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--- /dev/null
+++ Libc/Libc-763.13/gen/stack_logging_disk.c
@@ -0,0 +1,1678 @@
+/*
+ * Copyright (c) 2007-2009 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 <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 <sys/sysctl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <pthread.h>
+#include <paths.h>
+#include <errno.h>
+#include "stack_logging.h"
+#include "malloc_printf.h"
+#include "_simple.h" // as included by malloc.c, this defines ASL_LEVEL_INFO
+
+#pragma mark -
+#pragma mark Defines
+
+#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(longlongvar) (uint8_t)((uint64_t)(longlongvar) >> 56)
+#define STACK_LOGGING_OFFSET(longlongvar) ((longlongvar) & 0x00FFFFFFFFFFFFFFull)
+#define STACK_LOGGING_OFFSET_AND_FLAGS(longlongvar, realshortvar) (((uint64_t)(longlongvar) & 0x00FFFFFFFFFFFFFFull) | ((uint64_t)(realshortvar) << 56))
+
+#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;
+
+#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
+ mach_vm_address_t *table; // allocated using vm_allocate()
+} 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;
+ mach_vm_address_t uniquing_table_address;
+ 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 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;
+ remote_index_cache *cache;
+} remote_task_file_streams;
+
+#pragma mark -
+#pragma mark Constants/Globals
+
+static OSSpinLock stack_logging_lock = OS_SPINLOCK_INIT;
+
+// support for multi-threaded forks
+extern void __stack_logging_fork_prepare();
+extern void __stack_logging_fork_parent();
+extern void __stack_logging_fork_child();
+
+// support for gdb and others checking for stack_logging locks
+__private_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 stack logging file path names.
+// Files will get written as /tmp/stack-logs.<pid>.<progname>.XXXXXX.index
+// unless the base directory is specified otherwise with MallocStackLoggingDirectory.
+// In this case, a file /tmp/stack-logs.<pid>.<progname>.XXXXXX.link will also be created.
+static const char *stack_log_file_base_name = "stack-logs.";
+static const char *stack_log_file_suffix = ".index";
+static const char *stack_log_link_suffix = ".link";
+
+static void *stack_log_path_buffers = NULL;
+static char *stack_log_location = NULL;
+static char *stack_log_reference_file = NULL;
+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 OSSpinLock remote_fd_list_lock = OS_SPINLOCK_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;
+
+#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 exhaused!\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->table = (mach_vm_address_t*)(uintptr_t)allocate_pages(uniquing_table->tableSize);
+ uniquing_table->table_address = (uintptr_t)uniquing_table->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
+__expand_uniquing_table(backtrace_uniquing_table *uniquing_table)
+{
+ mach_vm_address_t *oldTable = uniquing_table->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->table = newTable;
+ uniquing_table->table_address = (uintptr_t)uniquing_table->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->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->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;
+}
+
+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 = uniquing_table->table + (index_pos * 2);
+ 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 = uniquing_table->table + (node[1] * 2);
+ }
+ }
+
+ *out_frames_count = foundFrames;
+}
+
+#pragma mark -
+#pragma mark Disk Stack Logging
+
+static void delete_log_files(void); // pre-declare
+static int delete_logging_file(char *log_location);
+
+static void
+append_int(char * filename, pid_t pid, size_t maxLength)
+{
+ size_t len = strlen(filename);
+
+ uint32_t count = 0;
+ pid_t value = pid;
+ while (value > 0) {
+ value /= 10;
+ count++;
+ }
+
+ if (len + count >= maxLength) return; // don't modify the string if it would violate maxLength
+
+ filename[len + count] = '\0';
+
+ value = pid;
+ uint32_t i;
+ for (i = 0 ; i < count ; i ++) {
+ filename[len + count - 1 - i] = '0' + value % 10;
+ value /= 10;
+ }
+}
+
+/*
+ * Check various temporary directory options starting with _PATH_TMP and use confstr.
+ * Allocating and releasing target buffer is the caller's responsibility.
+ */
+static bool
+get_writeable_temp_dir(char* target)
+{
+ if (!target) return false;
+ if (-1 != access(_PATH_TMP, W_OK)) {
+ strlcpy(target, _PATH_TMP, (size_t)PATH_MAX);
+ return true;
+ }
+ size_t n = confstr(_CS_DARWIN_USER_TEMP_DIR, target, (size_t) PATH_MAX);
+ if ((n > 0) && (n < PATH_MAX)) return true;
+ n = confstr(_CS_DARWIN_USER_CACHE_DIR, target, (size_t) PATH_MAX);
+ if ((n > 0) && (n < PATH_MAX)) return true;
+ /* No writeable tmp directory found. Maybe shd try /private/var/tmp for device here ... */
+ *target = '\0';
+ return false;
+}
+
+/*
+ * If successful, returns path to log file that was created, otherwise NULL.
+ *
+ * The log could be in one of 3 places (in decreasing order of preference)
+ *
+ * 1) value of environment variable MallocStackLoggingDirectory
+ * 2) the temp directory /tmp for desktop apps and internal apps on devices, or
+ * 3) the sandbox location + tmp/ in case of 3rd party apps on the device.
+ *
+ * For 1 and 3, we create a .link file with the path of the file. We prefer to
+ * create this file in /tmp, but if we are unable to (device 3rd party case),
+ * we create it in the same location as the .index file and issue a message
+ * in syslog asking for it to be copied to /tmp to enable tools.
+ *
+ */
+static char *
+create_log_file(void)
+{
+ pid_t pid = getpid();
+ const char *progname = getprogname();
+ char *created_log_location = NULL;
+
+ if (stack_log_path_buffers == NULL) {
+ /*
+ * on first use, allocate buffers directly from the OS without
+ * using malloc
+ */
+
+ stack_log_path_buffers = allocate_pages((uint64_t)round_page(3*PATH_MAX));
+ if (stack_log_path_buffers == NULL) {
+ _malloc_printf(ASL_LEVEL_INFO, "unable to allocate memory for path buffers\n");
+ return NULL;
+ }
+
+ stack_log_location = &((char *)stack_log_path_buffers)[0*PATH_MAX];
+ stack_log_reference_file = &((char *)stack_log_path_buffers)[1*PATH_MAX];
+ __stack_log_file_path__ = &((char *)stack_log_path_buffers)[2*PATH_MAX];
+ }
+
+ // WARNING! use of snprintf can induce malloc() calls
+ bool use_alternate_location = false;
+ char *evn_log_directory = getenv("MallocStackLoggingDirectory");
+ size_t stack_log_len;
+ if (evn_log_directory && *evn_log_directory) {
+ use_alternate_location = true;
+ strlcpy(stack_log_location, evn_log_directory, (size_t)PATH_MAX);
+ }
+ if (!use_alternate_location || (access(stack_log_location, W_OK) == -1)) {
+ if (!get_writeable_temp_dir(stack_log_location)) {
+ _malloc_printf(ASL_LEVEL_INFO, "No writeable tmp dir\n");
+ return NULL;
+ }
+ if (0 != strcmp(stack_log_location, _PATH_TMP))
+ use_alternate_location = true;
+ }
+ stack_log_len = strlen(stack_log_location);
+ // add the '/' only if it's not already there.
+ if (stack_log_location[stack_log_len-1] != '/') {
+ strlcat(stack_log_location, "/", (size_t)PATH_MAX);
+ ++stack_log_len;
+ }
+
+ strlcpy(__stack_log_file_path__, stack_log_location, (size_t)PATH_MAX);
+
+ strlcat(__stack_log_file_path__, stack_log_file_base_name, (size_t)PATH_MAX);
+ append_int(__stack_log_file_path__, pid, (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);
+ }
+ if (!use_alternate_location) 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_location);
+ if (use_alternate_location) delete_logging_file(stack_log_reference_file);
+ stack_log_reference_file[0] = '\0';
+ stack_log_location[0] = '\0';
+ __stack_log_file_path__[0] = '\0';
+ created_log_location = NULL;
+ return created_log_location;
+ }
+
+ // in the case where the user has specified an alternate location, drop a reference file
+ // in /tmp with the suffix 'stack_log_link_suffix' (".link") and save the path of the
+ // stack logging file there.
+ bool use_alternate_link_location = false;
+ if (use_alternate_location) {
+ strlcpy(stack_log_reference_file, _PATH_TMP, (size_t)PATH_MAX);
+ if (access(stack_log_reference_file, W_OK) == -1) {
+ strlcpy(stack_log_reference_file, stack_log_location, (size_t)PATH_MAX);
+ use_alternate_link_location = true;
+ }
+ strlcat(stack_log_reference_file, stack_log_file_base_name, (size_t)PATH_MAX);
+ append_int(stack_log_reference_file, pid, (size_t)PATH_MAX);
+ if (progname && progname[0] != '\0') {
+ strlcat(stack_log_reference_file, ".", (size_t)PATH_MAX);
+ strlcat(stack_log_reference_file, progname, (size_t)PATH_MAX);
+ }
+ if (!use_alternate_link_location)
+ strlcat(stack_log_reference_file, ".XXXXXX", (size_t)PATH_MAX);
+ strlcat(stack_log_reference_file, ".XXXXXX", (size_t)PATH_MAX);
+ strlcat(stack_log_reference_file, stack_log_link_suffix, (size_t)PATH_MAX);
+
+ int link_file_descriptor = mkstemps(stack_log_reference_file, (int)strlen(stack_log_link_suffix));
+ if (link_file_descriptor == -1) {
+ _malloc_printf(ASL_LEVEL_INFO, "unable to create stack reference file %s at %s\n",
+ stack_log_reference_file, stack_log_location);
+ } else {
+ ssize_t written = write(link_file_descriptor, __stack_log_file_path__, strlen(__stack_log_file_path__));
+ if (written < (ssize_t)strlen(__stack_log_file_path__)) {
+ _malloc_printf(ASL_LEVEL_INFO, "unable to write to stack reference file %s at %s\n",
+ stack_log_reference_file, stack_log_location);
+ } else {
+ const char *description_string = "\n(This is a reference file to the stack logs at the path above.)\n";
+ write(link_file_descriptor, description_string, strlen(description_string));
+ }
+ }
+ close(link_file_descriptor);
+ }
+ if (use_alternate_link_location) {
+ _malloc_printf(ASL_LEVEL_INFO, "Please issue: cp %s %s\n", stack_log_reference_file, _PATH_TMP);
+ }
+ return created_log_location;
+}
+
+// Check to see if the log file is actually a reference to another location
+static int
+log_file_is_reference(char *log_location, char *out_reference_loc_buffer, size_t max_reference_path_size)
+{
+ if (log_location == NULL || log_location[0] == '\0') return 0;
+
+ size_t log_len = strlen(log_location);
+ size_t link_suffix_len = strlen(stack_log_link_suffix);
+ if (log_len < link_suffix_len || strncmp(log_location+log_len-link_suffix_len, stack_log_link_suffix, link_suffix_len) != 0) {
+ // not a reference file.
+ return 0;
+ }
+
+ if (!out_reference_loc_buffer || max_reference_path_size == 0) return 1;
+
+ FILE *reference_file = fopen(log_location, "r");
+ if (reference_file == NULL) {
+ // if unable to open the file, it may be because another user created it; no need to warn.
+ out_reference_loc_buffer[0] = '\0';
+ return 1;
+ }
+
+ char *ret = fgets(out_reference_loc_buffer, (int)max_reference_path_size, reference_file);
+ if (!ret) {
+ out_reference_loc_buffer[0] = '\0';
+ _malloc_printf(ASL_LEVEL_INFO, "unable to read from stack logging reference file at %s\n", log_location);
+ return 1;
+ } else {
+ size_t read_line_len = strlen(out_reference_loc_buffer);
+ if (read_line_len >= 1 && out_reference_loc_buffer[read_line_len-1] == '\n') {
+ out_reference_loc_buffer[read_line_len-1] = '\0';
+ }
+ }
+
+ fclose(reference_file);
+
+ return 1;
+}
+
+// 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__);
+ }
+ }
+ if (stack_log_reference_file && stack_log_reference_file[0]) {
+ delete_logging_file(stack_log_reference_file);
+ }
+}
+
+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));
+}
+
+// The log files can be quite large and aren't too useful after the process that created them no longer exists.
+// Normally they should get removed when the process exits, but if the process crashed the log files might remain.
+// So, reap any stack log files for processes that no longer exist.
+//
+// lf the remove_for_this_pid flag is set, then any log files that already exist for the current process will also be deleted.
+// Those log files are probably the result of this process having been exec'ed from another one (without a fork()).
+// The remove_for_this_pid flag is only set for a target process (one just starting logging); a stack logging "client"
+// process reaps log files too, but if we're using stack logging on the client process itself, then we don't want to remove
+// its own log files.
+static void
+reap_orphaned_log_files(bool remove_for_this_pid)
+{
+ DIR *dp;
+ struct dirent *entry;
+ char prefix_name[PATH_MAX];
+ char pathname[PATH_MAX];
+ pid_t current_pid = getpid();
+
+ if ((dp = opendir(_PATH_TMP)) == NULL) {
+ return;
+ }
+
+ strlcpy(prefix_name, stack_log_file_base_name, (size_t)PATH_MAX);
+ size_t prefix_length = strlen(prefix_name);
+
+ while ( (entry = readdir(dp)) != NULL ) {
+ if ( entry->d_type != DT_DIR && entry->d_type != DT_LNK && ( strncmp( entry->d_name, prefix_name, prefix_length) == 0 ) ) {
+ long pid = strtol(&entry->d_name[prefix_length], (char **)NULL, 10);
+ if ( (! is_process_running((pid_t)pid)) || (remove_for_this_pid && (pid_t)pid == current_pid) ) {
+ strlcpy(pathname, _PATH_TMP, (size_t)PATH_MAX);
+ strlcat(pathname, entry->d_name, (size_t)PATH_MAX);
+ char reference_file_buffer[PATH_MAX];
+ bool pathname_is_ref_file = false;
+ if (log_file_is_reference(pathname, reference_file_buffer, (size_t)PATH_MAX) && *reference_file_buffer) {
+ pathname_is_ref_file = true;
+ if (delete_logging_file(reference_file_buffer) == 0) {
+ if (remove_for_this_pid && pid == current_pid) {
+ _malloc_printf(ASL_LEVEL_INFO, "stack logs deleted from %s\n", reference_file_buffer);
+ } else {
+ _malloc_printf(ASL_LEVEL_INFO, "process %ld no longer exists, stack logs deleted from %s\n", pid, reference_file_buffer);
+ }
+ }
+ }
+ if (delete_logging_file(pathname) == 0) {
+ if (remove_for_this_pid && pid == current_pid) {
+ if (!pathname_is_ref_file) _malloc_printf(ASL_LEVEL_INFO, "stack logs deleted from %s\n", pathname);
+ } else {
+ if (!pathname_is_ref_file) _malloc_printf(ASL_LEVEL_INFO, "process %ld no longer exists, stack logs deleted from %s\n", pid, pathname);
+ }
+ char shmem_name_string[PATH_MAX];
+ strlcpy(shmem_name_string, stack_log_file_base_name, (size_t)PATH_MAX);
+ append_int(shmem_name_string, (pid_t)pid, (size_t)PATH_MAX);
+ if (pid != current_pid) shm_unlink(shmem_name_string);
+ }
+ }
+ }
+ }
+ closedir(dp);
+}
+
+/*
+ * 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;
+}
+
+/* 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;
+}
+
+static 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 shared memory region to hold the pre-write index and stack buffers. This will allow 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.
+ char shmem_name_string[PATH_MAX];
+ strlcpy(shmem_name_string, stack_log_file_base_name, (size_t)PATH_MAX);
+ append_int(shmem_name_string, getpid(), (size_t)PATH_MAX);
+
+ int shmid = shm_open(shmem_name_string, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+ if (shmid < 0) {
+ // Failed to create shared memory region; turn off stack logging.
+ _malloc_printf(ASL_LEVEL_INFO, "error while allocating shared memory for disk-based stack logging output buffers\n");
+ disable_stack_logging();
+ return;
+ }
+
+ size_t full_shared_mem_size = sizeof(stack_buffer_shared_memory);
+ ftruncate(shmid, (off_t)full_shared_mem_size);
+ pre_write_buffers = (stack_buffer_shared_memory*)mmap(0, full_shared_mem_size, PROT_READ | PROT_WRITE, MAP_SHARED, shmid, (off_t)0);
+ close(shmid);
+
+ if (MAP_FAILED == pre_write_buffers) {
+ _malloc_printf(ASL_LEVEL_INFO, "error mapping in shared memory for disk-based 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();
+ pre_write_buffers->uniquing_table_address = (mach_vm_address_t)(uintptr_t)pre_write_buffers->uniquing_table;
+ if (!pre_write_buffers->uniquing_table) {
+ _malloc_printf(ASL_LEVEL_INFO, "error while allocating stack uniquing table\n");
+ disable_stack_logging();
+ return;
+ }
+
+ stack_buffer = (vm_address_t*)allocate_pages((uint64_t)round_page(sizeof(vm_address_t) * STACK_LOGGING_MAX_STACK_SIZE));
+ if (!stack_buffer) {
+ _malloc_printf(ASL_LEVEL_INFO, "error while allocating stack trace buffer\n");
+ disable_stack_logging();
+ return;
+ }
+
+ // 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()
+ reap_orphaned_log_files(true); // this calls opendir() which calls malloc()
+
+ // this call ensures that the log files exist; analyzing processes will rely on this assumption.
+ if (create_log_file() == NULL) {
+ disable_stack_logging();
+ return;
+ }
+ }
+}
+
+void
+__disk_stack_logging_log_stack(uint32_t type_flags, uintptr_t zone_ptr, uintptr_t size, uintptr_t ptr_arg, uintptr_t return_val, uint32_t num_hot_to_skip)
+{
+ if (!stack_logging_enable_logging) return;
+
+ // check incoming data
+ if (type_flags & stack_logging_type_alloc && type_flags & stack_logging_type_dealloc) {
+ uintptr_t swapper = size;
+ size = ptr_arg;
+ ptr_arg = swapper;
+ 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) {
+ if (size) {
+ ptr_arg = size;
+ size = 0;
+ } else return; // free(nil)
+ }
+ if (type_flags & stack_logging_type_alloc && return_val == 0) return; // alloc that failed
+
+ type_flags &= 0x7;
+
+ // 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 this variable before continuing
+ if (!stack_logging_enable_logging) return;
+ vm_address_t self_thread = (vm_address_t)pthread_self(); // use pthread_self() rather than mach_thread_self() to avoid system call
+
+ // lock and enter
+ OSSpinLockLock(&stack_logging_lock);
+
+ if (!stack_logging_enable_logging) {
+ OSSpinLockUnlock(&stack_logging_lock);
+ return;
+ }
+
+ // 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;
+
+ OSSpinLockUnlock(&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().
+ OSSpinLockUnlock(&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) {
+ 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 = 0ul;
+ 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, ¤t_index, sizeof(stack_logging_index_event));
+ pre_write_buffers->next_free_index_buffer_offset += (uint32_t)sizeof(stack_logging_index_event);
+
+ OSSpinLockUnlock(&stack_logging_lock);
+}
+
+void
+__stack_logging_fork_prepare() {
+ OSSpinLockLock(&stack_logging_lock);
+}
+
+void
+__stack_logging_fork_parent() {
+ OSSpinLockUnlock(&stack_logging_lock);
+}
+
+void
+__stack_logging_fork_child() {
+ malloc_logger = NULL;
+ stack_logging_enable_logging = 0;
+ OSSpinLockUnlock(&stack_logging_lock);
+}
+
+boolean_t
+__stack_logging_locked()
+{
+ bool acquired_lock = OSSpinLockTry(&stack_logging_lock);
+ if (acquired_lock) OSSpinLockUnlock(&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 - 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);
+
+ bool inserted = false;
+ while (!inserted) {
+ 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 = true;
+ 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;
+ }
+ }
+
+}
+
+static void
+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));
+
+ // now map in the shared memory, if possible
+ char shmem_name_string[PATH_MAX];
+ strlcpy(shmem_name_string, stack_log_file_base_name, (size_t)PATH_MAX);
+ append_int(shmem_name_string, descriptors->remote_pid, (size_t)PATH_MAX);
+
+ int shmid = shm_open(shmem_name_string, O_RDWR, S_IRUSR | S_IWUSR);
+ if (shmid >= 0) {
+ cache->shmem = mmap(0, sizeof(stack_buffer_shared_memory), PROT_READ | PROT_WRITE, MAP_SHARED, shmid, (off_t)0);
+ close(shmid);
+ }
+
+ if (shmid < 0 || cache->shmem == MAP_FAILED) {
+ // failed to connect to the shared memory region; warn and continue.
+ _malloc_printf(ASL_LEVEL_INFO, "warning: unable to connect to remote process' shared memory; allocation histories may not be up-to-date.\n");
+ }
+ }
+
+ // 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.
+ 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));
+ kern_return_t err;
+ if ((err = mach_vm_read(descriptors->remote_task, cache->shmem->uniquing_table_address, 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
+ if (cache->uniquing_table.table) mach_vm_deallocate(mach_task_self(), (mach_vm_address_t)(uintptr_t)(cache->uniquing_table.table), cache->uniquing_table.tableSize);
+
+ // the following line gathers the uniquing table structure data, but the actual table memory is invalid since it's a pointer from the
+ // remote process. this pointer will be mapped shared in a few lines.
+ cache->uniquing_table = *((backtrace_uniquing_table*)local_uniquing_address);
+
+ vm_address_t local_table_address = 0ul;
+ mach_msg_type_number_t local_table_size = 0;
+
+ err = mach_vm_read(descriptors->remote_task, cache->uniquing_table.table_address, cache->uniquing_table.tableSize, &local_table_address, &local_table_size);
+ if (err == KERN_SUCCESS) cache->uniquing_table.table = (mach_vm_address_t*)local_table_address;
+ else cache->uniquing_table.table = NULL;
+
+ 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 (!update_snapshot && delta_indecies == 0) return; // 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)));
+ }
+ }
+ }
+}
+
+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 files for target process <pid>
+// by scanning the temporary directory for directory entries with names of the form "stack-logs.<pid>."
+// If we find such a directory then open the stack logging files in there.
+// We might also have been passed the file path if the client first read it from __stack_log_file_path__
+// global variable in the target task, as will be needed if the .link cannot be put in /tmp.
+static void
+open_log_files(pid_t pid, char* file_path, remote_task_file_streams *this_task_streams)
+{
+ DIR *dp;
+ struct dirent *entry;
+ char prefix_name[PATH_MAX];
+ char pathname[PATH_MAX];
+
+ reap_orphaned_log_files(false); // reap any left-over log files (for non-existant processes, but not for this analysis process)
+
+ if (file_path != NULL) {
+ this_task_streams->index_file_stream = fopen(file_path, "r");
+ return;
+ }
+
+ if ((dp = opendir(_PATH_TMP)) == NULL) {
+ return;
+ }
+
+ // 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_name, (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_length = strlen(prefix_name);
+
+ while ( (entry = readdir(dp)) != NULL ) {
+ if ( strncmp( entry->d_name, prefix_name, prefix_length) == 0 ) {
+ snprintf(pathname, (size_t)PATH_MAX, "%s%s", _PATH_TMP, entry->d_name);
+ char reference_file[PATH_MAX];
+ if (log_file_is_reference(pathname, reference_file, (size_t)PATH_MAX)) {
+ this_task_streams->index_file_stream = fopen(reference_file, "r");
+ } else {
+ this_task_streams->index_file_stream = fopen(pathname, "r");
+ }
+
+ break;
+ }
+ }
+ closedir(dp);
+}
+
+static remote_task_file_streams*
+retain_file_streams_for_task(task_t task, char* file_path)
+{
+ if (task == MACH_PORT_NULL) return NULL;
+
+ OSSpinLockLock(&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++;
+ OSSpinLockUnlock(&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) {
+ OSSpinLockUnlock(&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) {
+ OSSpinLockUnlock(&remote_fd_list_lock);
+ return NULL;
+ }
+
+ remote_task_file_streams *this_task_streams = &remote_fds[next_remote_task_fd];
+
+ open_log_files(pid, file_path, this_task_streams);
+
+ // check if opens failed
+ if (this_task_streams->index_file_stream == NULL) {
+ if (this_task_streams->index_file_stream) fclose(this_task_streams->index_file_stream);
+ OSSpinLockUnlock(&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);
+
+ OSSpinLockUnlock(&remote_fd_list_lock);
+ return this_task_streams;
+}
+
+static void
+release_file_streams_for_task(task_t task)
+{
+ OSSpinLockLock(&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;
+ }
+ }
+
+ OSSpinLockUnlock(&remote_fd_list_lock);
+}
+
+#pragma mark - extern
+
+//
+// The following is used by client tools like malloc_history and Instruments to pass along the path
+// of the index file as read from the target task's __stack_log_file_path__ variable (set in this file)
+// Eventually, at a suitable point, this additional argument should just be added to the other APIs below.
+//
+kern_return_t
+__mach_stack_logging_set_file_path(task_t task, char* file_path)
+{
+ remote_task_file_streams *remote_fd = retain_file_streams_for_task(task, file_path);
+ if (remote_fd == NULL) {
+ return KERN_FAILURE;
+ }
+ 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, NULL);
+ if (remote_fd == NULL) {
+ return KERN_FAILURE;
+ }
+
+ update_cache_for_file_streams(remote_fd);
+
+ 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, NULL);
+ 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)
+ update_cache_for_file_streams(remote_fd);
+
+ 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(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(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, NULL);
+ if (remote_fd == NULL) return KERN_FAILURE;
+
+ __unwind_stack_from_table_index(&remote_fd->cache->uniquing_table, 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_link_suffix: %lu\n", sizeof(stack_log_link_suffix)); total_globals += sizeof(stack_log_link_suffix);
+ fprintf(stderr, "sizeof stack_log_location: %lu\n", (size_t)PATH_MAX); total_globals += (size_t)PATH_MAX;
+ fprintf(stderr, "sizeof stack_log_reference_file: %lu\n", (size_t)PATH_MAX); total_globals += (size_t)PATH_MAX;
+ 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