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
5This file is part of libunwind.
6
7Permission is hereby granted, free of charge, to any person obtaining
8a copy of this software and associated documentation files (the
9"Software"), to deal in the Software without restriction, including
10without limitation the rights to use, copy, modify, merge, publish,
11distribute, sublicense, and/or sell copies of the Software, and to
12permit persons to whom the Software is furnished to do so, subject to
13the following conditions:
14
15The above copyright notice and this permission notice shall be
16included in all copies or substantial portions of the Software.
17
18THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
22LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24WITH 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. */
35HIDDEN struct map_info *
36map_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          && (flags & (PROT_EXEC | PROT_READ)) == (PROT_EXEC | PROT_READ)
82          && !(cur_map->flags & MAP_FLAGS_DEVICE_MEM))
83        {
84          struct elf_image ei;
85          // Do not map elf for local unwinds, it's faster to read
86          // from memory directly.
87          if (map_create_type == UNW_MAP_CREATE_REMOTE
88              && elf_map_image (&ei, cur_map->path))
89            {
90              unw_word_t load_base;
91              if (elf_w (get_load_base) (&ei, offset, &load_base))
92                cur_map->load_base = load_base;
93              munmap (ei.u.mapped.image, ei.u.mapped.size);
94            }
95          else
96            {
97              // Create an address space right here with enough initialized
98              // to read data.
99              if (as == NULL)
100                {
101                  if (map_create_type == UNW_MAP_CREATE_LOCAL)
102                    {
103                      // This is a very large structure, so allocate it.
104                      if (local_as == NULL)
105                        local_as = (struct unw_addr_space*) malloc(sizeof(*local_as));
106                      if (local_as != NULL)
107                        {
108                          as = local_as;
109                          unw_local_access_addr_space_init (as);
110                        }
111                    }
112                  else
113                    {
114                      // For a remote unwind, create the address space
115                      // and arg data the first time we need it.
116                      // We'll reuse these values if we need to attempt
117                      // to get elf data for another map.
118                      as = unw_create_addr_space (&_UPT_accessors, 0);
119                      if (as)
120                        {
121                          as_arg = (void*) _UPT_create (pid);
122                          if (!as_arg)
123                            {
124                              unw_destroy_addr_space (as);
125                              as = NULL;
126                            }
127                        }
128                    }
129                }
130              if (as)
131                {
132                  ei.mapped = false;
133                  ei.u.memory.start = cur_map->start;
134                  ei.u.memory.end = cur_map->end;
135                  ei.u.memory.as = as;
136                  ei.u.memory.as_arg = as_arg;
137                  ei.valid = elf_w (valid_object_memory) (&ei);
138                  unw_word_t load_base;
139                  if (ei.valid && elf_w (get_load_base) (&ei, cur_map->offset, &load_base))
140                    cur_map->load_base = load_base;
141                }
142            }
143        }
144
145      map_list = cur_map;
146    }
147
148  maps_close (&mi);
149
150  if (as && map_create_type == UNW_MAP_CREATE_REMOTE)
151    {
152      unw_destroy_addr_space (as);
153      _UPT_destroy (as_arg);
154    }
155
156  free(local_as);
157
158  return map_list;
159}
160/* End of ANDROID update. */
161