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 /*
23 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include <sys/types.h>
30 #include <sys/sysmacros.h>
31
32 #include <ucontext.h>
33 #include <strings.h>
34 #include <stdio.h>
35 #include <errno.h>
36
37 #include <fmd_trace.h>
38 #include <fmd_alloc.h>
39 #include <fmd_subr.h>
40 #include <fmd_conf.h>
41 #include <fmd.h>
42
43 fmd_tracebuf_t *
fmd_trace_create(void)44 fmd_trace_create(void)
45 {
46 fmd_tracebuf_t *tbp = fmd_zalloc(sizeof (fmd_tracebuf_t), FMD_SLEEP);
47 size_t bufsize;
48
49 (void) fmd_conf_getprop(fmd.d_conf, "trace.frames", &tbp->tb_frames);
50 (void) fmd_conf_getprop(fmd.d_conf, "trace.recs", &tbp->tb_recs);
51
52 /*
53 * We require 8-byte alignment of fmd_tracerec_t to store hrtime_t's.
54 * Since the trailing flexible array member is of type uintptr_t, we
55 * may need to allocate an additional element if we are compiling
56 * 32-bit; otherwise uintptr_t is 8 bytes so any value of tb_frames is
57 * acceptable.
58 *
59 * tb_frames includes the first element, whose size is reflected in
60 * sizeof (fmd_tracerec_t). Therefore, if fmd_tracerec_t's size is
61 * 0 mod 8, we must be sure the total number of frames is odd.
62 * Otherwise, we need at least one extra frame, so the total count
63 * must be even. This will continue to work even if the sizes or
64 * types of other fmd_tracerec_t members are changed.
65 */
66 #ifdef _ILP32
67 /*CONSTCOND*/
68 if (sizeof (fmd_tracerec_t) % sizeof (hrtime_t) == 0)
69 tbp->tb_frames = (tbp->tb_frames & ~1UL) + 1;
70 else
71 tbp->tb_frames = P2ROUNDUP(tbp->tb_frames, 2);
72 #endif
73 tbp->tb_size = sizeof (fmd_tracerec_t) +
74 sizeof (uintptr_t) * (MAX(tbp->tb_frames, 1) - 1);
75
76 bufsize = tbp->tb_size * tbp->tb_recs;
77
78 tbp->tb_buf = fmd_zalloc(bufsize, FMD_SLEEP);
79 tbp->tb_end = (void *)((uintptr_t)tbp->tb_buf + bufsize - tbp->tb_size);
80 tbp->tb_ptr = tbp->tb_buf;
81
82 return (tbp);
83 }
84
85 void
fmd_trace_destroy(fmd_tracebuf_t * tbp)86 fmd_trace_destroy(fmd_tracebuf_t *tbp)
87 {
88 fmd_free(tbp->tb_buf, tbp->tb_size * tbp->tb_recs);
89 fmd_free(tbp, sizeof (fmd_tracebuf_t));
90 }
91
92 /*
93 * Callback for walkcontext(3C) to store the stack trace. We use tr_tag below
94 * to store the maximum value of depth that is permitted so we can use it here.
95 */
96 /*ARGSUSED*/
97 static int
fmd_trace_frame(uintptr_t pc,int sig,fmd_tracerec_t * trp)98 fmd_trace_frame(uintptr_t pc, int sig, fmd_tracerec_t *trp)
99 {
100 trp->tr_stack[trp->tr_depth++] = pc;
101 return (trp->tr_depth >= trp->tr_tag);
102 }
103
104 /*ARGSUSED*/
105 fmd_tracerec_t *
fmd_trace_none(fmd_tracebuf_t * tbp,uint_t tag,const char * format,va_list ap)106 fmd_trace_none(fmd_tracebuf_t *tbp, uint_t tag, const char *format, va_list ap)
107 {
108 return (NULL);
109 }
110
111 fmd_tracerec_t *
fmd_trace_lite(fmd_tracebuf_t * tbp,uint_t tag,const char * format,va_list ap)112 fmd_trace_lite(fmd_tracebuf_t *tbp, uint_t tag, const char *format, va_list ap)
113 {
114 hrtime_t time = gethrtime();
115 fmd_tracerec_t *trp = tbp->tb_ptr;
116 char *p;
117
118 if (tbp->tb_depth++ != 0) {
119 tbp->tb_depth--;
120 return (NULL);
121 }
122
123 trp->tr_time = time;
124 trp->tr_file = NULL;
125 trp->tr_line = 0;
126 trp->tr_errno = (tag == FMD_DBG_ERR) ? errno : 0;
127 trp->tr_tag = fmd_ntz32(tag);
128
129 (void) vsnprintf(trp->tr_msg, sizeof (trp->tr_msg), format, ap);
130 p = &trp->tr_msg[strlen(trp->tr_msg)];
131 if (p > trp->tr_msg && p[-1] == '\n')
132 p[-1] = '\0';
133
134 if (tbp->tb_ptr != tbp->tb_end)
135 tbp->tb_ptr = (void *)((uintptr_t)tbp->tb_ptr + tbp->tb_size);
136 else
137 tbp->tb_ptr = tbp->tb_buf;
138
139 tbp->tb_depth--;
140 return (trp);
141 }
142
143 fmd_tracerec_t *
fmd_trace_full(fmd_tracebuf_t * tbp,uint_t tag,const char * format,va_list ap)144 fmd_trace_full(fmd_tracebuf_t *tbp, uint_t tag, const char *format, va_list ap)
145 {
146 hrtime_t time = gethrtime();
147 fmd_tracerec_t *trp = tbp->tb_ptr;
148 ucontext_t uc;
149 char *p;
150
151 if (tbp->tb_depth++ != 0) {
152 tbp->tb_depth--;
153 return (NULL);
154 }
155
156 (void) getcontext(&uc);
157 trp->tr_tag = tbp->tb_frames; /* for use by fmd_trace_frame() */
158 (void) walkcontext(&uc, (int (*)())fmd_trace_frame, trp);
159
160 trp->tr_time = time;
161 trp->tr_file = NULL;
162 trp->tr_line = 0;
163 trp->tr_errno = (tag == FMD_DBG_ERR) ? errno : 0;
164 trp->tr_tag = fmd_ntz32(tag);
165
166 if (fmd.d_fmd_debug & FMD_DBG_TRACE)
167 fmd_vdprintf(tag, format, ap);
168
169 (void) vsnprintf(trp->tr_msg, sizeof (trp->tr_msg), format, ap);
170 p = &trp->tr_msg[strlen(trp->tr_msg)];
171 if (p > trp->tr_msg && p[-1] == '\n')
172 p[-1] = '\0';
173
174 if (tbp->tb_ptr != tbp->tb_end)
175 tbp->tb_ptr = (void *)((uintptr_t)tbp->tb_ptr + tbp->tb_size);
176 else
177 tbp->tb_ptr = tbp->tb_buf;
178
179 tbp->tb_depth--;
180 return (trp);
181 }
182