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 #ifdef HAVE_KINFO_GETVMMAP
  30 #include <sys/user.h>
  31 #include <libutil.h>
  32 #endif
  33
  34 #include "elf-bfd.h"
  35 #include "fbsd-nat.h"
  36
  37 /* Return the name of a file that can be opened to get the symbols for
  38    the child process identified by PID.  */
  39
  40 char *
  41 fbsd_pid_to_exec_file (struct target_ops *self, int pid)
  42 {
  43   ssize_t len = PATH_MAX;
  44   static char buf[PATH_MAX];
  45   char name[PATH_MAX];
  46
  47 #ifdef KERN_PROC_PATHNAME
  48   int mib[4];
  49
  50   mib[0] = CTL_KERN;
  51   mib[1] = KERN_PROC;
  52   mib[2] = KERN_PROC_PATHNAME;
  53   mib[3] = pid;
  54   if (sysctl (mib, 4, buf, &len, NULL, 0) == 0)
  55     return buf;
  56 #endif
  57
  58   xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid);
  59   len = readlink (name, buf, PATH_MAX - 1);
  60   if (len != -1)
  61     {
  62       buf[len] = '\0';
  63       return buf;
  64     }
  65
  66   return NULL;
  67 }
  68
  69 #ifdef HAVE_KINFO_GETVMMAP
  70 /* Iterate over all the memory regions in the current inferior,
  71    calling FUNC for each memory region.  OBFD is passed as the last
  72    argument to FUNC.  */
  73
  74 int
  75 fbsd_find_memory_regions (struct target_ops *self,
  76                           find_memory_region_ftype func, void *obfd)
  77 {
  78   pid_t pid = ptid_get_pid (inferior_ptid);
  79   struct kinfo_vmentry *vmentl, *kve;
  80   uint64_t size;
  81   struct cleanup *cleanup;
  82   int i, nitems;
  83
  84   vmentl = kinfo_getvmmap (pid, &nitems);
  85   if (vmentl == NULL)
  86     perror_with_name (_("Couldn't fetch VM map entries."));
  87   cleanup = make_cleanup (free, vmentl);
  88
  89   for (i = 0; i < nitems; i++)
  90     {
  91       kve = &vmentl[i];
  92
  93       /* Skip unreadable segments and those where MAP_NOCORE has been set.  */
  94       if (!(kve->kve_protection & KVME_PROT_READ)
  95           || kve->kve_flags & KVME_FLAG_NOCOREDUMP)
  96         continue;
  97
  98       /* Skip segments with an invalid type.  */
  99       if (kve->kve_type != KVME_TYPE_DEFAULT
 100           && kve->kve_type != KVME_TYPE_VNODE
 101           && kve->kve_type != KVME_TYPE_SWAP
 102           && kve->kve_type != KVME_TYPE_PHYS)
 103         continue;
 104
 105       size = kve->kve_end - kve->kve_start;
 106       if (info_verbose)
 107         {
 108           fprintf_filtered (gdb_stdout,
 109                             "Save segment, %ld bytes at %s (%c%c%c)\n",
 110                             (long) size,
 111                             paddress (target_gdbarch (), kve->kve_start),
 112                             kve->kve_protection & KVME_PROT_READ ? 'r' : '-',
 113                             kve->kve_protection & KVME_PROT_WRITE ? 'w' : '-',
 114                             kve->kve_protection & KVME_PROT_EXEC ? 'x' : '-');
 115         }
 116
 117       /* Invoke the callback function to create the corefile segment.
 118          Pass MODIFIED as true, we do not know the real modification state.  */
 119       func (kve->kve_start, size, kve->kve_protection & KVME_PROT_READ,
 120             kve->kve_protection & KVME_PROT_WRITE,
 121             kve->kve_protection & KVME_PROT_EXEC, 1, obfd);
 122     }
 123   do_cleanups (cleanup);
 124   return 0;
 125 }
 126 #else
 127 static int
 128 fbsd_read_mapping (FILE *mapfile, unsigned long *start, unsigned long *end,
 129                    char *protection)
 130 {
 131   /* FreeBSD 5.1-RELEASE uses a 256-byte buffer.  */
 132   char buf[256];
 133   int resident, privateresident;
 134   unsigned long obj;
 135   int ret = EOF;
 136
 137   /* As of FreeBSD 5.0-RELEASE, the layout is described in
 138      /usr/src/sys/fs/procfs/procfs_map.c.  Somewhere in 5.1-CURRENT a
 139      new column was added to the procfs map.  Therefore we can't use
 140      fscanf since we need to support older releases too.  */
 141   if (fgets (buf, sizeof buf, mapfile) != NULL)
 142     ret = sscanf (buf, "%lx %lx %d %d %lx %s", start, end,
 143                   &resident, &privateresident, &obj, protection);
 144
 145   return (ret != 0 && ret != EOF);
 146 }
 147
 148 /* Iterate over all the memory regions in the current inferior,
 149    calling FUNC for each memory region.  OBFD is passed as the last
 150    argument to FUNC.  */
 151
 152 int
 153 fbsd_find_memory_regions (struct target_ops *self,
 154                           find_memory_region_ftype func, void *obfd)
 155 {
 156   pid_t pid = ptid_get_pid (inferior_ptid);
 157   char *mapfilename;
 158   FILE *mapfile;
 159   unsigned long start, end, size;
 160   char protection[4];
 161   int read, write, exec;
 162   struct cleanup *cleanup;
 163
 164   mapfilename = xstrprintf ("/proc/%ld/map", (long) pid);
 165   cleanup = make_cleanup (xfree, mapfilename);
 166   mapfile = fopen (mapfilename, "r");
 167   if (mapfile == NULL)
 168     error (_("Couldn't open %s."), mapfilename);
 169   make_cleanup_fclose (mapfile);
 170
 171   if (info_verbose)
 172     fprintf_filtered (gdb_stdout,
 173                       "Reading memory regions from %s\n", mapfilename);
 174
 175   /* Now iterate until end-of-file.  */
 176   while (fbsd_read_mapping (mapfile, &start, &end, &protection[0]))
 177     {
 178       size = end - start;
 179
 180       read = (strchr (protection, 'r') != 0);
 181       write = (strchr (protection, 'w') != 0);
 182       exec = (strchr (protection, 'x') != 0);
 183
 184       if (info_verbose)
 185         {
 186           fprintf_filtered (gdb_stdout,
 187                             "Save segment, %ld bytes at %s (%c%c%c)\n",
 188                             size, paddress (target_gdbarch (), start),
 189                             read ? 'r' : '-',
 190                             write ? 'w' : '-',
 191                             exec ? 'x' : '-');
 192         }
 193
 194       /* Invoke the callback function to create the corefile segment.
 195          Pass MODIFIED as true, we do not know the real modification state.  */
 196       func (start, size, read, write, exec, 1, obfd);
 197     }
 198
 199   do_cleanups (cleanup);
 200   return 0;
 201 }
 202 #endif