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src/vm.c libmalloc-715.120.13 /dev/null
--- libmalloc/libmalloc-715.120.13/src/vm.c
+++ /dev/null
@@ -1,586 +0,0 @@
-/*
- * Copyright (c) 2016 Apple Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-
-#include "internal.h"
-
-#if !MALLOC_TARGET_EXCLAVES
-static volatile uintptr_t entropic_address = 0;
-static volatile uintptr_t entropic_base = 0;
-static volatile uintptr_t entropic_limit = 0;
-#endif // !MALLOC_TARGET_EXCLAVES
-
-MALLOC_NOEXPORT
-uint64_t malloc_entropy[2] = {0, 0};
-
-#define ENTROPIC_KABILLION 0x10000000 /* 256Mb */
-#define ENTROPIC_USER_RANGE_SIZE 0x200000000ULL /* 8Gb */
-
-// <rdar://problem/22277891> align 64bit ARM shift to 32MB PTE entries
-#if MALLOC_TARGET_IOS && MALLOC_TARGET_64BIT
-#define ENTROPIC_SHIFT 25
-#else // MALLOC_TARGET_IOS && MALLOC_TARGET_64BIT
-#define ENTROPIC_SHIFT SMALL_BLOCKS_ALIGN
-#endif
-
-void
-mvm_aslr_init(void)
-{
-	// Prepare ASLR
-#if MALLOC_TARGET_EXCLAVES
-	arc4random_buf(malloc_entropy, sizeof(malloc_entropy));
-#elif defined(__i386__) || defined(__x86_64__) || defined(__arm64__) || TARGET_OS_DRIVERKIT || (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR)
-#if defined(__i386__)
-	uintptr_t stackbase = 0x8fe00000;
-	int entropic_bits = 3;
-#elif defined(__x86_64__)
-	uintptr_t stackbase = USRSTACK64;
-	int entropic_bits = 16;
-#elif defined(__arm64__)
-#if defined(__LP64__)
-	uintptr_t stackbase = USRSTACK64;
-	int entropic_bits = 7;
-#else // __LP64__
-	uintptr_t stackbase = USRSTACK;
-	int entropic_bits = 3;
-#endif
-#else
-	uintptr_t stackbase = USRSTACK;
-	int entropic_bits = 3;
-#endif
-	// assert(((1 << entropic_bits) - 1) << SMALL_BLOCKS_ALIGN < (stackbase - MAXSSIZ - ENTROPIC_KABILLION));
-
-	if (mvm_aslr_enabled()) {
-		if (0 == entropic_address) {
-			uintptr_t t = stackbase - MAXSSIZ - ((uintptr_t)(malloc_entropy[1] &
-				((1 << entropic_bits) - 1)) << ENTROPIC_SHIFT);
-#if MALLOC_TARGET_IOS && MALLOC_TARGET_64BIT
-			uintptr_t addr = 0;
-
-			/* If kernel VM user ranges are enabled mach_vm_allocate/map will provide memory
-			 * in the upper VM address range. This range is randomized per process. For now
-			 * we do not have this metadata plumbed through so we make a single allocation
-			 * with the appropriate tag to determine where our heap is. If we are given an
-			 * allocation above where we expect then we can safely assume VM ranges are enabled.
-			 *
-			 * If so we do not need to apply further entropy but do need to ensure
-			 * we mask off the address to a PTE boundary.
-			 */ 
-			if (KERN_SUCCESS == mach_vm_allocate(mach_task_self(), (mach_vm_address_t *)&addr,
-					vm_page_quanta_size, VM_FLAGS_ANYWHERE | VM_MAKE_TAG(VM_MEMORY_MALLOC_TINY))) {
-				// Fall through and use existing base if addr < stackbase
-				if (addr > stackbase) {
-					t = (addr + ENTROPIC_USER_RANGE_SIZE) & ~((1 << ENTROPIC_SHIFT) - 1);
-					OSAtomicCompareAndSwapLong(0, addr, (volatile long *)&entropic_base);
-				}
-
-				mach_vm_deallocate(mach_task_self(), addr, vm_page_quanta_size);
-			}
-#endif // MALLOC_TARGET_IOS && MALLOC_TARGET_64BIT
-
-			OSAtomicCompareAndSwapLong(0, t, (volatile long *)&entropic_limit);
-			OSAtomicCompareAndSwapLong(0, t - ENTROPIC_KABILLION, (volatile long *)&entropic_address);
-		}
-	} else {
-		// zero slide when ASLR has been disabled by boot-arg. Eliminate cloaking.
-		malloc_entropy[0] = 0;
-		malloc_entropy[1] = 0;
-	}
-#else // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
-#error ASLR unhandled on this platform
-#endif // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
-}
-
-void * __sized_by_or_null(size)
-mvm_allocate_plat(uintptr_t addr, size_t size, uint8_t align, int flags, int debug_flags, int vm_page_label, plat_map_t *map_out)
-{
-	void * __unsafe_indexable mapped;
-	kern_return_t kr;
-
-	if (addr && (flags & VM_FLAGS_ANYWHERE)) {
-		// Pass MALLOC_ABORT_ON_ERROR to make this call abort
-		malloc_zone_error(MALLOC_ABORT_ON_ERROR | debug_flags, false,
-			"Unsupported anywhere allocation at address 0x%lx of size 0x%lx with flags %d\n",
-			(unsigned long) addr, (unsigned long) size, flags);
-	}
-#if MALLOC_TARGET_EXCLAVES
-	// Memory will be reserved and/or populated, and the handle initialized
-	const _liblibc_map_type_t type = LIBLIBC_MAP_TYPE_PRIVATE |
-			((flags & VM_FLAGS_ANYWHERE) ? LIBLIBC_MAP_TYPE_NONE : LIBLIBC_MAP_TYPE_FIXED) |
-			((debug_flags & MALLOC_CAN_FAULT) ? LIBLIBC_MAP_TYPE_FAULTABLE : LIBLIBC_MAP_TYPE_NONE) |
-			((debug_flags & MALLOC_NO_POPULATE) ? LIBLIBC_MAP_TYPE_NOCOMMIT : LIBLIBC_MAP_TYPE_NONE) |
-			((debug_flags & DISABLE_ASLR) ? LIBLIBC_MAP_TYPE_NORAND : LIBLIBC_MAP_TYPE_NONE);
-	const _liblibc_map_perm_t perm = LIBLIBC_MAP_PERM_READ |
-			LIBLIBC_MAP_PERM_WRITE;
-	mapped = mmap_plat(map_out, addr, size, perm, type, align,
-			(unsigned)vm_page_label);
-	kr = errno;
-	// This message is not printed on non-exclaves targets. Certain code paths,
-	// like xzm_segment_group_try_realloc_huge_chunk, may fail under normal
-	// conditions, and would print a spurious message, but are disabled on
-	// exclaves.
-	if (!mapped) {
-		malloc_zone_error(debug_flags, false,
-			"Failed to allocate memory at address 0x%lx of size 0x%lx with flags %d: %d\n", addr, size, flags, kr);
-	}
-#else
-	(void)map_out;
-	if (debug_flags & (MALLOC_CAN_FAULT | MALLOC_NO_POPULATE)) {
-		// Pass MALLOC_ABORT_ON_ERROR to make this call abort
-		malloc_zone_error(MALLOC_ABORT_ON_ERROR | debug_flags, false,
-				"Unsupported unpopulated allocation at address 0x%lx of size 0x%lx with flags %d\n",
-				(unsigned long) addr, (unsigned long) size, flags);
-	}
-
-
-	mach_vm_address_t vm_addr = addr;
-	mach_vm_offset_t allocation_mask = ((mach_vm_offset_t)1 << align) - 1;
-	kr = mach_vm_map(mach_task_self(), &vm_addr, (mach_vm_size_t)size,
-			allocation_mask, flags | VM_MAKE_TAG(vm_page_label),
-			MEMORY_OBJECT_NULL, 0, FALSE, VM_PROT_DEFAULT, VM_PROT_ALL,
-			VM_INHERIT_DEFAULT);
-	mapped = (kr == KERN_SUCCESS) ? (void *)vm_addr : NULL;
-#endif // MALLOC_TARGET_EXCLAVES
-
-	return __unsafe_forge_bidi_indexable(void *, mapped, size);
-}
-
-void * __sized_by_or_null(size)
-mvm_allocate_pages(size_t size, uint8_t align, uint32_t debug_flags,
-		int vm_page_label)
-{
-	return mvm_allocate_pages_plat(size, align, debug_flags, vm_page_label, NULL);
-}
-
-void * __sized_by_or_null(size)
-mvm_allocate_pages_plat(size_t size, uint8_t align, uint32_t debug_flags,
-		int vm_page_label, plat_map_t *map_out)
-{
-#if MALLOC_TARGET_EXCLAVES
-	return mvm_allocate_plat(0, size, align, VM_FLAGS_ANYWHERE, debug_flags, vm_page_label, map_out);
-#else
-	(void)map_out;
-	boolean_t add_prelude_guard_page = debug_flags & MALLOC_ADD_PRELUDE_GUARD_PAGE;
-	boolean_t add_postlude_guard_page = debug_flags & MALLOC_ADD_POSTLUDE_GUARD_PAGE;
-	boolean_t purgeable = debug_flags & MALLOC_PURGEABLE;
-	boolean_t use_entropic_range = !(debug_flags & DISABLE_ASLR);
-	mach_vm_address_t vm_addr;
-	uintptr_t addr;
-	mach_vm_size_t allocation_size = round_page_quanta(size);
-	mach_vm_offset_t allocation_mask = ((mach_vm_offset_t)1 << align) - 1;
-	int alloc_flags = VM_FLAGS_ANYWHERE | VM_MAKE_TAG(vm_page_label);
-	kern_return_t kr;
-
-	if (!allocation_size) {
-		allocation_size = vm_page_quanta_size;
-	}
-	if (add_postlude_guard_page || add_prelude_guard_page) {
-		if (add_prelude_guard_page && align > vm_page_quanta_shift) {
-			/* <rdar://problem/16601499> alignment greater than pagesize needs more work */
-			allocation_size += (1 << align) + large_vm_page_quanta_size;
-		} else {
-			allocation_size += add_prelude_guard_page && add_postlude_guard_page ?
-					2 * large_vm_page_quanta_size : large_vm_page_quanta_size;
-		}
-	}
-
-	if (purgeable) {
-		alloc_flags |= VM_FLAGS_PURGABLE;
-	}
-
-
-	if (allocation_size < size) { // size_t arithmetic wrapped!
-		return NULL;
-	}
-
-retry:
-	vm_addr = use_entropic_range ? entropic_address : vm_page_quanta_size;
-	kr = mach_vm_map(mach_task_self(), &vm_addr, allocation_size,
-			allocation_mask, alloc_flags, MEMORY_OBJECT_NULL, 0, FALSE,
-			VM_PROT_DEFAULT, VM_PROT_ALL, VM_INHERIT_DEFAULT);
-	if (kr == KERN_NO_SPACE && use_entropic_range) {
-		vm_addr = vm_page_quanta_size;
-		kr = mach_vm_map(mach_task_self(), &vm_addr, allocation_size,
-				allocation_mask, alloc_flags, MEMORY_OBJECT_NULL, 0, FALSE,
-				VM_PROT_DEFAULT, VM_PROT_ALL, VM_INHERIT_DEFAULT);
-	}
-	if (kr) {
-		if (kr != KERN_NO_SPACE) {
-			malloc_zone_error(debug_flags, false, "can't allocate region\n:"
-					"*** mach_vm_map(size=%lu, flags: %x) failed (error code=%d)\n",
-					size, debug_flags, kr);
-		}
-		return NULL;
-	}
-	addr = (uintptr_t)vm_addr;
-
-	if (use_entropic_range) {
-		// Don't allow allocation to rise above entropic_limit (for tidiness).
-		if (addr + allocation_size > entropic_limit) { // Exhausted current range?
-			uintptr_t t = entropic_address;
-			uintptr_t u = t - ENTROPIC_KABILLION;
-
-			// provided we don't wrap, deallocate and retry, in theexpanded
-			// entropic range
-			if (u < t && u >= entropic_base) {
-				mach_vm_deallocate(mach_task_self(), vm_addr, allocation_size);
-				OSAtomicCompareAndSwapLong(t, u,
-						(volatile long *)&entropic_address);  // Just one reduction please
-				goto retry;
-			}
-			// fall through to use what we got
-		}
-		
-		if (addr < entropic_address) { // we wrapped to find this allocation, expand the entropic range
-			uintptr_t t = entropic_address;
-			uintptr_t u = t - ENTROPIC_KABILLION;
-			if (u < t && u >= entropic_base) {
-				OSAtomicCompareAndSwapLong(t, u, (volatile long *)&entropic_address);  // Just one reduction please
-			}
-			// fall through to use what we got
-		}
-	}
-
-	if (add_postlude_guard_page || add_prelude_guard_page) {
-		if (add_prelude_guard_page && align > vm_page_quanta_shift) {
-			/* <rdar://problem/16601499> calculate the first address inside the alignment padding
-			 * where we can place the guard page and still be aligned.
-			 *
-			 * |-----------------------------------------------------------|
-			 * |leading|gp|                  alloc                  |gp| t |
-			 * |-----------------------------------------------------------|
-			 */
-			uintptr_t alignaddr = ((addr + large_vm_page_quanta_size) + (1 << align) - 1) & ~((1 << align) - 1);
-			size_t leading = alignaddr - addr - large_vm_page_quanta_size;
-			size_t trailing = (1 << align) - large_vm_page_quanta_size - leading;
-
-			/* Unmap the excess area. */
-			kr = mach_vm_deallocate(mach_task_self(), addr, leading);
-			if (kr) {
-				malloc_zone_error(debug_flags, false, "can't unmap excess guard region\n"
-						"*** mach_vm_deallocate(addr=%p, size=%lu) failed (code=%d)\n",
-						(void *)addr, leading, kr);
-				return NULL;
-			}
-
-			if (trailing) {
-				kr = mach_vm_deallocate(mach_task_self(), addr + allocation_size - trailing, trailing);
-				if (kr) {
-					malloc_zone_error(debug_flags, false, "can't unmap excess trailing guard region\n"
-							"*** mach_vm_deallocate(addr=%p, size=%lu) failed (code=%d)\n",
-							(void *)(addr + allocation_size - trailing), trailing, kr);
-					return NULL;
-				}
-			}
-
-			addr = alignaddr;
-		} else if (add_prelude_guard_page) {
-			addr += large_vm_page_quanta_size;
-		}
-		mvm_protect_plat((void *)addr, size, PROT_NONE, debug_flags, map_out);
-	}
-	return (void *)addr;
-#endif // MALLOC_TARGET_EXCLAVES
-}
-
-void
-mvm_deallocate_plat(void * __sized_by(size) addr, size_t size, int debug_flags, plat_map_t *map)
-{
-	kern_return_t kr;
-
-#if MALLOC_TARGET_EXCLAVES
-	kr = munmap_plat(map, addr, size) ? KERN_SUCCESS : errno;
-#else
-	(void)map;
-	kr = mach_vm_deallocate(mach_task_self(), (mach_vm_address_t)addr,
-			(mach_vm_size_t)size);
-#endif // MALLOC_TARGET_EXCLAVES
-
-	if (kr != KERN_SUCCESS) {
-		malloc_zone_error(debug_flags, false,
-			"Failed to deallocate at address %p of size 0x%lx: %d\n", addr, size, kr);
-	}
-}
-
-void
-mvm_deallocate_pages(void * __sized_by(size) addr, size_t size,
-		unsigned debug_flags)
-{
-	mvm_deallocate_pages_plat(addr, size, debug_flags, NULL);
-}
-
-void
-mvm_deallocate_pages_plat(void * __sized_by(size) addr, size_t size,
-		unsigned debug_flags, plat_map_t *map)
-{
-#if MALLOC_TARGET_EXCLAVES
-	if (debug_flags & (MALLOC_ADD_GUARD_PAGE_FLAGS | MALLOC_PURGEABLE)) {
-		malloc_zone_error(MALLOC_ABORT_ON_ERROR | debug_flags, true,
-			"Unsupported deallocation debug flags %u\n", debug_flags);
-	}
-	mvm_deallocate_plat(addr, size, debug_flags, map);
-#else
-	(void)map;
-	boolean_t added_prelude_guard_page = debug_flags & MALLOC_ADD_PRELUDE_GUARD_PAGE;
-	boolean_t added_postlude_guard_page = debug_flags & MALLOC_ADD_POSTLUDE_GUARD_PAGE;
-	mach_vm_address_t vm_addr = (mach_vm_address_t)addr;
-	mach_vm_size_t allocation_size = size;
-
-	if (added_prelude_guard_page) {
-		vm_addr -= large_vm_page_quanta_size;
-		allocation_size += large_vm_page_quanta_size;
-	}
-	if (added_postlude_guard_page) {
-		allocation_size += large_vm_page_quanta_size;
-	}
-	mvm_deallocate_plat(__unsafe_forge_bidi_indexable(void *, vm_addr,
-			allocation_size), (size_t)allocation_size, debug_flags, NULL);
-#endif // MALLOC_TARGET_EXCLAVES
-}
-
-void
-mvm_protect(void * __sized_by(size) address, size_t size, unsigned protection,
-		unsigned debug_flags)
-{
-	mvm_protect_plat(address, size, protection, debug_flags, NULL);
-}
-
-void
-mvm_protect_plat(void * __sized_by(size) address, size_t size, unsigned protection,
-		unsigned debug_flags, plat_map_t *map)
-{
-#if MALLOC_TARGET_EXCLAVES
-	const _liblibc_map_perm_t perm =
-		((protection & PROT_READ) ? LIBLIBC_MAP_PERM_READ : LIBLIBC_MAP_PERM_NONE) |
-		((protection & PROT_WRITE) ? LIBLIBC_MAP_PERM_WRITE : LIBLIBC_MAP_PERM_NONE) |
-		((protection & PROT_EXEC) ? LIBLIBC_MAP_PERM_EXECUTE : LIBLIBC_MAP_PERM_NONE);
-	if (debug_flags & (MALLOC_ADD_GUARD_PAGE_FLAGS | MALLOC_PURGEABLE)) {
-		malloc_zone_error(MALLOC_ABORT_ON_ERROR | debug_flags, true,
-			"Unsupported deallocation debug flags %u\n", debug_flags);
-	}
-	if (!mprotect_plat(map, address, size, perm)) {
-		malloc_zone_error(MALLOC_ABORT_ON_ERROR | debug_flags, true,
-			"Unsupported deallocation address %p or size %lu: %d\n", address, size, errno);
-	}
-#else
-	(void)map;
-	kern_return_t err;
-
-	if ((debug_flags & MALLOC_ADD_PRELUDE_GUARD_PAGE) && !(debug_flags & MALLOC_DONT_PROTECT_PRELUDE)) {
-		err = mprotect((void *)((uintptr_t)address - large_vm_page_quanta_size), large_vm_page_quanta_size, protection);
-		if (err) {
-			malloc_report(ASL_LEVEL_ERR, "*** can't mvm_protect(%u) region for prelude guard page at %p\n", protection,
-					(void *)((uintptr_t)address - large_vm_page_quanta_size));
-		}
-	}
-	if ((debug_flags & MALLOC_ADD_POSTLUDE_GUARD_PAGE) && !(debug_flags & MALLOC_DONT_PROTECT_POSTLUDE)) {
-		err = mprotect((void *)(round_page_quanta(((uintptr_t)address + size))), large_vm_page_quanta_size, protection);
-		if (err) {
-			malloc_report(ASL_LEVEL_ERR, "*** can't mvm_protect(%u) region for postlude guard page at %p\n", protection,
-					(void *)((uintptr_t)address + size));
-		}
-	}
-#endif // MALLOC_TARGET_EXCLAVES
-}
-
-int
-mvm_madvise(void * __sized_by(sz) addr, size_t sz, int advice, unsigned debug_flags)
-{
-	return mvm_madvise_plat(addr, sz, advice, debug_flags, NULL);
-}
-
-int
-mvm_madvise_plat(void * __sized_by(sz) addr, size_t sz, int advice, unsigned debug_flags, plat_map_t *map)
-{
-	kern_return_t kr;
-
-#if MALLOC_TARGET_EXCLAVES
-	if ((debug_flags & (MALLOC_ADD_GUARD_PAGE_FLAGS | MALLOC_PURGEABLE))) {
-		malloc_zone_error(MALLOC_ABORT_ON_ERROR | debug_flags, true,
-			"Unsupported debug flags %u\n", debug_flags);
-	}
-
-	kr = !madvise_plat(map, addr, sz, advice) ? KERN_SUCCESS : errno;
-	if (kr != KERN_SUCCESS) {
-		malloc_zone_error(debug_flags, false,
-			"Failed to madvise %d at address %p of size 0x%lx: %d\n", advice,
-			addr, sz, kr);
-	}
-#else
-	(void)map;
-	kr = !madvise(addr, sz, advice) ? KERN_SUCCESS : errno;
-#endif // MALLOC_TARGET_EXCLAVES
-
-	return !(kr == KERN_SUCCESS);
-}
-
-int
-mvm_madvise_free(void *rack, void *r, uintptr_t pgLo, uintptr_t pgHi, uintptr_t *last, boolean_t scribble)
-{
-	return mvm_madvise_free_plat(rack, r, pgLo, pgHi, last, scribble, NULL);
-}
-
-int
-mvm_madvise_free_plat(void *rack, void *r, uintptr_t pgLo, uintptr_t pgHi, uintptr_t *last, boolean_t scribble, plat_map_t *map)
-{
-	if (pgHi > pgLo) {
-		size_t len = pgHi - pgLo;
-		void *ptr = __unsafe_forge_bidi_indexable(void *, pgLo, len);
-
-		if (scribble && malloc_zero_policy != MALLOC_ZERO_ON_FREE) {
-			memset(ptr, SCRUBBLE_BYTE, len); // Scribble on MADV_FREEd memory
-		}
-
-#if MALLOC_TARGET_IOS
-		if (last) {
-			if (*last == pgLo) {
-				return 0;
-			}
-
-			*last = pgLo;
-		}
-#endif // MALLOC_TARGET_IOS
-
-#if MALLOC_TARGET_EXCLAVES
-		if (mvm_madvise_plat(ptr, len, CONFIG_MADVISE_STYLE, 0, map)) {
-			return 1;
-		}
-#else
-		MAGMALLOC_MADVFREEREGION(rack, r, (void *)pgLo, (int)len); // DTrace USDT Probe
-		if (mvm_madvise(ptr, len, CONFIG_MADVISE_STYLE, 0)) {
-			/* -1 return: VM map entry change makes this unfit for reuse. Something evil lurks. */
-#if DEBUG_MADVISE
-			malloc_zone_error(NULL, false,
-					"madvise_free_range madvise(..., MADV_FREE_REUSABLE) failed for %p, length=%d\n",
-					(void *)pgLo, len);
-#endif // DEBUG_MADVISE
-			return 1;
-		} else {
-			MALLOC_TRACE(TRACE_madvise, (uintptr_t)r, (uintptr_t)pgLo, len, CONFIG_MADVISE_STYLE);
-		}
-#endif // MALLOC_TARGET_EXCLAVES
-	}
-	return 0;
-}
-
-#if CONFIG_MAGAZINE_DEFERRED_RECLAIM
-static mach_vm_reclaim_ring_t reclaim_buffer;
-static _malloc_lock_s reclaim_buffer_lock = _MALLOC_LOCK_INIT;
-
-mach_vm_reclaim_error_t
-mvm_deferred_reclaim_init(void)
-{
-	// Pick a sane minimum number of entries and let vm_reclaim round up
-	// to a page boundary. The intention is for the initial size to be
-	// one page. We don't support ringbuffer growth on the legacy DRC, so
-	// the maximum size will be unmodified.
-	mach_vm_reclaim_count_t capacity = mach_vm_reclaim_round_capacity(512);
-	return mach_vm_reclaim_ring_allocate(&reclaim_buffer, capacity, capacity);
-}
-
-
-bool
-mvm_reclaim_mark_used(mach_vm_reclaim_id_t id, mach_vm_address_t ptr, mach_vm_size_t size, unsigned int debug_flags)
-{
-	mach_vm_reclaim_error_t kr;
-	mach_vm_reclaim_state_t state;
-	bool update_accounting;
-
-	if (id == VM_RECLAIM_ID_NULL) {
-		// Region was never entered into ring
-		// FIXME: Understand why the all cache entries aren't being
-		// assigned reclaim IDs (rdar://137709029)
-		return true;
-	}
-
-	if (debug_flags & MALLOC_ADD_GUARD_PAGE_FLAGS) {
-		if (os_add_overflow(size, 2 * large_vm_page_quanta_size, &size)) {
-			return false;
-		}
-		ptr -= large_vm_page_quanta_size;
-	}
-	_malloc_lock_lock(&reclaim_buffer_lock);
-	kr = mach_vm_reclaim_try_cancel(reclaim_buffer, id, ptr, size,
-			VM_RECLAIM_DEALLOCATE, &state, &update_accounting);
-	MALLOC_ASSERT(kr == VM_RECLAIM_SUCCESS);
-	_malloc_lock_unlock(&reclaim_buffer_lock);
-	if (update_accounting) {
-		mach_vm_reclaim_update_kernel_accounting(reclaim_buffer);
-	}
-	return mach_vm_reclaim_is_reusable(state);
-}
-
-mach_vm_reclaim_id_t
-mvm_reclaim_mark_free(mach_vm_address_t ptr, mach_vm_size_t size, unsigned int debug_flags)
-{
-	mach_vm_reclaim_error_t kr;
-	mach_vm_reclaim_id_t id;
-	bool should_update_kernel_accounting = false;
-	if (debug_flags & MALLOC_ADD_GUARD_PAGE_FLAGS) {
-		if (os_add_overflow(size, 2 * large_vm_page_quanta_size, &size)) {
-			return VM_RECLAIM_ID_NULL;
-		}
-		ptr -= large_vm_page_quanta_size;
-	}
-
-	_malloc_lock_lock(&reclaim_buffer_lock);
-
-	do {
-		id = VM_RECLAIM_ID_NULL;
-		kr = mach_vm_reclaim_try_enter(reclaim_buffer, ptr, size,
-				VM_RECLAIM_DEALLOCATE, &id, &should_update_kernel_accounting);
-		MALLOC_ASSERT(kr == VM_RECLAIM_SUCCESS);
-		if (id == VM_RECLAIM_ID_NULL) {
-			mach_vm_reclaim_count_t capacity;
-			kr = mach_vm_reclaim_ring_capacity(reclaim_buffer, &capacity);
-			MALLOC_ASSERT(kr == VM_RECLAIM_SUCCESS);
-			kr = mach_vm_reclaim_ring_flush(reclaim_buffer, capacity);
-			MALLOC_ASSERT(kr == VM_RECLAIM_SUCCESS);
-		}
-	} while (id == VM_RECLAIM_ID_NULL);
-
-	_malloc_lock_unlock(&reclaim_buffer_lock);
-
-	if (should_update_kernel_accounting) {
-		mach_vm_reclaim_update_kernel_accounting(reclaim_buffer);
-	}
-	return id;
-}
-
-bool
-mvm_reclaim_is_available(mach_vm_reclaim_id_t id)
-{
-	mach_vm_reclaim_error_t err;
-	mach_vm_reclaim_state_t state;
-
-	if (id == VM_RECLAIM_ID_NULL) {
-		// Region was never entered into ring
-		// FIXME: Understand why the all cache entries aren't being
-		// assigned reclaim IDs (rdar://137709029)
-		return true;
-	}
-
-	err = mach_vm_reclaim_query_state(reclaim_buffer, id, VM_RECLAIM_DEALLOCATE, &state);
-	MALLOC_ASSERT(err == VM_RECLAIM_SUCCESS);
-	return mach_vm_reclaim_is_reusable(state);
-}
-#endif // CONFIG_MAGAZINE_DEFERRED_RECLAIM