gdb/fbsd-nat.c

   1 /* Native-dependent code for FreeBSD.
   2
   3    Copyright (C) 2002-2014 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
  27 #include "gdb_assert.h"
  28 #include <string.h>
  29 #include <sys/types.h>
  30 #include <sys/procfs.h>
  31 #include <sys/sysctl.h>
  32
  33 #include "elf-bfd.h"
  34 #include "fbsd-nat.h"
  35
  36 /* Return the name of a file that can be opened to get the symbols for
  37    the child process identified by PID.  */
  38
  39 char *
  40 fbsd_pid_to_exec_file (struct target_ops *self, int pid)
  41 {
  42   size_t len = PATH_MAX;
  43   char *buf = xcalloc (len, sizeof (char));
  44   char *path;
  45
  46 #ifdef KERN_PROC_PATHNAME
  47   int mib[4];
  48
  49   mib[0] = CTL_KERN;
  50   mib[1] = KERN_PROC;
  51   mib[2] = KERN_PROC_PATHNAME;
  52   mib[3] = pid;
  53   if (sysctl (mib, 4, buf, &len, NULL, 0) == 0)
  54     return buf;
  55 #endif
  56
  57   path = xstrprintf ("/proc/%d/file", pid);
  58   if (readlink (path, buf, PATH_MAX - 1) == -1)
  59     {
  60       xfree (buf);
  61       buf = NULL;
  62     }
  63
  64   xfree (path);
  65   return buf;
  66 }
  67
  68 static int
  69 fbsd_read_mapping (FILE *mapfile, unsigned long *start, unsigned long *end,
  70                    char *protection)
  71 {
  72   /* FreeBSD 5.1-RELEASE uses a 256-byte buffer.  */
  73   char buf[256];
  74   int resident, privateresident;
  75   unsigned long obj;
  76   int ret = EOF;
  77
  78   /* As of FreeBSD 5.0-RELEASE, the layout is described in
  79      /usr/src/sys/fs/procfs/procfs_map.c.  Somewhere in 5.1-CURRENT a
  80      new column was added to the procfs map.  Therefore we can't use
  81      fscanf since we need to support older releases too.  */
  82   if (fgets (buf, sizeof buf, mapfile) != NULL)
  83     ret = sscanf (buf, "%lx %lx %d %d %lx %s", start, end,
  84                   &resident, &privateresident, &obj, protection);
  85
  86   return (ret != 0 && ret != EOF);
  87 }
  88
  89 /* Iterate over all the memory regions in the current inferior,
  90    calling FUNC for each memory region.  OBFD is passed as the last
  91    argument to FUNC.  */
  92
  93 int
  94 fbsd_find_memory_regions (struct target_ops *self,
  95                           find_memory_region_ftype func, void *obfd)
  96 {
  97   pid_t pid = ptid_get_pid (inferior_ptid);
  98   char *mapfilename;
  99   FILE *mapfile;
 100   unsigned long start, end, size;
 101   char protection[4];
 102   int read, write, exec;
 103   struct cleanup *cleanup;
 104
 105   mapfilename = xstrprintf ("/proc/%ld/map", (long) pid);
 106   cleanup = make_cleanup (xfree, mapfilename);
 107   mapfile = fopen (mapfilename, "r");
 108   if (mapfile == NULL)
 109     error (_("Couldn't open %s."), mapfilename);
 110   make_cleanup_fclose (mapfile);
 111
 112   if (info_verbose)
 113     fprintf_filtered (gdb_stdout,
 114                       "Reading memory regions from %s\n", mapfilename);
 115
 116   /* Now iterate until end-of-file.  */
 117   while (fbsd_read_mapping (mapfile, &start, &end, &protection[0]))
 118     {
 119       size = end - start;
 120
 121       read = (strchr (protection, 'r') != 0);
 122       write = (strchr (protection, 'w') != 0);
 123       exec = (strchr (protection, 'x') != 0);
 124
 125       if (info_verbose)
 126         {
 127           fprintf_filtered (gdb_stdout,
 128                             "Save segment, %ld bytes at %s (%c%c%c)\n",
 129                             size, paddress (target_gdbarch (), start),
 130                             read ? 'r' : '-',
 131                             write ? 'w' : '-',
 132                             exec ? 'x' : '-');
 133         }
 134
 135       /* Invoke the callback function to create the corefile segment.
 136          Pass MODIFIED as true, we do not know the real modification state.  */
 137       func (start, size, read, write, exec, 1, obfd);
 138     }
 139
 140   do_cleanups (cleanup);
 141   return 0;
 142 }
 143
 144 static int
 145 find_signalled_thread (struct thread_info *info, void *data)
 146 {
 147   if (info->suspend.stop_signal != GDB_SIGNAL_0
 148       && ptid_get_pid (info->ptid) == ptid_get_pid (inferior_ptid))
 149     return 1;
 150
 151   return 0;
 152 }
 153
 154 static enum gdb_signal
 155 find_stop_signal (void)
 156 {
 157   struct thread_info *info =
 158     iterate_over_threads (find_signalled_thread, NULL);
 159
 160   if (info)
 161     return info->suspend.stop_signal;
 162   else
 163     return GDB_SIGNAL_0;
 164 }
 165
 166 /* Create appropriate note sections for a corefile, returning them in
 167    allocated memory.  */
 168
 169 char *
 170 fbsd_make_corefile_notes (struct target_ops *self, bfd *obfd, int *note_size)
 171 {
 172   const struct regcache *regcache = get_current_regcache ();
 173   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 174   gregset_t gregs;
 175   fpregset_t fpregs;
 176   char *note_data = NULL;
 177   Elf_Internal_Ehdr *i_ehdrp;
 178   const struct regset *regset;
 179   size_t size;
 180
 181   /* Put a "FreeBSD" label in the ELF header.  */
 182   i_ehdrp = elf_elfheader (obfd);
 183   i_ehdrp->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
 184
 185   gdb_assert (gdbarch_regset_from_core_section_p (gdbarch));
 186
 187   size = sizeof gregs;
 188   regset = gdbarch_regset_from_core_section (gdbarch, ".reg", size);
 189   gdb_assert (regset && regset->collect_regset);
 190   regset->collect_regset (regset, regcache, -1, &gregs, size);
 191
 192   note_data = elfcore_write_prstatus (obfd, note_data, note_size,
 193                                       ptid_get_pid (inferior_ptid),
 194                                       find_stop_signal (), &gregs);
 195
 196   size = sizeof fpregs;
 197   regset = gdbarch_regset_from_core_section (gdbarch, ".reg2", size);
 198   gdb_assert (regset && regset->collect_regset);
 199   regset->collect_regset (regset, regcache, -1, &fpregs, size);
 200
 201   note_data = elfcore_write_prfpreg (obfd, note_data, note_size,
 202                                      &fpregs, sizeof (fpregs));
 203
 204   if (get_exec_file (0))
 205     {
 206       const char *fname = lbasename (get_exec_file (0));
 207       char *psargs = xstrdup (fname);
 208
 209       if (get_inferior_args ())
 210         psargs = reconcat (psargs, psargs, " ", get_inferior_args (),
 211                            (char *) NULL);
 212
 213       note_data = elfcore_write_prpsinfo (obfd, note_data, note_size,
 214                                           fname, psargs);
 215     }
 216
 217   make_cleanup (xfree, note_data);
 218   return note_data;
 219 }