1 /*
2  * Copyright (c) 2013-2018 The strace developers.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #ifndef STRACE_MMAP_CACHE_H
28 #define STRACE_MMAP_CACHE_H
29 
30 /*
31  * Keep a sorted array of cache entries,
32  * so that we can binary search through it.
33  */
34 
35 struct mmap_cache_t {
36 	struct mmap_cache_entry_t *entry;
37 	void (*free_fn)(struct tcb *, const char *caller);
38 	unsigned int size;
39 	unsigned int generation;
40 };
41 
42 struct mmap_cache_entry_t {
43 	/**
44 	 * example entry:
45 	 * 7fabbb09b000-7fabbb09f000 r-xp 00179000 fc:00 1180246 /lib/libc-2.11.1.so
46 	 *
47 	 * start_addr  is 0x7fabbb09b000
48 	 * end_addr    is 0x7fabbb09f000
49 	 * mmap_offset is 0x179000
50 	 * protections is MMAP_CACHE_PROT_READABLE|MMAP_CACHE_PROT_EXECUTABLE
51 	 * major       is 0xfc
52 	 * minor       is 0x00
53 	 * binary_filename is "/lib/libc-2.11.1.so"
54 	 */
55 	unsigned long start_addr;
56 	unsigned long end_addr;
57 	unsigned long mmap_offset;
58 	unsigned char protections;
59 	unsigned long major, minor;
60 	char *binary_filename;
61 };
62 
63 enum mmap_cache_protection {
64 	MMAP_CACHE_PROT_READABLE   = 1 << 0,
65 	MMAP_CACHE_PROT_WRITABLE   = 1 << 1,
66 	MMAP_CACHE_PROT_EXECUTABLE = 1 << 2,
67 	MMAP_CACHE_PROT_SHARED     = 1 << 3,
68 };
69 
70 enum mmap_cache_rebuild_result {
71 	MMAP_CACHE_REBUILD_NOCACHE,
72 	MMAP_CACHE_REBUILD_READY,
73 	MMAP_CACHE_REBUILD_RENEWED,
74 };
75 
76 typedef bool (*mmap_cache_search_fn)(struct mmap_cache_entry_t *, void *);
77 
78 extern void
79 mmap_cache_enable(void);
80 
81 extern enum mmap_cache_rebuild_result
82 mmap_cache_rebuild_if_invalid(struct tcb *, const char *caller);
83 
84 extern struct mmap_cache_entry_t *
85 mmap_cache_search(struct tcb *, unsigned long ip);
86 
87 extern struct mmap_cache_entry_t *
88 mmap_cache_search_custom(struct tcb *, mmap_cache_search_fn, void *);
89 
90 #endif /* !STRACE_MMAP_CACHE_H */
91