/*      $NetBSD: kgmon.c,v 1.28 2025/06/28 07:04:52 andvar Exp $        */

/*
 * Copyright (c) 1983, 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1983, 1992, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "from: @(#)kgmon.c       8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: kgmon.c,v 1.28 2025/06/28 07:04:52 andvar Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/file.h>
#include <sys/sysctl.h>
#include <sys/gmon.h>

#include <ctype.h>
#include <errno.h>
#include <kvm.h>
#include <err.h>
#include <limits.h>
#include <nlist.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static struct nlist nl[] = {
#define N_GMONPARAM     0
        { "__gmonparam", 0, 0, 0, 0 },
#define N_PROFHZ        1
        { "_profhz", 0, 0, 0, 0 },
        { 0, 0, 0, 0, 0 }
};

struct kvmvars {
        kvm_t   *kd;
        struct gmonparam gpm;
};

static int      ncpu_mib[2] = { CTL_HW, HW_NCPU };
static int      bflag, cflag_all, hflag, kflag, rflag, pflag;
static int      debug = 0;
static void     setprof(struct kvmvars *kvp, int state, int cpuid);
static void     dumpstate(struct kvmvars *kvp, int cpuid);
static void     reset(struct kvmvars *kvp, int cpuid);
static int      openfiles(char *, char *, struct kvmvars *);
static int      getprof(struct kvmvars *, int);
static void     kern_readonly(int);
static int      getprofhz(struct kvmvars *);

int
main(int argc, char **argv)
{
        int ch, mode, disp, accessmode, ncpu, cpuid = -1;
        struct kvmvars kvmvars;
        size_t size;
        char *sys, *kmemf;
        char on_cpu[sizeof(" on cpuXXXXXXXXX")];

        size = sizeof(ncpu);
        if (sysctl(ncpu_mib, 2, &ncpu, &size, NULL, 0) < 0)
                ncpu = 1;

        setprogname(argv[0]);
        (void)seteuid(getuid());
        kmemf = NULL;
        sys = NULL;
        while ((ch = getopt(argc, argv, "M:N:bc:dhpr")) != -1) {
                switch((char)ch) {

                case 'M':
                        kmemf = optarg;
                        kflag = 1;
                        break;

                case 'N':
                        sys = optarg;
                        break;

                case 'b':
                        bflag = 1;
                        break;

                case 'c':
                        if (strcmp(optarg, "all") == 0) {
                                cflag_all = 1;
                                cpuid = 0;
                        } else {
                                cpuid = strtol(optarg, NULL, 10);
                                if (cpuid >= ncpu)
                                        errx(1, "illegal CPU id %s", optarg);
                        }
                        break;

                case 'h':
                        hflag = 1;
                        break;

                case 'p':
                        pflag = 1;
                        break;

                case 'r':
                        rflag = 1;
                        break;

                case 'd':
                        debug = 1;
                        break;

                default:
                        (void)fprintf(stderr,
                            "usage: %s [-bdhrp] [-c cpuid] [-M core] [-N system]\n",
                            getprogname());
                        exit(1);
                }
        }
        argc -= optind;
        argv += optind;

#define BACKWARD_COMPATIBILITY
#ifdef  BACKWARD_COMPATIBILITY
        if (*argv) {
                sys = *argv;
                if (*++argv) {
                        kmemf = *argv;
                        ++kflag;
                }
        }
#endif
        accessmode = openfiles(sys, kmemf, &kvmvars);

        do {
                if (cpuid == -1)
                        on_cpu[0] = '\0';
                else
                        snprintf(on_cpu, sizeof(on_cpu), " on cpu%d", cpuid);

                mode = getprof(&kvmvars, cpuid);
                if (hflag)
                        disp = GMON_PROF_OFF;
                else if (bflag)
                        disp = GMON_PROF_ON;
                else
                        disp = mode;
                if (pflag)
                        dumpstate(&kvmvars, cpuid);
                if (rflag)
                        reset(&kvmvars, cpuid);
                if (accessmode == O_RDWR)
                        setprof(&kvmvars, disp, cpuid);
                (void)fprintf(stdout, "%s: kernel profiling is %s%s.\n",
                    getprogname(), disp == GMON_PROF_OFF ? "off" : "running",
                    on_cpu);

        } while (cflag_all && ++cpuid < ncpu);
        return (0);
}

/*
 * Check that profiling is enabled and open any necessary files.
 */
static int
openfiles(char *sys, char *kmemf, struct kvmvars *kvp)
{
        int mib[3], state, openmode;
        size_t size;
        char errbuf[_POSIX2_LINE_MAX];

        if (!kflag) {
                mib[0] = CTL_KERN;
                mib[1] = KERN_PROF;
                mib[2] = GPROF_STATE;
                size = sizeof state;
                if (sysctl(mib, 3, &state, &size, NULL, 0) < 0)
                        err(EXIT_FAILURE, "profiling not defined in kernel");
                if (!(bflag || hflag || rflag ||
                    (pflag && state == GMON_PROF_ON)))
                        return (O_RDONLY);
                (void)seteuid(0);
                if (sysctl(mib, 3, NULL, NULL, &state, size) >= 0)
                        return (O_RDWR);
                (void)seteuid(getuid());
                kern_readonly(state);
                return (O_RDONLY);
        }
        openmode = (bflag || hflag || pflag || rflag) ? O_RDWR : O_RDONLY;
        kvp->kd = kvm_openfiles(sys, kmemf, NULL, openmode, errbuf);
        if (kvp->kd == NULL) {
                if (openmode == O_RDWR) {
                        openmode = O_RDONLY;
                        kvp->kd = kvm_openfiles(sys, kmemf, NULL, O_RDONLY,
                            errbuf);
                }
                if (kvp->kd == NULL)
                        errx(EXIT_FAILURE, "kvm_openfiles: %s", errbuf);
                kern_readonly(GMON_PROF_ON);
        }
        if (kvm_nlist(kvp->kd, nl) < 0)
                errx(EXIT_FAILURE, "%s: no namelist", sys);
        if (!nl[N_GMONPARAM].n_value)
                errx(EXIT_FAILURE, "profiling not defined in kernel");
        return (openmode);
}

/*
 * Suppress options that require a writable kernel.
 */
static void
kern_readonly(int mode)
{

        (void)fprintf(stderr, "%s: kernel read-only: ", getprogname());
        if (pflag && mode == GMON_PROF_ON)
                (void)fprintf(stderr, "data may be inconsistent\n");
        if (rflag)
                (void)fprintf(stderr, "-r suppressed\n");
        if (bflag)
                (void)fprintf(stderr, "-b suppressed\n");
        if (hflag)
                (void)fprintf(stderr, "-h suppressed\n");
        rflag = bflag = hflag = 0;
}

/*
 * Get the state of kernel profiling.
 */
static int
getprof(struct kvmvars *kvp, int cpuid)
{
        int mib[5], miblen, mibparam;
        size_t size;

        if (kflag) {
                size = kvm_read(kvp->kd, nl[N_GMONPARAM].n_value, &kvp->gpm,
                    sizeof kvp->gpm);
        } else {
                mib[0] = CTL_KERN;
                mib[1] = KERN_PROF;
                if (cpuid < 0) {
                        mibparam = 2;
                        miblen = 3;
                } else {
                        mib[2] = GPROF_PERCPU;
                        mib[3] = cpuid;
                        mibparam = 4;
                        miblen = 5;
                }
                mib[mibparam] = GPROF_GMONPARAM;
                size = sizeof kvp->gpm;
                if (sysctl(mib, miblen, &kvp->gpm, &size, NULL, 0) < 0)
                        size = 0;
        }
        if (size != sizeof kvp->gpm)
                errx(EXIT_FAILURE, "cannot get gmonparam: %s",
                    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
        return (kvp->gpm.state);
}

/*
 * Enable or disable kernel profiling according to the state variable.
 */
static void
setprof(struct kvmvars *kvp, int state, int cpuid)
{
        struct gmonparam *p = (struct gmonparam *)nl[N_GMONPARAM].n_value;
        int mib[5], miblen, mibparam, oldstate;
        size_t sz;

        sz = sizeof(state);
        if (!kflag) {
                mib[0] = CTL_KERN;
                mib[1] = KERN_PROF;
                if (cpuid < 0) {
                        mibparam = 2;
                        miblen = 3;
                } else {
                        mib[2] = GPROF_PERCPU;
                        mib[3] = cpuid;
                        mibparam = 4;
                        miblen = 5;
                }
                mib[mibparam] = GPROF_STATE;
                if (sysctl(mib, miblen, &oldstate, &sz, NULL, 0) < 0)
                        goto bad;
                if (oldstate == state)
                        return;
                (void)seteuid(0);
                if (sysctl(mib, miblen, NULL, NULL, &state, sz) >= 0) {
                        (void)seteuid(getuid());
                        return;
                }
                (void)seteuid(getuid());
        } else if ((size_t)kvm_write(kvp->kd, (u_long)&p->state, (void *)&state, sz) 
            == sz)
                return;
bad:
        warnx("cannot turn profiling %s", state == GMON_PROF_OFF ?
            "off" : "on");
}

/*
 * Build the gmon.out file.
 */
static void
dumpstate(struct kvmvars *kvp, int cpuid)
{
        FILE *fp;
        struct rawarc rawarc;
        struct tostruct *tos;
        u_long frompc;
        u_short *froms, *tickbuf;
        int mib[5], miblen, mibparam;
        size_t i;
        struct gmonhdr h;
        int fromindex, endfrom, toindex;
        size_t kcountsize;
        char gmon_out[sizeof("gmon-XXXXXXXXXXX.out")];

        mib[0] = CTL_KERN;
        mib[1] = KERN_PROF;
        if (cpuid < 0) {
                mibparam = 2;
                miblen = 3;
        } else {
                mib[2] = GPROF_PERCPU;
                mib[3] = cpuid;
                mibparam = 4;
                miblen = 5;
        }

        setprof(kvp, GMON_PROF_OFF, cpuid);
        if (cpuid < 0)
                strlcpy(gmon_out, "gmon.out", sizeof(gmon_out));
        else
                snprintf(gmon_out, sizeof(gmon_out), "gmon-%d.out", cpuid);

        fp = fopen(gmon_out, "w");
        if (fp == NULL) {
                warn("cannot open `%s'", gmon_out);
                return;
        }

        /*
         * Build the gmon header and write it to a file.
         */
        bzero(&h, sizeof(h));
        h.lpc = kvp->gpm.lowpc;
        h.hpc = kvp->gpm.highpc;
        h.ncnt = kvp->gpm.kcountsize + sizeof(h);
        h.version = GMONVERSION;
        h.profrate = getprofhz(kvp);
        if (fwrite(&h, sizeof(h), 1, fp) != 1)
                err(EXIT_FAILURE, "writing header to gmon.out");

        kcountsize = (size_t)kvp->gpm.kcountsize;

        /*
         * Write out the tick buffer.
         */
        if ((tickbuf = malloc(kcountsize)) == NULL)
                err(EXIT_FAILURE, "Cannot allocate %zu kcount space",
                    kcountsize);
        if (kflag) {
                i = kvm_read(kvp->kd, (u_long)kvp->gpm.kcount, tickbuf,
                    kcountsize);
        } else {
                mib[mibparam] = GPROF_COUNT;
                i = kcountsize;
                if (sysctl(mib, miblen, tickbuf, &i, NULL, 0) < 0)
                        i = 0;
        }
        if (i != kcountsize)
                errx(EXIT_FAILURE, "read ticks: read %zu, got %zu: %s",
                    kcountsize, i,
                    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
        if ((fwrite(tickbuf, kcountsize, 1, fp)) != 1)
                err(EXIT_FAILURE, "writing ticks to gmon.out");
        free(tickbuf);

        /*
         * Write out the arc info.
         */
        if ((froms = malloc((size_t)kvp->gpm.fromssize)) == NULL)
                err(EXIT_FAILURE, "cannot allocate %zu froms space",
                    (size_t)kvp->gpm.fromssize);
        if (kflag) {
                i = kvm_read(kvp->kd, (u_long)kvp->gpm.froms, froms,
                    (size_t)kvp->gpm.fromssize);
        } else {
                mib[mibparam] = GPROF_FROMS;
                i = kvp->gpm.fromssize;
                if (sysctl(mib, miblen, froms, &i, NULL, 0) < 0)
                        i = 0;
        }
        if (i != kvp->gpm.fromssize)
                errx(EXIT_FAILURE, "read froms: read %lu, got %lu: %s",
                    kvp->gpm.fromssize, (u_long)i,
                    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
        if ((tos = malloc((size_t)kvp->gpm.tossize)) == NULL)
                err(EXIT_FAILURE, "cannot allocate %zu tos space",
                    (size_t)kvp->gpm.tossize);
        if (kflag) {
                i = kvm_read(kvp->kd, (u_long)kvp->gpm.tos, (void *)tos,
                    (size_t)kvp->gpm.tossize);
        } else {
                mib[mibparam] = GPROF_TOS;
                i = kvp->gpm.tossize;
                if (sysctl(mib, miblen, tos, &i, NULL, 0) < 0)
                        i = 0;
        }
        if (i != kvp->gpm.tossize)
                errx(EXIT_FAILURE, "read tos: read %zu, got %zu: %s",
                    (size_t)kvp->gpm.tossize, i,
                    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
        if (debug)
                (void)fprintf(stderr, "%s: lowpc 0x%lx, textsize 0x%lx\n",
                     getprogname(), kvp->gpm.lowpc, kvp->gpm.textsize);
        endfrom = kvp->gpm.fromssize / sizeof(*froms);
        for (fromindex = 0; fromindex < endfrom; ++fromindex) {
                if (froms[fromindex] == 0)
                        continue;
                frompc = (u_long)kvp->gpm.lowpc +
                    (fromindex * kvp->gpm.hashfraction * sizeof(*froms));
                for (toindex = froms[fromindex]; toindex != 0;
                   toindex = tos[toindex].link) {
                        if (debug)
                            (void)fprintf(stderr,
                            "%s: [mcleanup] frompc 0x%lx selfpc 0x%lx count %ld\n",
                            getprogname(), frompc, tos[toindex].selfpc,
                            tos[toindex].count);
                        rawarc.raw_frompc = frompc;
                        rawarc.raw_selfpc = (u_long)tos[toindex].selfpc;
                        rawarc.raw_count = tos[toindex].count;
                        if (fwrite(&rawarc, sizeof(rawarc), 1,fp) != 1){
                                err(EXIT_FAILURE,
                                    "writing raw arc to gmon.out");
                        }
                }
        }
        free(tos);
        (void)fclose(fp);
}

/*
 * Get the profiling rate.
 */
static int
getprofhz(struct kvmvars *kvp)
{
        int mib[2], profrate;
        size_t size;
        struct clockinfo clockrate;

        if (kflag) {
                profrate = 1;
                if (kvm_read(kvp->kd, nl[N_PROFHZ].n_value, &profrate,
                    sizeof profrate) != sizeof profrate)
                        warnx("get clockrate: %s", kvm_geterr(kvp->kd));
                return (profrate);
        }
        mib[0] = CTL_KERN;
        mib[1] = KERN_CLOCKRATE;
        clockrate.profhz = 1;
        size = sizeof clockrate;
        if (sysctl(mib, 2, &clockrate, &size, NULL, 0) < 0)
                warn("get clockrate");
        return (clockrate.profhz);
}

/*
 * Reset the kernel profiling date structures.
 */
static void
reset(struct kvmvars *kvp, int cpuid)
{
        char *zbuf;
        size_t biggest;
        int mib[5], miblen, mibparam;

        mib[0] = CTL_KERN;
        mib[1] = KERN_PROF;
        if (cpuid < 0) {
                mibparam = 2;
                miblen = 3;
        } else {
                mib[2] = GPROF_PERCPU;
                mib[3] = cpuid;
                mibparam = 4;
                miblen = 5;
        }

        setprof(kvp, GMON_PROF_OFF, cpuid);

        biggest = (size_t)kvp->gpm.kcountsize;
        if ((size_t)kvp->gpm.fromssize > biggest)
                biggest = (size_t)kvp->gpm.fromssize;
        if ((size_t)kvp->gpm.tossize > biggest)
                biggest = (size_t)kvp->gpm.tossize;
        if ((zbuf = malloc(biggest)) == NULL)
                err(EXIT_FAILURE, "cannot allocate zbuf space");
        (void)memset(zbuf, 0, biggest);
        if (kflag) {
                if ((size_t)kvm_write(kvp->kd, (u_long)kvp->gpm.kcount, zbuf,
                    (size_t)kvp->gpm.kcountsize) != kvp->gpm.kcountsize)
                        errx(EXIT_FAILURE, "tickbuf zero: %s",
                             kvm_geterr(kvp->kd));
                if ((size_t)kvm_write(kvp->kd, (u_long)kvp->gpm.froms, zbuf,
                    (size_t)kvp->gpm.fromssize) != kvp->gpm.fromssize)
                        errx(EXIT_FAILURE, "froms zero: %s",
                             kvm_geterr(kvp->kd));
                if ((size_t)kvm_write(kvp->kd, (u_long)kvp->gpm.tos, zbuf,
                    (size_t)kvp->gpm.tossize) != kvp->gpm.tossize)
                        errx(EXIT_FAILURE, "tos zero: %s", kvm_geterr(kvp->kd));
                free(zbuf);
                return;
        }
        (void)seteuid(0);
        mib[mibparam] = GPROF_COUNT;
        if (sysctl(mib, miblen, NULL, NULL, zbuf, (size_t)kvp->gpm.kcountsize) < 0)
                err(EXIT_FAILURE, "tickbuf zero");
        mib[mibparam] = GPROF_FROMS;
        if (sysctl(mib, miblen, NULL, NULL, zbuf, (size_t)kvp->gpm.fromssize) < 0)
                err(EXIT_FAILURE, "froms zero");
        mib[mibparam] = GPROF_TOS;
        if (sysctl(mib, miblen, NULL, NULL, zbuf, (size_t)kvp->gpm.tossize) < 0)
                err(EXIT_FAILURE, "tos zero");
        (void)seteuid(getuid());
        free(zbuf);
}