usr/src/cmd/fm/fmd/common/fmd_trace.c

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