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
20typedef 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
28static int
29kmemlog_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
59static int
60kmemlog_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
82static void
83kmemlog_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
91static int
92kmemlog(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
121static const mdb_dcmd_t dcmds[] = {
122	{ "kmemlog", NULL, "print log of writes via /dev/kmem", kmemlog },
123	{ NULL }
124};
125
126static 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
132static const mdb_modinfo_t modinfo = {
133	MDB_API_VERSION, dcmds, walkers
134};
135
136const mdb_modinfo_t *
137_mdb_init(void)
138{
139	return (&modinfo);
140}
141