xref: /dragonfly/contrib/gdb-7/gdb/fbsd-nat.c (revision 6e278935)
1 /* Native-dependent code for FreeBSD.
2 
3    Copyright (C) 2002, 2003, 2004, 2007, 2008, 2009, 2010, 2011
4    Free Software Foundation, Inc.
5 
6    This file is part of GDB.
7 
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3 of the License, or
11    (at your option) any later version.
12 
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
20 
21 #include "defs.h"
22 #include "gdbcore.h"
23 #include "inferior.h"
24 #include "regcache.h"
25 #include "regset.h"
26 #include "gdbthread.h"
27 
28 #include "gdb_assert.h"
29 #include "gdb_string.h"
30 #include <sys/types.h>
31 #include <sys/procfs.h>
32 #include <sys/sysctl.h>
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 (int pid)
42 {
43   size_t len = MAXPATHLEN;
44   char *buf = xcalloc (len, sizeof (char));
45   char *path;
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   path = xstrprintf ("/proc/%d/file", pid);
59   if (readlink (path, buf, MAXPATHLEN) == -1)
60     {
61       xfree (buf);
62       buf = NULL;
63     }
64 
65   xfree (path);
66   return buf;
67 }
68 
69 static int
70 fbsd_read_mapping (FILE *mapfile, unsigned long *start, unsigned long *end,
71 		   char *protection)
72 {
73   /* FreeBSD 5.1-RELEASE uses a 256-byte buffer.  */
74   char buf[256];
75   int resident, privateresident;
76   unsigned long obj;
77   int ret = EOF;
78 
79   /* As of FreeBSD 5.0-RELEASE, the layout is described in
80      /usr/src/sys/fs/procfs/procfs_map.c.  Somewhere in 5.1-CURRENT a
81      new column was added to the procfs map.  Therefore we can't use
82      fscanf since we need to support older releases too.  */
83   if (fgets (buf, sizeof buf, mapfile) != NULL)
84     ret = sscanf (buf, "%lx %lx %d %d %lx %s", start, end,
85 		  &resident, &privateresident, &obj, protection);
86 
87   return (ret != 0 && ret != EOF);
88 }
89 
90 /* Iterate over all the memory regions in the current inferior,
91    calling FUNC for each memory region.  OBFD is passed as the last
92    argument to FUNC.  */
93 
94 int
95 fbsd_find_memory_regions (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       func (start, size, read, write, exec, 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 != TARGET_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 target_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 TARGET_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 (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   make_cleanup (xfree, note_data);
217   return note_data;
218 }
219