xnu-1228.tar.gz

[apple/xnu.git] / bsd / kern / subr_prof.c

/*
 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*-
 * Copyright (c) 1982, 1986, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 *
 *      @(#)subr_prof.c 8.3 (Berkeley) 9/23/93
 */

#ifdef GPROF
#include <kern/mach_header.h>
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc_internal.h>
#include <sys/user.h>
#include <machine/spl.h>
#include <machine/machine_routines.h>

#include <sys/mount_internal.h>
#include <sys/sysproto.h>

#include <mach/mach_types.h>
#include <kern/kern_types.h>
#include <kern/cpu_number.h>
#include <kern/kalloc.h>

#ifdef GPROF
#include <sys/malloc.h>
#include <sys/gmon.h>

extern int sysctl_doprof(int *, u_int, user_addr_t, size_t *, 
                user_addr_t, size_t newlen);
extern int sysctl_struct(user_addr_t, size_t *,
                user_addr_t, size_t, void *, int);

lck_spin_t * mcount_lock;
lck_grp_t * mcount_lock_grp;
lck_attr_t * mcount_lock_attr;

/*
 * Froms is actually a bunch of unsigned shorts indexing tos
 */
struct gmonparam _gmonparam = { .state = GMON_PROF_OFF };

/*
 * This code uses 32 bit mach object segment information from the currently
 * running kernel.
 */
void
kmstartup(void)
{
        char *cp;
        struct segment_command  *sgp;   /* 32 bit mach object file segment */
        struct gmonparam *p = &_gmonparam;
        
        sgp = getsegbyname("__TEXT");
        p->lowpc = (u_long)sgp->vmaddr;
        p->highpc = (u_long)(sgp->vmaddr + sgp->vmsize);
        
        /*
         * Round lowpc and highpc to multiples of the density we're using
         * so the rest of the scaling (here and in gprof) stays in ints.
         */
        p->lowpc = ROUNDDOWN(p->lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
        p->highpc = ROUNDUP(p->highpc, HISTFRACTION * sizeof(HISTCOUNTER));
        p->textsize = p->highpc - p->lowpc;
        printf("Profiling kernel, textsize=%lu [0x%016lx..0x%016lx]\n",
               p->textsize, p->lowpc, p->highpc);
        p->kcountsize = p->textsize / HISTFRACTION;
        p->hashfraction = HASHFRACTION;
        p->fromssize = p->textsize / HASHFRACTION;
        p->tolimit = p->textsize * ARCDENSITY / 100;
        if (p->tolimit < MINARCS)
                p->tolimit = MINARCS;
        else if (p->tolimit > MAXARCS)
                p->tolimit = MAXARCS;
        p->tossize = p->tolimit * sizeof(struct tostruct);
        /* Why not use MALLOC with M_GPROF ? */
        cp = (char *)kalloc(p->kcountsize + p->fromssize + p->tossize);
        if (cp == 0) {
                printf("No memory for profiling.\n");
                return;
        }
        bzero(cp, p->kcountsize + p->tossize + p->fromssize);
        p->tos = (struct tostruct *)cp;
        cp += p->tossize;
        p->kcount = (u_short *)cp;
        cp += p->kcountsize;
        p->froms = (u_short *)cp;
        
        mcount_lock_grp = lck_grp_alloc_init("MCOUNT", LCK_GRP_ATTR_NULL);
        mcount_lock_attr = lck_attr_alloc_init();
        mcount_lock = lck_spin_alloc_init(mcount_lock_grp, mcount_lock_attr);

}

/*
 * Return kernel profiling information.
 */
int
sysctl_doprof(int *name, u_int namelen, user_addr_t oldp, size_t *oldlenp, 
              user_addr_t newp, size_t newlen)
{
        struct gmonparam *gp = &_gmonparam;
        int error;

        /* all sysctl names at this level are terminal */
        if (namelen != 1)
                return (ENOTDIR);               /* overloaded */

        switch (name[0]) {
        case GPROF_STATE:
                error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state);
                if (error)
                        return (error);
                if (gp->state == GMON_PROF_OFF)
                        stopprofclock(kernproc);
                else
                        startprofclock(kernproc);
                return (0);
        case GPROF_COUNT:
                return (sysctl_struct(oldp, oldlenp, newp, newlen, 
                                      gp->kcount, gp->kcountsize));
        case GPROF_FROMS:
                return (sysctl_struct(oldp, oldlenp, newp, newlen,
                                      gp->froms, gp->fromssize));
        case GPROF_TOS:
                return (sysctl_struct(oldp, oldlenp, newp, newlen,
                                      gp->tos, gp->tossize));
        case GPROF_GMONPARAM:
                return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp));
        default:
                return (ENOTSUP);
        }
        /* NOTREACHED */
}


/*
 * mcount() called with interrupts disabled.
 */
void
mcount(
    u_long frompc,
    u_long selfpc
)
{
    unsigned short *frompcindex;
        struct tostruct *top, *prevtop;
        struct gmonparam *p = &_gmonparam;
        long toindex;

    /*
     * check that we are profiling
     * and that we aren't recursively invoked.
     */
    if (p->state != GMON_PROF_ON)
        return;

        lck_spin_lock(mcount_lock);

        /*
         *      check that frompcindex is a reasonable pc value.
         *      for example:    signal catchers get called from the stack,
         *                      not from text space.  too bad.
         */
        frompc -= p->lowpc;
        if (frompc > p->textsize)
                goto done;

        frompcindex = &p->froms[frompc / (p->hashfraction * sizeof(*p->froms))];
        toindex = *frompcindex;
        if (toindex == 0) {
                /*
                 *      first time traversing this arc
                 */
                toindex = ++p->tos[0].link;
                if (toindex >= p->tolimit) {
            /* halt further profiling */
                        goto overflow;
                }
                *frompcindex = toindex;
                top = &p->tos[toindex];
                top->selfpc = selfpc;
                top->count = 1;
                top->link = 0;
                goto done;
        }
        top = &p->tos[toindex];
        if (top->selfpc == selfpc) {
                /*
                 *      arc at front of chain; usual case.
                 */
                top->count++;
                goto done;
        }
        /*
         *      have to go looking down chain for it.
         *      top points to what we are looking at,
         *      prevtop points to previous top.
         *      we know it is not at the head of the chain.
         */
        for (; /* goto done */; ) {
                if (top->link == 0) {
                        /*
                         *      top is end of the chain and none of the chain
                         *      had top->selfpc == selfpc.
                         *      so we allocate a new tostruct
                         *      and link it to the head of the chain.
                         */
                        toindex = ++p->tos[0].link;
                        if (toindex >= p->tolimit) {
                                goto overflow;
                        }
                        top = &p->tos[toindex];
                        top->selfpc = selfpc;
                        top->count = 1;
                        top->link = *frompcindex;
                        *frompcindex = toindex;
                        goto done;
                }
                /*
                 *      otherwise, check the next arc on the chain.
                 */
                prevtop = top;
                top = &p->tos[top->link];
                if (top->selfpc == selfpc) {
                        /*
                         *      there it is.
                         *      increment its count
                         *      move it to the head of the chain.
                         */
                        top->count++;
                        toindex = prevtop->link;
                        prevtop->link = top->link;
                        top->link = *frompcindex;
                        *frompcindex = toindex;
                        goto done;
                }

        }
done:
        lck_spin_unlock(mcount_lock);
        return;

overflow:
    p->state = GMON_PROF_ERROR;
        lck_spin_unlock(mcount_lock);
        printf("mcount: tos overflow\n");
        return;
}

#endif /* GPROF */

#define PROFILE_LOCK(x)
#define PROFILE_UNLOCK(x)

static int profil_funneled(struct proc *p, struct profil_args *uap, register_t *retval);
static int add_profil_funneled(struct proc *p, struct add_profil_args *uap, register_t *retval);


int
profil(struct proc *p, struct profil_args *uap, register_t *retval)
{
        boolean_t funnel_state;
        int error;

        funnel_state = thread_funnel_set(kernel_flock, TRUE);
        error = profil_funneled(p, uap, retval);
        thread_funnel_set(kernel_flock, funnel_state);
        return(error);
}

static int
profil_funneled(struct proc *p, struct profil_args *uap, __unused register_t *retval)
{
        struct uprof *upp = &p->p_stats->p_prof;
        int s;

        if (uap->pcscale > (1 << 16))
                return (EINVAL);

        if (uap->pcscale == 0) {
                stopprofclock(p);
                return (0);
        }
        /*
         * Block profile interrupts while changing state.
         */
        s = ml_set_interrupts_enabled(FALSE);   

        if (proc_is64bit(p)) {
                struct user_uprof *user_upp = &p->p_stats->user_p_prof;
                struct user_uprof *upc, *nupc;
        
                PROFILE_LOCK(&user_upp->pr_lock);

                user_upp->pr_base = uap->bufbase;
                user_upp->pr_size = uap->bufsize;
                user_upp->pr_off = uap->pcoffset;
                user_upp->pr_scale = uap->pcscale;
                upp->pr_base = NULL;
                upp->pr_size = 0;
                upp->pr_scale = 0;

                /*
                 * remove buffers previously allocated with add_profil()
                 * don't do the kfree's while interrupts disabled
                 */
                upc = user_upp->pr_next;
                user_upp->pr_next = 0;

                PROFILE_UNLOCK(&user_upp->pr_lock);

                startprofclock(p);
                ml_set_interrupts_enabled(s);

                while (upc) {
                        nupc = upc->pr_next;
                        kfree(upc, sizeof (*upc));
                        upc = nupc;
                }

        } else {
                struct uprof *upc, *nupc;
            
                PROFILE_LOCK(&upp->pr_lock);

                upp->pr_base = CAST_DOWN(caddr_t, uap->bufbase);
                upp->pr_size = uap->bufsize;
                upp->pr_off = uap->pcoffset;
                upp->pr_scale = uap->pcscale;

                /*
                 * remove buffers previously allocated with add_profil()
                 * don't do the kfree's while interrupts disabled
                 */
                upc = upp->pr_next;
                upp->pr_next = 0;

                PROFILE_UNLOCK(&upp->pr_lock);

                startprofclock(p);
                ml_set_interrupts_enabled(s);

                while (upc) {
                        nupc = upc->pr_next;
                        kfree(upc, sizeof (struct uprof));
                        upc = nupc;
                }
        }
        return(0);
}

int
add_profil(struct proc *p, struct add_profil_args *uap, register_t *retval)
{
        boolean_t funnel_state;
        int error;

        funnel_state = thread_funnel_set(kernel_flock, TRUE);
        error = add_profil_funneled(p, uap, retval);
        thread_funnel_set(kernel_flock, funnel_state);
        return(error);
}


static int
add_profil_funneled(struct proc *p, struct add_profil_args *uap, __unused register_t *retval)
{
        struct uprof *upp = &p->p_stats->p_prof, *upc;
        struct user_uprof *user_upp = NULL, *user_upc;
        int s;
        boolean_t is64bit = proc_is64bit(p);


        upc = NULL;
        user_upc = NULL;

        if (is64bit) {
                user_upp = &p->p_stats->user_p_prof;

                if (user_upp->pr_scale == 0)
                        return (0);
        }
        else {
                if (upp->pr_scale == 0)
                        return (0);
        }
        if (is64bit) {
                user_upc = (struct user_uprof *) kalloc(sizeof (struct user_uprof));
                user_upc->pr_base = uap->bufbase;
                user_upc->pr_size = uap->bufsize;
                user_upc->pr_off = uap->pcoffset;
                user_upc->pr_scale = uap->pcscale;
        } else {
                upc = (struct uprof *) kalloc(sizeof (struct uprof));
                upc->pr_base = CAST_DOWN(caddr_t, uap->bufbase);
                upc->pr_size = uap->bufsize;
                upc->pr_off = uap->pcoffset;
                upc->pr_scale = uap->pcscale;
        }
        s = ml_set_interrupts_enabled(FALSE);   
    
        if (is64bit) {
                PROFILE_LOCK(&user_upp->pr_lock);
                if (user_upp->pr_scale) {
                        user_upc->pr_next = user_upp->pr_next;
                        user_upp->pr_next = user_upc;
                        user_upc = NULL;
                }
                PROFILE_UNLOCK(&user_upp->pr_lock);
        } else {
                PROFILE_LOCK(&upp->pr_lock);
                if (upp->pr_scale) {
                        upc->pr_next = upp->pr_next;
                        upp->pr_next = upc;
                        upc = NULL;
                }
                PROFILE_UNLOCK(&upp->pr_lock);
        }
        ml_set_interrupts_enabled(s);           

        if (upc)
                kfree(upc, sizeof(struct uprof));
        if (user_upc)
                kfree(user_upc, sizeof(struct user_uprof));

        return(0);
}

/*
 * Scale is a fixed-point number with the binary point 16 bits
 * into the value, and is <= 1.0.  pc is at most 32 bits, so the
 * intermediate result is at most 48 bits.
 */
#define PC_TO_INDEX(pc, prof) \
        ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \
                        (u_quad_t)((prof)->pr_scale)) >> 16) & ~1)

/*
 * Collect user-level profiling statistics; called on a profiling tick,
 * when a process is running in user-mode. We use
 * an AST that will vector us to trap() with a context in which copyin
 * and copyout will work.  Trap will then call addupc_task().
 *
 * Note that we may (rarely) not get around to the AST soon enough, and
 * lose profile ticks when the next tick overwrites this one, but in this
 * case the system is overloaded and the profile is probably already
 * inaccurate.
 *
 * We can afford to take faults here.  If the
 * update fails, we simply turn off profiling.
 */
void
addupc_task(struct proc *p, user_addr_t pc, u_int ticks)
{
        u_int off;
        u_short count;

        /* Testing P_PROFIL may be unnecessary, but is certainly safe. */
        if ((p->p_flag & P_PROFIL) == 0 || ticks == 0)
                return;

        if (proc_is64bit(p)) {
        struct user_uprof *prof;
        user_addr_t cell;

        for (prof = &p->p_stats->user_p_prof; prof; prof = prof->pr_next) {
            off = PC_TO_INDEX(pc, prof);
            cell = (prof->pr_base + off);
            if (cell >= prof->pr_base &&
                cell < (prof->pr_size + prof->pr_base)) {
                if (copyin(cell, (caddr_t) &count, sizeof(count)) == 0) {
                    count += ticks;
                    if(copyout((caddr_t) &count, cell, sizeof(count)) == 0)
                        return;
                }
                p->p_stats->user_p_prof.pr_scale = 0;
                stopprofclock(p);
                break;
            }
        }
        }
        else {
        struct uprof *prof;
        short *cell;

        for (prof = &p->p_stats->p_prof; prof; prof = prof->pr_next) {
            off = PC_TO_INDEX(CAST_DOWN(uint, pc),prof);
            cell = (short *)(prof->pr_base + off);
            if (cell >= (short *)prof->pr_base &&
                cell < (short*)(prof->pr_size + (int) prof->pr_base)) {
                if (copyin(CAST_USER_ADDR_T(cell), (caddr_t) &count, sizeof(count)) == 0) {
                    count += ticks;
                    if(copyout((caddr_t) &count, CAST_USER_ADDR_T(cell), sizeof(count)) == 0)
                        return;
                }
                p->p_stats->p_prof.pr_scale = 0;
                stopprofclock(p);
                break;
            }
        }
        }
}