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;
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