osfmk/kern/btlog.h

   1 /*
   2  * Copyright (c) 2012 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 #ifndef _KERN_BTLOG_H_
  30 #define _KERN_BTLOG_H_
  31
  32 #include <kern/kern_types.h>
  33 #include <sys/cdefs.h>
  34 #include <stdint.h>
  35
  36 #ifdef  XNU_KERNEL_PRIVATE
  37
  38 /*
  39  * The btlog subsystem allows for fast unobtrusive backtraces
  40  * to be recorded and maintained in chronological order.
  41  *
  42  * Each backtrace is associated with an element/object,
  43  * and an operation. For example, memory allocations and
  44  * frees can be tracked with this infrastructure. So
  45  * can refcounts. The "operation" namespace is maintained
  46  * by the caller.
  47  *
  48  * When the event buffer fills, records are reused in FIFO
  49  * order.
  50  *
  51  * When a btlog_t is created, callbacks can be provided
  52  * to ensure proper locking of the datastructures. If these
  53  * are not provided, the caller is responsible for
  54  * preventing simultaneous modification.
  55  */
  56
  57 /*
  58  * BTLOG_MAX_DEPTH configures how deep of a stack trace is stored.  15
  59  * levels is usually enough to get past all the layers of code in
  60  * kalloc and IOKit and see who the actual caller is up above these
  61  * lower levels, when used by the zone allocator logging code.
  62  */
  63
  64 #define BTLOG_MAX_DEPTH 15
  65
  66 struct btlog;
  67 typedef struct btlog btlog_t;
  68
  69 typedef void (*btlog_lock_t)(void *context);
  70 typedef void (*btlog_unlock_t)(void *context);
  71
  72 extern btlog_t *btlog_create(size_t numrecords,
  73                              size_t record_btdepth,
  74                              btlog_lock_t lock_callback,
  75                              btlog_unlock_t unlock_callback,
  76                              void *callback_context);
  77
  78 extern void btlog_add_entry(btlog_t *btlog,
  79                             void *element,
  80                             uint8_t operation,
  81                             void *bt[],
  82                             size_t btcount);
  83
  84 extern void btlog_remove_entries_for_element(btlog_t *btlog,
  85                                              void *element);
  86
  87 #endif  /* XNU_KERNEL_PRIVATE */
  88
  89 #endif  /* _KERN_BTLOG_H_ */