xref: /titanic_51/usr/src/cmd/mdb/common/modules/genunix/list.c (revision 9889d1c6ca2bae13060bd0690ee771c8bb53303d)
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 == NULL ? NULL : end + lwd->lw_offset);
89 	lwd->lw_elem_name = element_name;
90 	lwd->lw_elem_check = element_check;
91 	lwd->lw_elem_check_arg = arg;
92 
93 	wsp->walk_addr = (begin == NULL
94 	    ? (uintptr_t)list.list_head.list_next
95 	    : begin + lwd->lw_offset);
96 	wsp->walk_data = lwd;
97 
98 	return (WALK_NEXT);
99 }
100 
101 int
102 list_walk_init(mdb_walk_state_t *wsp)
103 {
104 	return (list_walk_init_range(wsp, NULL, NULL, NULL, NULL, NULL, NULL));
105 }
106 
107 int
108 list_walk_init_named(mdb_walk_state_t *wsp,
109     const char *list_name, const char *element_name)
110 {
111 	return (list_walk_init_range(wsp, NULL, NULL, list_name, element_name,
112 	    NULL, NULL));
113 }
114 
115 int
116 list_walk_init_checked(mdb_walk_state_t *wsp,
117     const char *list_name, const char *element_name,
118     int (*element_check)(void *, uintptr_t, void *), void *arg)
119 {
120 	return (list_walk_init_range(wsp, NULL, NULL, list_name, element_name,
121 	    element_check, arg));
122 }
123 
124 int
125 list_walk_step(mdb_walk_state_t *wsp)
126 {
127 	list_walk_data_t *lwd = wsp->walk_data;
128 	uintptr_t addr = wsp->walk_addr - lwd->lw_offset;
129 	list_node_t *node;
130 	int status;
131 
132 	if (wsp->walk_addr == lwd->lw_head)
133 		return (WALK_DONE);
134 
135 	if (lwd->lw_end != NULL && wsp->walk_addr == lwd->lw_end)
136 		return (WALK_DONE);
137 
138 	if (mdb_vread(lwd->lw_obj, lwd->lw_size, addr) == -1) {
139 		mdb_warn("failed to read %s at %#lx", lwd->lw_elem_name, addr);
140 		return (WALK_ERR);
141 	}
142 
143 	if (lwd->lw_elem_check != NULL) {
144 		int rc = lwd->lw_elem_check(lwd->lw_obj, addr,
145 		    lwd->lw_elem_check_arg);
146 		if (rc == -1)
147 			return (WALK_ERR);
148 		else if (rc == 1)
149 			return (WALK_DONE);
150 	}
151 
152 	status = wsp->walk_callback(addr, lwd->lw_obj, wsp->walk_cbdata);
153 	node = (list_node_t *)((uintptr_t)lwd->lw_obj + lwd->lw_offset);
154 	wsp->walk_addr = (uintptr_t)node->list_next;
155 
156 	return (status);
157 }
158 
159 void
160 list_walk_fini(mdb_walk_state_t *wsp)
161 {
162 	list_walk_data_t *lwd = wsp->walk_data;
163 
164 	mdb_free(lwd->lw_obj, lwd->lw_size);
165 	mdb_free(lwd, sizeof (list_walk_data_t));
166 }
167