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