fmd/common/fmd_trace.c

	fmd_trace.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <sys/sysmacros.h>

#include <ucontext.h>
#include <strings.h>
#include <stdio.h>
#include <errno.h>

#include <fmd_trace.h>
#include <fmd_alloc.h>
#include <fmd_subr.h>
#include <fmd_conf.h>
#include <fmd.h>

fmd_tracebuf_t *
fmd_trace_create(void)
{
    fmd_tracebuf_t *tbp = fmd_zalloc(sizeof (fmd_tracebuf_t), FMD_SLEEP);
    size_t bufsize;

    (void) fmd_conf_getprop(fmd.d_conf, "trace.frames", &tbp->tb_frames);
    (void) fmd_conf_getprop(fmd.d_conf, "trace.recs", &tbp->tb_recs);

    /*
     * We require 8-byte alignment of fmd_tracerec_t to store hrtime_t's.
     * Since the trailing flexible array member is of type uintptr_t, we
     * must make it a multiple of 2 if we are compiling 32-bit; otherwise
     * uintptr_t is 8 bytes so any value of tb_frames is acceptable.
     */
#ifdef _ILP32
    tbp->tb_frames = P2ROUNDUP(tbp->tb_frames, 2);
#endif
    tbp->tb_size = sizeof (fmd_tracerec_t) +
        sizeof (uintptr_t) * (MAX(tbp->tb_frames, 1) - 1);

    bufsize = tbp->tb_size * tbp->tb_recs;

    tbp->tb_buf = fmd_zalloc(bufsize, FMD_SLEEP);
    tbp->tb_end = (void *)((uintptr_t)tbp->tb_buf + bufsize - tbp->tb_size);
    tbp->tb_ptr = tbp->tb_buf;

    return (tbp);
}

void
fmd_trace_destroy(fmd_tracebuf_t *tbp)
{
    fmd_free(tbp->tb_buf, tbp->tb_size * tbp->tb_recs);
    fmd_free(tbp, sizeof (fmd_tracebuf_t));
}

/*
 * Callback for walkcontext(3C) to store the stack trace.  We use tr_tag below
 * to store the maximum value of depth that is permitted so we can use it here.
 */
/*ARGSUSED*/
static int
fmd_trace_frame(uintptr_t pc, int sig, fmd_tracerec_t *trp)
{
    trp->tr_stack[trp->tr_depth++] = pc;
    return (trp->tr_depth >= trp->tr_tag);
}

/*ARGSUSED*/
fmd_tracerec_t *
fmd_trace_none(fmd_tracebuf_t *tbp, uint8_t tag, const char *format, va_list ap)
{
    return (NULL);
}

fmd_tracerec_t *
fmd_trace_lite(fmd_tracebuf_t *tbp, uint8_t tag, const char *format, va_list ap)
{
    hrtime_t time = gethrtime();
    fmd_tracerec_t *trp = tbp->tb_ptr;
    char *p;

    trp->tr_time = time;
    trp->tr_file = NULL;
    trp->tr_line = 0;
    trp->tr_errno = (tag == FMD_DBG_ERR) ? errno : 0;
    trp->tr_tag = tag;

    (void) vsnprintf(trp->tr_msg, sizeof (trp->tr_msg), format, ap);
    p = &trp->tr_msg[strlen(trp->tr_msg)];
    if (p > trp->tr_msg && p[-1] == '\n')
        p[-1] = '\0';

    if (tbp->tb_ptr != tbp->tb_end)
        tbp->tb_ptr = (void *)((uintptr_t)tbp->tb_ptr + tbp->tb_size);
    else
        tbp->tb_ptr = tbp->tb_buf;

    return (trp);
}

fmd_tracerec_t *
fmd_trace_full(fmd_tracebuf_t *tbp, uint8_t tag, const char *format, va_list ap)
{
    hrtime_t time = gethrtime();
    fmd_tracerec_t *trp = tbp->tb_ptr;
    ucontext_t uc;
    char *p;

    (void) getcontext(&uc);
    trp->tr_tag = tbp->tb_frames; /* for use by fmd_trace_frame() */
    (void) walkcontext(&uc, (int (*)())fmd_trace_frame, trp);

    trp->tr_time = time;
    trp->tr_file = NULL;
    trp->tr_line = 0;
    trp->tr_errno = (tag == FMD_DBG_ERR) ? errno : 0;
    trp->tr_tag = tag;

    (void) vsnprintf(trp->tr_msg, sizeof (trp->tr_msg), format, ap);
    p = &trp->tr_msg[strlen(trp->tr_msg)];
    if (p > trp->tr_msg && p[-1] == '\n')
        p[-1] = '\0';

    if (tbp->tb_ptr != tbp->tb_end)
        tbp->tb_ptr = (void *)((uintptr_t)tbp->tb_ptr + tbp->tb_size);
    else
        tbp->tb_ptr = tbp->tb_buf;

    return (trp);
}