gdb/fbsd-nat.c

   1 /* Native-dependent code for FreeBSD.
   2
   3    Copyright (C) 2002-2015 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "gdbcore.h"
  22 #include "inferior.h"
  23 #include "regcache.h"
  24 #include "regset.h"
  25 #include "gdbthread.h"
  26 #include <sys/types.h>
  27 #include <sys/procfs.h>
  28 #include <sys/sysctl.h>
  29
  30 #include "elf-bfd.h"
  31 #include "fbsd-nat.h"
  32
  33 /* Return the name of a file that can be opened to get the symbols for
  34    the child process identified by PID.  */
  35
  36 char *
  37 fbsd_pid_to_exec_file (struct target_ops *self, int pid)
  38 {
  39   ssize_t len = PATH_MAX;
  40   static char buf[PATH_MAX];
  41   char name[PATH_MAX];
  42
  43 #ifdef KERN_PROC_PATHNAME
  44   int mib[4];
  45
  46   mib[0] = CTL_KERN;
  47   mib[1] = KERN_PROC;
  48   mib[2] = KERN_PROC_PATHNAME;
  49   mib[3] = pid;
  50   if (sysctl (mib, 4, buf, &len, NULL, 0) == 0)
  51     return buf;
  52 #endif
  53
  54   xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid);
  55   len = readlink (name, buf, PATH_MAX - 1);
  56   if (len != -1)
  57     {
  58       buf[len] = '\0';
  59       return buf;
  60     }
  61
  62   return NULL;
  63 }
  64
  65 static int
  66 fbsd_read_mapping (FILE *mapfile, unsigned long *start, unsigned long *end,
  67                    char *protection)
  68 {
  69   /* FreeBSD 5.1-RELEASE uses a 256-byte buffer.  */
  70   char buf[256];
  71   int resident, privateresident;
  72   unsigned long obj;
  73   int ret = EOF;
  74
  75   /* As of FreeBSD 5.0-RELEASE, the layout is described in
  76      /usr/src/sys/fs/procfs/procfs_map.c.  Somewhere in 5.1-CURRENT a
  77      new column was added to the procfs map.  Therefore we can't use
  78      fscanf since we need to support older releases too.  */
  79   if (fgets (buf, sizeof buf, mapfile) != NULL)
  80     ret = sscanf (buf, "%lx %lx %d %d %lx %s", start, end,
  81                   &resident, &privateresident, &obj, protection);
  82
  83   return (ret != 0 && ret != EOF);
  84 }
  85
  86 /* Iterate over all the memory regions in the current inferior,
  87    calling FUNC for each memory region.  OBFD is passed as the last
  88    argument to FUNC.  */
  89
  90 int
  91 fbsd_find_memory_regions (struct target_ops *self,
  92                           find_memory_region_ftype func, void *obfd)
  93 {
  94   pid_t pid = ptid_get_pid (inferior_ptid);
  95   char *mapfilename;
  96   FILE *mapfile;
  97   unsigned long start, end, size;
  98   char protection[4];
  99   int read, write, exec;
 100   struct cleanup *cleanup;
 101
 102   mapfilename = xstrprintf ("/proc/%ld/map", (long) pid);
 103   cleanup = make_cleanup (xfree, mapfilename);
 104   mapfile = fopen (mapfilename, "r");
 105   if (mapfile == NULL)
 106     error (_("Couldn't open %s."), mapfilename);
 107   make_cleanup_fclose (mapfile);
 108
 109   if (info_verbose)
 110     fprintf_filtered (gdb_stdout,
 111                       "Reading memory regions from %s\n", mapfilename);
 112
 113   /* Now iterate until end-of-file.  */
 114   while (fbsd_read_mapping (mapfile, &start, &end, &protection[0]))
 115     {
 116       size = end - start;
 117
 118       read = (strchr (protection, 'r') != 0);
 119       write = (strchr (protection, 'w') != 0);
 120       exec = (strchr (protection, 'x') != 0);
 121
 122       if (info_verbose)
 123         {
 124           fprintf_filtered (gdb_stdout,
 125                             "Save segment, %ld bytes at %s (%c%c%c)\n",
 126                             size, paddress (target_gdbarch (), start),
 127                             read ? 'r' : '-',
 128                             write ? 'w' : '-',
 129                             exec ? 'x' : '-');
 130         }
 131
 132       /* Invoke the callback function to create the corefile segment.
 133          Pass MODIFIED as true, we do not know the real modification state.  */
 134       func (start, size, read, write, exec, 1, obfd);
 135     }
 136
 137   do_cleanups (cleanup);
 138   return 0;
 139 }