osfmk/kern/extmod_statistics.c

   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 */
  66 extern void fslog_extmod_msgtracer(void *, void *);
  67
  68 /* local routines */
  69 static void
  70 extmod_statistics_log(task_t current_task, task_t target);
  71
  72 void
  73 extmod_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
  87 void
  88 extmod_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
 108 void
 109 extmod_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
 125 static void
 126 extmod_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 }