libumem/common/misc.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

#include <unistd.h>
#include <dlfcn.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>

#include <sys/machelf.h>

#include <umem_impl.h>
#include "misc.h"

#define UMEM_ERRFD  2   /* goes to standard error */
#define UMEM_MAX_ERROR_SIZE 4096 /* error messages are truncated to this */

/*
 * This is a circular buffer for holding error messages.
 * umem_error_enter appends to the buffer, adding "..." to the beginning
 * if data has been lost.
 */

#define ERR_SIZE 8192       /* must be a power of 2 */

static mutex_t umem_error_lock = DEFAULTMUTEX;

static char umem_error_buffer[ERR_SIZE] = "";
static uint_t umem_error_begin = 0;
static uint_t umem_error_end = 0;

#define WRITE_AND_INC(var, value) { \
    umem_error_buffer[(var)++] = (value); \
    var = P2PHASE((var), ERR_SIZE); \
}

static void
umem_log_enter(const char *error_str)
{
    int looped;
    char c;

    looped = 0;

    (void) mutex_lock(&umem_error_lock);

    while ((c = *error_str++) != '\0') {
        WRITE_AND_INC(umem_error_end, c);
        if (umem_error_end == umem_error_begin)
            looped = 1;
    }

    umem_error_buffer[umem_error_end] = 0;

    if (looped) {
        uint_t idx;
        umem_error_begin = P2PHASE(umem_error_end + 1, ERR_SIZE);

        idx = umem_error_begin;
        WRITE_AND_INC(idx, '.');
        WRITE_AND_INC(idx, '.');
        WRITE_AND_INC(idx, '.');
    }

    (void) mutex_unlock(&umem_error_lock);
}

void
umem_error_enter(const char *error_str)
{
#ifndef UMEM_STANDALONE
    if (umem_output && !issetugid())
        (void) write(UMEM_ERRFD, error_str, strlen(error_str));
#endif

    umem_log_enter(error_str);
}

int
highbit(ulong_t i)
{
    register int h = 1;

    if (i == 0)
        return (0);
#ifdef _LP64
    if (i & 0xffffffff00000000ul) {
        h += 32; i >>= 32;
    }
#endif
    if (i & 0xffff0000) {
        h += 16; i >>= 16;
    }
    if (i & 0xff00) {
        h += 8; i >>= 8;
    }
    if (i & 0xf0) {
        h += 4; i >>= 4;
    }
    if (i & 0xc) {
        h += 2; i >>= 2;
    }
    if (i & 0x2) {
        h += 1;
    }
    return (h);
}

int
lowbit(ulong_t i)
{
    register int h = 1;

    if (i == 0)
        return (0);
#ifdef _LP64
    if (!(i & 0xffffffff)) {
        h += 32; i >>= 32;
    }
#endif
    if (!(i & 0xffff)) {
        h += 16; i >>= 16;
    }
    if (!(i & 0xff)) {
        h += 8; i >>= 8;
    }
    if (!(i & 0xf)) {
        h += 4; i >>= 4;
    }
    if (!(i & 0x3)) {
        h += 2; i >>= 2;
    }
    if (!(i & 0x1)) {
        h += 1;
    }
    return (h);
}

void
hrt2ts(hrtime_t hrt, timestruc_t *tsp)
{
    tsp->tv_sec = hrt / NANOSEC;
    tsp->tv_nsec = hrt % NANOSEC;
}

void
log_message(const char *format, ...)
{
    char buf[UMEM_MAX_ERROR_SIZE] = "";

    va_list va;

    va_start(va, format);
    (void) vsnprintf(buf, UMEM_MAX_ERROR_SIZE-1, format, va);
    va_end(va);

#ifndef UMEM_STANDALONE
    if (umem_output > 1)
        (void) write(UMEM_ERRFD, buf, strlen(buf));
#endif

    umem_log_enter(buf);
}

#ifndef UMEM_STANDALONE
void
debug_printf(const char *format, ...)
{
    char buf[UMEM_MAX_ERROR_SIZE] = "";

    va_list va;

    va_start(va, format);
    (void) vsnprintf(buf, UMEM_MAX_ERROR_SIZE-1, format, va);
    va_end(va);

    (void) write(UMEM_ERRFD, buf, strlen(buf));
}
#endif

void
umem_vprintf(const char *format, va_list va)
{
    char buf[UMEM_MAX_ERROR_SIZE] = "";

    (void) vsnprintf(buf, UMEM_MAX_ERROR_SIZE-1, format, va);

    umem_error_enter(buf);
}

void
umem_printf(const char *format, ...)
{
    va_list va;

    va_start(va, format);
    umem_vprintf(format, va);
    va_end(va);
}

/*ARGSUSED*/
void
umem_printf_warn(void *ignored, const char *format, ...)
{
    va_list va;

    va_start(va, format);
    umem_vprintf(format, va);
    va_end(va);
}

/*
 * print_sym tries to print out the symbol and offset of a pointer
 */
int
print_sym(void *pointer)
{
    int result;
    Dl_info sym_info;

    uintptr_t end = NULL;

    Sym *ext_info = NULL;

    result = dladdr1(pointer, &sym_info, (void **)&ext_info,
        RTLD_DL_SYMENT);

    if (result != 0) {
        const char *endpath;

        end = (uintptr_t)sym_info.dli_saddr + ext_info->st_size;

        endpath = strrchr(sym_info.dli_fname, '/');
        if (endpath)
            endpath++;
        else
            endpath = sym_info.dli_fname;
        umem_printf("%s'", endpath);
    }

    if (result == 0 || (uintptr_t)pointer > end) {
        umem_printf("?? (0x%p)", pointer);
        return (0);
    } else {
        umem_printf("%s+0x%p", sym_info.dli_sname,
            (char *)pointer - (char *)sym_info.dli_saddr);
        return (1);
    }
}