xref: /xnu-8019.80.24/osfmk/kern/btlog.h (revision a325d9c4a84054e40bbe985afedcb50ab80993ea)
1 /*
2  * Copyright (c) 2012 Apple Inc. All rights reserved.
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4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
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6  * This file contains Original Code and/or Modifications of Original Code
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8  * Version 2.0 (the 'License'). You may not use this file except in
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15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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27  */
28 
29 #ifndef _KERN_BTLOG_H_
30 #define _KERN_BTLOG_H_
31 
32 #include <kern/kern_types.h>
33 #include <kern/debug.h>
34 #include <sys/cdefs.h>
35 #include <stdint.h>
36 #include <mach_debug/zone_info.h>
37 
38 #ifdef  XNU_KERNEL_PRIVATE
39 
40 /*
41  * The btlog subsystem allows for fast unobtrusive backtraces
42  * to be recorded and maintained in chronological order.
43  *
44  * Each backtrace is associated with an element/object,
45  * and an operation. For example, memory allocations and
46  * frees can be tracked with this infrastructure. So
47  * can refcounts. The "operation" namespace is maintained
48  * by the caller.
49  *
50  * When the event buffer fills, records are reused in FIFO
51  * order.
52  *
53  * When a btlog_t is created, callbacks can be provided
54  * to ensure proper locking of the datastructures. If these
55  * are not provided, the caller is responsible for
56  * preventing simultaneous modification.
57  */
58 
59 /*
60  * BTLOG_MAX_DEPTH configures how deep of a stack trace is stored.  15
61  * levels is usually enough to get past all the layers of code in
62  * kalloc and IOKit and see who the actual caller is up above these
63  * lower levels, when used by the zone allocator logging code.
64  */
65 
66 #define BTLOG_MAX_DEPTH 15
67 
68 struct btlog;
69 typedef struct btlog btlog_t;
70 
71 extern btlog_t *btlog_create(size_t numrecords,
72     size_t record_btdepth,
73     boolean_t caller_will_remove_entries_for_element);
74 
75 extern void btlog_destroy(btlog_t *);
76 
77 extern void btlog_add_entry(btlog_t * btlog,
78     void *element,
79     uint8_t operation,
80     void **__counted_by(btcount) bt,
81     size_t btcount);
82 
83 extern void btlog_remove_entries_for_element(btlog_t *btlog,
84     void *element);
85 
86 #if DEBUG || DEVELOPMENT
87 void btlog_copy_backtraces_for_elements(btlog_t      * btlog,
88     uintptr_t    * instances,
89     uint32_t     * count,
90     uint32_t       zoneSize,
91     leak_site_proc proc,
92     void         * refCon);
93 
94 size_t get_btlog_records_count(btlog_t *btlog);
95 
96 void get_btlog_records(btlog_t *btlog,
97     zone_btrecord_t *records,
98     unsigned int *numrecs);
99 
100 #endif  /* DEBUG || DEVELOPMENT */
101 
102 #endif  /* XNU_KERNEL_PRIVATE */
103 
104 #endif  /* _KERN_BTLOG_H_ */
105