prof/common/profv.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"

/*
 * All routines in this file are for processing new-style, *versioned*
 * mon.out format. Together with rdelf.c, lookup.c and profv.h, these
 * form the complete set of files to profile new-style mon.out files.
 */

#include <stdlib.h>
#include <string.h>
#include "conv.h"
#include "profv.h"

bool        time_in_ticks = FALSE;
size_t      n_pcsamples, n_accounted_ticks, n_zeros, total_funcs;
unsigned char   sort_flag;

mod_info_t  modules;
size_t      n_modules = 1;  /* always include the aout object */

struct stat aout_stat, monout_stat;
profrec_t   *profsym;

int
cmp_by_name(const void *arg1, const void *arg2)
{
    profrec_t *a = (profrec_t *)arg1;
    profrec_t *b = (profrec_t *)arg2;

    return (strcmp(a->demangled_name, b->demangled_name));
}

static void
setup_demangled_names(void)
{
    const char  *p;
    char    *nbp, *nbe, *namebuf;
    size_t  cur_len = 0, namebuf_sz = BUCKET_SZ;
    size_t  i, namelen;

    if ((namebuf = malloc(namebuf_sz)) == NULL) {
        (void) fprintf(stderr, "%s: can't allocate %d bytes\n",
            cmdname, namebuf_sz);
        exit(ERR_MEMORY);
    }

    nbp = namebuf;
    nbe = namebuf + namebuf_sz;

    for (i = 0; i < total_funcs; i++) {
        if ((p = conv_demangle_name(profsym[i].name)) == NULL)
            continue;

        namelen = strlen(p);
        if ((nbp + namelen + 1) > nbe) {
            namebuf_sz += BUCKET_SZ;
            namebuf = realloc(namebuf, namebuf_sz);
            if (namebuf == NULL) {
                (void) fprintf(stderr,
                    "%s: can't alloc %d bytes\n",
                    cmdname, BUCKET_SZ);
                exit(ERR_MEMORY);
            }

            nbp = namebuf + cur_len;
            nbe = namebuf + namebuf_sz;
        }

        (void) strcpy(nbp, p);
        profsym[i].demangled_name = nbp;

        nbp += namelen + 1;
        cur_len += namelen + 1;
    }
}

int
cmp_by_time(const void *arg1, const void *arg2)
{
    profrec_t *a = (profrec_t *)arg1;
    profrec_t *b = (profrec_t *)arg2;

    if (a->percent_time > b->percent_time)
        return (-1);
    else if (a->percent_time < b->percent_time)
        return (1);
    else
        return (0);
}

int
cmp_by_ncalls(const void *arg1, const void *arg2)
{
    profrec_t *a = (profrec_t *)arg1;
    profrec_t *b = (profrec_t *)arg2;

    if (a->ncalls > b->ncalls)
        return (-1);
    else if (a->ncalls < b->ncalls)
        return (1);
    else
        return (0);

}

static void
print_profile_data(void)
{
    int     i;
    int     (*sort_func)(const void *, const void *);
    mod_info_t  *mi;
    double      cumsecs = 0;
    char        filler[20];

    /*
     * Sort the compiled data; the sort flags are mutually exclusive.
     */
    switch (sort_flag) {
        case BY_NCALLS:
            sort_func = cmp_by_ncalls;
            break;

        case BY_NAME:
            if (Cflag)
                setup_demangled_names();
            sort_func = cmp_by_name;
            break;

        case BY_ADDRESS:
            sort_flag |= BY_ADDRESS;
            sort_func = NULL;   /* already sorted by addr */
            break;

        case BY_TIME:       /* default is to sort by time */
        default:
            sort_func = cmp_by_time;
    }


    if (sort_func) {
        qsort(profsym, total_funcs, sizeof (profrec_t), sort_func);
    }

    /*
     * If we're sorting by name, and if it is a verbose print, we wouldn't
     * have set up the print_mid fields yet.
     */
    if ((flags & F_VERBOSE) && (sort_flag == BY_NAME)) {
        for (i = 0; i < total_funcs; i++) {
            /*
             * same as previous or next (if there's one) ?
             */
            if (i && (strcmp(profsym[i].demangled_name,
                profsym[i-1].demangled_name) == 0)) {
                profsym[i].print_mid = TRUE;
            } else if ((i < (total_funcs - 1)) &&
                (strcmp(profsym[i].demangled_name,
                profsym[i+1].demangled_name) == 0)) {
                profsym[i].print_mid = TRUE;
            }
        }
    }

    /*
     * The actual printing part.
     */
    if (!(flags & F_NHEAD)) {
        if (flags & F_PADDR)
            (void) printf("        %s", atitle);

        if (time_in_ticks)
            (void) puts(
                " %Time   Tiks  Cumtiks  #Calls   tiks/call  Name");
        else
            (void) puts(
                " %Time Seconds Cumsecs  #Calls   msec/call  Name");
    }

    mi = NULL;
    for (i = 0; i < total_funcs; i++) {
        /*
         * Since the same value may denote different symbols in
         * different shared objects, it is debatable if it is
         * meaningful to print addresses at all. Especially so
         * if we were asked to sort by symbol addresses.
         *
         * If we've to sort by address, I think it is better to sort
         * it on a per-module basis and if verbose mode is on too,
         * print a newline to separate out modules.
         */
        if ((flags & F_VERBOSE) && (sort_flag == BY_ADDRESS)) {
            if (mi != profsym[i].module) {
                (void) printf("\n");
                mi = profsym[i].module;
            }
        }

        if (flags & F_PADDR) {
            if (aformat[2] == 'x')
                (void) printf("%16llx ", profsym[i].addr);
            else
                (void) printf("%16llo ", profsym[i].addr);
        }

        cumsecs += profsym[i].seconds;
        (void) printf("%6.1f%8.2f%8.2f", profsym[i].percent_time,
            profsym[i].seconds, cumsecs);

        (void) printf("%8d%12.4f  ",
            profsym[i].ncalls, profsym[i].msecs_per_call);

        if (profsym[i].print_mid)
            (void) printf("%d:", (profsym[i].module)->id);

        (void) printf("%s\n", profsym[i].demangled_name);
    }

    if (flags & F_PADDR)
        (void) sprintf(filler, "%16s", "");
    else
        filler[0] = 0;

    if (flags & F_VERBOSE) {
        (void) puts("\n");
        (void) printf("%s   Total Object Modules     %7d\n",
            filler, n_modules);
        (void) printf("%s   Qualified Symbols        %7d\n",
            filler, total_funcs);
        (void) printf("%s   Symbols with zero usage  %7d\n",
            filler, n_zeros);
        (void) printf("%s   Total pc-hits            %7d\n",
            filler, n_pcsamples);
        (void) printf("%s   Accounted pc-hits        %7d\n",
            filler, n_accounted_ticks);
        if ((!gflag) && (n_pcsamples - n_accounted_ticks)) {
            (void) printf("%s   Missed pc-hits (try -g)  %7d\n\n",
                filler, n_pcsamples - n_accounted_ticks);
        } else {
            (void) printf("%s   Missed pc-hits           %7d\n\n",
                filler, n_pcsamples - n_accounted_ticks);
        }
        (void) printf("%s   Module info\n", filler);
        for (mi = &modules; mi; mi = mi->next)
            (void) printf("%s      %d: `%s'\n", filler,
                mi->id, mi->path);
    }
}

int
name_cmp(const void *arg1, const void *arg2)
{
    profnames_t *a = (profnames_t *)arg1;
    profnames_t *b = (profnames_t *)arg2;

    return (strcmp(a->name, b->name));
}

static void
check_dupnames(void)
{
    int     i;
    profnames_t *pn;

    pn = calloc(total_funcs, sizeof (profnames_t));
    if (pn == NULL) {
        (void) fprintf(stderr, "%s: no room for %d bytes\n",
            cmdname, total_funcs * sizeof (profnames_t));
        exit(ERR_MEMORY);
    }

    for (i = 0; i < total_funcs; i++) {
        pn[i].name = profsym[i].demangled_name;
        pn[i].pfrec = &profsym[i];
    }

    qsort(pn, total_funcs, sizeof (profnames_t), name_cmp);

    for (i = 0; i < total_funcs; i++) {
        /*
         * same as previous or next (if there's one) ?
         */
        if (i && (strcmp(pn[i].name, pn[i-1].name) == 0))
            (pn[i].pfrec)->print_mid = TRUE;
        else if ((i < (total_funcs - 1)) &&
            (strcmp(pn[i].name, pn[i+1].name) == 0)) {
            (pn[i].pfrec)->print_mid = TRUE;
        }
    }

    free(pn);
}

static void
compute_times(nltype *nl, profrec_t *psym)
{
    static int  first_time = TRUE;
    static long hz;

    if (first_time) {
        if ((hz = sysconf(_SC_CLK_TCK)) == -1)
            time_in_ticks = TRUE;
        first_time = FALSE;
    }

    if (time_in_ticks) {
        psym->seconds = (double)nl->nticks;
        if (nl->ncalls) {
            psym->msecs_per_call = (double)nl->nticks /
                (double)nl->ncalls;
        } else
            psym->msecs_per_call = (double)0.0;
    } else {
        psym->seconds = (double)nl->nticks / (double)hz;
        if (nl->ncalls) {
            psym->msecs_per_call =
                ((double)psym->seconds * 1000.0) /
                (double)nl->ncalls;
        } else
            psym->msecs_per_call = (double)0.0;
    }

    if (n_pcsamples) {
        psym->percent_time =
            ((double)nl->nticks / (double)n_pcsamples) * 100;
    }
}

static void
collect_profsyms(void)
{
    mod_info_t  *mi;
    nltype      *nl;
    size_t      i, ndx;


    for (mi = &modules; mi; mi = mi->next)
        total_funcs += mi->nfuncs;

    profsym = calloc(total_funcs, sizeof (profrec_t));
    if (profsym == NULL) {
        (void) fprintf(stderr, "%s: no room for %d bytes\n",
            cmdname, total_funcs * sizeof (profrec_t));
        exit(ERR_MEMORY);
    }

    ndx = 0;
    for (mi = &modules; mi; mi = mi->next) {
        nl = mi->nl;
        for (i = 0; i < mi->nfuncs; i++) {
            /*
             * I think F_ZSYMS doesn't make sense for the new
             * mon.out format, since we don't have a profiling
             * *range*, per se. But the man page demands it,
             * so...
             */
            if ((nl[i].ncalls == 0) && (nl[i].nticks == 0)) {
                n_zeros++;
                if (!(flags & F_ZSYMS))
                    continue;
            }

            /*
             * Initially, we set demangled_name to be
             * the same as name. If Cflag is set, we later
             * change this to be the demangled name ptr.
             */
            profsym[ndx].addr = nl[i].value;
            profsym[ndx].ncalls = nl[i].ncalls;
            profsym[ndx].name = nl[i].name;
            profsym[ndx].demangled_name = nl[i].name;
            profsym[ndx].module = mi;
            profsym[ndx].print_mid = FALSE;
            compute_times(&nl[i], &profsym[ndx]);
            ndx++;
        }
    }

    /*
     * Adjust total_funcs to actual printable funcs
     */
    total_funcs = ndx;
}

static void
assign_pcsamples(mod_info_t *module, Address *pcsmpl,
    size_t n_samples)
{
    Address     *pcptr, *pcse = pcsmpl + n_samples;
    Address     nxt_func;
    nltype      *nl;
    size_t      nticks;

    /* Locate the first pc-hit for this module */
    if ((pcptr = locate(pcsmpl, n_samples, module->load_base)) == NULL)
        return;         /* no pc-hits in this module */

    /* Assign all pc-hits in this module to appropriate functions */
    while ((pcptr < pcse) && (*pcptr < module->load_end)) {

        /* Update the corresponding function's time */
        if (nl = nllookup(module, *pcptr, &nxt_func)) {
            /*
             * Collect all pc-hits in this function. Each
             * pc-hit counts as 1 tick.
             */
            nticks = 0;
            while ((pcptr < pcse) && (*pcptr < nxt_func)) {
                nticks++;
                pcptr++;
            }

            nl->nticks += nticks;
            n_accounted_ticks += nticks;
        } else {
            /*
             * pc sample could not be assigned to function;
             * probably in a PLT
             */
            pcptr++;
        }
    }
}

static int
pc_cmp(const void *arg1, const void *arg2)
{
    Address *pc1 = (Address *)arg1;
    Address *pc2 = (Address *)arg2;

    if (*pc1 > *pc2)
        return (1);

    if (*pc1 < *pc2)
        return (-1);

    return (0);
}

static void
process_pcsamples(ProfBuffer *bufp)
{
    Address     *pc_samples;
    mod_info_t  *mi;
    size_t      nelem = bufp->bufsize;

    /* buffer with no pc samples ? */
    if (nelem == 0)
        return;

    /* Allocate for the pcsample chunk */
    pc_samples = (Address *) calloc(nelem, sizeof (Address));
    if (pc_samples == NULL) {
        (void) fprintf(stderr, "%s: no room for %d sample pc's\n",
            cmdname, nelem);
        exit(ERR_MEMORY);
    }

    (void) memcpy(pc_samples, (caddr_t)bufp + bufp->buffer,
        nelem * sizeof (Address));

    /* Sort the pc samples */
    qsort(pc_samples, nelem, sizeof (Address), pc_cmp);

    /*
     * Assign pcsamples to functions in the currently active
     * module list
     */
    for (mi = &modules; mi; mi = mi->next) {
        if (mi->active == FALSE)
            continue;
        assign_pcsamples(mi, pc_samples, nelem);
    }

    free(pc_samples);

    /* Update total number of pcsamples read so far */
    n_pcsamples += nelem;
}

static void
process_cgraph(ProfCallGraph *cgp)
{
    mod_info_t  *mi;
    Address     f_end;
    Index       callee_off;
    ProfFunction    *calleep;
    nltype      *nl;

    for (callee_off = cgp->functions; callee_off;
        callee_off = calleep->next_to) {

        /* LINTED: pointer cast */
        calleep = (ProfFunction *)((char *)cgp + callee_off);
        if (calleep->count == 0)
            continue;

        /*
         * If we cannot identify a callee with a module, we
         * cannot get to its namelist, just skip it.
         */
        for (mi = &modules; mi; mi = mi->next) {
            if (mi->active == FALSE)
                continue;

            if (calleep->topc >= mi->load_base &&
                calleep->topc < mi->load_end) {
                /*
                 * nllookup() returns the next lower entry
                 * point on a miss. So just make sure the
                 * callee's pc is not outside this function
                 */
                if (nl = nllookup(mi, calleep->topc, 0)) {
                    f_end = mi->load_base + (nl->value -
                        mi->txt_origin) + nl->size;
                    if (calleep->topc < f_end)
                        nl->ncalls += calleep->count;
                }
            }
        }
    }
}

static mod_info_t *
get_shobj_syms(char *pathname, GElf_Addr ld_base, GElf_Addr ld_end)
{
    mod_info_t  *mi;

    /* Create a new module element */
    if ((mi = malloc(sizeof (mod_info_t))) == NULL) {
        (void) fprintf(stderr, "%s: no room for %d bytes\n",
            cmdname, sizeof (mod_info_t));
        exit(ERR_MEMORY);
    }

    mi->path = malloc(strlen(pathname) + 1);
    if (mi->path == NULL) {
        (void) fprintf(stderr, "%s: can't allocate %d bytes\n",
            cmdname, strlen(pathname) + 1);
        exit(ERR_MEMORY);
    }
    (void) strcpy(mi->path, pathname);
    mi->next = NULL;

    get_syms(pathname, mi);

    /* and fill in info... */
    mi->id = n_modules + 1;
    mi->load_base = ld_base;
    mi->load_end = ld_end;
    mi->active = TRUE;

    n_modules++;

    return (mi);
}

/*
 * Two modules overlap each other if they don't lie completely *outside*
 * each other.
 */
static bool
does_overlap(ProfModule *new, mod_info_t *old)
{
    /* case 1: new module lies completely *before* the old one */
    if (new->startaddr < old->load_base && new->endaddr <= old->load_base)
        return (FALSE);

    /* case 2: new module lies completely *after* the old one */
    if (new->startaddr >= old->load_end && new->endaddr >= old->load_end)
        return (FALSE);

    /* probably a dlopen: the modules overlap each other */
    return (TRUE);
}

static bool
is_same_as_aout(char *modpath, struct stat *buf)
{
    if (stat(modpath, buf) == -1) {
        perror(modpath);
        exit(ERR_SYSCALL);
    }

    if ((buf->st_dev == aout_stat.st_dev) &&
        (buf->st_ino == aout_stat.st_ino)) {
        return (TRUE);
    } else
        return (FALSE);
}

static void
process_modules(ProfModuleList *modlp)
{
    ProfModule  *newmodp;
    mod_info_t  *mi, *last, *new_module;
    char        *so_path;
    bool        more_modules = TRUE;
    struct stat so_statbuf;

    /* Check version of module type object */
    if (modlp->version > PROF_MODULES_VER) {
        (void) fprintf(stderr,
            "%s: unsupported version %d for modules\n",
            cmdname, modlp->version);
        exit(ERR_INPUT);
    }


    /*
     * Scan the PROF_MODULES_T list and add modules to current list
     * of modules, if they're not present already
     */
    /* LINTED: pointer cast */
    newmodp = (ProfModule *)((caddr_t)modlp + modlp->modules);
    do {
        /*
         * Since the aout could've been renamed after its run, we
         * should see if current module overlaps aout. If it does, it
         * is probably the renamed aout. We should also skip any other
         * non-sharedobj's that we see (or should we report an error ?)
         */
        so_path = (caddr_t)modlp + newmodp->path;
        if (does_overlap(newmodp, &modules) ||
            is_same_as_aout(so_path, &so_statbuf) ||
            (!is_shared_obj(so_path))) {
            if (!newmodp->next)
                more_modules = FALSE;

            /* LINTED: pointer cast */
            newmodp = (ProfModule *)
                ((caddr_t)modlp + newmodp->next);
            continue;
        }

        /*
         * Check all modules (leave the first one, 'cos that
         * is the program executable info). If this module is already
         * there in the list, skip it.
         */
        last = &modules;
        while ((mi = last->next) != NULL) {
            /*
             * We expect the full pathname for all shared objects
             * needed by the program executable. In this case, we
             * simply need to compare the paths to see if they are
             * the same file.
             */
            if (strcmp(mi->path, so_path) == 0)
                break;

            /*
             * Check if this new shared object will overlap any
             * existing module. If yes, deactivate the old one.
             */
            if (does_overlap(newmodp, mi))
                mi->active = FALSE;

            last = mi;
        }

        /* Module already there, skip it */
        if (mi != NULL) {
            mi->load_base = newmodp->startaddr;
            mi->load_end = newmodp->endaddr;
            mi->active = TRUE;
            if (!newmodp->next)
                more_modules = FALSE;

            /* LINTED: pointer cast */
            newmodp = (ProfModule *)
                ((caddr_t)modlp + newmodp->next);
            continue;
        }

        /*
         * Check if mon.out is outdated with respect to the new
         * module we want to add
         */
        if (monout_stat.st_mtime < so_statbuf.st_mtime) {
            (void) fprintf(stderr,
                "%s: newer shared obj %s outdates profile info\n",
                cmdname, so_path);
            exit(ERR_INPUT);
        }

        /* Create this module's nameslist */
        new_module = get_shobj_syms(so_path,
            newmodp->startaddr, newmodp->endaddr);

        /* Add it to the tail of active module list */
        last->next = new_module;

        /*
         * Move to the next module in the PROF_MODULES_T list
         * (if present)
         */
        if (!newmodp->next)
            more_modules = FALSE;

        /* LINTED: pointer cast */
        newmodp = (ProfModule *)((caddr_t)modlp + newmodp->next);

    } while (more_modules);
}

static void
process_mon_out(caddr_t memp, size_t fsz)
{
    ProfObject  *objp;
    caddr_t     file_end;
    bool        found_pcsamples = FALSE, found_cgraph = FALSE;

    /*
     * Save file end pointer and start after header
     */
    file_end = memp + fsz;
    /* LINTED: pointer cast */
    objp = (ProfObject *)(memp + ((ProfHeader *)memp)->size);
    while ((caddr_t)objp < file_end) {
        switch (objp->type) {
            case PROF_MODULES_T :
                process_modules((ProfModuleList *)objp);
                break;

            case PROF_CALLGRAPH_T :
                process_cgraph((ProfCallGraph *)objp);
                found_cgraph = TRUE;
                break;

            case PROF_BUFFER_T :
                process_pcsamples((ProfBuffer *)objp);
                found_pcsamples = TRUE;
                break;

            default :
                (void) fprintf(stderr,
                    "%s: unknown prof object type=%d\n",
                    cmdname, objp->type);
                exit(ERR_INPUT);
        }
        /* LINTED: pointer cast */
        objp = (ProfObject *)((caddr_t)objp + objp->size);
    }

    if (!found_cgraph || !found_pcsamples) {
        (void) fprintf(stderr,
            "%s: missing callgraph/pcsamples in `%s'\n",
            cmdname, mon_fn);
        exit(ERR_INPUT);
    }

    if ((caddr_t)objp > file_end) {
        (void) fprintf(stderr, "%s: malformed file `%s'\n",
            cmdname, mon_fn);
        exit(ERR_INPUT);
    }
}

static void
get_aout_syms(char *pathname, mod_info_t *mi)
{
    mi->path = malloc(strlen(pathname) + 1);
    if (mi->path == NULL) {
        (void) fprintf(stderr, "%s: can't allocate %d bytes\n",
            cmdname, strlen(pathname) + 1);
        exit(ERR_MEMORY);
    }

    (void) strcpy(mi->path, pathname);
    mi->next = NULL;

    get_syms(pathname, mi);

    mi->id = 1;
    mi->load_base = mi->txt_origin;
    mi->load_end = mi->data_end;
    mi->active = TRUE;
}

void
profver(void)
{
    int     fd;
    unsigned int    magic_num;
    bool        invalid_version;
    caddr_t     fmem;
    ProfHeader  prof_hdr;

    /*
     * Check the magic and see if this is versioned or *old-style*
     * mon.out.
     */
    if ((fd = open(mon_fn, O_RDONLY)) == -1) {
        perror(mon_fn);
        exit(ERR_SYSCALL);
    }
    if (read(fd, (char *)&magic_num, sizeof (unsigned int)) == -1) {
        perror("read");
        exit(ERR_SYSCALL);
    }
    if (magic_num != (unsigned int) PROF_MAGIC) {
        (void) close(fd);
        return;
    }


    /*
     * Check versioning info. For now, let's say we provide
     * backward compatibility, so we accept all older versions.
     */
    (void) lseek(fd, 0L, SEEK_SET);
    if (read(fd, (char *)&prof_hdr, sizeof (ProfHeader)) == -1) {
        perror("read");
        exit(ERR_SYSCALL);
    }
    invalid_version = FALSE;
    if (prof_hdr.h_major_ver > PROF_MAJOR_VERSION)
        invalid_version = TRUE;
    else if (prof_hdr.h_major_ver == PROF_MAJOR_VERSION) {
        if (prof_hdr.h_minor_ver > PROF_MINOR_VERSION)
        invalid_version = FALSE;
    }
    if (invalid_version) {
        (void) fprintf(stderr,
            "%s: mon.out version %d.%d not supported\n",
            cmdname, prof_hdr.h_major_ver, prof_hdr.h_minor_ver);
        exit(ERR_INPUT);
    }


    /*
     * Map mon.out onto memory.
     */
    if (stat(mon_fn, &monout_stat) == -1) {
        perror(mon_fn);
        exit(ERR_SYSCALL);
    }
    if ((fmem = mmap(0, monout_stat.st_size,
        PROT_READ, MAP_PRIVATE, fd, 0)) == MAP_FAILED) {
        perror("mmap");
        exit(ERR_SYSCALL);
    }
    (void) close(fd);


    /*
     * Now, read program executable's symbol table. Also save it's
     * stat in aout_stat for use while processing mon.out
     */
    if (stat(sym_fn, &aout_stat) == -1) {
        perror(sym_fn);
        exit(ERR_SYSCALL);
    }
    get_aout_syms(sym_fn, &modules);

    /*
     * Process the mon.out, all shared objects it references
     * and collect statistics on ticks spent in each function,
     * number of calls, etc.
     */
    process_mon_out(fmem, monout_stat.st_size);

    /*
     * Based on the flags and the statistics we've got, create
     * a list of relevant symbols whose profiling details should
     * be printed
     */
    collect_profsyms();

    /*
     * Check for duplicate names in output. We need to print the
     * module id's if verbose. Also, if we are sorting by name anyway,
     * we don't need to check for duplicates here. We'll do that later.
     */
    if ((flags & F_VERBOSE) && (sort_flag != BY_NAME))
        check_dupnames();

    /*
     * Print output
     */
    print_profile_data();


    (void) munmap(fmem, monout_stat.st_size);
    exit(0);
}