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 = NULL;
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 cur_map->ei.mini_debug_info_data = NULL;
66 cur_map->ei.mini_debug_info_size = 0;
67
68 /* Indicate mapped memory of devices is special and should not
69 be read or written. Use a special flag instead of zeroing the
70 flags to indicate that the maps do not need to be rebuilt if
71 any values ever wind up in these special maps.
72 /dev/ashmem/... maps are special and don't have any restrictions,
73 so don't mark them as device memory. */
74 if (strncmp ("/dev/", cur_map->path, 5) == 0
75 && strncmp ("ashmem/", cur_map->path + 5, 7) != 0)
76 cur_map->flags |= MAP_FLAGS_DEVICE_MEM;
77
78 /* If this is a readable executable map, and not a stack map or an
79 empty map, find the load_base. */
80 if (cur_map->path[0] != '\0' && strncmp ("[stack:", cur_map->path, 7) != 0
81 && strncmp ("[vsyscall]", cur_map->path, 10) != 0
82 && (flags & (PROT_EXEC | PROT_READ)) == (PROT_EXEC | PROT_READ)
83 && !(cur_map->flags & MAP_FLAGS_DEVICE_MEM))
84 {
85 struct elf_image ei;
86 // Do not map elf for local unwinds, it's faster to read
87 // from memory directly.
88 if (map_create_type == UNW_MAP_CREATE_REMOTE
89 && elf_map_image (&ei, cur_map->path))
90 {
91 unw_word_t load_base;
92 if (elf_w (get_load_base) (&ei, offset, &load_base))
93 cur_map->load_base = load_base;
94 munmap (ei.u.mapped.image, ei.u.mapped.size);
95 }
96 else
97 {
98 // Create an address space right here with enough initialized
99 // to read data.
100 if (as == NULL)
101 {
102 if (map_create_type == UNW_MAP_CREATE_LOCAL)
103 {
104 // This is a very large structure, so allocate it.
105 if (local_as == NULL)
106 local_as = (struct unw_addr_space*) malloc(sizeof(*local_as));
107 if (local_as != NULL)
108 {
109 as = local_as;
110 unw_local_access_addr_space_init (as);
111 }
112 }
113 else
114 {
115 // For a remote unwind, create the address space
116 // and arg data the first time we need it.
117 // We'll reuse these values if we need to attempt
118 // to get elf data for another map.
119 as = unw_create_addr_space (&_UPT_accessors, 0);
120 if (as)
121 {
122 as_arg = (void*) _UPT_create (pid);
123 if (!as_arg)
124 {
125 unw_destroy_addr_space (as);
126 as = NULL;
127 }
128 }
129 }
130 }
131 if (as)
132 {
133 ei.mapped = false;
134 ei.u.memory.start = cur_map->start;
135 ei.u.memory.end = cur_map->end;
136 ei.u.memory.as = as;
137 ei.u.memory.as_arg = as_arg;
138 ei.valid = elf_w (valid_object_memory) (&ei);
139 unw_word_t load_base;
140 if (ei.valid && elf_w (get_load_base) (&ei, cur_map->offset, &load_base))
141 cur_map->load_base = load_base;
142 }
143 }
144 }
145
146 map_list = cur_map;
147 }
148
149 maps_close (&mi);
150
151 if (as && map_create_type == UNW_MAP_CREATE_REMOTE)
152 {
153 unw_destroy_addr_space (as);
154 _UPT_destroy (as_arg);
155 }
156
157 free(local_as);
158
159 return map_list;
160 }
161 /* End of ANDROID update. */
162