usr/src/common/ctf/ctf_util.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 2005 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 /*
  27  * Copyright (c) 2015, Joyent, Inc.
  28  */
  29
  30 #include <ctf_impl.h>
  31 #include <sys/debug.h>
  32
  33 /*
  34  * Simple doubly-linked list append routine.  This implementation assumes that
  35  * each list element contains an embedded ctf_list_t as the first member.
  36  * An additional ctf_list_t is used to store the head (l_next) and tail
  37  * (l_prev) pointers.  The current head and tail list elements have their
  38  * previous and next pointers set to NULL, respectively.
  39  */
  40 void
  41 ctf_list_append(ctf_list_t *lp, void *new)
  42 {
  43         ctf_list_t *p = lp->l_prev;     /* p = tail list element */
  44         ctf_list_t *q = new;            /* q = new list element */
  45
  46         lp->l_prev = q;
  47         q->l_prev = p;
  48         q->l_next = NULL;
  49
  50         if (p != NULL)
  51                 p->l_next = q;
  52         else
  53                 lp->l_next = q;
  54 }
  55
  56 /*
  57  * Prepend the specified existing element to the given ctf_list_t.  The
  58  * existing pointer should be pointing at a struct with embedded ctf_list_t.
  59  */
  60 void
  61 ctf_list_prepend(ctf_list_t *lp, void *new)
  62 {
  63         ctf_list_t *p = new;            /* p = new list element */
  64         ctf_list_t *q = lp->l_next;     /* q = head list element */
  65
  66         lp->l_next = p;
  67         p->l_prev = NULL;
  68         p->l_next = q;
  69
  70         if (q != NULL)
  71                 q->l_prev = p;
  72         else
  73                 lp->l_prev = p;
  74 }
  75
  76 void
  77 ctf_list_insert_before(ctf_list_t *head, void *item, void *nitem)
  78 {
  79         ctf_list_t *lp = item;
  80         ctf_list_t *new = nitem;
  81         ctf_list_t *prev = lp->l_prev;
  82
  83         lp->l_prev = new;
  84         new->l_next = lp;
  85         new->l_prev = prev;
  86         if (prev != NULL) {
  87                 prev->l_next = new;
  88         } else {
  89                 ASSERT(head->l_next == lp);
  90                 head->l_next = new;
  91         }
  92 }
  93
  94 /*
  95  * Delete the specified existing element from the given ctf_list_t.  The
  96  * existing pointer should be pointing at a struct with embedded ctf_list_t.
  97  */
  98 void
  99 ctf_list_delete(ctf_list_t *lp, void *existing)
 100 {
 101         ctf_list_t *p = existing;
 102
 103         if (p->l_prev != NULL)
 104                 p->l_prev->l_next = p->l_next;
 105         else
 106                 lp->l_next = p->l_next;
 107
 108         if (p->l_next != NULL)
 109                 p->l_next->l_prev = p->l_prev;
 110         else
 111                 lp->l_prev = p->l_prev;
 112 }
 113
 114 /*
 115  * Convert an encoded CTF string name into a pointer to a C string by looking
 116  * up the appropriate string table buffer and then adding the offset.
 117  */
 118 const char *
 119 ctf_strraw(ctf_file_t *fp, uint_t name)
 120 {
 121         ctf_strs_t *ctsp = &fp->ctf_str[CTF_NAME_STID(name)];
 122
 123         if (ctsp->cts_strs != NULL && CTF_NAME_OFFSET(name) < ctsp->cts_len)
 124                 return (ctsp->cts_strs + CTF_NAME_OFFSET(name));
 125
 126         /* string table not loaded or corrupt offset */
 127         return (NULL);
 128 }
 129
 130 const char *
 131 ctf_strptr(ctf_file_t *fp, uint_t name)
 132 {
 133         const char *s = ctf_strraw(fp, name);
 134         return (s != NULL ? s : "(?)");
 135 }
 136
 137 /*
 138  * Same strdup(3C), but use ctf_alloc() to do the memory allocation.
 139  */
 140 char *
 141 ctf_strdup(const char *s1)
 142 {
 143         char *s2 = ctf_alloc(strlen(s1) + 1);
 144
 145         if (s2 != NULL)
 146                 (void) strcpy(s2, s1);
 147
 148         return (s2);
 149 }
 150
 151 /*
 152  * Store the specified error code into errp if it is non-NULL, and then
 153  * return NULL for the benefit of the caller.
 154  */
 155 ctf_file_t *
 156 ctf_set_open_errno(int *errp, int error)
 157 {
 158         if (errp != NULL)
 159                 *errp = error;
 160         return (NULL);
 161 }
 162
 163 /*
 164  * Store the specified error code into the CTF container, and then return
 165  * CTF_ERR for the benefit of the caller.
 166  */
 167 long
 168 ctf_set_errno(ctf_file_t *fp, int err)
 169 {
 170         fp->ctf_errno = err;
 171         return (CTF_ERR);
 172 }
 173
 174 boolean_t
 175 ctf_sym_valid(uintptr_t strbase, int type, uint16_t shndx, uint64_t val,
 176     uint32_t noff)
 177 {
 178         const char *name;
 179
 180         if (type != STT_OBJECT && type != STT_FUNC)
 181                 return (B_FALSE);
 182         if (shndx == SHN_UNDEF || noff == 0)
 183                 return (B_FALSE);
 184         if (type == STT_OBJECT && shndx == SHN_ABS && val == 0)
 185                 return (B_FALSE);
 186         name = (char *)(strbase + noff);
 187         if (strcmp(name, "_START_") == 0 || strcmp(name, "_END_") == 0)
 188                 return (B_FALSE);
 189
 190         return (B_TRUE);
 191 }