--- libmalloc/libmalloc-67.40.1/src/stack_logging_disk.c
+++ /dev/null
@@ -1,1981 +0,0 @@
-/*
- * Copyright (c) 2007-2013 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 <_simple.h>            // as included by malloc.c, this defines ASL_LEVEL_INFO
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <limits.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <dirent.h>
-#include <libkern/OSAtomic.h>
-#include <mach/mach.h>
-#include <mach/mach_vm.h>
-#include <os/tsd.h>
-#include <sys/sysctl.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
-#include <paths.h>
-#include <errno.h>
-#include <assert.h>
-#include <TargetConditionals.h>		// for TARGET_OS_EMBEDDED, TARGET_IPHONE_SIMULATOR
-#include "stack_logging.h"
-#include "malloc_printf.h"
-#include "malloc_internal.h"
-
-#pragma mark -
-#pragma mark Defines
-
-#if TARGET_OS_EMBEDDED || TARGET_IPHONE_SIMULATOR
-// _malloc_printf(ASL_LEVEL_INFO...) on iOS doesn't show up in the Xcode Console log of the device,
-// but ASL_LEVEL_NOTICE does.  So raising the log level is helpful.
-#undef ASL_LEVEL_INFO
-#define ASL_LEVEL_INFO ASL_LEVEL_NOTICE
-#endif
-
-#ifdef TEST_DISK_STACK_LOGGING
-#define _malloc_printf fprintf
-#undef ASL_LEVEL_INFO
-#define ASL_LEVEL_INFO stderr
-#endif
-
-#define STACK_LOGGING_MAX_STACK_SIZE 512
-#define STACK_LOGGING_BLOCK_WRITING_SIZE 8192
-#define STACK_LOGGING_MAX_SIMUL_REMOTE_TASKS_INSPECTED 3
-
-#define BACKTRACE_UNIQUING_DEBUG 0
-
-// The expansion factor controls the shifting up of table size. A factor of 1 will double the size upon expanding,
-// 2 will quadruple the size, etc. Maintaining a 66% fill in an ideal table requires the collision allowance to
-// increase by 3 for every quadrupling of the table size (although this the constant applied to insertion
-// performance O(c*n))
-#define EXPAND_FACTOR 2
-#define COLLISION_GROWTH_RATE 3
-
-// For a uniquing table, the useful node size is slots := floor(table_byte_size / (2 * sizeof(mach_vm_address_t)))
-// Some useful numbers for the initial max collision value (desiring 66% fill):
-// 16K-23K slots -> 16 collisions
-// 24K-31K slots -> 17 collisions
-// 32K-47K slots -> 18 collisions
-// 48K-79K slots -> 19 collisions
-// 80K-96K slots -> 20 collisions
-#define INITIAL_MAX_COLLIDE	19
-#define DEFAULT_UNIQUING_PAGE_SIZE 256
-
-#pragma mark -
-#pragma mark Macros
-
-#define STACK_LOGGING_FLAGS_SHIFT 56
-#define STACK_LOGGING_USER_TAG_SHIFT 24
-#define STACK_LOGGING_FLAGS(longlongvar) (uint32_t)((uint64_t)(longlongvar) >> STACK_LOGGING_FLAGS_SHIFT)
-#define STACK_LOGGING_FLAGS_AND_USER_TAG(longlongvar) (uint32_t)(STACK_LOGGING_FLAGS(longlongvar) | (((uint64_t)(longlongvar) & 0x00FF000000000000ull) >> STACK_LOGGING_USER_TAG_SHIFT) )
-
-#define STACK_LOGGING_OFFSET_MASK 0x0000FFFFFFFFFFFFull
-#define STACK_LOGGING_OFFSET(longlongvar) ((longlongvar) & STACK_LOGGING_OFFSET_MASK)
-
-#define STACK_LOGGING_OFFSET_AND_FLAGS(longlongvar, type_flags) ( ((uint64_t)(longlongvar) & STACK_LOGGING_OFFSET_MASK) | ((uint64_t)(type_flags) << STACK_LOGGING_FLAGS_SHIFT) | (((uint64_t)(type_flags) & 0xFF000000ull) << STACK_LOGGING_USER_TAG_SHIFT) )
-
-#pragma mark -
-#pragma mark Types
-
-typedef struct {
-	uintptr_t	argument;
-	uintptr_t	address;
-	uint64_t	offset_and_flags; // top 8 bits are actually the flags!
-} stack_logging_index_event;
-
-typedef struct {
-	uint32_t	argument;
-	uint32_t	address;
-	uint64_t	offset_and_flags; // top 8 bits are actually the flags!
-} stack_logging_index_event32;
-
-typedef struct {
-	uint64_t	argument;
-	uint64_t	address;
-	uint64_t	offset_and_flags; // top 8 bits are actually the flags!
-} stack_logging_index_event64;
-
-// backtrace uniquing table chunks used in client-side stack log reading code,
-// in case we can't read the whole table in one mach_vm_read() call.
-typedef struct table_chunk_header {
-	uint64_t							num_nodes_in_chunk;
-	uint64_t							table_chunk_size;
-	mach_vm_address_t					*table_chunk;
-	struct table_chunk_header			*next_table_chunk_header;
-} table_chunk_header_t;
-
-#pragma pack(push,4)
-typedef struct {
-	uint64_t							numPages; // number of pages of the table
-	uint64_t							numNodes;
-	uint64_t							tableSize;
-	uint64_t							untouchableNodes;
-	mach_vm_address_t					table_address;
-	int32_t								max_collide;
-	// 'table_address' is just an always 64-bit version of the pointer-sized 'table' field to remotely read;
-	// it's important that the offset of 'table_address' in the struct does not change between 32 and 64-bit.
-#if BACKTRACE_UNIQUING_DEBUG
-	uint64_t nodesFull;
-	uint64_t backtracesContained;
-#endif
-	union {
-		mach_vm_address_t				*table;		// in "target" process;  allocated using vm_allocate()
-		table_chunk_header_t			*first_table_chunk_hdr;		// in analysis process
-	} u;
-} backtrace_uniquing_table;
-#pragma pack(pop)
-
-// for storing/looking up allocations that haven't yet be written to disk; consistent size across 32/64-bit processes.
-// It's important that these fields don't change alignment due to the architecture because they may be accessed from an
-// analyzing process with a different arch - hence the pragmas.
-#pragma pack(push,4)
-typedef struct {
-	uint64_t			start_index_offset;
-	uint32_t			next_free_index_buffer_offset;
-	char				index_buffer[STACK_LOGGING_BLOCK_WRITING_SIZE];
-	backtrace_uniquing_table	*uniquing_table;
-} stack_buffer_shared_memory;
-#pragma pack(pop)
-
-// target process address -> record table (for __mach_stack_logging_get_frames)
-typedef struct {
-	uint64_t		address;
-	uint64_t		index_file_offset;
-} remote_index_node;
-
-// for caching index information client-side:
-typedef struct {
-	size_t			cache_size;
-	size_t			cache_node_capacity;
-	uint32_t		collision_allowance;
-	remote_index_node	*table_memory; // this can be malloced; it's on the client side.
-	stack_buffer_shared_memory *shmem; // shared memory
-	stack_buffer_shared_memory snapshot; // memory snapshot of the remote process' shared memory
-	uint32_t		last_pre_written_index_size;
-	uint64_t		last_index_file_offset;
-	backtrace_uniquing_table uniquing_table_snapshot; // snapshot of the remote process' uniquing table
-} remote_index_cache;
-
-// for reading stack history information from remote processes:
-typedef struct {
-	task_t			remote_task;
-	pid_t			remote_pid;
-	int32_t			task_is_64_bit;
-	int32_t			in_use_count;
-	FILE			*index_file_stream;
-	uint64_t		remote_stack_buffer_shared_memory_address;
-	remote_index_cache	*cache;
-} remote_task_file_streams;
-
-#pragma mark -
-#pragma mark Constants/Globals
-
-static _malloc_lock_s stack_logging_lock = _MALLOC_LOCK_INIT;
-
-// support for multi-threaded forks
-extern void __stack_logging_fork_prepare();
-extern void __stack_logging_fork_parent();
-extern void __stack_logging_fork_child();
-extern void __stack_logging_early_finished();
-
-// support for gdb and others checking for stack_logging locks
-extern boolean_t __stack_logging_locked();
-
-// single-thread access variables
-static stack_buffer_shared_memory *pre_write_buffers;
-static vm_address_t *stack_buffer;
-static uintptr_t last_logged_malloc_address = 0;
-
-// Constants to define part of stack logging file path names.
-// File names are of the form stack-logs.<pid>.<address>.<progname>.XXXXXX.index
-// where <address> is the address of the pre_write_buffers VM region in the target
-// process that will need to be mapped into analysis tool processes. 
-static const char *stack_log_file_base_name = "stack-logs.";
-static const char *stack_log_file_suffix = ".index";
-
-char *__stack_log_file_path__ = NULL;
-static int index_file_descriptor = -1;
-
-// for accessing remote log files
-static remote_task_file_streams remote_fds[STACK_LOGGING_MAX_SIMUL_REMOTE_TASKS_INSPECTED];
-static uint32_t next_remote_task_fd = 0;
-static uint32_t remote_task_fd_count = 0;
-static _malloc_lock_s remote_fd_list_lock = _MALLOC_LOCK_INIT;
-
-// activation variables
-static int logging_use_compaction = 1; // set this to zero to always disable compaction.
-
-// We set malloc_logger to NULL to disable logging, if we encounter errors
-// during file writing
-typedef void (malloc_logger_t)(uint32_t type, uintptr_t arg1, uintptr_t arg2, uintptr_t arg3, uintptr_t result, uint32_t num_hot_frames_to_skip);
-extern malloc_logger_t *malloc_logger;
-
-extern malloc_logger_t *__syscall_logger;	// use this to set up syscall logging (e.g., vm_allocate, vm_deallocate, mmap, munmap)
-
-#pragma mark -
-#pragma mark In-Memory Backtrace Uniquing
-
-static __attribute__((always_inline))
-inline void*
-allocate_pages(uint64_t memSize)
-{
-	mach_vm_address_t allocatedMem = 0ull;
-	if (mach_vm_allocate(mach_task_self(), &allocatedMem, memSize, VM_FLAGS_ANYWHERE | VM_MAKE_TAG(VM_MEMORY_ANALYSIS_TOOL)) != KERN_SUCCESS) {
-		malloc_printf("allocate_pages(): virtual memory exhausted!\n");
-	}
-	return (void*)(uintptr_t)allocatedMem;
-}
-
-static __attribute__((always_inline))
-inline int
-deallocate_pages(void* memPointer, uint64_t memSize)
-{
-	return mach_vm_deallocate(mach_task_self(), (mach_vm_address_t)(uintptr_t)memPointer, memSize);
-}
-
-static backtrace_uniquing_table*
-__create_uniquing_table(void)
-{
-	backtrace_uniquing_table *uniquing_table = (backtrace_uniquing_table*)allocate_pages((uint64_t)round_page(sizeof(backtrace_uniquing_table)));
-	if (!uniquing_table) return NULL;
-	bzero(uniquing_table, sizeof(backtrace_uniquing_table));
-	uniquing_table->numPages = DEFAULT_UNIQUING_PAGE_SIZE;
-	uniquing_table->tableSize = uniquing_table->numPages * vm_page_size;
-	uniquing_table->numNodes = ((uniquing_table->tableSize / (sizeof(mach_vm_address_t) * 2)) >> 1) << 1; // make sure it's even.
-	uniquing_table->u.table = (mach_vm_address_t*)(uintptr_t)allocate_pages(uniquing_table->tableSize);
-	uniquing_table->table_address = (uintptr_t)uniquing_table->u.table;
-	uniquing_table->max_collide = INITIAL_MAX_COLLIDE;
-	uniquing_table->untouchableNodes = 0;
-
-#if BACKTRACE_UNIQUING_DEBUG
-	malloc_printf("create_uniquing_table(): creating. size: %lldKB == %lldMB, numnodes: %lld (%lld untouchable)\n", uniquing_table->tableSize >> 10, uniquing_table->tableSize >> 20, uniquing_table->numNodes, uniquing_table->untouchableNodes);
-	malloc_printf("create_uniquing_table(): table: %p; end: %p\n", uniquing_table->table, (void*)((uintptr_t)uniquing_table->table + (uintptr_t)uniquing_table->tableSize));
-#endif
-	return uniquing_table;
-}
-
-static void
-__destroy_uniquing_table(backtrace_uniquing_table* table)
-{
-	deallocate_pages(table->u.table, table->tableSize);
-	deallocate_pages(table, sizeof(backtrace_uniquing_table));
-}
-
-static void
-__expand_uniquing_table(backtrace_uniquing_table *uniquing_table)
-{
-	mach_vm_address_t *oldTable = uniquing_table->u.table;
-	uint64_t oldsize = uniquing_table->tableSize;
-	uint64_t oldnumnodes = uniquing_table->numNodes;
-
-	uniquing_table->numPages = uniquing_table->numPages << EXPAND_FACTOR;
-	uniquing_table->tableSize = uniquing_table->numPages * vm_page_size;
-	uniquing_table->numNodes = ((uniquing_table->tableSize / (sizeof(mach_vm_address_t) * 2)) >> 1) << 1; // make sure it's even.
-	mach_vm_address_t *newTable = (mach_vm_address_t*)(uintptr_t)allocate_pages(uniquing_table->tableSize);
-
-	uniquing_table->u.table = newTable;
-	uniquing_table->table_address = (uintptr_t)uniquing_table->u.table;
-	uniquing_table->max_collide = uniquing_table->max_collide + COLLISION_GROWTH_RATE;
-
-	if (mach_vm_copy(mach_task_self(), (mach_vm_address_t)(uintptr_t)oldTable, oldsize, (mach_vm_address_t)(uintptr_t)newTable) != KERN_SUCCESS) {
-		malloc_printf("expandUniquingTable(): VMCopyFailed\n");
-	}
-	uniquing_table->untouchableNodes = oldnumnodes;
-
-#if BACKTRACE_UNIQUING_DEBUG
-	malloc_printf("expandUniquingTable(): expanded from nodes full: %lld of: %lld (~%2d%%); to nodes: %lld (inactive = %lld); unique bts: %lld\n",
-				  uniquing_table->nodesFull, oldnumnodes, (int)(((uniquing_table->nodesFull * 100.0) / (double)oldnumnodes) + 0.5),
-				  uniquing_table->numNodes, uniquing_table->untouchableNodes, uniquing_table->backtracesContained);
-	malloc_printf("expandUniquingTable(): allocate: %p; end: %p\n", newTable, (void*)((uintptr_t)newTable + (uintptr_t)(uniquing_table->tableSize)));
-	malloc_printf("expandUniquingTable(): deallocate: %p; end: %p\n", oldTable, (void*)((uintptr_t)oldTable + (uintptr_t)oldsize));
-#endif
-
-	if (deallocate_pages(oldTable, oldsize) != KERN_SUCCESS) {
-		malloc_printf("expandUniquingTable(): mach_vm_deallocate failed. [%p]\n", uniquing_table->u.table);
-	}
-}
-
-static int
-__enter_frames_in_table(backtrace_uniquing_table *uniquing_table, uint64_t *foundIndex, mach_vm_address_t *frames, int32_t count)
-{
-	// The hash values need to be the same size as the addresses (because we use the value -1), for clarity, define a new type
-	typedef mach_vm_address_t hash_index_t;
-
-	mach_vm_address_t thisPC;
-	hash_index_t hash, uParent = (hash_index_t)(-1ll), modulus = (uniquing_table->numNodes-uniquing_table->untouchableNodes-1);
-	int32_t collisions, lcopy = count, returnVal = 1;
-	hash_index_t hash_multiplier = ((uniquing_table->numNodes - uniquing_table->untouchableNodes)/(uniquing_table->max_collide*2+1));
-	mach_vm_address_t *node;
-	while (--lcopy >= 0) {
-		thisPC = frames[lcopy];
-
-		// hash = initialHash(uniquing_table, uParent, thisPC);
-		hash = uniquing_table->untouchableNodes + (((uParent << 4) ^ (thisPC >> 2)) % modulus);
-		collisions = uniquing_table->max_collide;
-
-		while (collisions--) {
-			node = uniquing_table->u.table + (hash * 2);
-
-			if (*node == 0 && node[1] == 0) {
-				// blank; store this entry!
-				// Note that we need to test for both head[0] and head[1] as (0, -1) is a valid entry
-				node[0] = thisPC;
-				node[1] = uParent;
-				uParent = hash;
-#if BACKTRACE_UNIQUING_DEBUG
-				uniquing_table->nodesFull++;
-				if (lcopy == 0) {
-					uniquing_table->backtracesContained++;
-				}
-#endif
-				break;
-			}
-			if (*node == thisPC && node[1] == uParent) {
-				// hit! retrieve index and go.
-				uParent = hash;
-				break;
-			}
-
-			hash += collisions * hash_multiplier + 1;
-
-			if (hash >= uniquing_table->numNodes) {
-				hash -= (uniquing_table->numNodes - uniquing_table->untouchableNodes); // wrap around.
-			}
-		}
-
-		if (collisions < 0) {
-			returnVal = 0;
-			break;
-		}
-	}
-
-	if (returnVal) *foundIndex = uParent;
-
-	return returnVal;
-}
-
-#pragma mark -
-#pragma mark Disk Stack Logging
-
-// pre-declarations
-static void delete_log_files(void);
-static int delete_logging_file(char *log_location);
-static bool getenv_from_process(pid_t pid, char *env_var_name, char *env_var_value_buf, size_t max_path_len);
-
-#define BASE10 10
-#define BASE16 16
-
-static void
-append_int(char * filename, uint64_t inputValue, unsigned base, size_t maxLength)
-{
-	const char *digits = "0123456789abcdef";
-	if (base > strlen(digits)) return;		// sanity check
-	
-	size_t len = strlen(filename);
-
-	uint32_t count = 0;
-	uint64_t value = inputValue;
-	while (value > 0) {
-		value /= base;
-		count++;
-	}
-
-	if (len + count >= maxLength) return; // don't modify the string if it would violate maxLength
-
-	filename[len + count] = '\0';
-
-	value = inputValue;
-	uint32_t i;
-	for (i = 0 ; i < count ; i ++) {
-		filename[len + count - 1 - i] = digits[value % base];
-		value /= base;
-	}
-}
-
-/*
- * <rdar://problem/11128080> if we needed to call confstr during init then setting this
- * flag will postpone stack logging until after Libsystem's initialiser has run.
- */
-static void
-postpone_stack_logging(void)
-{
-	_malloc_printf(ASL_LEVEL_INFO, "stack logging postponed until after initialization.\n");
-	stack_logging_postponed = 1;
-}
-
-/*
- * Check various logging directory options, in order of preference:
- *
- *      value of MallocStackLoggingDirectory env var if user has set it.  Typically
- *			used on Mac OS X to write to a non-root file system with more free space.
- *
- *      _PATH_TMP - /tmp usually writable for desktop apps and internal iOS apps
- *
- *      value of TMPDIR env var - for sandboxed apps that can't write into /tmp
- *
- *      confstr(_CS_DARWIN_USER_TEMP_DIR, ...) - should be same as TMPDIR if that is set,
- *          but will create it safely if it doesn't yet exist.  (See <rdar://problem/4706096>)
- *
- * Allocating and releasing target buffer is the caller's responsibility.
- */
-static bool
-get_writeable_logging_directory(char* target)
-{
-	if (!target) return false;
-
-	char *evn_log_directory = getenv("MallocStackLoggingDirectory");
-	if (evn_log_directory) {
-		if (-1 != access(evn_log_directory, W_OK)) {
-			strlcpy(target, evn_log_directory, (size_t)PATH_MAX);
-			return true;
-		} else {
-			_malloc_printf(ASL_LEVEL_INFO, "MallocStackLoggingDirectory env var set to unwritable path '%s'\n", evn_log_directory);
-		}
-	}
-
-	if (-1 != access(_PATH_TMP, W_OK)) {
-		strlcpy(target, _PATH_TMP, (size_t)PATH_MAX);
-		return true;
-	}
-
-	evn_log_directory = getenv("TMPDIR");
-	if (evn_log_directory && (-1 != access(evn_log_directory, W_OK))) {
-		strlcpy(target, evn_log_directory, (size_t)PATH_MAX);
-		return true;
-	}
-
-	if (stack_logging_finished_init) {
-		size_t n = confstr(_CS_DARWIN_USER_TEMP_DIR, target, (size_t) PATH_MAX);
-		if ((n > 0) && (n < PATH_MAX)) return true;
-	} else {
-		/* <rdar://problem/11128080> Can't call confstr during init, so postpone
-		 logging till after */
-		postpone_stack_logging();
-	}
-	*target = '\0';
-	return false;
-}
-
-// If successful, returns path to log file that was created, otherwise NULL.
-static char *
-create_log_file(void)
-{
-	pid_t pid = getpid();
-	const char *progname = getprogname();
-	char *created_log_location = NULL;
-
-	if (__stack_log_file_path__ == NULL) {
-		// On first use, allocate space directly from the OS without using malloc
-		__stack_log_file_path__ = allocate_pages((uint64_t)round_page(PATH_MAX));
-		if (__stack_log_file_path__ == NULL) {
-			_malloc_printf(ASL_LEVEL_INFO, "unable to allocate memory for stack log file path\n");
-			return NULL;
-		}
-	}
-
-	if (!get_writeable_logging_directory(__stack_log_file_path__)) {
-		if (!stack_logging_postponed) {
-			_malloc_printf(ASL_LEVEL_INFO, "No writeable tmp dir\n");
-		}
-		return NULL;
-	}
-
-	// Add the '/' only if it's not already there.  Having multiple '/' characters works
-	// but is unsightly when we print these stack log file names out.
-	size_t stack_log_len = strlen(__stack_log_file_path__);
-	if (__stack_log_file_path__[stack_log_len-1] != '/') {
-		// use strlcat to null-terminate for the next strlcat call, and to check buffer size
-		strlcat(__stack_log_file_path__ + stack_log_len, "/", (size_t)PATH_MAX);
-	}
-	
-	// Append the file name to __stack_log_file_path__ but don't use snprintf since
-	// it can cause malloc() calls.
-	//
-	// The file name is of the form "stack-logs.<pid>.<address>.<progname>.XXXXXX.index"
-	// where <address> is the address of the pre_write_buffers VM region in the target
-	// process that will need to be mapped into analysis tool processes. We used to just
-	// use a shared memory segment for that, but sandbox'ed target apps may not be able
-	// to create shared memory segments so including the address of the VM region in the
-	// file name is a simple way to communicate the address to analysis tools so the
-	// stack log reading code can map in the region with mach_vm_remap().
-	
-	strlcat(__stack_log_file_path__, stack_log_file_base_name, (size_t)PATH_MAX);
-	append_int(__stack_log_file_path__, pid, BASE10, (size_t)PATH_MAX);
-	strlcat(__stack_log_file_path__, ".", (size_t)PATH_MAX);
-	append_int(__stack_log_file_path__, pre_write_buffers, BASE16, (size_t)PATH_MAX);
-	if (progname && progname[0] != '\0') {
-		strlcat(__stack_log_file_path__, ".", (size_t)PATH_MAX);
-		strlcat(__stack_log_file_path__, progname, (size_t)PATH_MAX);
-	}
-	strlcat(__stack_log_file_path__, ".XXXXXX", (size_t)PATH_MAX);
-	strlcat(__stack_log_file_path__, stack_log_file_suffix, (size_t)PATH_MAX);
-
-	// Securely create the log file.
-	if ((index_file_descriptor = mkstemps(__stack_log_file_path__, (int)strlen(stack_log_file_suffix))) != -1) {
-		_malloc_printf(ASL_LEVEL_INFO, "stack logs being written into %s\n", __stack_log_file_path__);
-		created_log_location = __stack_log_file_path__;
-	} else {
-		_malloc_printf(ASL_LEVEL_INFO, "unable to create stack logs at %s\n", __stack_log_file_path__);
-		__stack_log_file_path__[0] = '\0';
-		created_log_location = NULL;
-	}
-
-	return created_log_location;
-}
-
-// This function may be called from either the target process when exiting, or from either the the target process or
-// a stack log analysis process, when reaping orphaned stack log files.
-// Returns -1 if the files exist and they couldn't be removed, returns 0 otherwise.
-static int
-delete_logging_file(char *log_location)
-{
-	if (log_location == NULL || log_location[0] == '\0') return 0;
-
-	struct stat statbuf;
-	if (unlink(log_location) != 0 && stat(log_location, &statbuf) == 0) {
-		return -1;
-	}
-	return 0;
-}
-
-// This function will be called from atexit() in the target process.
-static void
-delete_log_files(void)
-{
-	if (__stack_log_file_path__ && __stack_log_file_path__[0]) {
-		if (delete_logging_file(__stack_log_file_path__) == 0) {
-			_malloc_printf(ASL_LEVEL_INFO, "stack logs deleted from %s\n", __stack_log_file_path__);
-			__stack_log_file_path__[0] = '\0';
-		} else {
-			_malloc_printf(ASL_LEVEL_INFO, "unable to delete stack logs from %s\n", __stack_log_file_path__);
-		}
-	}
-}
-
-static bool
-is_process_running(pid_t pid)
-{
-	struct kinfo_proc kpt[1];
-	size_t size = sizeof(struct kinfo_proc);
-	int mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_PID, pid};
-
-	sysctl(mib, 4, kpt, &size, NULL, (size_t)0); // size is either 1 or 0 entries when we ask for a single pid
-
-	return (size==sizeof(struct kinfo_proc));
-}
-
-// Stack log files can be quite large and aren't useful after the process that created them no longer exists because
-// the stack backtrace uniquing tree was only kept in the process memory, not on disk.  Normally the log files
-// should get removed when the process exits, by the delete_log_files() atexit function.  However, there are
-// several situations in which that atexit function doesn't get called so the log files remain:
-//		- if the process crashes or is force-killed
-//		- if the app supported sudden termination, and was terminated through that
-//		- if a process such as a shell execs another binary to transform the pid into a different process;
-//			the new process will get a new log file but the old one would still be there.
-//
-// So, reap any stack log files for processes that no longer exist, or for the current process if we find a file
-// other than __stack_log_file_path__
-//
-// This function looks for log files with prefix name "stack-logs.<pid>." underneath <directory>.
-// <remaining_path_format> specifies a simple pattern of where stack logs can be down inside <directory>.
-// The pattern is essentially a relative path, where a level that start with '<' matches any name, otherwise
-// it has to be an exact name match.  See the calling function for examples.
-static void
-reap_orphaned_log_files_in_hierarchy(char *directory, char *remaining_path_format)
-{
-	DIR *dp;
-	struct dirent *entry;
-	
-	// Ensure that we can access this directory - permissions or sandbox'ing might prevent it.
-	if (access(directory, R_OK | W_OK | X_OK) == -1 || (dp = opendir(directory)) == NULL) {
-		//_malloc_printf(ASL_LEVEL_INFO, "reaping: no access to %s\n", directory);
-		return;
-	}
-	
-	char pathname[PATH_MAX];
-	strlcpy(pathname, directory, (size_t)PATH_MAX);
-	size_t pathname_len = strlen(pathname);
-	if (pathname[pathname_len-1] != '/') pathname[pathname_len++] = '/';
-	char *suffix = pathname + pathname_len;
-	
-	// Recurse down to deeper levels of the temp directory hierarchy if necessary.
-	if (remaining_path_format) {
-		char *separator = remaining_path_format;
-		while (*separator != '/' && *separator != '\0') { separator++; }
-		size_t length_to_match = (*remaining_path_format == '<') ? 0 : separator - remaining_path_format;
-		char *next_remaining_path_format = (*separator == '\0') ? NULL : separator + 1;
-		
-		while ( (entry = readdir(dp)) != NULL ) {
-			if (entry->d_type == DT_DIR && entry->d_name[0] != '.') {
-				if (length_to_match > 0 && strncmp(entry->d_name, remaining_path_format, length_to_match) != 0) {
-					continue;
-				}
-				strlcpy(suffix, entry->d_name, (size_t)PATH_MAX - pathname_len);
-				reap_orphaned_log_files_in_hierarchy(pathname, next_remaining_path_format);
-			}
-		}
-		closedir(dp);
-		
-		return;
-	}
-	
-	// OK, we found a lowest-level directory matching <remaining_path_format>, and we have access to it.
-	// Reap any unnecessary stack log files in here.
-	
-	//_malloc_printf(ASL_LEVEL_INFO, "reaping: looking in %s\n", directory);
-	
-	// __stack_log_file_path__ may be NULL if this code is running in an analysis tool client process that is not
-	// itself running with MallocStackLogging set.
-	char *curproc_stack_log_file = __stack_log_file_path__ ? strrchr(__stack_log_file_path__, '/') + 1 : NULL;
-	pid_t curpid = getpid();
-	size_t prefix_length = strlen(stack_log_file_base_name);
-	
-	while ( (entry = readdir(dp)) != NULL ) {
-		if ( (entry->d_type == DT_REG || entry->d_type == DT_LNK) && ( strncmp( entry->d_name, stack_log_file_base_name, prefix_length) == 0 ) ) {
-			long pid = strtol(&entry->d_name[prefix_length], (char **)NULL, 10);
-			if ( ! is_process_running((pid_t)pid) || (pid == curpid && curproc_stack_log_file && strcmp(entry->d_name, curproc_stack_log_file) != 0) ) {
-				strlcpy(suffix, entry->d_name, (size_t)PATH_MAX - pathname_len);
-				if (delete_logging_file(pathname) == 0) {
-					if (pid == curpid) {
-						_malloc_printf(ASL_LEVEL_INFO, "stack logs deleted from %s\n", pathname);
-					} else {
-						_malloc_printf(ASL_LEVEL_INFO, "process %ld no longer exists, stack logs deleted from %s\n", pid, pathname);
-					}
-				}
-			}
-		}
-	}
-	closedir(dp);
-}
-
-static void
-reap_orphaned_log_files(pid_t pid)
-{
-	reap_orphaned_log_files_in_hierarchy(_PATH_TMP, NULL);
-	
-	char *env_var_names[] = { "TMPDIR", "MallocStackLoggingDirectory" };
-	for (unsigned i = 0; i < sizeof(env_var_names) / sizeof(char *); i++) {
-		char directory[PATH_MAX];
-		bool success = getenv_from_process(pid, env_var_names[i], directory, sizeof(directory));
-		if (success && strcmp(directory, _PATH_TMP) != 0) {
-			reap_orphaned_log_files_in_hierarchy(directory, NULL);
-		}
-	}
-
-	// Now reap files left over in any other accessible app-specific temp directories.
-	// These could be from sandbox'ed apps.
-#if TARGET_OS_EMBEDDED
-	char *root_of_temp_directories = "/private/var/mobile/Containers/Data/Application";	// ugh - hard-coding to user name "mobile".  Works for all iOS's up to now.
-	char *temp_directories_path_format = "<application-UUID>/tmp";
-#else
-	char *root_of_temp_directories = "/private/var/folders";
-	char *temp_directories_path_format = "<xx>/<random>/T";
-#endif
-	reap_orphaned_log_files_in_hierarchy(root_of_temp_directories, temp_directories_path_format);
-}
-
-/*
- * Since there a many errors that could cause stack logging to get disabled, this is a convenience method
- * for disabling any future logging in this process and for informing the user.
- */
-static void
-disable_stack_logging(void)
-{
-	_malloc_printf(ASL_LEVEL_INFO, "stack logging disabled due to previous errors.\n");
-	stack_logging_enable_logging = 0;
-	malloc_logger = NULL;
-	__syscall_logger = NULL;
-}
-
-/* A wrapper around write() that will try to reopen the index/stack file and
- * write to it if someone closed it underneath us (e.g. the process we just
- * started decide to close all file descriptors except stin/err/out). Some
- * programs like to do that and calling abort() on them is rude.
- */
-static ssize_t
-robust_write(int fd, const void *buf, size_t nbyte) {
-	extern int errno;
-	ssize_t written = write(fd, buf, nbyte);
-	if (written == -1 && errno == EBADF) {
-		char *file_to_reopen = NULL;
-		int *fd_to_reset = NULL;
-
-		// descriptor was closed on us. We need to reopen it
-		if (fd == index_file_descriptor) {
-			file_to_reopen = __stack_log_file_path__;
-			fd_to_reset = &index_file_descriptor;
-		} else {
-			// We don't know about this file. Return (and abort()).
-			_malloc_printf(ASL_LEVEL_INFO, "Unknown file descriptor; expecting stack logging index file\n");
-			return -1;
-		}
-
-		// The file *should* already exist. If not, fail.
-		fd = open(file_to_reopen, O_WRONLY | O_APPEND);
-		if (fd < 3) {
-			// If we somehow got stdin/out/err, we need to relinquish them and
-			// get another fd.
-			int fds_to_close[3] = { 0 };
-			while (fd < 3) {
-				if (fd == -1) {
-					_malloc_printf(ASL_LEVEL_INFO, "unable to re-open stack logging file %s\n", file_to_reopen);
-					delete_log_files();
-					return -1;
-				}
-				fds_to_close[fd] = 1;
-				fd = dup(fd);
-			}
-
-			// We have an fd we like. Close the ones we opened.
-			if (fds_to_close[0]) close(0);
-			if (fds_to_close[1]) close(1);
-			if (fds_to_close[2]) close(2);
-		}
-
-		*fd_to_reset = fd;
-		written = write(fd, buf, nbyte);
-	}
-	return written;
-}
-
-static void
-flush_data(void)
-{
-	ssize_t written; // signed size_t
-	size_t remaining;
-	char * p;
-
-	if (index_file_descriptor == -1) {
-		if (create_log_file() == NULL) {
-			return;
-		}
-	}
-
-	// Write the events before the index so that hopefully the events will be on disk if the index refers to them.
-	p = pre_write_buffers->index_buffer;
-	remaining = (size_t)pre_write_buffers->next_free_index_buffer_offset;
-	while (remaining > 0) {
-		written = robust_write(index_file_descriptor, p, remaining);
-		if (written == -1) {
-			_malloc_printf(ASL_LEVEL_INFO, "Unable to write to stack logging file %s (%s)\n",
-						   __stack_log_file_path__, strerror(errno));
-			disable_stack_logging();
-			return;
-		}
-		p += written;
-		remaining -= written;
-	}
-
-	pre_write_buffers->start_index_offset += pre_write_buffers->next_free_index_buffer_offset;
-	pre_write_buffers->next_free_index_buffer_offset = 0;
-}
-
-__attribute__((visibility("hidden")))
-void
-__prepare_to_log_stacks(void)
-{
-	if (!pre_write_buffers) {
-		last_logged_malloc_address = 0ul;
-		logging_use_compaction = (stack_logging_dontcompact ? 0 : logging_use_compaction);
-
-		// Create a VM region to hold the pre-write index and stack buffers. The address of this VM region will be
-		// encoded into the stack log file name, so that the stack log reading code running in remote analysis
-		// processes can find it and map it into the analysis process. This allows remote analysis processes to access
-		// these buffers to get logs for even the most recent allocations. The remote process will need to pause this
-		// process to assure that the contents of these buffers don't change while being inspected.
-		//
-		// We used to use shm_open() to create a shared memory region for this, but since this code runs in arbitrary
-		// processes that may have sandbox restrictions that don't allow the creation of shared memory regions,
-		// we're using this "create a region and put its address in the stack log file name" approach.
-		size_t full_shared_mem_size = sizeof(stack_buffer_shared_memory);
-		pre_write_buffers = mmap(0, full_shared_mem_size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, VM_MAKE_TAG(VM_MEMORY_ANALYSIS_TOOL), 0);
-		if (MAP_FAILED == pre_write_buffers) {
-			_malloc_printf(ASL_LEVEL_INFO, "error creating VM region for stack logging output buffers\n");
-			disable_stack_logging();
-			return;
-		}
-
-		// Store and use the buffer offsets in shared memory so that they can be accessed remotely
-		pre_write_buffers->start_index_offset = 0ull;
-		pre_write_buffers->next_free_index_buffer_offset = 0;
-
-		// create the backtrace uniquing table
-		pre_write_buffers->uniquing_table = __create_uniquing_table();
-		if (!pre_write_buffers->uniquing_table) {
-			_malloc_printf(ASL_LEVEL_INFO, "error while allocating stack uniquing table\n");
-			disable_stack_logging();
-			return;
-		}
-
-		uint64_t stack_buffer_sz = (uint64_t)round_page(sizeof(vm_address_t) * STACK_LOGGING_MAX_STACK_SIZE);
-		stack_buffer = (vm_address_t*)allocate_pages(stack_buffer_sz);
-		if (!stack_buffer) {
-			_malloc_printf(ASL_LEVEL_INFO, "error while allocating stack trace buffer\n");
-			disable_stack_logging();
-			return;
-		}
-
-		// this call ensures that the log files exist; analyzing processes will rely on this assumption.
-		if (create_log_file() == NULL) {
-			/* postponement support requires cleaning up these structures now */
-			__destroy_uniquing_table(pre_write_buffers->uniquing_table);
-			deallocate_pages(stack_buffer, stack_buffer_sz);
-			stack_buffer = NULL;
-
-			munmap(pre_write_buffers, full_shared_mem_size);
-			pre_write_buffers = NULL;
-
-			if (!stack_logging_postponed) {
-				disable_stack_logging();
-			}
-			return;
-		}
-	}
-}
-
-static void
-__prepare_to_log_stacks_stage2(void)
-{
-	static int stage2done = 0;
-
-	if (! stage2done) {
-		// malloc() can be called by the following, so these need to be done outside the stack_logging_lock but after the buffers have been set up.
-		atexit(delete_log_files);				// atexit() can call malloc()
-
-		// Reaping orphaned stack log files from dead processes is a nicety, to help
-		// reduce wasted disk space.  But we don't *always* have to do it.  Specifically,
-		// do not reap orphaned stack log files if the process name is sandboxd or taskgated,
-		// or if the MallocStackLoggingNoReaping env var is set to any value other than "no"
-		// (case-insensitive) or "0".  This provides multiple ways to fix
-		// <rdar://problem/14409213> "processes hang if sandboxd is running with
-		// MallocStackLogging enabled", which happened because there were two different
-		// places down inside reap_orphaned_log_files() which called sysctl() for KERN_PROCARGS2
-		// or KERN_PROC_PID, causing iteration of the process list in the kernel, which takes
-		// a lock, which can't happen when processes are in a transitional state.
-		bool should_reap = true;
-		const char *progname = getprogname();
-		if (progname && (strcmp(progname, "sandboxd") == 0 || strcmp(progname, "taskgated") == 0)) {
-			should_reap = false;
-		}
-		if (should_reap) {
-			char *noreap = getenv("MallocStackLoggingNoReaping");
-			if (noreap && strcasecmp(noreap, "no") != 0 && strcmp(noreap, "0") != 0) {
-				should_reap = false;
-			}
-		}
-		if (should_reap) {
-			reap_orphaned_log_files(getpid());	// this calls opendir() which calls malloc()
-		}
-
-		stage2done = 1;
-	}
-}
-
-
-void
-__disk_stack_logging_log_stack(uint32_t type_flags, uintptr_t zone_ptr, uintptr_t arg2, uintptr_t arg3, uintptr_t return_val, uint32_t num_hot_to_skip)
-{
-	if (!stack_logging_enable_logging || stack_logging_postponed) return;
-
-	uintptr_t size;
-	uintptr_t ptr_arg;
-
-	// check incoming data
-	if (type_flags & stack_logging_type_alloc && type_flags & stack_logging_type_dealloc) {
-		size = arg3;
-		ptr_arg = arg2; // the original pointer
-		if (ptr_arg == return_val) return; // realloc had no effect, skipping
-
-		if (ptr_arg == 0) { // realloc(NULL, size) same as malloc(size)
-			type_flags ^= stack_logging_type_dealloc;
-		} else {
-			// realloc(arg1, arg2) -> result is same as free(arg1); malloc(arg2) -> result
-			__disk_stack_logging_log_stack(stack_logging_type_dealloc, zone_ptr, ptr_arg, (uintptr_t)0, (uintptr_t)0, num_hot_to_skip + 1);
-			__disk_stack_logging_log_stack(stack_logging_type_alloc, zone_ptr, size, (uintptr_t)0, return_val, num_hot_to_skip + 1);
-			return;
-		}
-	}
-	if (type_flags & stack_logging_type_dealloc || type_flags & stack_logging_type_vm_deallocate) {
-		// For VM deallocations we need to know the size, since they don't always match the
-		// VM allocations.  It would be nice if arg2 was the size, for consistency with alloc and
-		// realloc events.  However we can't easily make that change because all projects
-		// (malloc.c, GC auto_zone, and gmalloc) have historically put the pointer in arg2 and 0 as
-		// the size in arg3.  We'd need to change all those projects in lockstep, which isn't worth
-		// the trouble.
-		ptr_arg = arg2;
-		size = arg3;
-		if (ptr_arg == 0) return; // free(nil)
-	}
-	if (type_flags & stack_logging_type_alloc || type_flags & stack_logging_type_vm_allocate) {
-		if (return_val == 0) return; // alloc that failed
-		size = arg2;
-	}
-
-	if (type_flags & stack_logging_type_vm_allocate || type_flags & stack_logging_type_vm_deallocate) {
-		mach_port_t targetTask = (mach_port_t)zone_ptr;
-		// For now, ignore "injections" of VM into other tasks.
-		if (targetTask != mach_task_self()) return;
-	}
-
-
-	type_flags &= stack_logging_valid_type_flags;
-
-	vm_address_t self_thread = (vm_address_t)_os_tsd_get_direct(__TSD_THREAD_SELF);
-	static vm_address_t thread_doing_logging = 0;
-
-	if (thread_doing_logging == self_thread) {
-		// Prevent a thread from deadlocking against itself if vm_allocate() or malloc()
-		// is called below here, from __prepare_to_log_stacks() or _prepare_to_log_stacks_stage2(),
-		// or if we are logging an event and need to call __expand_uniquing_table() which calls
-		// vm_allocate() to grow stack logging data structures.  Any such "administrative"
-		// vm_allocate or malloc calls would attempt to recursively log those events.
-		return;
-	}
-
-	// lock and enter
-	_malloc_lock_lock(&stack_logging_lock);
-
-	thread_doing_logging = self_thread;		// for preventing deadlock'ing on stack logging on a single thread
-
-	// now actually begin
-	__prepare_to_log_stacks();
-
-	// since there could have been a fatal (to stack logging) error such as the log files not being created, check these variables before continuing
-	if (!stack_logging_enable_logging || stack_logging_postponed) {
-		thread_doing_logging = 0;
-		_malloc_lock_unlock(&stack_logging_lock);
-		return;
-	}
-
-	if (type_flags & stack_logging_type_alloc) {
-		// Only do this second stage of setup when we first record a malloc (as opposed to a VM allocation),
-		// to ensure that the malloc zone has already been created as is necessary for this.
-		__prepare_to_log_stacks_stage2();
-	}
-
-	// compaction
-	if (last_logged_malloc_address && (type_flags & stack_logging_type_dealloc) && STACK_LOGGING_DISGUISE(ptr_arg) == last_logged_malloc_address) {
-		// *waves hand* the last allocation never occurred
-		pre_write_buffers->next_free_index_buffer_offset -= (uint32_t)sizeof(stack_logging_index_event);
-		last_logged_malloc_address = 0ul;
-
-		thread_doing_logging = 0;
-		_malloc_lock_unlock(&stack_logging_lock);
-		return;
-	}
-
-	// gather stack
-	uint32_t count;
-	thread_stack_pcs(stack_buffer, STACK_LOGGING_MAX_STACK_SIZE-1, &count); // only gather up to STACK_LOGGING_MAX_STACK_SIZE-1 since we append thread id
-	stack_buffer[count++] = self_thread + 1;		// stuffing thread # in the coldest slot.  Add 1 to match what the old stack logging did.
-	num_hot_to_skip += 2;
-	if (count <= num_hot_to_skip) {
-		// Oops!  Didn't get a valid backtrace from thread_stack_pcs().
-		thread_doing_logging = 0;
-		_malloc_lock_unlock(&stack_logging_lock);
-		return;
-	}
-
-	// unique stack in memory
-	count -= num_hot_to_skip;
-#if __LP64__
-	mach_vm_address_t *frames = (mach_vm_address_t*)stack_buffer + num_hot_to_skip;
-#else
-	mach_vm_address_t frames[STACK_LOGGING_MAX_STACK_SIZE];
-	uint32_t i;
-	for (i = 0; i < count; i++) {
-		frames[i] = stack_buffer[i+num_hot_to_skip];
-	}
-#endif
-
-	uint64_t uniqueStackIdentifier = (uint64_t)(-1ll);
-	while (!__enter_frames_in_table(pre_write_buffers->uniquing_table, &uniqueStackIdentifier, frames, (int32_t)count)) {
-		__expand_uniquing_table(pre_write_buffers->uniquing_table);
-	}
-
-	stack_logging_index_event current_index;
-	if (type_flags & stack_logging_type_alloc || type_flags & stack_logging_type_vm_allocate) {
-		current_index.address = STACK_LOGGING_DISGUISE(return_val);
-		current_index.argument = size;
-		if (logging_use_compaction) {
-			last_logged_malloc_address = current_index.address; // disguised
-		}
-	} else {
-		current_index.address = STACK_LOGGING_DISGUISE(ptr_arg);
-		current_index.argument = size;
-		last_logged_malloc_address = 0ul;
-	}
-	current_index.offset_and_flags = STACK_LOGGING_OFFSET_AND_FLAGS(uniqueStackIdentifier, type_flags);
-
-	//	the following line is a good debugging tool for logging each allocation event as it happens.
-	//	malloc_printf("{0x%lx, %lld}\n", STACK_LOGGING_DISGUISE(current_index.address), uniqueStackIdentifier);
-
-	// flush the data buffer to disk if necessary
-	if (pre_write_buffers->next_free_index_buffer_offset + sizeof(stack_logging_index_event) >= STACK_LOGGING_BLOCK_WRITING_SIZE) {
-		flush_data();
-	}
-
-	// store bytes in buffers
-	memcpy(pre_write_buffers->index_buffer+pre_write_buffers->next_free_index_buffer_offset, &current_index, sizeof(stack_logging_index_event));
-	pre_write_buffers->next_free_index_buffer_offset += (uint32_t)sizeof(stack_logging_index_event);
-
-	thread_doing_logging = 0;
-	_malloc_lock_unlock(&stack_logging_lock);
-}
-
-void
-__stack_logging_fork_prepare(void) {
-	_malloc_lock_lock(&stack_logging_lock);
-}
-
-void
-__stack_logging_fork_parent(void) {
-	_malloc_lock_unlock(&stack_logging_lock);
-}
-
-void
-__stack_logging_fork_child(void) {
-	malloc_logger = NULL;
-	stack_logging_enable_logging = 0;
-	_malloc_lock_unlock(&stack_logging_lock);
-}
-
-void
-__stack_logging_early_finished(void) {
-	stack_logging_finished_init = 1;
-	stack_logging_postponed = 0;
-}
-
-__attribute__((visibility("hidden")))
-boolean_t
-__stack_logging_locked(void)
-{
-	bool acquired_lock = _malloc_lock_trylock(&stack_logging_lock);
-	if (acquired_lock) _malloc_lock_unlock(&stack_logging_lock);
-	return (acquired_lock ? false : true);
-}
-
-#pragma mark -
-#pragma mark Remote Stack Log Access
-
-#pragma mark - Design notes:
-
-/*
-
- this first one will look through the index, find the "stack_identifier" (i.e. the offset in the log file), and call the third function listed here.
- extern kern_return_t __mach_stack_logging_get_frames(task_t task, mach_vm_address_t address, mach_vm_address_t *stack_frames_buffer, uint32_t max_stack_frames, uint32_t *num_frames);
- //  Gets the last allocation record about address
-
- if !address, will load index and iterate through (expensive)
- else will load just index, search for stack, and then use third function here to retrieve. (also expensive)
- extern kern_return_t __mach_stack_logging_enumerate_records(task_t task, mach_vm_address_t address, void enumerator(mach_stack_logging_record_t, void *), void *context);
- // Applies enumerator to all records involving address sending context as enumerator's second parameter; if !address, applies enumerator to all records
-
- this function will load the stack file, look for the stack, and follow up to STACK_LOGGING_FORCE_FULL_BACKTRACE_EVERY references to reconstruct.
- extern kern_return_t __mach_stack_logging_frames_for_uniqued_stack(task_t task, uint64_t stack_identifier, mach_vm_address_t *stack_frames_buffer, uint32_t max_stack_frames, uint32_t *count);
- // Given a uniqued_stack fills stack_frames_buffer
-
- */
-
-#pragma mark -
-#pragma mark Backtrace Uniquing Table Reading and Lookup
-
-// This is client-side code to get a stack log from a uniquing_table.
-static void
-free_uniquing_table_chunks(backtrace_uniquing_table *uniquing_table) {
-	table_chunk_header_t *table_chunk_header = uniquing_table->u.first_table_chunk_hdr;
-	while (table_chunk_header) {
-		mach_vm_deallocate(mach_task_self(), (mach_vm_address_t)(uintptr_t)(table_chunk_header->table_chunk), table_chunk_header->table_chunk_size);
-		table_chunk_header_t *next = table_chunk_header->next_table_chunk_header;
-		free(table_chunk_header);
-		table_chunk_header = next;
-	}
-}
-
-static kern_return_t
-read_uniquing_table_from_task(task_t remote_task, backtrace_uniquing_table *uniquing_table) {
-	mach_vm_address_t next_address_to_read = uniquing_table->table_address;
-	uint64_t remaining_size_to_read = uniquing_table->tableSize;
-	const mach_vm_size_t two_gigabytes = 2ull * 1024 * 1024 * 1024;		// attempting to read 4 GB in one call fails, so try a max of 2 GB
-	table_chunk_header_t **table_chunk_hdr_ptr = &(uniquing_table->u.first_table_chunk_hdr);
-	*table_chunk_hdr_ptr = NULL;
-	
-	while (remaining_size_to_read > 0ull) {
-		vm_address_t local_table_chunk_address = 0ul;
-		mach_msg_type_number_t local_table_chunk_size = 0;
-		
-		mach_vm_size_t next_size_to_read = (remaining_size_to_read > two_gigabytes) ? two_gigabytes : remaining_size_to_read;
-		while (1) {
-			kern_return_t err = mach_vm_read(remote_task, next_address_to_read, next_size_to_read, &local_table_chunk_address, &local_table_chunk_size);
-			if (err == KERN_SUCCESS) {
-				*table_chunk_hdr_ptr = malloc(sizeof(table_chunk_header_t));
-				table_chunk_header_t *table_chunk_hdr = *table_chunk_hdr_ptr;
-				table_chunk_hdr->num_nodes_in_chunk = local_table_chunk_size / (sizeof(mach_vm_address_t) * 2);;
-				table_chunk_hdr->table_chunk = local_table_chunk_address;
-				table_chunk_hdr->table_chunk_size = local_table_chunk_size;
-				table_chunk_hdr->next_table_chunk_header = NULL;	// initialize it, in case it is the last chunk
-				table_chunk_hdr_ptr = &(table_chunk_hdr->next_table_chunk_header);		// set up to assign next chunk to this
-
-				next_address_to_read += local_table_chunk_size;
-				remaining_size_to_read -= local_table_chunk_size;
-				//fprintf(stderr, "requested %#qx, got %#x of %#qx at %p from backtrace uniquing table of target process\n", next_size_to_read, local_table_chunk_size, uniquing_table->tableSize, table_chunk_hdr);
-				break;
-			} else {
-				//fprintf(stderr, "requested %#qx, failed\n", next_size_to_read);
-				next_size_to_read /= 2;
-				if (next_size_to_read <= 1024 * 1024) {
-					// We couldn't even map one megabyte?  Let's call that an error...
-					free_uniquing_table_chunks(uniquing_table);
-					return err;
-				}
-			}
-		}
-	}
-	return KERN_SUCCESS;
-}
-
-static mach_vm_address_t *
-get_node_from_uniquing_table(backtrace_uniquing_table *uniquing_table, uint64_t index_pos)
-{
-	table_chunk_header_t *table_chunk_hdr = uniquing_table->u.first_table_chunk_hdr;
-	uint64_t start_node_of_chunk = 0;
-	while (table_chunk_hdr && index_pos > start_node_of_chunk + table_chunk_hdr->num_nodes_in_chunk) {
-		table_chunk_hdr = table_chunk_hdr->next_table_chunk_header;
-		if (table_chunk_hdr) {
-			start_node_of_chunk += table_chunk_hdr->num_nodes_in_chunk;
-		}
-	}
-	assert(table_chunk_hdr);
-	uint64_t index_in_chunk = index_pos - start_node_of_chunk;
-	mach_vm_address_t *node = table_chunk_hdr->table_chunk + (index_in_chunk * 2);
-	return node;
-}
-
-static void
-unwind_stack_from_table_index(backtrace_uniquing_table *uniquing_table, uint64_t index_pos, mach_vm_address_t *out_frames_buffer, uint32_t *out_frames_count, uint32_t max_frames)
-{
-	mach_vm_address_t *node = get_node_from_uniquing_table(uniquing_table, index_pos);
-	uint32_t foundFrames = 0;
-	if (index_pos < uniquing_table->numNodes) {
-		while (foundFrames < max_frames) {
-			out_frames_buffer[foundFrames++] = node[0];
-			if (node[1] == (mach_vm_address_t)(-1ll)) break;
-			node = get_node_from_uniquing_table(uniquing_table, node[1]);
-		}
-	}
-	
-	*out_frames_count = foundFrames;
-}
-
-#pragma mark - caching
-
-__attribute__((always_inline)) static inline size_t
-hash_index(uint64_t address, size_t max_pos) {
-	return (size_t)((address >> 2) % (max_pos-1)); // simplicity rules.
-}
-
-__attribute__((always_inline)) static inline size_t
-hash_multiplier(size_t capacity, uint32_t allowed_collisions) {
-	return (capacity/(allowed_collisions*2+1));
-}
-
-__attribute__((always_inline)) static inline size_t
-next_hash(size_t hash, size_t multiplier, size_t capacity, uint32_t collisions) {
-	hash += multiplier * collisions;
-	if (hash >= capacity) hash -= capacity;
-	return hash;
-}
-
-static void
-transfer_node(remote_index_cache *cache, remote_index_node *old_node)
-{
-	uint32_t collisions = 0;
-	size_t pos = hash_index(old_node->address, cache->cache_node_capacity);
-	size_t multiplier = hash_multiplier(cache->cache_node_capacity, cache->collision_allowance);
-	do {
-		if (cache->table_memory[pos].address == old_node->address) { // hit like this shouldn't happen.
-			fprintf(stderr, "impossible collision! two address==address lists! (transfer_node)\n");
-			break;
-		} else if (cache->table_memory[pos].address == 0) { // empty
-			cache->table_memory[pos] = *old_node;
-			break;
-		} else {
-			collisions++;
-			pos = next_hash(pos, multiplier, cache->cache_node_capacity, collisions);
-		}
-	} while (collisions <= cache->collision_allowance);
-
-	if (collisions > cache->collision_allowance) {
-		fprintf(stderr, "reporting bad hash function! disk stack logging reader %lu bit. (transfer_node)\n", sizeof(void*)*8);
-	}
-}
-
-static void
-expand_cache(remote_index_cache *cache)
-{
-	// keep old stats
-	size_t old_node_capacity = cache->cache_node_capacity;
-	remote_index_node *old_table = cache->table_memory;
-
-	// double size
-	cache->cache_size <<= 2;
-	cache->cache_node_capacity <<= 2;
-	cache->collision_allowance += 3;
-	cache->table_memory = (void*)calloc(cache->cache_node_capacity, sizeof(remote_index_node));
-
-	// repopulate (expensive!)
-	size_t i;
-	for (i = 0; i < old_node_capacity; i++) {
-		if (old_table[i].address) {
-			transfer_node(cache, &old_table[i]);
-		}
-	}
-	free(old_table);
-	//	printf("cache expanded to %0.2f mb (eff: %3.0f%%, capacity: %lu, nodes: %llu, llnodes: %llu)\n", ((float)(cache->cache_size))/(1 << 20), ((float)(cache->cache_node_count)*100.0)/((float)(cache->cache_node_capacity)), cache->cache_node_capacity, cache->cache_node_count, cache->cache_llnode_count);
-}
-
-static void
-insert_node(remote_index_cache *cache, uint64_t address, uint64_t index_file_offset)
-{
-	uint32_t collisions = 0;
-	size_t pos = hash_index(address, cache->cache_node_capacity);
-	size_t multiplier = hash_multiplier(cache->cache_node_capacity, cache->collision_allowance);
-
-	while (1) {
-		if (cache->table_memory[pos].address == 0ull || cache->table_memory[pos].address == address) { // hit or empty
-			cache->table_memory[pos].address = address;
-			cache->table_memory[pos].index_file_offset = index_file_offset;
-			// Inserted it!  Break out of the loop.
-			break;
-		}
-
-		collisions++;
-		pos = next_hash(pos, multiplier, cache->cache_node_capacity, collisions);
-
-		if (collisions > cache->collision_allowance) {
-			expand_cache(cache);
-			pos = hash_index(address, cache->cache_node_capacity);
-			multiplier = hash_multiplier(cache->cache_node_capacity, cache->collision_allowance);
-			collisions = 0;
-		}
-	}
-}
-
-// Kudos to Daniel Delwood for this function.  This is called in an analysis tool process
-// to share a VM region from a target process, without the target process needing to explicitly
-// share the region itself via shm_open().  The VM_FLAGS_RETURN_DATA_ADDR flag is necessary
-// for iOS in case the target process uses a different VM page size than the analysis tool process.
-static mach_vm_address_t
-map_shared_memory_from_task(task_t sourceTask, mach_vm_address_t sourceAddress, mach_vm_size_t sourceSize) {
-#if TARGET_OS_EMBEDDED
-	int mapRequestFlags = VM_FLAGS_ANYWHERE | VM_FLAGS_RETURN_DATA_ADDR;
-	mach_vm_address_t mapRequestAddress = sourceAddress;
-	mach_vm_size_t mapRequestSize = sourceSize;
-#else
-	// Sadly, VM_FLAGS_RETURN_DATA_ADDR isn't available to us; align everything manually.
-	int mapRequestFlags = VM_FLAGS_ANYWHERE;
-	mach_vm_address_t mapRequestAddress = trunc_page(sourceAddress);
-	mach_vm_size_t mapRequestSize = round_page(sourceAddress + sourceSize) - mapRequestAddress;
-#endif
-	mach_vm_address_t mappedAddress = 0;
-	vm_prot_t outCurrentProt = VM_PROT_NONE;
-	vm_prot_t outMaxProt = VM_PROT_NONE;
-	kern_return_t err = mach_vm_remap(mach_task_self(), &mappedAddress, mapRequestSize, 0, mapRequestFlags, sourceTask, mapRequestAddress, false, &outCurrentProt, &outMaxProt, VM_INHERIT_NONE);
-	if (err != KERN_SUCCESS) {
-		return 0;
-	}
-	return mappedAddress + (sourceAddress - mapRequestAddress);
-}
-
-static kern_return_t
-update_cache_for_file_streams(remote_task_file_streams *descriptors)
-{
-	remote_index_cache *cache = descriptors->cache;
-
-	// create from scratch if necessary.
-	if (!cache) {
-		descriptors->cache = cache = (remote_index_cache*)calloc((size_t)1, sizeof(remote_index_cache));
-		cache->cache_node_capacity = 1 << 14;
-		cache->collision_allowance = 17;
-		cache->last_index_file_offset = 0;
-		cache->cache_size = cache->cache_node_capacity*sizeof(remote_index_node);
-		cache->table_memory = (void*)calloc(cache->cache_node_capacity, sizeof(remote_index_node));
-
-		cache->shmem = map_shared_memory_from_task(descriptors->remote_task, descriptors->remote_stack_buffer_shared_memory_address, sizeof(stack_buffer_shared_memory));
-		if (! cache->shmem) {
-			// failed to connect to the shared memory region; warn and continue.
-			_malloc_printf(ASL_LEVEL_INFO, "warning: unable to map shared memory from %llx in target process %d; no stack backtraces will be available.\n", descriptors->remote_stack_buffer_shared_memory_address, descriptors->remote_pid);
-		}
-	}
-
-	// suspend and see how much updating there is to do. there are three scenarios, listed below
-	bool update_snapshot = false;
-	if (descriptors->remote_task != mach_task_self()) {
-		task_suspend(descriptors->remote_task);
-	}
-
-	struct stat file_statistics;
-	fstat(fileno(descriptors->index_file_stream), &file_statistics);
-	size_t read_size = (descriptors->task_is_64_bit ? sizeof(stack_logging_index_event64) : sizeof(stack_logging_index_event32));
-	uint64_t read_this_update = 0;
-
-	// the delta indecies is a complex number; there are three cases:
-	// 1. there is no shared memory (or we can't connect); diff the last_index_file_offset from the filesize.
-	// 2. the only updates have been in shared memory; disk file didn't change at all. delta_indecies should be zero, scan snapshot only.
-	// 3. the updates have flushed to disk, meaning that most likely there is new data on disk that wasn't read from shared memory.
-	//    correct delta_indecies for the pre-scanned amount and read the new data from disk and shmem.
-	uint64_t delta_indecies = (file_statistics.st_size - cache->last_index_file_offset) / read_size;
-	uint32_t last_snapshot_scan_index = 0;
-	if (delta_indecies && cache->shmem) {
-		// case 3: add cache scanned to known from disk and recalc
-		cache->last_index_file_offset += cache->snapshot.next_free_index_buffer_offset;
-		delta_indecies = (file_statistics.st_size - cache->last_index_file_offset) / read_size;
-		update_snapshot = true;
-	} else if (cache->shmem) {
-		// case 2: set the last snapshot scan count so we don't rescan something we've seen.
-		last_snapshot_scan_index = cache->snapshot.next_free_index_buffer_offset / (uint32_t)read_size;
-	}
-
-	// no update necessary for the file; check if need a snapshot.
-	if (delta_indecies == 0) {
-		if (cache->shmem && !update_snapshot) {
-			update_snapshot = (cache->shmem->next_free_index_buffer_offset != cache->snapshot.next_free_index_buffer_offset);
-		}
-	}
-
-	// if a snapshot is necessary, memcpy from remote frozen process' memory
-	// note: there were two ways to do this - spin lock or suspend. suspend allows us to
-	// analyze processes even if they were artificially suspended. with a lock, there'd be
-	// worry that the target was suspended with the lock taken.
-	kern_return_t err = KERN_SUCCESS;
-	if (update_snapshot) {
-		memcpy(&cache->snapshot, cache->shmem, sizeof(stack_buffer_shared_memory));
-		// also need to update our version of the remote uniquing table
-		vm_address_t local_uniquing_address = 0ul;
-		mach_msg_type_number_t local_uniquing_size = 0;
-		mach_vm_size_t desired_size = round_page(sizeof(backtrace_uniquing_table));
-		if ((err = mach_vm_read(descriptors->remote_task, cache->shmem->uniquing_table, desired_size, &local_uniquing_address, &local_uniquing_size)) != KERN_SUCCESS
-			|| local_uniquing_size != desired_size) {
-			fprintf(stderr, "error while attempting to mach_vm_read remote stack uniquing table (%d): %s\n", err, mach_error_string(err));
-		} else {
-			// the mach_vm_read was successful, so acquire the uniquing table
-
-			// need to re-read the table, so deallocate the current memory
-			free_uniquing_table_chunks(&cache->uniquing_table_snapshot);
-
-			// The following line copies the uniquing table structure data, but the actual uniquing table memory is invalid
-			// since it's a pointer from the remote process.
-			cache->uniquing_table_snapshot = *((backtrace_uniquing_table*)local_uniquing_address);
-
-			// Read the uniquing table memory from the target process.
-			err = read_uniquing_table_from_task(descriptors->remote_task, &(cache->uniquing_table_snapshot));
-			if (err) {
-				fprintf(stderr, "error while attempting to mach_vm_read remote stack uniquing table contents (%d): %s\n", err, mach_error_string(err));
-			}
-			// Check the error status below, after further deallocating and resuming the target task.
-
-			mach_vm_deallocate(mach_task_self(), (mach_vm_address_t)local_uniquing_address, (mach_vm_size_t)local_uniquing_size);
-		}
-	}
-
-	// resume
-	if (descriptors->remote_task != mach_task_self()) {
-		task_resume(descriptors->remote_task);
-	}
-	
-	if (err != KERN_SUCCESS) {
-		// To Do:  further clean up allocated resources, and also try to prevent printing numerous identical "out of memory" errors (maybe we should abort?).
-		return err;
-	}
-
-	if (!update_snapshot && delta_indecies == 0) return KERN_SUCCESS; // absolutely no updating needed.
-
-	FILE *the_index = (descriptors->index_file_stream);
-
-	// prepare for the read; target process could be 32 or 64 bit.
-
-	stack_logging_index_event32 *target_32_index = NULL;
-	stack_logging_index_event64 *target_64_index = NULL;
-
-	// perform the update from the file
-	uint32_t i;
-	if (delta_indecies) {
-		char bufferSpace[4096]; // 4 kb
-		target_32_index = (stack_logging_index_event32*)bufferSpace;
-		target_64_index = (stack_logging_index_event64*)bufferSpace;
-		size_t number_slots = (size_t)(4096/read_size);
-
-		size_t read_count = 0;
-		if (fseeko(the_index, (off_t)(cache->last_index_file_offset), SEEK_SET)) {
-			fprintf(stderr, "error while attempting to cache information from remote stack index file. (update_cache_for_file_streams)\n");
-		}
-		off_t current_index_position = cache->last_index_file_offset;
-		do {
-			number_slots = (size_t)MIN(delta_indecies - read_this_update, number_slots);
-			read_count = fread(bufferSpace, read_size, number_slots, the_index);
-			if (descriptors->task_is_64_bit) {
-				for (i = 0; i < read_count; i++) {
-					insert_node(cache, STACK_LOGGING_DISGUISE(target_64_index[i].address), (uint64_t)current_index_position);
-					read_this_update++;
-					current_index_position += read_size;
-				}
-			} else {
-				for (i = 0; i < read_count; i++) {
-					insert_node(cache, (mach_vm_address_t)STACK_LOGGING_DISGUISE(target_32_index[i].address), (uint64_t)current_index_position);
-					read_this_update++;
-					current_index_position += read_size;
-				}
-			}
-		} while (read_count);
-
-		if (read_this_update < delta_indecies) {
-			fprintf(stderr, "insufficient data in remote stack index file; expected more records.\n");
-		}
-		cache->last_index_file_offset += read_this_update * read_size;
-	}
-
-	if (update_snapshot) {
-		target_32_index = (stack_logging_index_event32*)(cache->snapshot.index_buffer);
-		target_64_index = (stack_logging_index_event64*)(cache->snapshot.index_buffer);
-
-		uint32_t free_snapshot_scan_index = cache->snapshot.next_free_index_buffer_offset / (uint32_t)read_size;
-		off_t current_index_position = cache->snapshot.start_index_offset;
-		if (descriptors->task_is_64_bit) {
-			for (i = last_snapshot_scan_index; i < free_snapshot_scan_index; i++) {
-				insert_node(cache, STACK_LOGGING_DISGUISE(target_64_index[i].address), (uint64_t)(current_index_position + (i * read_size)));
-			}
-		} else {
-			for (i = last_snapshot_scan_index; i < free_snapshot_scan_index; i++) {
-				insert_node(cache, (mach_vm_address_t)STACK_LOGGING_DISGUISE(target_32_index[i].address), (uint64_t)(current_index_position + (i * read_size)));
-			}
-		}
-	}
-	
-	return KERN_SUCCESS;
-}
-
-static void
-destroy_cache_for_file_streams(remote_task_file_streams *descriptors)
-{
-	if (descriptors->cache->shmem) {
-		munmap(descriptors->cache->shmem, sizeof(stack_buffer_shared_memory));
-	}
-	free(descriptors->cache->table_memory);
-	free(descriptors->cache);
-	descriptors->cache = NULL;
-}
-
-#pragma mark - internal
-
-// In the stack log analysis process, find the stack logging file for target process <pid>
-// by scanning the given directory for entries with names of the form "stack-logs.<pid>.*.index"
-// If we find such an entry then open that stack logging file.
-static FILE *
-open_log_file_from_directory(pid_t pid, char* directory, remote_task_file_streams *streams)
-{
-	DIR *dp;
-	struct dirent *entry;
-	char prefix_and_pid[PATH_MAX];
-	char pathname[PATH_MAX];
-	FILE *file = NULL;
-
-	// Check for access permissions in case we're sandbox'ed.
-	if (access(directory, R_OK | X_OK) == 0 && (dp = opendir(directory)) != NULL) {
-		// It's OK to use snprintf in this routine since it should only be called by the clients
-		// of stack logging, and thus calls to malloc are OK.
-		snprintf(prefix_and_pid	, (size_t)PATH_MAX, "%s%d.", stack_log_file_base_name, pid);	// make sure to use "%s%d." rather than just "%s%d" to match the whole pid
-		size_t prefix_and_pid_length = strlen(prefix_and_pid);
-
-		while ( (entry = readdir(dp)) != NULL ) {
-			if ( strncmp( entry->d_name, prefix_and_pid, prefix_and_pid_length) == 0 ) {
-				snprintf(pathname, (size_t)PATH_MAX, "%s/%s", directory, entry->d_name);
-				file = fopen(pathname, "r");
-				
-				// The hex address of the remote_index_cache in the target process
-				// is given in the stack log file name, following the pid and a period.
-				streams->remote_stack_buffer_shared_memory_address = strtoll(entry->d_name + prefix_and_pid_length, NULL, 16);
-				break;
-			}
-		}
-		closedir(dp);
-	}
-	streams->index_file_stream = file;
-	return file;
-}
-
-// Read the launch data of the target process from the kernel to find the
-// value of the environment variable named env_var_name.  Since this function
-// uses alloca() to temporarily allocate space for data copied from the kernel,
-// and we don't want to malloc space so that this can be called from malloc stack
-// logging code in the target process as well, we copy the result into the
-// env_var_value_buf of length max_path_len supplied by the caller.
-static bool
-getenv_from_process(pid_t pid, char *env_var_name, char *env_var_value_buf, size_t buf_length	)
-{
-	env_var_value_buf[0] = '\0';
-
-	// Just call getenv() if pid is the current process, partly to avoid the sysctl()
-	// call which can cause system deadlock (<rdar://problem/14409213> "processes hang
-	// if sandboxd is running with MallocStackLogging enabled").  But it probably
-	// doesn't completely fix that since there is another sysctl() call in is_process_running()
-	// when checking to see if the process corresponding to an existing stack log file
-	// is still running.
-	if (pid == getpid()) {
-		char *env_var_value = getenv(env_var_name);
-		if (! env_var_value) {
-			return false;
-		} else {
-			strlcpy(env_var_value_buf, env_var_value, buf_length);
-			return true;
-		}
-	}
-
-	int mib[3];
-	size_t argbufSize = 0;	// Must initialize this to 0 so this works when compiled for x86_64.
-
-	// First get the maximum arguments size, to determine the necessary buffer size.
-	mib[0] = CTL_KERN;
-	mib[1] = KERN_ARGMAX;
-
-	size_t size = sizeof(argbufSize);
-	int ret = sysctl(mib, 2, &argbufSize, &size, NULL, 0);
-	if (ret != 0) return false;
-
-	mib[0] = CTL_KERN;
-	mib[1] = KERN_PROCARGS2;	// The older KERN_PROCARGS is deprecated.
-	mib[2] = pid;
-
-	char *argbuf = (char *) alloca(argbufSize);
-	ret = sysctl(mib, 3, argbuf, &argbufSize, (void*)NULL, 0);
-	if (ret != 0) return false;
-	argbuf[argbufSize - 1] = '\0';	// make sure the buffer is null-terminated
-	char *p = argbuf;
-	char *endp = &argbuf[argbufSize];
-
-	// Skip over argc, which is always 4 bytes long (int-sized), even in 64-bit architectures.
-	int argumentCount = *((int*)argbuf);
-	p += sizeof(argumentCount);
-
-	// Skip over arguments, using the argumentCount read from the start of argbuf.
-	argumentCount++;	// increment argumentCount to also skip saved exec path, which comes first
-	for (int argumentNum = 0; argumentNum < argumentCount && p < endp; argumentNum++) {
-		while (p < endp && *p != '\0') p++;
-		while (p < endp && *p == '\0') p++;		// saved exec path sometimes has multiple nul's
-	}
-
-	size_t env_var_name_length = strlen(env_var_name);
-		
-	// Examine environment variables.
-	while ((p + env_var_name_length + 1) < endp && *p != '\0') {
-		if (strncmp(p, env_var_name, env_var_name_length) == 0 && p[env_var_name_length] == '=') {
-			p += env_var_name_length + 1;
-			strlcpy(env_var_value_buf, p, buf_length);
-			//_malloc_printf(ASL_LEVEL_INFO, "found env var %s='%s'\n", env_var_name, env_var_value_buf);
-			return true;
-		}
-		while (p < endp && *p != '\0') p++;
-		p++;
-	}
-	return false;
-}
-
-static FILE *
-open_log_file(pid_t pid, remote_task_file_streams *streams)
-{
-	static bool already_reaped = false;
-	if (! already_reaped) {
-		reap_orphaned_log_files(pid);	// reap any left-over log files (for non-existant processes, but not for this analysis process)
-		already_reaped = true;
-	}
-
-	// Since we're searching for the log file here, not creating it, we can search in any order we want.
-	// So look at MallocStackLoggingDirectory last since that is almost never set.
-	FILE *file = open_log_file_from_directory(pid, _PATH_TMP, streams);
-	if (! file) {
-		char *env_var_names[] = { "TMPDIR", "MallocStackLoggingDirectory" };
-		for (unsigned i = 0; i < sizeof(env_var_names) / sizeof(char *); i++) {
-			char directory[PATH_MAX];
-			bool success = getenv_from_process(pid, env_var_names[i], directory, sizeof(directory));
-			if (success) {
-				file = open_log_file_from_directory(pid, directory, streams);
-				if (file) break;
-			}
-		}
-	}
-	return file;
-}
-
-static remote_task_file_streams*
-retain_file_streams_for_task(task_t task)
-{
-	if (task == MACH_PORT_NULL) return NULL;
-
-	_malloc_lock_lock(&remote_fd_list_lock);
-
-	// see if they're already in use
-	uint32_t i = 0;
-	for (i = 0; i < remote_task_fd_count; i++) {
-		if (remote_fds[i].remote_task == task) {
-			remote_fds[i].in_use_count++;
-			_malloc_lock_unlock(&remote_fd_list_lock);
-			return &remote_fds[i];
-		}
-	}
-
-	// open them
-	uint32_t failures = 0;
-	if (remote_task_fd_count == STACK_LOGGING_MAX_SIMUL_REMOTE_TASKS_INSPECTED) {
-		while (remote_fds[next_remote_task_fd].in_use_count > 0) {
-			next_remote_task_fd++;
-			if (next_remote_task_fd == STACK_LOGGING_MAX_SIMUL_REMOTE_TASKS_INSPECTED) next_remote_task_fd = 0;
-			failures++;
-			if (failures >= STACK_LOGGING_MAX_SIMUL_REMOTE_TASKS_INSPECTED) {
-				_malloc_lock_unlock(&remote_fd_list_lock);
-				return NULL;
-			}
-		}
-		fclose(remote_fds[next_remote_task_fd].index_file_stream);
-		destroy_cache_for_file_streams(&remote_fds[next_remote_task_fd]);
-	}
-
-	pid_t pid;
-	kern_return_t err = pid_for_task(task, &pid);
-	if (err != KERN_SUCCESS) {
-		_malloc_lock_unlock(&remote_fd_list_lock);
-		return NULL;
-	}
-
-	remote_task_file_streams *this_task_streams = &remote_fds[next_remote_task_fd];
-
-	open_log_file(pid, this_task_streams);
-
-	// check if opens failed
-	if (this_task_streams->index_file_stream == NULL) {
-		_malloc_lock_unlock(&remote_fd_list_lock);
-		return NULL;
-	}
-
-	// check if target pid is running 64-bit
-	int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, pid };
-	struct kinfo_proc processInfo;
-	size_t bufsize = sizeof(processInfo);
-	if (sysctl(mib, (unsigned)(sizeof(mib)/sizeof(int)), &processInfo, &bufsize, NULL, (size_t)0) == 0 && bufsize > 0) {
-		this_task_streams->task_is_64_bit = processInfo.kp_proc.p_flag & P_LP64;
-	} else {
-		this_task_streams->task_is_64_bit = 0;
-	}
-
-	// otherwise set vars and go
-	this_task_streams->in_use_count = 1;
-	this_task_streams->remote_task = task;
-	this_task_streams->remote_pid = pid;
-	next_remote_task_fd++;
-	if (next_remote_task_fd == STACK_LOGGING_MAX_SIMUL_REMOTE_TASKS_INSPECTED) next_remote_task_fd = 0;
-	remote_task_fd_count = MIN(remote_task_fd_count + 1, STACK_LOGGING_MAX_SIMUL_REMOTE_TASKS_INSPECTED);
-
-	_malloc_lock_unlock(&remote_fd_list_lock);
-	return this_task_streams;
-}
-
-static void
-release_file_streams_for_task(task_t task)
-{
-	_malloc_lock_lock(&remote_fd_list_lock);
-
-	// decrement in-use count
-	uint32_t i = 0;
-	for (i = 0; i < remote_task_fd_count; i++) {
-		if (remote_fds[i].remote_task == task) {
-			remote_fds[i].in_use_count--;
-			break;
-		}
-	}
-
-	_malloc_lock_unlock(&remote_fd_list_lock);
-}
-
-#pragma mark - extern
-
-// This function is no longer used.  It was a hack that required an analysis tool process
-// to read the target tasks's __stack_log_file_path__ variable then pass the value of
-// that to this function.  This is now handled automatically all within this file, by
-// having the stack log reading code read the environment variables of the target process.
-// This function should be removed once no clients are calling it.
-kern_return_t
-__mach_stack_logging_set_file_path(task_t task, char* file_path)
-{
-	return KERN_SUCCESS;
-}
-
-kern_return_t
-__mach_stack_logging_get_frames(task_t task, mach_vm_address_t address, mach_vm_address_t *stack_frames_buffer, uint32_t max_stack_frames, uint32_t *count)
-{
-	remote_task_file_streams *remote_fd = retain_file_streams_for_task(task);
-	if (remote_fd == NULL) {
-		return KERN_FAILURE;
-	}
-
-	kern_return_t err = update_cache_for_file_streams(remote_fd);
-	if (err != KERN_SUCCESS) {
-		release_file_streams_for_task(task);
-		return err;
-	}
-
-	uint32_t collisions = 0;
-	size_t hash = hash_index(address, remote_fd->cache->cache_node_capacity);
-	size_t multiplier = hash_multiplier(remote_fd->cache->cache_node_capacity, remote_fd->cache->collision_allowance);
-	uint64_t located_file_position = 0;
-
-	bool found = false;
-	do {
-		if (remote_fd->cache->table_memory[hash].address == address) { // hit!
-			located_file_position = remote_fd->cache->table_memory[hash].index_file_offset;
-			found = true;
-			break;
-		} else if (remote_fd->cache->table_memory[hash].address == 0ull) { // failure!
-			break;
-		}
-
-		collisions++;
-		hash = next_hash(hash, multiplier, remote_fd->cache->cache_node_capacity, collisions);
-
-	} while (collisions <= remote_fd->cache->collision_allowance);
-
-	if (found) {
-		// prepare for the read; target process could be 32 or 64 bit.
-		stack_logging_index_event32 *target_32_index = NULL;
-		stack_logging_index_event64 *target_64_index = NULL;
-
-		if (located_file_position >= remote_fd->cache->last_index_file_offset) {
-			// must be in shared memory
-			if (remote_fd->cache->shmem) {
-				if (remote_fd->task_is_64_bit) {
-					target_64_index = (stack_logging_index_event64*)(remote_fd->cache->snapshot.index_buffer + (located_file_position - remote_fd->cache->snapshot.start_index_offset));
-					located_file_position = STACK_LOGGING_OFFSET(target_64_index->offset_and_flags);
-				} else {
-					target_32_index = (stack_logging_index_event32*)(remote_fd->cache->snapshot.index_buffer + (located_file_position - remote_fd->cache->snapshot.start_index_offset));
-					located_file_position = STACK_LOGGING_OFFSET(target_32_index->offset_and_flags);
-				}
-			} else {
-				found = false;
-			}
-
-		} else {
-			// it's written to disk
-			char bufferSpace[128];
-
-			size_t read_size = (remote_fd->task_is_64_bit ? sizeof(stack_logging_index_event64) : sizeof(stack_logging_index_event32));
-			fseeko(remote_fd->index_file_stream, (off_t)located_file_position, SEEK_SET);
-			size_t read_count = fread(bufferSpace, read_size, (size_t)1, remote_fd->index_file_stream);
-			if (read_count) {
-				if (remote_fd->task_is_64_bit) {
-					target_64_index = (stack_logging_index_event64*)bufferSpace;
-					located_file_position = STACK_LOGGING_OFFSET(target_64_index->offset_and_flags);
-				} else {
-					target_32_index = (stack_logging_index_event32*)bufferSpace;
-					located_file_position = STACK_LOGGING_OFFSET(target_32_index->offset_and_flags);
-				}
-			} else {
-				found = false;
-			}
-		}
-	}
-
-	release_file_streams_for_task(task);
-
-	if (!found) {
-		return KERN_FAILURE;
-	}
-
-	return __mach_stack_logging_frames_for_uniqued_stack(task, located_file_position, stack_frames_buffer, max_stack_frames, count);
-}
-
-
-kern_return_t
-__mach_stack_logging_enumerate_records(task_t task, mach_vm_address_t address, void enumerator(mach_stack_logging_record_t, void *), void *context)
-{
-	remote_task_file_streams *remote_fd = retain_file_streams_for_task(task);
-	if (remote_fd == NULL) {
-		return KERN_FAILURE;
-	}
-
-	bool reading_all_addresses = (address == 0 ? true : false);
-	mach_stack_logging_record_t pass_record;
-	kern_return_t err = KERN_SUCCESS;
-
-	// update (read index file once and only once)
-	err = update_cache_for_file_streams(remote_fd);
-	if (err != KERN_SUCCESS) {
-		release_file_streams_for_task(task);
-		return err;
-	}
-	
-	FILE *the_index = (remote_fd->index_file_stream);
-
-	// prepare for the read; target process could be 32 or 64 bit.
-	char bufferSpace[2048]; // 2 kb
-	stack_logging_index_event32 *target_32_index = (stack_logging_index_event32*)bufferSpace;
-	stack_logging_index_event64 *target_64_index = (stack_logging_index_event64*)bufferSpace;
-	uint32_t target_addr_32 = (uint32_t)STACK_LOGGING_DISGUISE((uint32_t)address);
-	uint64_t target_addr_64 = STACK_LOGGING_DISGUISE((uint64_t)address);
-	size_t read_size = (remote_fd->task_is_64_bit ? sizeof(stack_logging_index_event64) : sizeof(stack_logging_index_event32));
-	size_t number_slots = (size_t)(2048/read_size);
-	uint64_t total_slots = remote_fd->cache->last_index_file_offset / read_size;
-
-	// perform the search
-	size_t read_count = 0;
-	int64_t current_file_offset = 0;
-	uint32_t i;
-	do {
-		// at this point, we need to read index events; read them from the file until it's necessary to grab them from the shared memory snapshot
-		// and crop file reading to the point where we last scanned
-		number_slots = (size_t)MIN(number_slots, total_slots);
-
-		// if out of file to read (as of the time we entered this function), try to use shared memory snapshot
-		if (number_slots == 0) {
-			if (remote_fd->cache->shmem && remote_fd->cache->snapshot.start_index_offset + remote_fd->cache->snapshot.next_free_index_buffer_offset > (uint64_t)current_file_offset) {
-				// use shared memory
-				target_32_index = (stack_logging_index_event32*)remote_fd->cache->snapshot.index_buffer;
-				target_64_index = (stack_logging_index_event64*)remote_fd->cache->snapshot.index_buffer;
-				read_count = (uint32_t)(remote_fd->cache->snapshot.start_index_offset + remote_fd->cache->snapshot.next_free_index_buffer_offset - current_file_offset) / read_size;
-				current_file_offset += read_count * read_size;
-			} else {
-				break;
-			}
-		} else {
-			// get and save index (enumerator could modify)
-			fseeko(the_index, current_file_offset, SEEK_SET);
-			read_count = fread(bufferSpace, read_size, number_slots, the_index);
-			current_file_offset = ftello(the_index);
-			total_slots -= read_count;
-		}
-
-		if (remote_fd->task_is_64_bit) {
-			for (i = 0; i < read_count; i++) {
-				if (reading_all_addresses || target_64_index[i].address == target_addr_64) {
-					pass_record.address = STACK_LOGGING_DISGUISE(target_64_index[i].address);
-					pass_record.argument = target_64_index[i].argument;
-					pass_record.stack_identifier = STACK_LOGGING_OFFSET(target_64_index[i].offset_and_flags);
-					pass_record.type_flags = STACK_LOGGING_FLAGS_AND_USER_TAG(target_64_index[i].offset_and_flags);
-					enumerator(pass_record, context);
-				}
-			}
-		} else {
-			for (i = 0; i < read_count; i++) {
-				if (reading_all_addresses || target_32_index[i].address == target_addr_32) {
-					pass_record.address = STACK_LOGGING_DISGUISE(target_32_index[i].address);
-					pass_record.argument = target_32_index[i].argument;
-					pass_record.stack_identifier = STACK_LOGGING_OFFSET(target_32_index[i].offset_and_flags);
-					pass_record.type_flags = STACK_LOGGING_FLAGS_AND_USER_TAG(target_32_index[i].offset_and_flags);
-					enumerator(pass_record, context);
-				}
-			}
-		}
-	} while (read_count);
-
-	release_file_streams_for_task(task);
-	return err;
-}
-
-
-kern_return_t
-__mach_stack_logging_frames_for_uniqued_stack(task_t task, uint64_t stack_identifier, mach_vm_address_t *stack_frames_buffer, uint32_t max_stack_frames, uint32_t *count)
-{
-	remote_task_file_streams *remote_fd = retain_file_streams_for_task(task);
-	if (remote_fd == NULL) return KERN_FAILURE;
-
-	unwind_stack_from_table_index(&remote_fd->cache->uniquing_table_snapshot, stack_identifier, stack_frames_buffer, count, max_stack_frames);
-
-	release_file_streams_for_task(task);
-
-	if (*count) return KERN_SUCCESS;
-	else return KERN_FAILURE;
-}
-
-
-#ifdef TEST_DISK_STACK_LOGGING
-
-// cc -o stack_logging_disk stack_logging_disk.c -DTEST_DISK_STACK_LOGGING
-
-#include <sys/wait.h>
-
-int
-main()
-{
-	int status;
-	int i;
-	size_t total_globals = 0ul;
-
-	fprintf(stderr, "master test process is %d\n", getpid());
-	fprintf(stderr, "sizeof pre_write_buffers: %lu\n", sizeof(pre_write_buffers)); total_globals += sizeof(pre_write_buffers);
-	fprintf(stderr, "sizeof stack_buffer: %lu\n", sizeof(stack_buffer)); total_globals += sizeof(stack_buffer);
-	fprintf(stderr, "sizeof last_logged_malloc_address: %lu\n", sizeof(last_logged_malloc_address)); total_globals += sizeof(last_logged_malloc_address);
-	fprintf(stderr, "sizeof stack_log_file_base_name: %lu\n", sizeof(stack_log_file_base_name)); total_globals += sizeof(stack_log_file_base_name);
-	fprintf(stderr, "sizeof stack_log_file_suffix: %lu\n", sizeof(stack_log_file_suffix)); total_globals += sizeof(stack_log_file_suffix);
-	fprintf(stderr, "sizeof __stack_log_file_path__ (index_file_path): %lu\n", (size_t)PATH_MAX); total_globals += (size_t)PATH_MAX;
-	fprintf(stderr, "sizeof index_file_descriptor: %lu\n", sizeof(index_file_descriptor)); total_globals += sizeof(index_file_descriptor);
-	fprintf(stderr, "sizeof remote_fds: %lu\n", sizeof(remote_fds)); total_globals += sizeof(remote_fds);
-	fprintf(stderr, "sizeof next_remote_task_fd: %lu\n", sizeof(next_remote_task_fd)); total_globals += sizeof(next_remote_task_fd);
-	fprintf(stderr, "sizeof remote_task_fd_count: %lu\n", sizeof(remote_task_fd_count)); total_globals += sizeof(remote_task_fd_count);
-	fprintf(stderr, "sizeof remote_fd_list_lock: %lu\n", sizeof(remote_fd_list_lock)); total_globals += sizeof(remote_fd_list_lock);
-	fprintf(stderr, "sizeof logging_use_compaction: %lu\n", sizeof(logging_use_compaction)); total_globals += sizeof(logging_use_compaction);
-	
-	fprintf(stderr, "size of all global data: %lu\n", total_globals);
-	
-	create_log_file();
-	
-	// create a few child processes and exit them cleanly so their logs should get cleaned up
-	fprintf(stderr, "\ncreating child processes and exiting cleanly\n");
-	for (i = 0; i < 3; i++) {
-		if (fork() == 0) {
-			fprintf(stderr, "\nin child processes %d\n", getpid());
-			create_log_file();
-			fprintf(stderr, "exiting child processes %d\n", getpid());
-			exit(1);
-		}
-		wait(&status);
-	}
-	
-	// create a few child processes and abruptly _exit them, leaving their logs around
-	fprintf(stderr, "\ncreating child processes and exiting abruptly, leaving logs around\n");
-	for (i = 0; i < 3; i++) {
-		if (fork() == 0) {
-			fprintf(stderr, "\nin child processes %d\n", getpid());
-			create_log_file();
-			fprintf(stderr, "exiting child processes %d\n", getpid());
-			_exit(1);
-		}
-		wait(&status);
-	}
-	
-	// this should reap any remaining logs
-	fprintf(stderr, "\nexiting master test process %d\n", getpid());
-	delete_log_files();
-	return 0;
-}
-
-#endif
-
-/* vim: set noet:ts=4:sw=4:cindent: */