1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
6 *
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
10 */
11
12 /*
13 * Copyright 2016 Joyent, Inc.
14 */
15
16 #include "dnlc.h"
17
18 #include <mdb/mdb_modapi.h>
19 #include <sys/dnlc.h>
20
21 typedef struct dnlc_walk {
22 int dw_hashsz;
23 int dw_index;
24 uintptr_t dw_hash;
25 uintptr_t dw_head;
26 } dnlc_walk_t;
27
28
29 int
dnlc_walk_init(mdb_walk_state_t * wsp)30 dnlc_walk_init(mdb_walk_state_t *wsp)
31 {
32 dnlc_walk_t *dwp;
33
34 if (wsp->walk_addr != 0) {
35 mdb_warn("dnlc walk doesn't support global walks\n");
36 return (WALK_ERR);
37 }
38
39 dwp = mdb_zalloc(sizeof (dnlc_walk_t), UM_SLEEP);
40 if (mdb_readvar(&dwp->dw_hashsz, "nc_hashsz") == -1 ||
41 dwp->dw_hashsz <= 0) {
42 mdb_warn("failed to read 'nc_hashsz'\n");
43 mdb_free(dwp, sizeof (dnlc_walk_t));
44 return (WALK_ERR);
45 }
46 if (dwp->dw_hashsz <= 0) {
47 mdb_warn("invalid 'nc_hashsz' value\n");
48 mdb_free(dwp, sizeof (dnlc_walk_t));
49 return (WALK_ERR);
50 }
51 if (mdb_readvar(&dwp->dw_hash, "nc_hash") == -1) {
52 mdb_warn("failed to read 'nc_hash'\n");
53 mdb_free(dwp, sizeof (dnlc_walk_t));
54 return (WALK_ERR);
55 }
56
57 wsp->walk_data = dwp;
58 return (WALK_NEXT);
59 }
60
61 int
dnlc_walk_step(mdb_walk_state_t * wsp)62 dnlc_walk_step(mdb_walk_state_t *wsp)
63 {
64 dnlc_walk_t *dwp = wsp->walk_data;
65 nc_hash_t hash;
66 uintptr_t result, addr = wsp->walk_addr;
67
68 next:
69 while (addr == dwp->dw_head || addr == 0) {
70 if (dwp->dw_index >= dwp->dw_hashsz) {
71 return (WALK_DONE);
72 }
73 dwp->dw_head = dwp->dw_hash +
74 (sizeof (nc_hash_t) * dwp->dw_index);
75 if (mdb_vread(&hash, sizeof (hash), dwp->dw_head) == -1) {
76 mdb_warn("failed to read nc_hash_t at %#lx",
77 dwp->dw_hash);
78 return (WALK_ERR);
79 }
80 dwp->dw_index++;
81 addr = (uintptr_t)hash.hash_next;
82 }
83
84 result = addr;
85 if (mdb_vread(&addr, sizeof (uintptr_t), addr) == -1) {
86 /*
87 * This entry may have become bogus since acquiring the address
88 * from its neighbor. Continue on if that is the case.
89 */
90 addr = 0;
91 goto next;
92 }
93 wsp->walk_addr = addr;
94
95 return (wsp->walk_callback(result, &result, wsp->walk_cbdata));
96 }
97
98 void
dnlc_walk_fini(mdb_walk_state_t * wsp)99 dnlc_walk_fini(mdb_walk_state_t *wsp)
100 {
101 dnlc_walk_t *dwp = wsp->walk_data;
102
103 mdb_free(dwp, sizeof (dnlc_walk_t));
104 }
105