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--- libmalloc/libmalloc-283.60.1/src/vm.c
+++ /dev/null
@@ -1,295 +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"
-
-static volatile uintptr_t entropic_address = 0;
-static volatile uintptr_t entropic_limit = 0;
-
-MALLOC_NOEXPORT
-uint64_t malloc_entropy[2] = {0, 0};
-
-#define ENTROPIC_KABILLION 0x10000000 /* 256Mb */
-
-// <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 __i386__ || __x86_64__ || __arm64__ || (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR)
-#if __i386__
- uintptr_t stackbase = 0x8fe00000;
- int entropic_bits = 3;
-#elif __x86_64__
- uintptr_t stackbase = USRSTACK64;
- int entropic_bits = 16;
-#elif __arm64__
-#if __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);
- 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 *
-mvm_allocate_pages(size_t size, unsigned char align, unsigned debug_flags, int vm_page_label)
-{
- boolean_t add_guard_pages = debug_flags & MALLOC_ADD_GUARD_PAGES;
- boolean_t purgeable = debug_flags & MALLOC_PURGEABLE;
- 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_guard_pages) {
- if (align > vm_page_quanta_shift) {
- /* <rdar://problem/16601499> alignment greater than pagesize needs more work */
- allocation_size += (1 << align) + vm_page_quanta_size;
- } else {
- allocation_size += 2 * vm_page_quanta_size;
- }
- }
-
- if (purgeable) {
- alloc_flags |= VM_FLAGS_PURGABLE;
- }
- if (allocation_size < size) { // size_t arithmetic wrapped!
- return NULL;
- }
-
- 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) {
- malloc_zone_error(debug_flags, false, "can't allocate region\n*** mach_vm_map(size=%lu) failed (error code=%d)\n", size, kr);
- return NULL;
- }
- addr = (uintptr_t)vm_addr;
-
- if (add_guard_pages) {
- if (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 + vm_page_quanta_size) + (1 << align) - 1) & ~((1 << align) - 1);
- size_t leading = alignaddr - addr - vm_page_quanta_size;
- size_t trailing = (1 << align) - 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;
- }
-
- 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 {
- addr += vm_page_quanta_size;
- }
- mvm_protect((void *)addr, size, PROT_NONE, debug_flags);
- }
- return (void *)addr;
-}
-
-void *
-mvm_allocate_pages_securely(size_t size, unsigned char align, int vm_page_label, uint32_t debug_flags)
-{
- 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 (debug_flags & DISABLE_ASLR) {
- return mvm_allocate_pages(size, align, 0, vm_page_label);
- }
-
- if (!allocation_size) {
- allocation_size = vm_page_quanta_size;
- }
- if (allocation_size < size) { // size_t arithmetic wrapped!
- return NULL;
- }
-
-retry:
- vm_addr = entropic_address;
- 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) {
- 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) {
- malloc_zone_error(debug_flags, false, "can't allocate region securely\n",
- "*** mach_vm_map(size=%lu) failed (error code=%d)\n", size, kr);
- return NULL;
- }
- addr = (uintptr_t)vm_addr;
-
- // 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;
-
- if (u < t) { // provided we don't wrap, deallocate and retry, in the expanded entropic range
- 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) {
- OSAtomicCompareAndSwapLong(t, u, (volatile long *)&entropic_address); // Just one reduction please
- }
- // fall through to use what we got
- }
- return (void *)addr;
-}
-
-void
-mvm_deallocate_pages(void *addr, size_t size, unsigned debug_flags)
-{
- boolean_t add_guard_pages = debug_flags & MALLOC_ADD_GUARD_PAGES;
- mach_vm_address_t vm_addr = (mach_vm_address_t)addr;
- mach_vm_size_t allocation_size = size;
- kern_return_t kr;
-
- if (add_guard_pages) {
- vm_addr -= vm_page_quanta_size;
- allocation_size += 2 * vm_page_quanta_size;
- }
- kr = mach_vm_deallocate(mach_task_self(), vm_addr, allocation_size);
- if (kr) {
- malloc_zone_error(debug_flags, false, "Can't deallocate_pages region at %p\n", addr);
- }
-}
-
-void
-mvm_protect(void *address, size_t size, unsigned protection, unsigned debug_flags)
-{
- kern_return_t err;
-
- if (!(debug_flags & MALLOC_DONT_PROTECT_PRELUDE)) {
- err = mprotect((void *)((uintptr_t)address - vm_page_quanta_size), 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 - vm_page_quanta_size));
- }
- }
- if (!(debug_flags & MALLOC_DONT_PROTECT_POSTLUDE)) {
- err = mprotect((void *)(round_page_quanta(((uintptr_t)address + size))), 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));
- }
- }
-}
-
-int
-mvm_madvise_free(void *rack, void *r, uintptr_t pgLo, uintptr_t pgHi, uintptr_t *last, boolean_t scribble)
-{
- if (pgHi > pgLo) {
- size_t len = pgHi - pgLo;
-
- if (scribble) {
- memset((void *)pgLo, SCRUBBLE_BYTE, len); // Scribble on MADV_FREEd memory
- }
-
-#if TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
- if (last) {
- if (*last == pgLo) {
- return 0;
- }
-
- *last = pgLo;
- }
-#endif // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
-
- MAGMALLOC_MADVFREEREGION(rack, r, (void *)pgLo, (int)len); // DTrace USDT Probe
- if (-1 == madvise((void *)pgLo, len, CONFIG_MADVISE_STYLE)) {
- /* -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
- return 1;
- } else {
- MALLOC_TRACE(TRACE_madvise, (uintptr_t)r, (uintptr_t)pgLo, len, CONFIG_MADVISE_STYLE);
- }
- }
- return 0;
-}