madv/common/madv.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 (c) 2002, 2011, Oracle and/or its affiliates. All rights reserved.
 */

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/shm.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/auxv.h>
#include <stdarg.h>
#include <syslog.h>
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <procfs.h>
#include <dlfcn.h>
#include <assert.h>
#include <libintl.h>
#include <locale.h>

extern int  gmatch(const char *s, const char *p);

#pragma init(__madvmain)

static FILE *errfp = NULL;
static const char *madvident = "madv.so.1";
static int pagesize;
static int advice_all = -1;
static int advice_heap = -1;
static int advice_shm = -1;
static int advice_ism = -1;
static int advice_dism = -1;
static int advice_map = -1;
static int advice_mapshared = -1;
static int advice_mapprivate = -1;
static int advice_mapanon = -1;

/* environment variables */

#define ENV_MADV        "MADV"
#define ENV_MADVCFGFILE     "MADVCFGFILE"
#define ENV_MADVERRFILE     "MADVERRFILE"

/* config file */

#define DEF_MADVCFGFILE     "/etc/madv.conf"
#define MAXLINELEN  MAXPATHLEN + 64
#define CFGDELIMITER    ':'
#define ARGDELIMITER    ' '

/*
 * avoid malloc which causes certain applications to crash
 */
static char     lbuf[MAXLINELEN];
static char     pbuf[MAXPATHLEN];

#ifdef MADVDEBUG
#define ENV_MADVDEBUG   "MADVDEBUG"
#define MADVPRINT(x, y) if (madvdebug & x) (void) fprintf y;

static int madvdebug = 0;
#else
#define MADVPRINT(x, y)
#endif

/*
 * advice options
 */
static char *legal_optstr[] = {
    "madv",
    "heap",
    "shm",
    "ism",
    "dism",
    "map",
    "mapshared",
    "mapprivate",
    "mapanon",
    NULL
};

enum optenum {
    OPT_MADV,
    OPT_HEAP,
    OPT_SHM,
    OPT_ISM,
    OPT_DISM,
    OPT_MAP,
    OPT_MAPSHARED,
    OPT_MAPPRIVATE,
    OPT_MAPANON
};

/*
 * Advice values
 * These need to correspond to the order of the MADV_ flags in mman.h
 * since the position infers the value for the flag.
 */
static char *legal_madvice[] = {
    "normal",
    "random",
    "sequential",
    "willneed_NOT_SUPPORTED!",
    "dontneed_NOT_SUPPORTED!",
    "free_NOT_SUPPORTED!",
    "access_default",
    "access_lwp",
    "access_many",
    "access_many_pset",
    NULL
};

#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif

/*PRINTFLIKE2*/
static void
madverr(FILE *fp, char *fmt, ...)
{
    va_list     ap;
    va_start(ap, fmt);
    if (fp)
        (void) vfprintf(fp, fmt, ap);
    else
        vsyslog(LOG_ERR, fmt, ap);
    va_end(ap);
}

/*
 * Return the pointer to the fully-resolved path name of the process's
 * executable file obtained from the AT_SUN_EXECNAME aux vector entry.
 */
static const char *
mygetexecname(void)
{
    const char  *execname = NULL;
    static auxv_t   auxb;

    /*
     * The first time through, read the initial aux vector that was
     * passed to the process at exec(2).  Only do this once.
     */
    int fd = open("/proc/self/auxv", O_RDONLY);

    if (fd >= 0) {
        while (read(fd, &auxb, sizeof (auxv_t)) == sizeof (auxv_t)) {
            if (auxb.a_type == AT_SUN_EXECNAME) {
                execname = auxb.a_un.a_ptr;
                break;
            }
        }
        (void) close(fd);
    }
    return (execname);
}

/*
 * Return the process's current brk base and size.
 */
static int
mygetbrk(uintptr_t *base, size_t *size)
{
    int fd;
    pstatus_t ps;
    int rc;

    fd = open("/proc/self/status", O_RDONLY);

    if (fd >= 0) {
        if (read(fd, &ps, sizeof (ps)) == sizeof (ps)) {
            *base = ps.pr_brkbase;
            *size = ps.pr_brksize;
            rc = 0;
        } else {
            rc = errno;
        }
        (void) close(fd);
    } else {
        rc = errno;
    }
    return (rc);
}

/*
 * Check if exec name matches cfgname found in madv cfg file.
 */
static int
fnmatch(const char *execname, char *cfgname, char *cwd)
{
    const char  *ename;
    int     rc;

    /* cfgname should not have a '/' unless it begins with one */
    if (cfgname[0] == '/') {
        /*
         * if execname does not begin with a '/', prepend the
         * current directory.
         */
        if (execname[0] != '/') {
            ename = (const char *)strcat(cwd, execname);
        } else
            ename = execname;
    } else {    /* simple cfg name */
        if (ename = strrchr(execname, '/'))
            /* execname is a path name - get the base name */
            ename++;
        else
            ename = execname;
    }
    rc = gmatch(ename, cfgname);
    MADVPRINT(2, (stderr, "gmatch: %s %s %s %d\n",
        cfgname, ename, execname, rc));

    return (rc);
}

/*
 * Check if string matches any of exec arguments.
 */
static int
argmatch(char *str)
{
    int fd;
    psinfo_t pi;
    int rc = 0;
    int arg;
    char **argv;

    fd = open("/proc/self/psinfo", O_RDONLY);

    if (fd >= 0) {
        if (read(fd, &pi, sizeof (pi)) == sizeof (pi)) {
            argv = (char **)pi.pr_argv;
            argv++;
            MADVPRINT(2, (stderr, "argmatch: %s ", str));
            for (arg = 1; arg < pi.pr_argc; arg++, argv++) {
                if (rc = gmatch(*argv, str)) {
                    MADVPRINT(2, (stderr, "%s ", *argv));
                    break;
                }
            }
            MADVPRINT(2, (stderr, "%d\n", rc));
        } else {
            madverr(errfp, dgettext(TEXT_DOMAIN,
                "%s: /proc/self/psinfo read failed [%s]\n"),
                madvident, strerror(errno));
        }
        (void) close(fd);
    } else {
        madverr(errfp, dgettext(TEXT_DOMAIN,
            "%s: /proc/self/psinfo open failed [%s]\n"),
            madvident, strerror(errno));
    }
    return (rc);
}

static int
empty(char *str)
{
    char    c;

    while ((c = *str) == '\n' || c == ' ' || c == '\t')
        str++;
    return (*str == '\0');
}

static int
strtoadv(char *advstr)
{
    char *dummy, *locstr = advstr;

    return (getsubopt(&locstr, legal_madvice, &dummy));
}

static void
advice_opts(char *optstr, const char *execname, char *cfgfile, int lineno)
{
    char *value;
    int opt;
    int advice = 0;

    while (*optstr != '\0') {
        opt = getsubopt(&optstr, legal_optstr, &value);
        if (opt < 0) {
            madverr(errfp, dgettext(TEXT_DOMAIN,
                "%s: invalid advice option (%s)"
                " for %s - cfgfile: %s, line: %d\n"),
                madvident, value, execname, cfgfile, lineno);
            break;
        } else if (!value) {
            madverr(errfp, dgettext(TEXT_DOMAIN,
                "%s: option missing advice"
                " for %s - cfgfile: %s, line: %d\n"),
                madvident, execname, cfgfile, lineno);
            break;
        }
        advice = strtoadv(value);
        if (advice < 0) {
            madverr(errfp, dgettext(TEXT_DOMAIN,
                "%s: invalid advice specified (%s)"
                " for %s - cfgfile: %s, line: %d\n"),
                madvident, value, execname, cfgfile, lineno);
            break;
        }
        switch (opt) {
        case OPT_MADV:
            advice_all = advice;
            break;
        case OPT_HEAP:
            if (advice_heap < 0) {
                advice_heap = advice;
            } else {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: duplicate advice specified "
                    "(%s) for %s - cfgfile: %s, line: %d\n"),
                    madvident, value, execname, cfgfile,
                    lineno);
            }
            break;
        case OPT_SHM:
            if (advice_shm < 0) {
                advice_shm = advice;
            } else {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: duplicate advice specified "
                    "(%s) for %s - cfgfile: %s, line: %d\n"),
                    madvident, value, execname, cfgfile,
                    lineno);
            }
            break;
        case OPT_ISM:
            if (advice_ism < 0) {
                advice_ism = advice;
            } else {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: duplicate advice specified "
                    "(%s) for %s - cfgfile: %s, line: %d\n"),
                    madvident, value, execname, cfgfile,
                    lineno);
            }
            break;
        case OPT_DISM:
            if (advice_dism < 0) {
                advice_dism = advice;
            } else {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: duplicate advice specified "
                    "(%s) for %s - cfgfile: %s, line: %d\n"),
                    madvident, value, execname, cfgfile,
                    lineno);
            }
            break;
        case OPT_MAP:
            if (advice_map < 0) {
                advice_map = advice;
            } else {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: duplicate advice specified "
                    "(%s) for %s - cfgfile: %s, line: %d\n"),
                    madvident, value, execname, cfgfile,
                    lineno);
            }
            break;
        case OPT_MAPSHARED:
            if (advice_mapshared < 0) {
                advice_mapshared = advice;
            } else {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: duplicate advice specified "
                    "(%s) for %s - cfgfile: %s, line: %d\n"),
                    madvident, value, execname, cfgfile,
                    lineno);
            }
            break;
        case OPT_MAPPRIVATE:
            if (advice_mapprivate < 0) {
                advice_mapprivate = advice;
            } else {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: duplicate advice specified "
                    "(%s) for %s - cfgfile: %s, line: %d\n"),
                    madvident, value, execname, cfgfile,
                    lineno);
            }
            break;
        case OPT_MAPANON:
            if (advice_mapanon < 0) {
                advice_mapanon = advice;
            } else {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: duplicate advice specified "
                    "(%s) for %s - cfgfile: %s, line: %d\n"),
                    madvident, value, execname, cfgfile,
                    lineno);
            }
            break;
        default:
            madverr(errfp, dgettext(TEXT_DOMAIN,
                "%s: invalid advice option (%s)"
                " for %s - cfgfile: %s, line: %d\n"),
                madvident, value, execname, cfgfile, lineno);
            break;
        }
    }
}

static void
__madvmain()
{
    char        *cfgfile, *errfile;
    FILE        *fp = NULL;
    const char  *execname;
    char        *cwd;
    int     cwdlen;
    char        *tok, *tokadv, *tokarg;
    char        *str, *envadv;
    int     lineno = 0;
    int     advice;
    uintptr_t   brkbase, brkend;
    size_t      brksize;
    int     rc;
    char        *locale;

    /*
     * If a private error file is indicated then set the locale
     * for error messages for the duration of this routine.
     * Error messages destined for syslog should not be translated
     * and thus come from the default C locale.
     */
    if ((errfile = getenv(ENV_MADVERRFILE)) != NULL) {
        errfp = fopen(errfile, "aF");
        if (errfp) {
            locale = setlocale(LC_MESSAGES, "");
        } else {
            madverr(NULL, dgettext(TEXT_DOMAIN,
                "%s: cannot open error file: %s [%s]\n"),
                madvident, errfile, strerror(errno));
        }
    }

#ifdef MADVDEBUG
    if (str = getenv(ENV_MADVDEBUG))
        madvdebug = atoi(str);
#endif

    if (envadv = getenv(ENV_MADV)) {
        if ((advice = strtoadv(envadv)) >= 0)
            advice_all = advice;
        else
            madverr(errfp, dgettext(TEXT_DOMAIN,
                "%s: invalid advice specified: MADV=%s\n"),
                madvident, envadv);
    }

    /*
     * Open specified cfg file or default one.
     */
    if (cfgfile = getenv(ENV_MADVCFGFILE)) {
        fp = fopen(cfgfile, "rF");
        if (!fp) {
            madverr(errfp, dgettext(TEXT_DOMAIN,
                "%s: cannot open configuration file: %s [%s]\n"),
                madvident, cfgfile, strerror(errno));
        }
    } else {
        cfgfile = DEF_MADVCFGFILE;
        fp = fopen(cfgfile, "rF");
    }

    if (fp) {
        execname = mygetexecname();

        cwd = getcwd(pbuf, MAXPATHLEN);
        if (!cwd)
            return;

        cwd = strcat(cwd, "/");
        cwdlen = strlen(cwd);

        while (fgets(lbuf, MAXLINELEN, fp)) {
            lineno++;

            /*
             * Make sure line wasn't truncated.
             */
            if (strlen(lbuf) >= MAXLINELEN - 1) {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: invalid entry, "
                    "line too long - cfgfile:"
                    " %s, line: %d\n"),
                    madvident, cfgfile, lineno);
                continue;
            }

            if (empty(lbuf))
                continue;

            /*
             * Get advice options.
             * Parse right to left in case delimiter is in name.
             */
            if (!(tokadv = strrchr(lbuf, CFGDELIMITER))) {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: no delimiter specified - cfgfile:"
                    " %s, line: %d\n"),
                    madvident, cfgfile, lineno);
                continue;
            }
            *tokadv++ = '\0';

            /*
             * Remove newline from end of advice options.
             */
            if (str = strrchr(tokadv, '\n'))
                *str = '\0';

            /*
             * Get optional argument string.
             */
            if (tokarg = strrchr(lbuf, ARGDELIMITER)) {
                *tokarg++ = '\0';
            }

            /*
             * Compare exec name.
             */
            tok = lbuf;
            if (!fnmatch(execname, tok, cwd)) {
                tokadv = tokarg = NULL;
                cwd[cwdlen] = '\0';
                continue;
            }

            /*
             * Compare arguments if argument string specified.
             */
            if (tokarg &&
                !empty(tokarg) &&
                !argmatch(tokarg)) {
                tokadv = tokarg = NULL;
                cwd[cwdlen] = '\0';
                continue;
            }

            /*
             * Parse advice options.
             * If empty, any advice from ENV_MADV is reset.
             */
            if (empty(tokadv)) {
                advice_all = -1;
            } else {
                advice_opts(tokadv, execname, cfgfile, lineno);
            }
            break;
        }
        (void) fclose(fp);
    }

    /*
     * Pagesize needed for proper aligning by brk interpose.
     */
    pagesize = sysconf(_SC_PAGESIZE);

    /*
     * Apply global advice if set.
     * Specific options in the cfgfile take precedence.
     */
    if (advice_all >= 0) {
        if (advice_heap < 0)
            advice_heap = advice_all;
        if (advice_shm < 0)
            advice_shm = advice_all;
        if (advice_map < 0)
            advice_map = advice_all;
    }

    MADVPRINT(2, (stderr, "advice_all %d\n", advice_all));
    MADVPRINT(2, (stderr, "advice_heap %d\n", advice_heap));
    MADVPRINT(2, (stderr, "advice_shm %d\n", advice_shm));
    MADVPRINT(2, (stderr, "advice_ism %d\n", advice_ism));
    MADVPRINT(2, (stderr, "advice_dism %d\n", advice_dism));
    MADVPRINT(2, (stderr, "advice_map %d\n", advice_map));
    MADVPRINT(2, (stderr, "advice_mapshared %d\n", advice_mapshared));
    MADVPRINT(2, (stderr, "advice_mapprivate %d\n", advice_mapprivate));
    MADVPRINT(2, (stderr, "advice_mapanon %d\n", advice_mapanon));

    /*
     * If heap advice is specified, apply it to the existing heap.
     * As the heap grows the kernel applies the advice automatically
     * to new portions of the heap.
     */
    if (advice_heap >= 0) {
        if (rc = mygetbrk(&brkbase, &brksize)) {
            madverr(errfp, dgettext(TEXT_DOMAIN,
                "%s: /proc/self/status read failed [%s]\n"),
                madvident, strerror(rc));
        } else {
            MADVPRINT(4, (stderr, "brkbase 0x%x brksize 0x%x\n",
                brkbase, brksize));
            /*
             * Align start address for memcntl and apply advice
             * on full pages of heap.  Create a page of heap if
             * it does not already exist.
             */
            brkend = roundup(brkbase+brksize, pagesize);
            brkbase = roundup(brkbase, pagesize);
            brksize = brkend - brkbase;
            if (brksize < pagesize) {
                if (sbrk(pagesize) == (void *)-1) {
                    madverr(errfp, dgettext(TEXT_DOMAIN,
                        "%s: sbrk failed [%s]\n"),
                        madvident, strerror(errno));
                    goto out;
                }
                brksize = pagesize;
            }
            MADVPRINT(1, (stderr, "heap advice: 0x%x 0x%x %d\n",
                brkbase, brksize, advice_heap));
            if (memcntl((caddr_t)brkbase, brksize, MC_ADVISE,
                (caddr_t)(intptr_t)advice_heap, 0, 0) < 0) {
                madverr(errfp, dgettext(TEXT_DOMAIN,
                    "%s: memcntl() failed [%s]: heap advice\n"),
                    madvident, strerror(errno));
            }
        }
    }
out:
    if (errfp) {
        (void) fclose(errfp);
        (void) setlocale(LC_MESSAGES, locale);
    } else {
        /* close log file: no-op if nothing logged to syslog */
        closelog();
    }

}

/*
 * shmat interpose
 */
void *
shmat(int shmid, const void *shmaddr, int shmflag)
{
    static caddr_t (*shmatfunc)() = NULL;
    void *result;
    int advice = -1;
    struct shmid_ds mds;
#ifdef MADVDEBUG
    int rc;
#else
    /* LINTED */
    int rc;
#endif

    if (!shmatfunc) {
        shmatfunc = (caddr_t (*)()) dlsym(RTLD_NEXT, "shmat");
        assert(shmatfunc);
    }

    result = shmatfunc(shmid, shmaddr, shmflag);

    /*
     * Options ism, dism take precedence over option shm.
     */
    if (advice_ism >= 0 && (shmflag & SHM_SHARE_MMU)) {
        advice = advice_ism;
    } else if (advice_dism >= 0 && (shmflag & SHM_PAGEABLE)) {
        advice = advice_dism;
    } else if (advice_shm >= 0) {
        advice = advice_shm;
    }

    /*
     * Apply advice if specified and shmat succeeded.
     */
    if (advice >= 0 && result != (void *)-1) {
        /* First determine segment size */
        rc = shmctl(shmid, IPC_STAT, &mds);
        MADVPRINT(4, (stderr, "shmctl rc %d errno %d\n",
            strerror(errno)));

        rc = memcntl(result, mds.shm_segsz, MC_ADVISE,
            (caddr_t)(intptr_t)advice, 0, 0);
        MADVPRINT(1, (stderr,
            "shmat advice: 0x%x 0x%x %d, rc %d errno %d\n",
            result, mds.shm_segsz, advice, rc, errno));
    }

    return (result);
}

/*
 * mmap interpose
 */
void *
mmap(void *addr, size_t len, int prot, int flags, int fd, off_t pos)
{
    static void *(*mmapfunc)() = NULL;
    void *result;
    int advice = -1;
#ifdef MADVDEBUG
    int rc;
#else
    /* LINTED */
    int rc;
#endif

    if (!mmapfunc) {
        mmapfunc = (void *(*)())dlsym(RTLD_NEXT, "mmap");
        assert(mmapfunc);
    }

    result = mmapfunc(addr, len, prot, flags, fd, pos);

    /*
     * Option mapanon has highest precedence while option map
     * has lowest precedence.
     */
    if (advice_mapanon >= 0 && (flags & MAP_ANON)) {
        advice = advice_mapanon;
    } else if (advice_mapshared >= 0 && (flags & MAP_SHARED)) {
        advice = advice_mapshared;
    } else if (advice_mapprivate >= 0 && (flags & MAP_PRIVATE)) {
        advice = advice_mapprivate;
    } else if (advice_map >= 0) {
        advice = advice_map;
    }

    /*
     * Apply advice if specified and mmap succeeded.
     */
    if (advice >= 0 && result != MAP_FAILED) {
        rc = memcntl(result, len, MC_ADVISE,
            (caddr_t)(intptr_t)advice, 0, 0);
        MADVPRINT(1, (stderr,
            "mmap advice: 0x%x 0x%x %d, rc %d errno %d\n",
            result, len, advice, rc, errno));
    }

    return (result);
}

#if !defined(_LP64)
/*
 * mmap64 interpose
 */
void *
mmap64(void *addr, size_t len, int prot, int flags, int fd, off64_t pos)
{
    static void *(*mmap64func)();
    void *result;
    int advice = -1;
#ifdef MADVDEBUG
    int rc;
#else
    /* LINTED */
    int rc;
#endif

    if (!mmap64func) {
        mmap64func = (void *(*)())dlsym(RTLD_NEXT, "mmap64");
        assert(mmap64func);
    }

    result = mmap64func(addr, len, prot, flags, fd, pos);

    /*
     * Option mapanon has highest precedence while option map
     * has lowest precedence.
     */
    if (advice_mapanon >= 0 && (flags & MAP_ANON)) {
        advice = advice_mapanon;
    } else if (advice_mapshared >= 0 && (flags & MAP_SHARED)) {
        advice = advice_mapshared;
    } else if (advice_mapprivate >= 0 && (flags & MAP_PRIVATE)) {
        advice = advice_mapprivate;
    } else if (advice_map >= 0) {
        advice = advice_map;
    }

    /*
     * Apply advice if specified and mmap succeeded.
     */
    if (advice >= 0 && result != MAP_FAILED) {
        rc = memcntl(result, len, MC_ADVISE, (caddr_t)advice, 0, 0);
        MADVPRINT(1, (stderr,
            "mmap64 advice: 0x%x 0x%x %d, rc %d errno %d\n",
            result, len, advice, rc, errno));
    }

    return (result);
}
#endif  /* !_LP64 */