/*      $OpenBSD: kgmon.c,v 1.26 2019/06/28 13:32:48 deraadt 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/types.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/gmon.h>

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

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

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

extern char *__progname;

int     bflag, cflag, hflag, kflag, rflag, pflag;
int     debug = 0;
void    kgmon(char *, char *, struct kvmvars *, int);
void    setprof(struct kvmvars *, int, int);
void    dumpstate(struct kvmvars *, int);
void    reset(struct kvmvars *, int);
void    kern_readonly(int);
int     getprof(struct kvmvars *, int);
int     getprofhz(struct kvmvars *);
int     openfiles(char *, char *, struct kvmvars *, int);
int     getncpu(void);

int
main(int argc, char **argv)
{
        int ch, ncpu, cpuid = -1;
        struct kvmvars kvmvars;
        char *sys, *kmemf;
        const char *p;

        kmemf = NULL;
        sys = NULL;
        while ((ch = getopt(argc, argv, "M:N:bc:hpr")) != -1) {
                switch(ch) {

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

                case 'N':
                        sys = optarg;
                        break;

                case 'b':
                        bflag = 1;
                        break;

                case 'c':
                        cflag = 1;
                        cpuid = strtonum(optarg, 0, 1024, &p);
                        if (p)
                                errx(1, "illegal CPU id %s: %s", optarg, p);
                        break;

                case 'h':
                        hflag = 1;
                        break;

                case 'p':
                        pflag = 1;
                        break;

                case 'r':
                        rflag = 1;
                        break;

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

#define BACKWARD_COMPATIBILITY
#ifdef  BACKWARD_COMPATIBILITY
        if (*argv) {
                sys = *argv;
                if (*++argv) {
                        kmemf = *argv;
                        ++kflag;
                }
        }
#endif

        if (cflag) {
                kgmon(sys, kmemf, &kvmvars, cpuid);
        } else {
                ncpu = getncpu();
                for (cpuid = 0; cpuid < ncpu; cpuid++)
                        kgmon(sys, kmemf, &kvmvars, cpuid);
        }

        return (0);
}

void
kgmon(char *sys, char *kmemf, struct kvmvars *kvp, int cpuid)
{
        int mode, disp, accessmode;

        accessmode = openfiles(sys, kmemf, kvp, cpuid);
        mode = getprof(kvp, cpuid);
        if (hflag)
                disp = GMON_PROF_OFF;
        else if (bflag)
                disp = GMON_PROF_ON;
        else
                disp = mode;
        if (pflag)
                dumpstate(kvp, cpuid);
        if (rflag)
                reset(kvp, cpuid);
        if (accessmode == O_RDWR)
                setprof(kvp, cpuid, disp);
        printf("%s: kernel profiling is %s for cpu %d.\n", __progname,
            disp == GMON_PROF_OFF ? "off" : "running", cpuid);
}

/*
 * Check that profiling is enabled and open any ncessary files.
 */
int
openfiles(char *sys, char *kmemf, struct kvmvars *kvp, int cpuid)
{
        int mib[4], state, openmode;
        size_t size;
        char errbuf[_POSIX2_LINE_MAX];

        if (!kflag) {
                mib[0] = CTL_KERN;
                mib[1] = KERN_PROF;
                mib[2] = GPROF_STATE;
                mib[3] = cpuid;
                size = sizeof state;
                if (sysctl(mib, 4, &state, &size, NULL, 0) == -1)
                        errx(20, "profiling not defined in kernel.");
                if (!(bflag || hflag || rflag ||
                    (pflag && state == GMON_PROF_ON)))
                        return (O_RDONLY);
                if (sysctl(mib, 4, NULL, NULL, &state, size) >= 0)
                        return (O_RDWR);
                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(2, "kvm_openfiles: %s", errbuf);
                kern_readonly(GMON_PROF_ON);
        }
        if (kvm_nlist(kvp->kd, nl) == -1)
                errx(3, "%s: no namelist", sys ? sys : _PATH_UNIX);
        if (!nl[N_GMONPARAM].n_value)
                errx(20, "profiling not defined in kernel.");
        return (openmode);
}

/*
 * Suppress options that require a writable kernel.
 */
void
kern_readonly(int mode)
{
        extern char *__progname;

        (void)fprintf(stderr, "%s: kernel read-only: ", __progname);
        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.
 */
int
getprof(struct kvmvars *kvp, int cpuid)
{
        int mib[4];
        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;
                mib[2] = GPROF_GMONPARAM;
                mib[3] = cpuid;
                size = sizeof kvp->gpm;
                if (sysctl(mib, 4, &kvp->gpm, &size, NULL, 0) == -1)
                        size = 0;
        }
        if (size != sizeof kvp->gpm)
                errx(4, "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.
 */
void
setprof(struct kvmvars *kvp, int cpuid, int state)
{
        struct gmonparam *p = (struct gmonparam *)nl[N_GMONPARAM].n_value;
        int mib[4], oldstate;
        size_t sz;

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

/*
 * Build the gmon.out file.
 */
void
dumpstate(struct kvmvars *kvp, int cpuid)
{
        FILE *fp;
        struct rawarc rawarc;
        struct tostruct *tos;
        u_long frompc;
        u_short *froms, *tickbuf;
        int mib[4];
        size_t i;
        struct gmonhdr h;
        int fromindex, endfrom, toindex;
        char buf[16];

        snprintf(buf, sizeof(buf), "gmon-%02d.out", cpuid);

        setprof(kvp, cpuid, GMON_PROF_OFF);
        fp = fopen(buf, "w");
        if (fp == 0) {
                perror(buf);
                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);
        fwrite((char *)&h, sizeof(h), 1, fp);

        /*
         * Write out the tick buffer.
         */
        mib[0] = CTL_KERN;
        mib[1] = KERN_PROF;
        if ((tickbuf = malloc(kvp->gpm.kcountsize)) == NULL)
                errx(5, "cannot allocate kcount space");
        if (kflag) {
                i = kvm_read(kvp->kd, (u_long)kvp->gpm.kcount, (void *)tickbuf,
                    kvp->gpm.kcountsize);
        } else {
                mib[2] = GPROF_COUNT;
                mib[3] = cpuid;
                i = kvp->gpm.kcountsize;
                if (sysctl(mib, 4, tickbuf, &i, NULL, 0) == -1)
                        i = 0;
        }
        if (i != kvp->gpm.kcountsize)
                errx(6, "read ticks: read %lu, got %zu: %s",
                    kvp->gpm.kcountsize, i,
                    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
        if ((fwrite(tickbuf, kvp->gpm.kcountsize, 1, fp)) != 1)
                err(7, "writing tocks to gmon.out");
        free(tickbuf);

        /*
         * Write out the arc info.
         */
        if ((froms = malloc(kvp->gpm.fromssize)) == NULL)
                errx(8, "cannot allocate froms space");
        if (kflag) {
                i = kvm_read(kvp->kd, (u_long)kvp->gpm.froms, (void *)froms,
                    kvp->gpm.fromssize);
        } else {
                mib[2] = GPROF_FROMS;
                mib[3] = cpuid;
                i = kvp->gpm.fromssize;
                if (sysctl(mib, 4, froms, &i, NULL, 0) == -1)
                        i = 0;
        }
        if (i != kvp->gpm.fromssize)
                errx(9, "read froms: read %lu, got %zu: %s",
                    kvp->gpm.fromssize, i,
                    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
        if ((tos = malloc(kvp->gpm.tossize)) == NULL)
                errx(10, "cannot allocate tos space");
        if (kflag) {
                i = kvm_read(kvp->kd, (u_long)kvp->gpm.tos, (void *)tos,
                    kvp->gpm.tossize);
        } else {
                mib[2] = GPROF_TOS;
                mib[3] = cpuid;
                i = kvp->gpm.tossize;
                if (sysctl(mib, 4, tos, &i, NULL, 0) == -1)
                        i = 0;
        }
        if (i != kvp->gpm.tossize)
                errx(11, "read tos: read %lu, got %zu: %s",
                    kvp->gpm.tossize, i,
                    kflag ? kvm_geterr(kvp->kd) : strerror(errno));
        if (debug)
                warnx("lowpc 0x%lx, textsize 0x%lx",
                    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)
                          warnx("[mcleanup] frompc 0x%lx selfpc 0x%lx count %ld",
                            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;
                        fwrite((char *)&rawarc, sizeof(rawarc), 1, fp);
                }
        }
        fclose(fp);
}

/*
 * Get the profiling rate.
 */
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) == -1)
                warn("get clockrate");
        return (clockrate.profhz);
}

/*
 * Reset the kernel profiling date structures.
 */
void
reset(struct kvmvars *kvp, int cpuid)
{
        char *zbuf;
        u_long biggest;
        int mib[4];

        setprof(kvp, cpuid, GMON_PROF_OFF);

        biggest = kvp->gpm.kcountsize;
        if (kvp->gpm.fromssize > biggest)
                biggest = kvp->gpm.fromssize;
        if (kvp->gpm.tossize > biggest)
                biggest = kvp->gpm.tossize;
        if ((zbuf = malloc(biggest)) == NULL)
                errx(12, "cannot allocate zbuf space");
        bzero(zbuf, biggest);
        if (kflag) {
                if (kvm_write(kvp->kd, (u_long)kvp->gpm.kcount, zbuf,
                    kvp->gpm.kcountsize) != kvp->gpm.kcountsize)
                        errx(13, "tickbuf zero: %s", kvm_geterr(kvp->kd));
                if (kvm_write(kvp->kd, (u_long)kvp->gpm.froms, zbuf,
                    kvp->gpm.fromssize) != kvp->gpm.fromssize)
                        errx(14, "froms zero: %s", kvm_geterr(kvp->kd));
                if (kvm_write(kvp->kd, (u_long)kvp->gpm.tos, zbuf,
                    kvp->gpm.tossize) != kvp->gpm.tossize)
                        errx(15, "tos zero: %s", kvm_geterr(kvp->kd));
                return;
        }
        mib[0] = CTL_KERN;
        mib[1] = KERN_PROF;
        mib[2] = GPROF_COUNT;
        mib[3] = cpuid;
        if (sysctl(mib, 4, NULL, NULL, zbuf, kvp->gpm.kcountsize) == -1)
                err(13, "tickbuf zero");
        mib[2] = GPROF_FROMS;
        if (sysctl(mib, 4, NULL, NULL, zbuf, kvp->gpm.fromssize) == -1)
                err(14, "froms zero");
        mib[2] = GPROF_TOS;
        if (sysctl(mib, 4, NULL, NULL, zbuf, kvp->gpm.tossize) == -1)
                err(15, "tos zero");
        free(zbuf);
}

int
getncpu(void)
{
        int mib[2] = { CTL_HW, HW_NCPU };
        size_t size;
        int ncpu;

        size = sizeof(ncpu);
        if (sysctl(mib, 2, &ncpu, &size, NULL, 0) == -1) {
                warnx("cannot read hw.ncpu");
                return (1);
        }

        return (ncpu);
}