/*
* Copyright (c) 2011 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_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. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* 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_OSREFERENCE_LICENSE_HEADER_END@
*/
#include <mach/mach_types.h>
#include <kern/host.h>
#include <kern/thread.h>
#include <kern/task.h>
#include <kern/extmod_statistics.h>
#include <libkern/OSAtomic.h>
#include <uuid/uuid.h>
/*
* This code module adds statistics to track when
* a userspace task is modified by another userspace
* task. This can facilitate triage of crashes
* and abberant behavior, which are not expected
* to occur when the program is running in its
* qualified environment.
*
* We assume the target task has a lifecycle lock
* that will prevent it from exiting
* (task_reference/task_reference_internal), which
* should be called either explicitly, or implicitly
* via MIG glue code (convert_port_to_task).
*
* Host-wide statistics don't asssume any locks are
* held, and use atomic operations.
*
* If we can detect that the kernel proper is
* performing these operations, don't count
* it as an external modification. Some of the
* external modification routines are called
* by the kernel during thread setup, in which
* case we rename the userspace entrypoint called
* by the MIG demuxer to have a "_from_user" suffix.
*/
/* externs for BSD kernel */
extern void fslog_extmod_msgtracer(void *, void *);
/* local routines */
static void
extmod_statistics_log(task_t current_task, task_t target);
void
extmod_statistics_incr_task_for_pid(task_t target)
{
task_t ctask = current_task();
if ((ctask == kernel_task) || (target == TASK_NULL)) {
return;
}
if (target != ctask) {
ctask->extmod_statistics.task_for_pid_caller_count++;
target->extmod_statistics.task_for_pid_count++;
OSIncrementAtomic64(&host_extmod_statistics.task_for_pid_count);
}
}
void
extmod_statistics_incr_thread_set_state(thread_t target)
{
task_t ctask = current_task();
task_t ttask;
if ((ctask == kernel_task) || (target == THREAD_NULL)) {
return;
}
ttask = get_threadtask(target);
if (ttask == TASK_NULL) {
return;
}
if (ttask != ctask) {
ctask->extmod_statistics.thread_set_state_caller_count++;
ttask->extmod_statistics.thread_set_state_count++;
OSIncrementAtomic64(&host_extmod_statistics.thread_set_state_count);
}
}
void
extmod_statistics_incr_thread_create(task_t target)
{
task_t ctask = current_task();
if ((ctask == kernel_task) || (target == TASK_NULL)) {
return;
}
if (target != ctask) {
ctask->extmod_statistics.thread_creation_caller_count++;
target->extmod_statistics.thread_creation_count++;
OSIncrementAtomic64(&host_extmod_statistics.thread_creation_count);
extmod_statistics_log(ctask, target);
}
}
static void
extmod_statistics_log(task_t current_task, task_t target)
{
void *c_proc;
void *t_proc;
c_proc = get_bsdtask_info(current_task);
t_proc = get_bsdtask_info(target);
if (c_proc && t_proc) {
fslog_extmod_msgtracer(c_proc, t_proc);
}
}