xnu-4903.270.47.tar.gz

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

/*
 * Copyright (c) 2000-2008 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 <libkern/kernel_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/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)
{
	tostruct_t *cp;
	kernel_segment_command_t        *sgp;   /* 32 bit mach object file segment */
	struct gmonparam *p = &_gmonparam;

	sgp = getsegbyname("__TEXT");
	p->lowpc = (u_int32_t)sgp->vmaddr;
	p->highpc = (u_int32_t)(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(tostruct_t);
	/* Why not use MALLOC with M_GPROF ? */
	cp = (tostruct_t *)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 = cp;
	cp = (tostruct_t *)((vm_offset_t)cp + p->tossize);
	p->kcount = (u_short *)cp;
	cp = (tostruct_t *)((vm_offset_t)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);
}

/*
 * XXX		These should be broken out into per-argument OID values,
 * XXX		since there are no sub-OID parameter values, but unfortunately
 * XXX		there is barely enough time for an initial conversion.
 *
 * Note:	These items appear to be read/write.
 */
STATIC int
sysctl_doprofhandle SYSCTL_HANDLER_ARGS
{
	sysctl_doprof(int *name, u_int namelen, user_addr_t oldp, size_t * oldlenp,
    user_addr_t newp, size_t newlen)
	{
		__unused int cmd = oidp->oid_arg2; /* subcommand*/
		int *name = arg1;       /* oid element argument vector */
		int namelen = arg2;     /* number of oid element arguments */
		user_addr_t oldp = req->oldptr; /* user buffer copy out address */
		size_t *oldlenp = req->oldlen; /* user buffer copy out size */
		user_addr_t newp = req->newptr; /* user buffer copy in address */
		size_t newlen = req->newlen; /* user buffer copy in size */

		struct gmonparam *gp = &_gmonparam;
		int error = 0;

		/* 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) {
				break;
			}
			if (gp->state == GMON_PROF_OFF) {
				stopprofclock(kernproc);
			} else {
				startprofclock(kernproc);
			}
			break;
		case GPROF_COUNT:
			error = sysctl_struct(oldp, oldlenp, newp, newlen,
			    gp->kcount, gp->kcountsize);
			break;
		case GPROF_FROMS:
			error = sysctl_struct(oldp, oldlenp, newp, newlen,
			    gp->froms, gp->fromssize);
			break;
		case GPROF_TOS:
			error = sysctl_struct(oldp, oldlenp, newp, newlen,
			    gp->tos, gp->tossize);
			break;
		case GPROF_GMONPARAM:
			error = sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp);
			break;
		default:
			error = ENOTSUP;
			break;
		}

		/* adjust index so we return the right required/consumed amount */
		if (!error) {
			req->oldidx += req->oldlen;
		}

		return error;
	}
	SYSCTL_PROC(_kern, KERN_PROF, prof, STLFLAG_NODE | CTLFLAG_RW | CTLFLAG_LOCKED,
	    0,                  /* Pointer argument (arg1) */
	    0,                  /* Integer argument (arg2) */
	    sysctl_doprofhandle, /* Handler function */
	    NULL,               /* No explicit data */
	    "");


/*
 * mcount() called with interrupts disabled.
 */
	void
	mcount(
		uintptr_t frompc,
		uintptr_t selfpc
		)
	{
		unsigned short *frompcindex;
		tostruct_t *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)


/*
 * 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.
 */
//K64todo - this doesn't fit into 64 bit any more, it needs 64+16
#define PC_TO_INDEX(pc, prof) \
	((user_addr_t)(((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)
{
	user_addr_t 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(pc, prof);
			cell = (short *)(prof->pr_base + off);
			if (cell >= (short *)prof->pr_base &&
			    cell < (short*)(prof->pr_size + 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;
			}
		}
	}
}