1/* 2 * Copyright (c) 2011 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29#include <mach/mach_types.h> 30 31#include <kern/host.h> 32#include <kern/thread.h> 33#include <kern/task.h> 34#include <kern/extmod_statistics.h> 35#include <libkern/OSAtomic.h> 36 37#include <uuid/uuid.h> 38 39/* 40 * This code module adds statistics to track when 41 * a userspace task is modified by another userspace 42 * task. This can facilitate triage of crashes 43 * and abberant behavior, which are not expected 44 * to occur when the program is running in its 45 * qualified environment. 46 * 47 * We assume the target task has a lifecycle lock 48 * that will prevent it from exiting 49 * (task_reference/task_reference_internal), which 50 * should be called either explicitly, or implicitly 51 * via MIG glue code (convert_port_to_task). 52 * 53 * Host-wide statistics don't asssume any locks are 54 * held, and use atomic operations. 55 * 56 * If we can detect that the kernel proper is 57 * performing these operations, don't count 58 * it as an external modification. Some of the 59 * external modification routines are called 60 * by the kernel during thread setup, in which 61 * case we rename the userspace entrypoint called 62 * by the MIG demuxer to have a "_from_user" suffix. 63 */ 64 65/* externs for BSD kernel */ 66extern void fslog_extmod_msgtracer(void *, void *); 67 68/* local routines */ 69static void 70extmod_statistics_log(task_t current_task, task_t target); 71 72void 73extmod_statistics_incr_task_for_pid(task_t target) 74{ 75 task_t ctask = current_task(); 76 77 if ((ctask == kernel_task) || (target == TASK_NULL)) 78 return; 79 80 if (target != ctask) { 81 ctask->extmod_statistics.task_for_pid_caller_count++; 82 target->extmod_statistics.task_for_pid_count++; 83 OSIncrementAtomic64(&host_extmod_statistics.task_for_pid_count); 84 } 85} 86 87void 88extmod_statistics_incr_thread_set_state(thread_t target) 89{ 90 task_t ctask = current_task(); 91 task_t ttask; 92 93 if ((ctask == kernel_task) || (target == THREAD_NULL)) 94 return; 95 96 ttask = get_threadtask(target); 97 98 if (ttask == TASK_NULL) 99 return; 100 101 if (ttask != ctask) { 102 ctask->extmod_statistics.thread_set_state_caller_count++; 103 ttask->extmod_statistics.thread_set_state_count++; 104 OSIncrementAtomic64(&host_extmod_statistics.thread_set_state_count); 105 } 106} 107 108void 109extmod_statistics_incr_thread_create(task_t target) 110{ 111 task_t ctask = current_task(); 112 113 if ((ctask == kernel_task) || (target == TASK_NULL)) 114 return; 115 116 if (target != ctask) { 117 ctask->extmod_statistics.thread_creation_caller_count++; 118 target->extmod_statistics.thread_creation_count++; 119 OSIncrementAtomic64(&host_extmod_statistics.thread_creation_count); 120 121 extmod_statistics_log(ctask, target); 122 } 123} 124 125static void 126extmod_statistics_log(task_t current_task, task_t target) 127{ 128 void *c_proc; 129 void *t_proc; 130 131 c_proc = get_bsdtask_info(current_task); 132 t_proc = get_bsdtask_info(target); 133 if (c_proc && t_proc) { 134 fslog_extmod_msgtracer(c_proc, t_proc); 135 } 136} 137