* base = (uint8*)mmap(nullptr, alloc_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (base == MAP_FAILED) + return nullptr; + + // Guard page at the end + uint8* guard = base + alloc_size - page_size; + mprotect(guard, page_size, PROT_NONE); + + // User allocation right before the guard, header right before that + T* user_ptr = (T*)(guard - size); + auto* hdr = (StompHeader*)((uint8*)user_ptr - sizeof(StompHeader)); + hdr->base = base; + hdr->total_size = alloc_size; + + return user_ptr; +} + +static void tt_free_stomp(void* address) +{ + if (address == nullptr) + return; + + *(uint32*)address = 0x30493049; + + auto* hdr = (StompHeader*)((uint8*)address - sizeof(StompHeader)); + mprotect(hdr->base, hdr->total_size, PROT_NONE); +} + +#endif + +//------------------------------------------------------------------------------ +void tt_memory_stomp_on() +{ + tt_malloc_impl = tt_malloc_stomp; + tt_free = tt_free_stomp; +} |