xnu-1699.22.73.tar.gz

[apple/xnu.git] / osfmk / kern / extmod_statistics.c

diff --git a/osfmk/kern/extmod_statistics.c b/osfmk/kern/extmod_statistics.c
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+++ b/osfmk/kern/extmod_statistics.c
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+/*
+ * 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);
+       }
+}