diff --git a/src/alloc-override-win.c b/src/alloc-override-win.c deleted file mode 100644 index 7b0fe69f..00000000 --- a/src/alloc-override-win.c +++ /dev/null @@ -1,702 +0,0 @@ -/* ---------------------------------------------------------------------------- -Copyright (c) 2018, Microsoft Research, Daan Leijen -This is free software; you can redistribute it and/or modify it under the -terms of the MIT license. A copy of the license can be found in the file -"LICENSE" at the root of this distribution. ------------------------------------------------------------------------------*/ - -#include "mimalloc.h" -#include "mimalloc-internal.h" - -#if !defined(_WIN32) -#error "this file should only be included on Windows" -#endif - -#include -#include - - -/* -To override the C runtime `malloc` on Windows we need to patch the allocation -functions at runtime initialization. Unfortunately we can never patch before the -runtime initializes itself, because as soon as we call `GetProcAddress` on the -runtime module (a DLL or EXE in Windows speak), it will first load and initialize -(by the OS calling `DllMain` on it). - -This means that some things might be already allocated by the C runtime itself -(and possibly other DLL's) before we get to resolve runtime adresses. This is -no problem if everyone unwinds in order: when we unload, we unpatch and restore -the original crt `free` routines and crt malloc'd memory is freed correctly. - -But things go wrong if such early CRT alloc'd memory is freed or re-allocated -_after_ we patch, but _before_ we unload (and unpatch), or if any memory allocated -by us is freed after we unpatched. - -There are two tricky situations to deal with: - -1. The Thread Local Storage (TLS): when the main thread stops it will call registered - callbacks on TLS entries (allocated by `FlsAlloc`). This is done by the OS - before any DLL's are unloaded. Unfortunately, the C runtime registers such - TLS entries with CRT allocated memory which is freed in the callback. - -2. Inside the CRT: - a. Some variables might get initialized by patched allocated - blocks but freed during CRT unloading after we unpatched - (like temporary file buffers). - b. Some blocks are allocated at CRT and freed by the CRT (like the - environment storage). - c. And some blocks are allocated by the CRT and then reallocated - while patched, and finally freed after unpatching! This - happens with the `atexit` functions for example to grow the array - of registered functions. - -In principle situation 2 is hopeless: since we cannot patch before CRT initialization, -we can never be sure how to free or reallocate a pointer during CRT unloading. -However, in practice there is a good solution: when terminating, we just patch -the reallocation and free routines to no-ops -- we are winding down anyway! This leaves -just the reallocation problm of CRT alloc'd memory once we are patched. Here, a study of the -CRT reveals that there seem to be just three such situations: - -1. When registering `atexit` routines (to grow the exit function table), -2. When calling `_setmaxstdio` (to grow the file handle table), -3. and `_popen`/`_wpopen` (to grow handle pairs). These turn out not to be - a problem as these are NULL initialized. - -We fix these by providing wrappers: - -1. We first register a _global_ `atexit` routine ourselves (`mi_patches_at_exit`) before patching, - and then patch the `_crt_atexit` function to implement our own global exit list (and the - same for `_crt_at_quick_exit`). All module local lists are no problem since they are always fully - (un)patched from initialization to end. We can register in the global list by dynamically - getting the global `_crt_atexit` entry from `ucrtbase.dll`. - -2. The `_setmaxstdio` is _detoured_: we patch it by a stub that unpatches first, - calls the original routine and repatches again. - -That leaves us to reliably shutdown and enter "termination mode": - -1. Using our trick to get the global exit list entry point, we register an exit function `mi_patches_atexit` - that first executes all our home brew list of exit functions, and then enters a _termination_ - phase that patches realloc/free variants with no-ops. Patching later again with special no-ops for - `free` also improves efficiency during the program run since no flags need to be checked. - -2. That is not quite good enough yet since after executing exit routines after us on the - global exit list (registered by the CRT), - the OS starts to unwind the TLS callbacks and we would like to run callbacks registered after loading - our DLL to be done in patched mode. So, we also allocate a TLS entry when our DLL is loaded and when its - callback is called, we re-enable the original patches again. Since TLS is destroyed in FIFO order - this runs any callbacks in later DLL's in patched mode. - -3. Finally the DLL's get unloaded by the OS in order (still patched) until our DLL gets unloaded - and then we start a termination phase again, and patch realloc/free with no-ops for good this time. - -*/ - -static int __cdecl mi_setmaxstdio(int newmax); - -// ------------------------------------------------------ -// Microsoft allocation extensions -// ------------------------------------------------------ - - -typedef size_t mi_nothrow_t; - -static void mi_free_nothrow(void* p, mi_nothrow_t tag) { - UNUSED(tag); - mi_free(p); -} - -// Versions of `free`, `realloc`, `recalloc`, `expand` and `msize` -// that are used during termination and are no-ops. -static void mi_free_term(void* p) { - UNUSED(p); -} - -static void mi_free_size_term(void* p, size_t size) { - UNUSED(size); - UNUSED(p); -} - -static void mi_free_nothrow_term(void* p, mi_nothrow_t tag) { - UNUSED(tag); - UNUSED(p); -} - -static void* mi_realloc_term(void* p, size_t newsize) { - UNUSED(p); UNUSED(newsize); - return NULL; -} - -static void* mi__recalloc_term(void* p, size_t newcount, size_t newsize) { - UNUSED(p); UNUSED(newcount); UNUSED(newsize); - return NULL; -} - -static void* mi__expand_term(void* p, size_t newsize) { - UNUSED(p); UNUSED(newsize); - return NULL; -} - -static size_t mi__msize_term(void* p) { - UNUSED(p); - return 0; -} - - -// Debug versions, forward to base versions (that get patched) - -static void* mi__malloc_dbg(size_t size, int block_type, const char* fname, int line) { - UNUSED(block_type); UNUSED(fname); UNUSED(line); - return _malloc_base(size); -} - -static void* mi__calloc_dbg(size_t count, size_t size, int block_type, const char* fname, int line) { - UNUSED(block_type); UNUSED(fname); UNUSED(line); - return _calloc_base(count, size); -} - -static void* mi__realloc_dbg(void* p, size_t size, int block_type, const char* fname, int line) { - UNUSED(block_type); UNUSED(fname); UNUSED(line); - return _realloc_base(p, size); -} - -static void mi__free_dbg(void* p, int block_type) { - UNUSED(block_type); - _free_base(p); -} - - -// the `recalloc`,`expand`, and `msize` don't have base versions and thus need a separate term version - -static void* mi__recalloc_dbg(void* p, size_t count, size_t size, int block_type, const char* fname, int line) { - UNUSED(block_type); UNUSED(fname); UNUSED(line); - return mi_recalloc(p, count, size); -} - -static void* mi__expand_dbg(void* p, size_t size, int block_type, const char* fname, int line) { - UNUSED(block_type); UNUSED(fname); UNUSED(line); - return mi__expand(p, size); -} - -static size_t mi__msize_dbg(void* p, int block_type) { - UNUSED(block_type); - return mi_usable_size(p); -} - -static void* mi__recalloc_dbg_term(void* p, size_t count, size_t size, int block_type, const char* fname, int line) { - UNUSED(block_type); UNUSED(fname); UNUSED(line); - return mi__recalloc_term(p, count, size); -} - -static void* mi__expand_dbg_term(void* p, size_t size, int block_type, const char* fname, int line) { - UNUSED(block_type); UNUSED(fname); UNUSED(line); - return mi__expand_term(p, size); -} - -static size_t mi__msize_dbg_term(void* p, int block_type) { - UNUSED(block_type); - return mi__msize_term(p); -} - - -// ------------------------------------------------------ -// implement our own global atexit handler -// ------------------------------------------------------ -typedef void (cbfun_t)(void); -typedef int (atexit_fun_t)(cbfun_t* fn); -typedef uintptr_t encoded_t; - -typedef struct exit_list_s { - encoded_t functions; // encoded pointer to array of encoded function pointers - size_t count; - size_t capacity; -} exit_list_t; - -#define MI_EXIT_INC (64) - -static exit_list_t atexit_list = { 0, 0, 0 }; -static exit_list_t at_quick_exit_list = { 0, 0, 0 }; -static CRITICAL_SECTION atexit_lock; - -// encode/decode function pointers with a random canary for security -static encoded_t canary; - -static inline void *decode(encoded_t x) { - return (void*)(x^canary); -} - -static inline encoded_t encode(void* p) { - return ((uintptr_t)p ^ canary); -} - - -static void init_canary() -{ - canary = _mi_random_init(0); - atexit_list.functions = at_quick_exit_list.functions = encode(NULL); -} - - -// initialize the list -static void mi_initialize_atexit(void) { - InitializeCriticalSection(&atexit_lock); - init_canary(); -} - -// register an exit function -static int mi_register_atexit(exit_list_t* list, cbfun_t* fn) { - if (fn == NULL) return EINVAL; - EnterCriticalSection(&atexit_lock); - encoded_t* functions = (encoded_t*)decode(list->functions); - if (list->count >= list->capacity) { // at first `functions == decode(0) == NULL` - encoded_t* newf = (encoded_t*)mi_recalloc(functions, list->capacity + MI_EXIT_INC, sizeof(cbfun_t*)); - if (newf != NULL) { - list->capacity += MI_EXIT_INC; - list->functions = encode(newf); - functions = newf; - } - } - int result; - if (list->count < list->capacity && functions != NULL) { - functions[list->count] = encode(fn); - list->count++; - result = 0; // success - } - else { - result = ENOMEM; - } - LeaveCriticalSection(&atexit_lock); - return result; -} - -// Register a global `atexit` function -static int mi_atexit(cbfun_t* fn) { - return mi_register_atexit(&atexit_list,fn); -} - -static int mi_at_quick_exit(cbfun_t* fn) { - return mi_register_atexit(&at_quick_exit_list,fn); -} - -static int mi_register_onexit(void* table, cbfun_t* fn) { - // TODO: how can we distinguish a quick_exit from atexit? - return mi_atexit(fn); -} - -// Execute exit functions in a list -static void mi_execute_exit_list(exit_list_t* list) { - // copy and zero the list structure - EnterCriticalSection(&atexit_lock); - exit_list_t clist = *list; - memset(list,0,sizeof(*list)); - LeaveCriticalSection(&atexit_lock); - - // now execute the functions outside of the lock - encoded_t* functions = (encoded_t*)decode(clist.functions); - if (functions != NULL) { - for (size_t i = clist.count; i > 0; i--) { // careful with unsigned count down.. - cbfun_t* fn = (cbfun_t*)decode(functions[i-1]); - if (fn==NULL) break; // corrupted! - fn(); - } - mi_free(functions); - } -} - - - -// ------------------------------------------------------ -// Jump assembly instructions for patches -// ------------------------------------------------------ - -#if defined(_M_IX86) || defined(_M_X64) - -#define MI_JUMP_SIZE 14 // at most 2+4+8 for a long jump or 1+5 for a short one - -typedef struct mi_jump_s { - uint8_t opcodes[MI_JUMP_SIZE]; -} mi_jump_t; - -void mi_jump_restore(void* current, const mi_jump_t* saved) { - memcpy(current, &saved->opcodes, MI_JUMP_SIZE); -} - -void mi_jump_write(void* current, void* target, mi_jump_t* save) { - if (save != NULL) { - memcpy(&save->opcodes, current, MI_JUMP_SIZE); - } - uint8_t* opcodes = ((mi_jump_t*)current)->opcodes; - ptrdiff_t diff = (uint8_t*)target - (uint8_t*)current; - uint32_t ofs32 = (uint32_t)diff; - #ifdef _M_X64 - uint64_t ofs64 = (uint64_t)diff; - if (ofs64 != (uint64_t)ofs32) { - // use long jump - opcodes[0] = 0xFF; - opcodes[1] = 0x25; - *((uint32_t*)&opcodes[2]) = 0; - *((uint64_t*)&opcodes[6]) = (uint64_t)target; - } - else - #endif - { - // use short jump - opcodes[0] = 0xE9; - *((uint32_t*)&opcodes[1]) = ofs32 - 5 /* size of the short jump instruction */; - } -} - -#elif defined(_M_ARM64) - -#define MI_JUMP_SIZE 16 - -typedef struct mi_jump_s { - uint8_t opcodes[MI_JUMP_SIZE]; -} mi_jump_t; - -void mi_jump_restore(void* current, const mi_jump_t* saved) { - memcpy(current, &saved->opcodes, MI_JUMP_SIZE); -} - -void mi_jump_write(void* current, void* target, mi_jump_t* save) { - if (save != NULL) { - memcpy(&save->opcodes, current, MI_JUMP_SIZE); - } - uint8_t* opcodes = ((mi_jump_t*)current)->opcodes; - uint64_t diff = (uint8_t*)target - (uint8_t*)current; - - // 0x50 0x00 0x00 0x58 ldr x16, .+8 # load PC relative +8 - // 0x00 0x02 0x3F 0xD6 blr x16 # and jump - //
- //
- static const uint8_t jump_opcodes[8] = { 0x50, 0x00, 0x00, 0x58, 0x00, 0x02, 0x3F, 0xD6 }; - memcpy(&opcodes[0], jump_opcodes, sizeof(jump_opcodes)); - *((uint64_t*)&opcodes[8]) = diff; -} - -#else -#error "define jump instructions for this platform" -#endif - - -// ------------------------------------------------------ -// Patches -// ------------------------------------------------------ -typedef enum patch_apply_e { - PATCH_NONE, - PATCH_TARGET, - PATCH_TARGET_TERM -} patch_apply_t; - -#define MAX_ENTRIES 4 // maximum number of patched entry points (like `malloc` in ucrtbase and msvcrt) - -typedef struct mi_patch_s { - const char* name; // name of the function to patch - void* target; // the address of the new target (never NULL) - void* target_term; // the address of the target during termination (or NULL) - patch_apply_t applied; // what target has been applied? - void* originals[MAX_ENTRIES]; // the resolved addresses of the function (or NULLs) - mi_jump_t saves[MAX_ENTRIES]; // the saved instructions in case it was applied -} mi_patch_t; - -#define MI_PATCH_NAME3(name,target,term) { name, &target, &term, PATCH_NONE, {NULL,NULL,NULL,NULL} } -#define MI_PATCH_NAME2(name,target) { name, &target, NULL, PATCH_NONE, {NULL,NULL,NULL,NULL} } -#define MI_PATCH3(name,target,term) MI_PATCH_NAME3(#name, target, term) -#define MI_PATCH2(name,target) MI_PATCH_NAME2(#name, target) -#define MI_PATCH1(name) MI_PATCH2(name,mi_##name) - -static mi_patch_t patches[] = { - // we implement our own global exit handler (as the CRT versions do a realloc internally) - //MI_PATCH2(_crt_atexit, mi_atexit), - //MI_PATCH2(_crt_at_quick_exit, mi_at_quick_exit), - MI_PATCH2(_setmaxstdio, mi_setmaxstdio), - MI_PATCH2(_register_onexit_function, mi_register_onexit), - - // override higher level atexit functions so we can implement at_quick_exit correcty - MI_PATCH2(atexit, mi_atexit), - MI_PATCH2(at_quick_exit, mi_at_quick_exit), - - // regular entries - MI_PATCH2(malloc, mi_malloc), - MI_PATCH2(calloc, mi_calloc), - MI_PATCH3(realloc, mi_realloc,mi_realloc_term), - MI_PATCH3(free, mi_free,mi_free_term), - - // extended api - MI_PATCH2(_strdup, mi_strdup), - MI_PATCH2(_strndup, mi_strndup), - MI_PATCH3(_expand, mi__expand,mi__expand_term), - MI_PATCH3(_recalloc, mi_recalloc,mi__recalloc_term), - MI_PATCH3(_msize, mi_usable_size,mi__msize_term), - - // base versions - MI_PATCH2(_malloc_base, mi_malloc), - MI_PATCH2(_calloc_base, mi_calloc), - MI_PATCH3(_realloc_base, mi_realloc,mi_realloc_term), - MI_PATCH3(_free_base, mi_free,mi_free_term), - - // these base versions are in the crt but without import records - MI_PATCH_NAME3("_recalloc_base", mi_recalloc,mi__recalloc_term), - MI_PATCH_NAME3("_msize_base", mi_usable_size,mi__msize_term), - - // debug - MI_PATCH2(_malloc_dbg, mi__malloc_dbg), - MI_PATCH2(_realloc_dbg, mi__realloc_dbg), - MI_PATCH2(_calloc_dbg, mi__calloc_dbg), - MI_PATCH2(_free_dbg, mi__free_dbg), - - MI_PATCH3(_expand_dbg, mi__expand_dbg, mi__expand_dbg_term), - MI_PATCH3(_recalloc_dbg, mi__recalloc_dbg, mi__recalloc_dbg_term), - MI_PATCH3(_msize_dbg, mi__msize_dbg, mi__msize_dbg_term), - -#if 0 - // override new/delete variants for efficiency (?) -#ifdef _WIN64 - // 64 bit new/delete - MI_PATCH_NAME2("??2@YAPEAX_K@Z", mi_new), - MI_PATCH_NAME2("??_U@YAPEAX_K@Z", mi_new), - MI_PATCH_NAME3("??3@YAXPEAX@Z", mi_free, mi_free_term), - MI_PATCH_NAME3("??_V@YAXPEAX@Z", mi_free, mi_free_term), - MI_PATCH_NAME3("??3@YAXPEAX_K@Z", mi_free_size, mi_free_size_term), // delete sized - MI_PATCH_NAME3("??_V@YAXPEAX_K@Z", mi_free_size, mi_free_size_term), // delete sized - MI_PATCH_NAME2("??2@YAPEAX_KAEBUnothrow_t@std@@@Z", mi_new), - MI_PATCH_NAME2("??_U@YAPEAX_KAEBUnothrow_t@std@@@Z", mi_new), - MI_PATCH_NAME3("??3@YAXPEAXAEBUnothrow_t@std@@@Z", mi_free_nothrow, mi_free_nothrow_term), - MI_PATCH_NAME3("??_V@YAXPEAXAEBUnothrow_t@std@@@Z", mi_free_nothrow, mi_free_nothrow_term), - - -#else - // 32 bit new/delete - MI_PATCH_NAME2("??2@YAPAXI@Z", mi_new), - MI_PATCH_NAME2("??_U@YAPAXI@Z", mi_new), - MI_PATCH_NAME3("??3@YAXPAX@Z", mi_free, mi_free_term), - MI_PATCH_NAME3("??_V@YAXPAX@Z", mi_free, mi_free_term), - MI_PATCH_NAME3("??3@YAXPAXI@Z", mi_free_size, mi_free_size_term), // delete sized - MI_PATCH_NAME3("??_V@YAXPAXI@Z", mi_free_size, mi_free_size_term), // delete sized - - MI_PATCH_NAME2("??2@YAPAXIABUnothrow_t@std@@@Z", mi_new), - MI_PATCH_NAME2("??_U@YAPAXIABUnothrow_t@std@@@Z", mi_new), - MI_PATCH_NAME3("??3@YAXPAXABUnothrow_t@std@@@Z", mi_free_nothrow, mi_free_nothrow_term), - MI_PATCH_NAME3("??_V@YAXPAXABUnothrow_t@std@@@Z", mi_free_nothrow, mi_free_nothrow_term), - -#endif -#endif - { NULL, NULL, NULL, PATCH_NONE, {NULL,NULL,NULL,NULL} } -}; - - -// Apply a patch -static bool mi_patch_apply(mi_patch_t* patch, patch_apply_t apply) -{ - if (patch->originals[0] == NULL) return true; // unresolved - if (apply == PATCH_TARGET_TERM && patch->target_term == NULL) apply = PATCH_TARGET; // avoid re-applying non-term variants - if (patch->applied == apply) return false; - - for (int i = 0; i < MAX_ENTRIES; i++) { - void* original = patch->originals[i]; - if (original == NULL) break; // no more - - DWORD protect = PAGE_READWRITE; - if (!VirtualProtect(original, MI_JUMP_SIZE, PAGE_EXECUTE_READWRITE, &protect)) return false; - if (apply == PATCH_NONE) { - mi_jump_restore(original, &patch->saves[i]); - } - else { - void* target = (apply == PATCH_TARGET ? patch->target : patch->target_term); - mi_assert_internal(target != NULL); - if (target != NULL) mi_jump_write(original, target, &patch->saves[i]); - } - VirtualProtect(original, MI_JUMP_SIZE, protect, &protect); - } - patch->applied = apply; - return true; -} - -// Apply all patches -static bool _mi_patches_apply(patch_apply_t apply, patch_apply_t* previous) { - static patch_apply_t current = PATCH_NONE; - if (previous != NULL) *previous = current; - if (current == apply) return true; - current = apply; - bool ok = true; - for (size_t i = 0; patches[i].name != NULL; i++) { - if (!mi_patch_apply(&patches[i], apply)) ok = false; - } - return ok; -} - -// Export the following three functions just in case -// a user needs that level of control. - -// Disable all patches -mi_decl_export void mi_patches_disable(void) { - _mi_patches_apply(PATCH_NONE, NULL); -} - -// Enable all patches normally -mi_decl_export bool mi_patches_enable(void) { - return _mi_patches_apply( PATCH_TARGET, NULL ); -} - -// Enable all patches in termination phase where free is a no-op -mi_decl_export bool mi_patches_enable_term(void) { - return _mi_patches_apply(PATCH_TARGET_TERM, NULL); -} - -// ------------------------------------------------------ -// Stub for _setmaxstdio -// ------------------------------------------------------ - -static int __cdecl mi_setmaxstdio(int newmax) { - patch_apply_t previous; - _mi_patches_apply(PATCH_NONE, &previous); // disable patches - int result = _setmaxstdio(newmax); // call original function (that calls original CRT recalloc) - _mi_patches_apply(previous,NULL); // and re-enable patches - return result; -} - - -// ------------------------------------------------------ -// Resolve addresses dynamically -// ------------------------------------------------------ - -// Try to resolve patches for a given module (DLL) -static void mi_module_resolve(const char* fname, HMODULE mod, int priority) { - // see if any patches apply - for (size_t i = 0; patches[i].name != NULL; i++) { - mi_patch_t* patch = &patches[i]; - if (patch->applied == PATCH_NONE) { - // find an available entry - int i = 0; - while (i < MAX_ENTRIES && patch->originals[i] != NULL) i++; - if (i < MAX_ENTRIES) { - void* addr = GetProcAddress(mod, patch->name); - if (addr != NULL) { - // found it! set the address - patch->originals[i] = addr; - _mi_trace_message(" override %s at %s!%p (entry %i)\n", patch->name, fname, addr, i); - } - } - } - } -} - -#define MIMALLOC_NAME "mimalloc-override.dll" -#define UCRTBASE_NAME "ucrtbase.dll" -#define UCRTBASED_NAME "ucrtbased.dll" - -// Resolve addresses of all patches by inspecting the loaded modules -static atexit_fun_t* crt_atexit = NULL; -static atexit_fun_t* crt_at_quick_exit = NULL; - - -static bool mi_patches_resolve(void) { - // get all loaded modules - HANDLE process = GetCurrentProcess(); // always -1, no need to release - DWORD needed = 0; - HMODULE modules[400]; // try to stay under 4k to not trigger the guard page - EnumProcessModules(process, modules, sizeof(modules), &needed); - if (needed == 0) return false; - int count = needed / sizeof(HMODULE); - int ucrtbase_index = 0; - int mimalloc_index = 0; - // iterate through the loaded modules - _mi_trace_message("overriding malloc dynamically...\n"); - for (int i = 0; i < count; i++) { - HMODULE mod = modules[i]; - char filename[MAX_PATH] = { 0 }; - DWORD slen = GetModuleFileName(mod, filename, MAX_PATH); - if (slen > 0 && slen < MAX_PATH) { - // filter out potential crt modules only - filename[slen] = 0; - const char* lastsep = strrchr(filename, '\\'); - const char* basename = (lastsep==NULL ? filename : lastsep+1); - _mi_trace_message(" %i: dynamic module %s\n", i, filename); - - // remember indices so we can check load order (in debug mode) - if (_stricmp(basename, MIMALLOC_NAME) == 0) mimalloc_index = i; - if (_stricmp(basename, UCRTBASE_NAME) == 0) ucrtbase_index = i; - if (_stricmp(basename, UCRTBASED_NAME) == 0) ucrtbase_index = i; - - // see if we potentially patch in this module - int priority = 0; - if (i == 0) priority = 2; // main module to allow static crt linking - else if (_strnicmp(basename, "ucrt", 4) == 0) priority = 3; // new ucrtbase.dll in windows 10 - // NOTE: don't override msvcr -- leads to crashes in setlocale (needs more testing) - // else if (_strnicmp(basename, "msvcr", 5) == 0) priority = 1; // older runtimes - - if (priority > 0) { - // probably found a crt module, try to patch it - mi_module_resolve(basename,mod,priority); - - // try to find the atexit functions for the main process (in `ucrtbase.dll`) - if (crt_atexit==NULL) crt_atexit = (atexit_fun_t*)GetProcAddress(mod, "_crt_atexit"); - if (crt_at_quick_exit == NULL) crt_at_quick_exit = (atexit_fun_t*)GetProcAddress(mod, "_crt_at_quick_exit"); - } - } - } - int diff = mimalloc_index - ucrtbase_index; - if (diff > 1) { - _mi_warning_message("warning: the \"mimalloc-override\" DLL seems not to load before or right after the C runtime (\"ucrtbase\").\n" - " Try to fix this by changing the linking order.\n"); - } - return true; -} - - -// ------------------------------------------------------ -// Dll Entry -// ------------------------------------------------------ - -extern BOOL WINAPI _DllMainCRTStartup(HINSTANCE inst, DWORD reason, LPVOID reserved); - -static DWORD mi_fls_unwind_entry; -static void NTAPI mi_fls_unwind(PVOID value) { - if (value != NULL) mi_patches_enable(); // and re-enable normal patches again for DLL's loaded after us - return; -} - -static void mi_patches_atexit(void) { - mi_execute_exit_list(&atexit_list); - mi_patches_enable_term(); // enter termination phase and patch realloc/free with a no-op -} - -static void mi_patches_at_quick_exit(void) { - mi_execute_exit_list(&at_quick_exit_list); - mi_patches_enable_term(); // enter termination phase and patch realloc/free with a no-op -} - -__declspec(dllexport) BOOL WINAPI DllEntry(HINSTANCE inst, DWORD reason, LPVOID reserved) { - if (reason == DLL_PROCESS_ATTACH) { - __security_init_cookie(); - } - else if (reason == DLL_PROCESS_DETACH) { - // enter termination phase for good now - mi_patches_enable_term(); - } - // C runtime main - BOOL ok = _DllMainCRTStartup(inst, reason, reserved); - if (reason == DLL_PROCESS_ATTACH && ok) { - // Now resolve patches - ok = mi_patches_resolve(); - if (ok) { - // and register our unwind entry (this must be after resolving due to possible delayed DLL initialization from GetProcAddress) - mi_fls_unwind_entry = FlsAlloc(&mi_fls_unwind); - if (mi_fls_unwind_entry != FLS_OUT_OF_INDEXES) { - FlsSetValue(mi_fls_unwind_entry, (void*)1); - } - - // register our patch disabler in the global exit list - mi_initialize_atexit(); - if (crt_atexit != NULL) (*crt_atexit)(&mi_patches_atexit); - if (crt_at_quick_exit != NULL) (*crt_at_quick_exit)(&mi_patches_at_quick_exit); - - // and patch ! this also redirects the `atexit` handling for the global exit list - mi_patches_enable(); - - // hide internal allocation - mi_stats_reset(); - } - } - return ok; -}