1 /* libunwind - a platform-independent unwind library
2 Copyright (C) 2003-2005 Hewlett-Packard Co
3 Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
4
5 This file is part of libunwind.
6
7 Permission is hereby granted, free of charge, to any person obtaining
8 a copy of this software and associated documentation files (the
9 "Software"), to deal in the Software without restriction, including
10 without limitation the rights to use, copy, modify, merge, publish,
11 distribute, sublicense, and/or sell copies of the Software, and to
12 permit persons to whom the Software is furnished to do so, subject to
13 the following conditions:
14
15 The above copyright notice and this permission notice shall be
16 included in all copies or substantial portions of the Software.
17
18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
25
26 #include <limits.h>
27 #include <stdio.h>
28
29 #include "libunwind_i.h"
30 #include "libunwind-ptrace.h"
31 #include "map_info.h"
32 #include "os-linux.h"
33
34 /* ANDROID support update. */
35 HIDDEN struct map_info *
map_create_list(int map_create_type,pid_t pid)36 map_create_list (int map_create_type, pid_t pid)
37 {
38 struct map_iterator mi;
39 unsigned long start, end, offset, flags;
40 struct map_info *map_list = NULL;
41 struct map_info *cur_map;
42 unw_addr_space_t as = NULL;
43 struct unw_addr_space local_as;
44 void* as_arg = NULL;
45
46 if (maps_init (&mi, pid) < 0)
47 return NULL;
48
49 while (maps_next (&mi, &start, &end, &offset, &flags))
50 {
51 cur_map = map_alloc_info ();
52 if (cur_map == MAP_FAILED)
53 break;
54 cur_map->next = map_list;
55 cur_map->start = start;
56 cur_map->end = end;
57 cur_map->offset = offset;
58 cur_map->load_base = 0;
59 cur_map->flags = flags;
60 cur_map->path = strdup (mi.path);
61 mutex_init (&cur_map->ei_lock);
62 cur_map->ei.valid = false;
63 cur_map->ei.load_attempted = false;
64 cur_map->ei.mapped = false;
65
66 /* Indicate mapped memory of devices is special and should not
67 be read or written. Use a special flag instead of zeroing the
68 flags to indicate that the maps do not need to be rebuilt if
69 any values ever wind up in these special maps.
70 /dev/ashmem/... maps are special and don't have any restrictions,
71 so don't mark them as device memory. */
72 if (strncmp ("/dev/", cur_map->path, 5) == 0
73 && strncmp ("ashmem/", cur_map->path + 5, 7) != 0)
74 cur_map->flags |= MAP_FLAGS_DEVICE_MEM;
75
76 /* If this is a readable executable map, and not a stack map or an
77 empty map, find the load_base. */
78 if (cur_map->path[0] != '\0' && strncmp ("[stack:", cur_map->path, 7) != 0
79 && (flags & (PROT_EXEC | PROT_READ)) == (PROT_EXEC | PROT_READ)
80 && !(cur_map->flags & MAP_FLAGS_DEVICE_MEM))
81 {
82 struct elf_image ei;
83 // Do not map elf for local unwinds, it's faster to read
84 // from memory directly.
85 if (map_create_type == UNW_MAP_CREATE_REMOTE
86 && elf_map_image (&ei, cur_map->path))
87 {
88 unw_word_t load_base;
89 if (elf_w (get_load_base) (&ei, offset, &load_base))
90 cur_map->load_base = load_base;
91 munmap (ei.u.mapped.image, ei.u.mapped.size);
92 }
93 else
94 {
95 // Create an address space right here with enough initialized
96 // to read data.
97 if (as == NULL)
98 {
99 if (map_create_type == UNW_MAP_CREATE_LOCAL)
100 {
101 as = &local_as;
102 unw_local_access_addr_space_init (as);
103 }
104 else
105 {
106 // For a remote unwind, create the address space
107 // and arg data the first time we need it.
108 // We'll reuse these values if we need to attempt
109 // to get elf data for another map.
110 as = unw_create_addr_space (&_UPT_accessors, 0);
111 if (as)
112 {
113 as_arg = (void*) _UPT_create (pid);
114 if (!as_arg)
115 {
116 unw_destroy_addr_space (as);
117 as = NULL;
118 }
119 }
120 }
121 }
122 if (as)
123 {
124 ei.mapped = false;
125 ei.u.memory.map = cur_map;
126 ei.u.memory.as = as;
127 ei.u.memory.as_arg = as_arg;
128 ei.valid = elf_w (valid_object_memory) (&ei);
129 unw_word_t load_base;
130 if (ei.valid && elf_w (get_load_base) (&ei, cur_map->offset, &load_base))
131 cur_map->load_base = load_base;
132 }
133 }
134 }
135
136 map_list = cur_map;
137 }
138
139 maps_close (&mi);
140
141 if (as && map_create_type == UNW_MAP_CREATE_REMOTE)
142 {
143 unw_destroy_addr_space (as);
144 _UPT_destroy (as_arg);
145 }
146
147 return map_list;
148 }
149 /* End of ANDROID update. */
150