usr/src/cmd/mdb/common/kmdb/kmdb_ctf_open.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  * Copyright (c) 2015, Joyent, Inc.
  26  */
  27
  28 /*
  29  * libctf open/close interposition layer
  30  *
  31  * This interposition layer serves two purposes.  First, it allows the
  32  * introduction of a kmdb-specific implementation of ctf_open().  The normal
  33  * ctf_open() call open(2)s a file, and reads the CTF data directly from it.
  34  * No such facility is available in kmdb, as kmdb does not run in userland.  We
  35  * can, however, observe that kmdb uses this interface only to read CTF data
  36  * from dmods.  dmods, as viewed by kmdb, do have CTF data, but they have it
  37  * in a form that is best accessed by ctf_bufopen().  This interposition layer
  38  * allows us to translate ctf_open() calls into ctf_bufopen() calls.
  39  *
  40  * The second purpose of the interposition layer is to reduce the work needed
  41  * to call mdb_ctf_bufopen.
  42  */
  43
  44 #include <sys/types.h>
  45 #include <sys/kobj.h>
  46 #include <libctf.h>
  47 #include <ctf_impl.h>
  48
  49 #include <kmdb/kmdb_module.h>
  50 #include <mdb/mdb_ctf.h>
  51 #include <mdb/mdb_string.h>
  52 #include <mdb/mdb_debug.h>
  53 #include <mdb/mdb_err.h>
  54 #include <mdb/mdb.h>
  55
  56 static kmdb_modctl_t *
  57 mdb_ctf_name2ctl(const char *pathname)
  58 {
  59         mdb_var_t *v;
  60
  61         if ((v = mdb_nv_lookup(&mdb.m_dmodctl, strbasename(pathname))) ==
  62             NULL)
  63                 return (NULL);
  64
  65         return ((kmdb_modctl_t *)MDB_NV_COOKIE(v));
  66 }
  67
  68 ctf_file_t *
  69 mdb_ctf_open(const char *pathname, int *errp)
  70 {
  71         struct module *mp;
  72         kmdb_modctl_t *kmc;
  73         ctf_file_t *ctfp;
  74
  75         if ((kmc = mdb_ctf_name2ctl(pathname)) == NULL) {
  76                 if (errp != NULL)
  77                         *errp = ENOENT;
  78                 return (NULL);
  79         }
  80
  81         mp = kmc->kmc_modctl->mod_mp;
  82         if (mp->ctfdata == NULL) {
  83                 if (errp != NULL)
  84                         *errp = ECTF_NOCTFDATA;
  85                 return (NULL);
  86         }
  87
  88         if ((ctfp = mdb_ctf_bufopen(mp->ctfdata, mp->ctfsize, mp->symtbl,
  89             mp->symhdr, mp->strings, mp->strhdr, errp)) == NULL)
  90                 return (NULL);
  91
  92         mdb_dprintf(MDB_DBG_MODULE, "loaded %lu bytes of CTF data for %s\n",
  93             (ulong_t)mp->ctfsize, kmc->kmc_modname);
  94
  95         return (ctfp);
  96 }
  97
  98 void
  99 mdb_ctf_close(ctf_file_t *fp)
 100 {
 101         ctf_close(fp);
 102 }
 103
 104 /*ARGSUSED*/
 105 int
 106 mdb_ctf_write(const char *file, ctf_file_t *fp)
 107 {
 108         return (ENOTSUP);
 109 }