kvm_proc.c

早期freebsd实现

/*-
 * Copyright (c) 1989, 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software developed by the Computer Systems
 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
 * BG 91-66 and contributed to Berkeley.
 *
 * 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)kvm_proc.c	8.3 (Berkeley) 9/23/93";
#endif /* LIBC_SCCS and not lint */

/*
 * Proc traversal interface for kvm.  ps and w are (probably) the exclusive
 * users of this code, so we've factored it out into a separate module.
 * Thus, we keep this grunge out of the other kvm applications (i.e.,
 * most other applications are interested only in open/close/read/nlist).
 */

#include <sys/param.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/exec.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <unistd.h>
#include <nlist.h>
#include <kvm.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/swap_pager.h>

#include <sys/sysctl.h>

#include <limits.h>
#include <db.h>
#include <paths.h>

#include "kvm_private.h"

static char *
kvm_readswap(kd, p, va, cnt)
	kvm_t *kd;
	const struct proc *p;
	u_long va;
	u_long *cnt;
{
	register int ix;
	register u_long addr, head;
	register u_long offset, pagestart, sbstart, pgoff;
	register off_t seekpoint;
	struct vm_map_entry vme;
	struct vm_object vmo;
	struct pager_struct pager;
	struct swpager swap;
	struct swblock swb;
	static char page[NBPG];

	head = (u_long)&p->p_vmspace->vm_map.header;
	/*
	 * Look through the address map for the memory object
	 * that corresponds to the given virtual address.
	 * The header just has the entire valid range.
	 */
	addr = head;
	while (1) {
		if (kvm_read(kd, addr, (char *)&vme, sizeof(vme)) != 
		    sizeof(vme))
			return (0);

		if (va >= vme.start && va <= vme.end && 
		    vme.object.vm_object != 0)
			break;

		addr = (u_long)vme.next;
		if (addr == 0 || addr == head)
			return (0);
	}
	/*
	 * We found the right object -- follow shadow links.
	 */
	offset = va - vme.start + vme.offset;
	addr = (u_long)vme.object.vm_object;
	while (1) {
		if (kvm_read(kd, addr, (char *)&vmo, sizeof(vmo)) != 
		    sizeof(vmo))
			return (0);
		addr = (u_long)vmo.shadow;
		if (addr == 0)
			break;
		offset += vmo.shadow_offset;
	}
	if (vmo.pager == 0)
		return (0);

	offset += vmo.paging_offset;
	/*
	 * Read in the pager info and make sure it's a swap device.
	 */
	addr = (u_long)vmo.pager;
	if (kvm_read(kd, addr, (char *)&pager, sizeof(pager)) != sizeof(pager)
	    || pager.pg_type != PG_SWAP)
		return (0);

	/*
	 * Read in the swap_pager private data, and compute the
	 * swap offset.
	 */
	addr = (u_long)pager.pg_data;
	if (kvm_read(kd, addr, (char *)&swap, sizeof(swap)) != sizeof(swap))
		return (0);
	ix = offset / dbtob(swap.sw_bsize);
	if (swap.sw_blocks == 0 || ix >= swap.sw_nblocks)
		return (0);

	addr = (u_long)&swap.sw_blocks[ix];
	if (kvm_read(kd, addr, (char *)&swb, sizeof(swb)) != sizeof(swb))
		return (0);

	sbstart = (offset / dbtob(swap.sw_bsize)) * dbtob(swap.sw_bsize);
	sbstart /= NBPG;
	pagestart = offset / NBPG;
	pgoff = pagestart - sbstart;

	if (swb.swb_block == 0 || (swb.swb_mask & (1 << pgoff)) == 0)
		return (0);

	seekpoint = dbtob(swb.swb_block) + ctob(pgoff);
	errno = 0;
	if (lseek(kd->swfd, seekpoint, 0) == -1 && errno != 0)
		return (0);
	if (read(kd->swfd, page, sizeof(page)) != sizeof(page))
		return (0);

	offset %= NBPG;
	*cnt = NBPG - offset;
	return (&page[offset]);
}

#define KREAD(kd, addr, obj) \
	(kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))

/*
 * Read proc's from memory file into buffer bp, which has space to hold
 * at most maxcnt procs.
 */
static int
kvm_proclist(kd, what, arg, p, bp, maxcnt)
	kvm_t *kd;
	int what, arg;
	struct proc *p;
	struct kinfo_proc *bp;
	int maxcnt;
{
	register int cnt = 0;
	struct eproc eproc;
	struct pgrp pgrp;
	struct session sess;
	struct tty tty;
	struct proc proc;

	for (; cnt < maxcnt && p != NULL; p = proc.p_next) {
		if (KREAD(kd, (u_long)p, &proc)) {
			_kvm_err(kd, kd->program, "can't read proc at %x", p);
			return (-1);
		}
		if (KREAD(kd, (u_long)proc.p_cred, &eproc.e_pcred) == 0)
			KREAD(kd, (u_long)eproc.e_pcred.pc_ucred,
			      &eproc.e_ucred);

		switch(what) {
			
		case KERN_PROC_PID:
			if (proc.p_pid != (pid_t)arg)
				continue;
			break;

		case KERN_PROC_UID:
			if (eproc.e_ucred.cr_uid != (uid_t)arg)
				continue;
			break;

		case KERN_PROC_RUID:
			if (eproc.e_pcred.p_ruid != (uid_t)arg)
				continue;
			break;
		}
		/*
		 * We're going to add another proc to the set.  If this
		 * will overflow the buffer, assume the reason is because
		 * nprocs (or the proc list) is corrupt and declare an error.
		 */
		if (cnt >= maxcnt) {
			_kvm_err(kd, kd->program, "nprocs corrupt");
			return (-1);
		}
		/*
		 * gather eproc
		 */
		eproc.e_paddr = p;
		if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
			_kvm_err(kd, kd->program, "can't read pgrp at %x",
				 proc.p_pgrp);
			return (-1);
		}
		eproc.e_sess = pgrp.pg_session;
		eproc.e_pgid = pgrp.pg_id;
		eproc.e_jobc = pgrp.pg_jobc;
		if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
			_kvm_err(kd, kd->program, "can't read session at %x", 
				pgrp.pg_session);
			return (-1);
		}
		if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) {
			if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
				_kvm_err(kd, kd->program,
					 "can't read tty at %x", sess.s_ttyp);
				return (-1);
			}
			eproc.e_tdev = tty.t_dev;
			eproc.e_tsess = tty.t_session;
			if (tty.t_pgrp != NULL) {
				if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
					_kvm_err(kd, kd->program,
						 "can't read tpgrp at &x", 
						tty.t_pgrp);
					return (-1);
				}
				eproc.e_tpgid = pgrp.pg_id;
			} else
				eproc.e_tpgid = -1;
		} else
			eproc.e_tdev = NODEV;
		eproc.e_flag = sess.s_ttyvp ? EPROC_CTTY : 0;
		if (sess.s_leader == p)
			eproc.e_flag |= EPROC_SLEADER;
		if (proc.p_wmesg)
			(void)kvm_read(kd, (u_long)proc.p_wmesg, 
			    eproc.e_wmesg, WMESGLEN);

#ifdef sparc
		(void)kvm_read(kd, (u_long)&proc.p_vmspace->vm_rssize,
		    (char *)&eproc.e_vm.vm_rssize,
		    sizeof(eproc.e_vm.vm_rssize));
		(void)kvm_read(kd, (u_long)&proc.p_vmspace->vm_tsize,
		    (char *)&eproc.e_vm.vm_tsize,
		    3 * sizeof(eproc.e_vm.vm_rssize));	/* XXX */
#else
		(void)kvm_read(kd, (u_long)proc.p_vmspace,
		    (char *)&eproc.e_vm, sizeof(eproc.e_vm));
#endif
		eproc.e_xsize = eproc.e_xrssize = 0;
		eproc.e_xccount = eproc.e_xswrss = 0;

		switch (what) {

		case KERN_PROC_PGRP:
			if (eproc.e_pgid != (pid_t)arg)
				continue;
			break;

		case KERN_PROC_TTY:
			if ((proc.p_flag & P_CONTROLT) == 0 || 
			     eproc.e_tdev != (dev_t)arg)
				continue;
			break;
		}
		bcopy(&proc, &bp->kp_proc, sizeof(proc));
		bcopy(&eproc, &bp->kp_eproc, sizeof(eproc));
		++bp;
		++cnt;
	}
	return (cnt);
}

/*
 * Build proc info array by reading in proc list from a crash dump.
 * Return number of procs read.  maxcnt is the max we will read.
 */
static int
kvm_deadprocs(kd, what, arg, a_allproc, a_zombproc, maxcnt)
	kvm_t *kd;
	int what, arg;
	u_long a_allproc;
	u_long a_zombproc;
	int maxcnt;
{
	register struct kinfo_proc *bp = kd->procbase;
	register int acnt, zcnt;
	struct proc *p;

	if (KREAD(kd, a_allproc, &p)) {
		_kvm_err(kd, kd->program, "cannot read allproc");
		return (-1);
	}
	acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt);
	if (acnt < 0)
		return (acnt);

	if (KREAD(kd, a_zombproc, &p)) {
		_kvm_err(kd, kd->program, "cannot read zombproc");
		return (-1);
	}
	zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt);
	if (zcnt < 0)
		zcnt = 0;

	return (acnt + zcnt);
}

struct kinfo_proc *
kvm_getprocs(kd, op, arg, cnt)
	kvm_t *kd;
	int op, arg;
	int *cnt;
{
	int mib[4], size, st, nprocs;

	if (kd->procbase != 0) {
		free((void *)kd->procbase);
		/* 
		 * Clear this pointer in case this call fails.  Otherwise,