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 (c) 2015, Joyent, Inc. All rights reserved.
14 */
15
16 #include <sys/mdb_modapi.h>
17 #include <sys/time.h>
18 #include <sys/mem.h>
19
20 typedef struct kmemlog_walk {
21 uintptr_t kmlw_addr;
22 mm_logentry_t *kmlw_entries;
23 int kmlw_nentries;
24 int kmlw_entry;
25 int kmlw_oldest;
26 } kmemlog_walk_t;
27
28 static int
kmemlog_walk_init(mdb_walk_state_t * wsp)29 kmemlog_walk_init(mdb_walk_state_t *wsp)
30 {
31 kmemlog_walk_t *kw;
32 GElf_Sym sym;
33
34 if (mdb_lookup_by_name("mm_kmemlog", &sym) != 0) {
35 mdb_warn("couldn't find symbol 'mm_kmemlog'");
36 return (WALK_ERR);
37 }
38
39 kw = mdb_zalloc(sizeof (kmemlog_walk_t), UM_SLEEP);
40 kw->kmlw_entries = mdb_zalloc(sym.st_size, UM_SLEEP);
41 kw->kmlw_addr = sym.st_value;
42
43 if (mdb_vread(kw->kmlw_entries, sym.st_size, sym.st_value) == -1) {
44 mdb_warn("couldn't read log at %p", sym.st_value);
45 mdb_free(kw->kmlw_entries, sym.st_size);
46 mdb_free(kw, sizeof (kmemlog_walk_t));
47 return (WALK_ERR);
48 }
49
50 kw->kmlw_nentries = sym.st_size / sizeof (mm_logentry_t);
51
52 mdb_readvar(&kw->kmlw_entry, "mm_kmemlogent");
53 kw->kmlw_oldest = kw->kmlw_entry;
54 wsp->walk_data = kw;
55
56 return (WALK_NEXT);
57 }
58
59 static int
kmemlog_walk_step(mdb_walk_state_t * wsp)60 kmemlog_walk_step(mdb_walk_state_t *wsp)
61 {
62 kmemlog_walk_t *kw = wsp->walk_data;
63 mm_logentry_t *ent;
64 int rval = WALK_NEXT;
65
66 ent = &kw->kmlw_entries[kw->kmlw_entry];
67
68 if (++kw->kmlw_entry == kw->kmlw_nentries)
69 kw->kmlw_entry = 0;
70
71 if (ent->mle_hrtime != 0) {
72 rval = wsp->walk_callback(kw->kmlw_addr + ((uintptr_t)ent -
73 (uintptr_t)kw->kmlw_entries), ent, wsp->walk_cbdata);
74 }
75
76 if (rval == WALK_NEXT && kw->kmlw_entry == kw->kmlw_oldest)
77 return (WALK_DONE);
78
79 return (rval);
80 }
81
82 static void
kmemlog_walk_fini(mdb_walk_state_t * wsp)83 kmemlog_walk_fini(mdb_walk_state_t *wsp)
84 {
85 kmemlog_walk_t *kw = wsp->walk_data;
86
87 mdb_free(kw->kmlw_entries, kw->kmlw_nentries * sizeof (mm_logentry_t));
88 mdb_free(kw, sizeof (kmemlog_walk_t));
89 }
90
91 static int
kmemlog(uintptr_t addr,uint_t flags,int argc,const mdb_arg_t * argv)92 kmemlog(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
93 {
94 mm_logentry_t ent;
95
96 if (!(flags & DCMD_ADDRSPEC)) {
97 if (mdb_walk_dcmd("kmemlog", "kmemlog", argc, argv) == -1) {
98 mdb_warn("can't walk 'kmemlog'");
99 return (DCMD_ERR);
100 }
101 return (DCMD_OK);
102 }
103
104 if (DCMD_HDRSPEC(flags)) {
105 mdb_printf("%?s %-20s %?s %5s %s\n",
106 "ADDR", "TIME", "VADDR", "PID", "PSARGS");
107 }
108
109 if (mdb_vread(&ent, sizeof (ent), addr) == -1) {
110 mdb_warn("can't read mm_logentry_t at %p", addr);
111 return (DCMD_ERR);
112 }
113
114 mdb_printf("%?p %-20Y %?p %5d %s\n",
115 addr, ent.mle_hrestime.tv_sec, ent.mle_vaddr, ent.mle_pid,
116 ent.mle_psargs);
117
118 return (DCMD_OK);
119 }
120
121 static const mdb_dcmd_t dcmds[] = {
122 { "kmemlog", NULL, "print log of writes via /dev/kmem", kmemlog },
123 { NULL }
124 };
125
126 static const mdb_walker_t walkers[] = {
127 { "kmemlog", "walk entries in /dev/kmem write log",
128 kmemlog_walk_init, kmemlog_walk_step, kmemlog_walk_fini },
129 { NULL }
130 };
131
132 static const mdb_modinfo_t modinfo = {
133 MDB_API_VERSION, dcmds, walkers
134 };
135
136 const mdb_modinfo_t *
_mdb_init(void)137 _mdb_init(void)
138 {
139 return (&modinfo);
140 }
141