usr/src/cmd/mdb/common/modules/genunix/list.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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 /*
  26  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  27  */
  28
  29 #include <mdb/mdb_modapi.h>
  30 #include <sys/list.h>
  31
  32 typedef struct list_walk_data {
  33         uintptr_t lw_head;      /* address of list head */
  34         size_t  lw_size;        /* size of list element */
  35         size_t  lw_offset;      /* list element linkage offset */
  36         void    *lw_obj;        /* buffer of lw_size to hold list element */
  37         uintptr_t lw_end;       /* last node in specified range */
  38         const char *lw_elem_name;
  39         int     (*lw_elem_check)(void *, uintptr_t, void *);
  40         void    *lw_elem_check_arg;
  41 } list_walk_data_t;
  42
  43 /*
  44  * Initialize a forward walk through a list.
  45  *
  46  * begin and end optionally specify objects other than the first and last
  47  * objects in the list; either or both may be NULL (defaulting to first and
  48  * last).
  49  *
  50  * list_name and element_name specify command-specific labels other than
  51  * "list_t" and "list element" for use in error messages.
  52  *
  53  * element_check() returns -1, 1, or 0: abort the walk with an error, stop
  54  * without an error, or allow the normal callback; arg is an optional user
  55  * argument to element_check().
  56  */
  57 int
  58 list_walk_init_range(mdb_walk_state_t *wsp, uintptr_t begin, uintptr_t end,
  59     const char *list_name, const char *element_name,
  60     int (*element_check)(void *, uintptr_t, void *), void *arg)
  61 {
  62         list_walk_data_t *lwd;
  63         list_t list;
  64
  65         if (list_name == NULL)
  66                 list_name = "list_t";
  67         if (element_name == NULL)
  68                 element_name = "list element";
  69
  70         if (mdb_vread(&list, sizeof (list_t), wsp->walk_addr) == -1) {
  71                 mdb_warn("failed to read %s at %#lx", list_name,
  72                     wsp->walk_addr);
  73                 return (WALK_ERR);
  74         }
  75
  76         if (list.list_size < list.list_offset + sizeof (list_node_t)) {
  77                 mdb_warn("invalid or uninitialized %s at %#lx\n", list_name,
  78                     wsp->walk_addr);
  79                 return (WALK_ERR);
  80         }
  81
  82         lwd = mdb_alloc(sizeof (list_walk_data_t), UM_SLEEP);
  83
  84         lwd->lw_size = list.list_size;
  85         lwd->lw_offset = list.list_offset;
  86         lwd->lw_obj = mdb_alloc(list.list_size, UM_SLEEP);
  87         lwd->lw_head = (uintptr_t)&((list_t *)wsp->walk_addr)->list_head;
  88         lwd->lw_end = (end == (uintptr_t)NULL ?
  89             (uintptr_t)NULL : end + lwd->lw_offset);
  90         lwd->lw_elem_name = element_name;
  91         lwd->lw_elem_check = element_check;
  92         lwd->lw_elem_check_arg = arg;
  93
  94         wsp->walk_addr = (begin == (uintptr_t)NULL
  95             ? (uintptr_t)list.list_head.list_next
  96             : begin + lwd->lw_offset);
  97         wsp->walk_data = lwd;
  98
  99         return (WALK_NEXT);
 100 }
 101
 102 int
 103 list_walk_init(mdb_walk_state_t *wsp)
 104 {
 105         return (list_walk_init_range(wsp, (uintptr_t)NULL, (uintptr_t)NULL,
 106             NULL, NULL, NULL, NULL));
 107 }
 108
 109 int
 110 list_walk_init_named(mdb_walk_state_t *wsp,
 111     const char *list_name, const char *element_name)
 112 {
 113         return (list_walk_init_range(wsp, (uintptr_t)NULL, (uintptr_t)NULL,
 114             list_name, element_name, NULL, NULL));
 115 }
 116
 117 int
 118 list_walk_init_checked(mdb_walk_state_t *wsp,
 119     const char *list_name, const char *element_name,
 120     int (*element_check)(void *, uintptr_t, void *), void *arg)
 121 {
 122         return (list_walk_init_range(wsp, (uintptr_t)NULL, (uintptr_t)NULL,
 123             list_name, element_name, element_check, arg));
 124 }
 125
 126 int
 127 list_walk_step(mdb_walk_state_t *wsp)
 128 {
 129         list_walk_data_t *lwd = wsp->walk_data;
 130         uintptr_t addr = wsp->walk_addr - lwd->lw_offset;
 131         list_node_t *node;
 132         int status;
 133
 134         if (wsp->walk_addr == lwd->lw_head)
 135                 return (WALK_DONE);
 136
 137         if (lwd->lw_end != (uintptr_t)NULL && wsp->walk_addr == lwd->lw_end)
 138                 return (WALK_DONE);
 139
 140         if (mdb_vread(lwd->lw_obj, lwd->lw_size, addr) == -1) {
 141                 mdb_warn("failed to read %s at %#lx", lwd->lw_elem_name, addr);
 142                 return (WALK_ERR);
 143         }
 144
 145         if (lwd->lw_elem_check != NULL) {
 146                 int rc = lwd->lw_elem_check(lwd->lw_obj, addr,
 147                     lwd->lw_elem_check_arg);
 148                 if (rc == -1)
 149                         return (WALK_ERR);
 150                 else if (rc == 1)
 151                         return (WALK_DONE);
 152         }
 153
 154         status = wsp->walk_callback(addr, lwd->lw_obj, wsp->walk_cbdata);
 155         node = (list_node_t *)((uintptr_t)lwd->lw_obj + lwd->lw_offset);
 156         wsp->walk_addr = (uintptr_t)node->list_next;
 157
 158         return (status);
 159 }
 160
 161 void
 162 list_walk_fini(mdb_walk_state_t *wsp)
 163 {
 164         list_walk_data_t *lwd = wsp->walk_data;
 165
 166         mdb_free(lwd->lw_obj, lwd->lw_size);
 167         mdb_free(lwd, sizeof (list_walk_data_t));
 168 }