1/* libunwind - a platform-independent unwind library
2
3This file is part of libunwind.
4
5Permission is hereby granted, free of charge, to any person obtaining
6a copy of this software and associated documentation files (the
7"Software"), to deal in the Software without restriction, including
8without limitation the rights to use, copy, modify, merge, publish,
9distribute, sublicense, and/or sell copies of the Software, and to
10permit persons to whom the Software is furnished to do so, subject to
11the following conditions:
12
13The above copyright notice and this permission notice shall be
14included in all copies or substantial portions of the Software.
15
16THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
23
24#include <elf.h>
25
26#include "_UCD_lib.h"
27#include "_UCD_internal.h"
28
29static int
30get_unwind_info(struct UCD_info *ui, unw_addr_space_t as, unw_word_t ip)
31{
32  unsigned long segbase, mapoff;
33
34#if UNW_TARGET_IA64 && defined(__linux)
35  if (!ui->edi.ktab.start_ip && _Uia64_get_kernel_table (&ui->edi.ktab) < 0)
36    return -UNW_ENOINFO;
37
38  if (ui->edi.ktab.format != -1 && ip >= ui->edi.ktab.start_ip && ip < ui->edi.ktab.end_ip)
39    return 0;
40#endif
41
42  if ((ui->edi.di_cache.format != -1
43       && ip >= ui->edi.di_cache.start_ip && ip < ui->edi.di_cache.end_ip)
44#if UNW_TARGET_ARM
45      || (ui->edi.di_debug.format != -1
46       && ip >= ui->edi.di_arm.start_ip && ip < ui->edi.di_arm.end_ip)
47#endif
48      || (ui->edi.di_debug.format != -1
49       && ip >= ui->edi.di_debug.start_ip && ip < ui->edi.di_debug.end_ip))
50    return 0;
51
52  invalidate_edi (&ui->edi);
53
54  /* Used to be tdep_get_elf_image() in ptrace unwinding code */
55  coredump_phdr_t *phdr = _UCD_get_elf_image(ui, ip);
56  if (!phdr)
57    {
58      Debug(1, "returns error: _UCD_get_elf_image failed\n");
59      return -UNW_ENOINFO;
60    }
61  /* segbase: where it is mapped in virtual memory */
62  /* mapoff: offset in the file */
63  segbase = phdr->p_vaddr;
64  /*mapoff  = phdr->p_offset; WRONG! phdr->p_offset is the offset in COREDUMP file */
65  mapoff  = 0;
66///FIXME. text segment is USUALLY, not always, at offset 0 in the binary/.so file.
67// ensure that at initialization.
68
69  /* Here, SEGBASE is the starting-address of the (mmap'ped) segment
70     which covers the IP we're looking for.  */
71  if (tdep_find_unwind_table(&ui->edi, as, phdr->backing_filename, segbase, mapoff, ip) < 0)
72    {
73      Debug(1, "returns error: tdep_find_unwind_table failed\n");
74      return -UNW_ENOINFO;
75    }
76
77  /* This can happen in corner cases where dynamically generated
78     code falls into the same page that contains the data-segment
79     and the page-offset of the code is within the first page of
80     the executable.  */
81  if (ui->edi.di_cache.format != -1
82      && (ip < ui->edi.di_cache.start_ip || ip >= ui->edi.di_cache.end_ip))
83     ui->edi.di_cache.format = -1;
84
85  if (ui->edi.di_debug.format != -1
86      && (ip < ui->edi.di_debug.start_ip || ip >= ui->edi.di_debug.end_ip))
87     ui->edi.di_debug.format = -1;
88
89  if (ui->edi.di_cache.format == -1
90#if UNW_TARGET_ARM
91      && ui->edi.di_arm.format == -1
92#endif
93      && ui->edi.di_debug.format == -1)
94  {
95    Debug(1, "returns error: all formats are -1\n");
96    return -UNW_ENOINFO;
97  }
98
99  Debug(1, "returns success\n");
100  return 0;
101}
102
103int
104_UCD_find_proc_info (unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
105		     int need_unwind_info, void *arg)
106{
107  struct UCD_info *ui = arg;
108
109  Debug(1, "entering\n");
110
111  int ret = -UNW_ENOINFO;
112
113  if (get_unwind_info(ui, as, ip) < 0) {
114    Debug(1, "returns error: get_unwind_info failed\n");
115    return -UNW_ENOINFO;
116  }
117
118#if UNW_TARGET_IA64
119  if (ui->edi.ktab.format != -1)
120    {
121      /* The kernel unwind table resides in local memory, so we have
122	 to use the local address space to search it.  Since
123	 _UCD_put_unwind_info() has no easy way of detecting this
124	 case, we simply make a copy of the unwind-info, so
125	 _UCD_put_unwind_info() can always free() the unwind-info
126	 without ill effects.  */
127      ret = tdep_search_unwind_table (unw_local_addr_space, ip, &ui->edi.ktab, pi,
128				      need_unwind_info, arg);
129      if (ret >= 0)
130	{
131	  if (!need_unwind_info)
132	    pi->unwind_info = NULL;
133	  else
134	    {
135	      void *mem = malloc (pi->unwind_info_size);
136
137	      if (!mem)
138		return -UNW_ENOMEM;
139	      memcpy (mem, pi->unwind_info, pi->unwind_info_size);
140	      pi->unwind_info = mem;
141	    }
142	}
143    }
144#endif
145
146  if (ret == -UNW_ENOINFO && ui->edi.di_cache.format != -1)
147    ret = tdep_search_unwind_table (as, ip, &ui->edi.di_cache,
148				    pi, need_unwind_info, arg);
149
150#if UNW_TARGET_ARM
151  if (ret == -UNW_ENOINFO && ui->edi.di_arm.format != -1)
152    ret = tdep_search_unwind_table (as, ip, &ui->edi.di_arm, pi,
153                                    need_unwind_info, arg);
154#endif
155
156  if (ret == -UNW_ENOINFO && ui->edi.di_debug.format != -1)
157    ret = tdep_search_unwind_table (as, ip, &ui->edi.di_debug, pi,
158				    need_unwind_info, arg);
159
160  Debug(1, "returns %d\n", ret);
161
162  return ret;
163}
164