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      1 /* libunwind - a platform-independent unwind library
      2    Copyright (C) 2013 Garmin International
      3 	Contributed by Matt Fischer <matt.fischer (at) garmin.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 <string.h>
     27 
     28 #include "libunwind_i.h"
     29 
     30 /* ANDROID support update. */
     31 static int callback(const struct dl_phdr_info *info, size_t size, void *data)
     32 {
     33   struct map_info **map_list = (struct map_info **)data;
     34   struct map_info *cur_map;
     35   int i;
     36   struct cb_info *cbi = (struct cb_info*)data;
     37   for(i=0; i<info->dlpi_phnum; i++) {
     38     int segbase = info->dlpi_addr + info->dlpi_phdr[i].p_vaddr;
     39 
     40     cur_map = map_alloc_info ();
     41     if (cur_map == NULL)
     42       break;
     43 
     44     cur_map->next = *map_list;
     45     cur_map->start = info->dlpi_addr + info->dlpi_phdr[i].p_vaddr;
     46     cur_map->end = cur_map->start + info->dlpi_phdr[i].p_memsz;
     47     cur_map->offset = info->dlpi_phdr[i].p_offset;
     48     cur_map->path = strdup(info->dlpi_name);
     49     mutex_init (&cur_map->ei_lock);
     50     cur_map->ei.size = 0;
     51     cur_map->ei.image = NULL;
     52     cur_map->ei.shared = 0;
     53 
     54     *map_list = cur_map;
     55   }
     56 
     57   return 0;
     58 }
     59 
     60 struct map_info *
     61 map_create_list (pid_t pid)
     62 {
     63   struct map_info *map_list = NULL;
     64 
     65   /* QNX's support for accessing symbol maps is severely broken.  There is
     66      a devctl() call that can be made on a proc node (DCMD_PROC_MAPDEBUG)
     67      which returns information similar to Linux's /proc/<pid>/maps
     68      node, however the filename that is returned by this call is not an
     69      absolute path, and there is no foolproof way to map the filename
     70      back to the file that it came from.
     71 
     72      Therefore, the normal approach for implementing this function,
     73      which works equally well for both local and remote unwinding,
     74      will not work here.  The only type of image lookup which works
     75      reliably is locally, using dl_iterate_phdr().  However, the only
     76      time that this function is required to look up a remote image is for
     77      ptrace support, which doesn't work on QNX anyway.  Local unwinding,
     78      which is the main case that makes use of this function, will work
     79      fine with dl_iterate_phdr().  Therefore, in lieu of any better
     80      platform support for remote image lookup, this function has just
     81      been implemented in terms of dl_iterate_phdr().
     82   */
     83 
     84   if (pid != getpid())
     85     {
     86       /* Return an error if an attempt is made to perform remote image lookup */
     87       return -1;
     88     }
     89 
     90   if (dl_iterate_phdr (callback, &map_list) != 0)
     91     return map_list;
     92   return NULL;
     93 }
     94 /* End of ANDROID update. */
     95