Return to kern_ktrace.c CVS log

Up to [cvs.NetBSD.org] / src / sys / kern

First sweep at scheduler state cleanup.  Collect MI scheduler
state into global and per-CPU scheduler state:

	- Global state: sched_qs (run queues), sched_whichqs (bitmap
	  of non-empty run queues), sched_slpque (sleep queues).
	  NOTE: These may collectively move into a struct schedstate
	  at some point in the future.

	- Per-CPU state, struct schedstate_percpu: spc_runtime
	  (time process on this CPU started running), spc_flags
	  (replaces struct proc's p_schedflags), and
	  spc_curpriority (usrpri of processes on this CPU).

	- Every platform must now supply a struct cpu_info and
	  a curcpu() macro.  Simplify existing cpu_info declarations
	  where appropriate.

	- All references to per-CPU scheduler state now made through
	  curcpu().  NOTE: this will likely be adjusted in the future
	  after further changes to struct proc are made.

Tested on i386 and Alpha.  Changes are mostly mechanical, but apologies
in advance if it doesn't compile on a particular platform.

/*	$NetBSD: kern_ktrace.c,v 1.41 2000/05/26 21:20:30 thorpej Exp $	*/

/*
 * Copyright (c) 1989, 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.
 *
 *	@(#)kern_ktrace.c	8.5 (Berkeley) 5/14/95
 */

#include "opt_ktrace.h"

#ifdef KTRACE

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/ktrace.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#include <sys/filedesc.h>

#include <sys/mount.h>
#include <sys/syscallargs.h>

void	ktrinitheader __P((struct ktr_header *, struct proc *, int));
int	ktrops __P((struct proc *, struct proc *, int, int, void *));
int	ktrsetchildren __P((struct proc *, struct proc *, int, int, void *));
int	ktrwrite __P((struct proc *, void *, struct ktr_header *));
int	ktrcanset __P((struct proc *, struct proc *));

void
ktrderef(p)
	struct proc *p;
{
	if (p->p_tracep == NULL)
		return;

	if (p->p_traceflag & KTRFAC_FD) {
		struct file *fp = p->p_tracep;

		FILE_USE(fp);
		closef(fp, NULL);
	} else {
		struct vnode *vp = p->p_tracep;

		vrele(vp);
	}
	p->p_tracep = NULL;
	p->p_traceflag = 0;
}

void
ktradref(p)
	struct proc *p;
{
	if (p->p_traceflag & KTRFAC_FD) {
		struct file *fp = p->p_tracep;

		fp->f_count++;
	} else {
		struct vnode *vp = p->p_tracep;

		VREF(vp);
	}
}

void
ktrinitheader(kth, p, type)
	struct ktr_header *kth;
	struct proc *p;
	int type;
{

	memset(kth, 0, sizeof(*kth));
	kth->ktr_type = type;
	microtime(&kth->ktr_time);
	kth->ktr_pid = p->p_pid;
	memcpy(kth->ktr_comm, p->p_comm, MAXCOMLEN);
}

void
ktrsyscall(v, code, argsize, args)
	void *v;
	register_t code;
	size_t argsize;
	register_t args[];
{
	struct ktr_header kth;
	struct ktr_syscall *ktp;
	struct proc *p = curproc;	/* XXX */
	register_t *argp;
	size_t len = sizeof(struct ktr_syscall) + argsize;
	int i;

	p->p_traceflag |= KTRFAC_ACTIVE;
	ktrinitheader(&kth, p, KTR_SYSCALL);
	ktp = malloc(len, M_TEMP, M_WAITOK);
	ktp->ktr_code = code;
	ktp->ktr_argsize = argsize;
	argp = (register_t *)((char *)ktp + sizeof(struct ktr_syscall));
	for (i = 0; i < (argsize / sizeof(*argp)); i++)
		*argp++ = args[i];
	kth.ktr_buf = (caddr_t)ktp;
	kth.ktr_len = len;
	(void) ktrwrite(p, v, &kth);
	free(ktp, M_TEMP);
	p->p_traceflag &= ~KTRFAC_ACTIVE;
}

void
ktrsysret(v, code, error, retval)
	void *v;
	register_t code;
	int error;
	register_t retval;
{
	struct ktr_header kth;
	struct ktr_sysret ktp;
	struct proc *p = curproc;	/* XXX */

	p->p_traceflag |= KTRFAC_ACTIVE;
	ktrinitheader(&kth, p, KTR_SYSRET);
	ktp.ktr_code = code;
	ktp.ktr_eosys = 0;			/* XXX unused */
	ktp.ktr_error = error;
	ktp.ktr_retval = retval;		/* what about val2 ? */

	kth.ktr_buf = (caddr_t)&ktp;
	kth.ktr_len = sizeof(struct ktr_sysret);

	(void) ktrwrite(p, v, &kth);
	p->p_traceflag &= ~KTRFAC_ACTIVE;
}

void
ktrnamei(v, path)
	void *v;
	char *path;
{
	struct ktr_header kth;
	struct proc *p = curproc;	/* XXX */

	p->p_traceflag |= KTRFAC_ACTIVE;
	ktrinitheader(&kth, p, KTR_NAMEI);
	kth.ktr_len = strlen(path);
	kth.ktr_buf = path;

	(void) ktrwrite(p, v, &kth);
	p->p_traceflag &= ~KTRFAC_ACTIVE;
}

void
ktremul(v, p, emul)
	void *v;
	struct proc *p;
	char *emul;
{
	struct ktr_header kth;

	p->p_traceflag |= KTRFAC_ACTIVE;
	ktrinitheader(&kth, p, KTR_EMUL);
	kth.ktr_len = strlen(emul);
	kth.ktr_buf = emul;

	(void) ktrwrite(p, v, &kth);
	p->p_traceflag &= ~KTRFAC_ACTIVE;
}

void
ktrgenio(v, fd, rw, iov, len, error)
	void *v;
	int fd;
	enum uio_rw rw;
	struct iovec *iov;
	int len, error;
{
	struct ktr_header kth;
	struct ktr_genio *ktp;
	caddr_t cp;
	int resid = len, cnt;
	struct proc *p = curproc;	/* XXX */
	int buflen;

	if (error)
		return;

	p->p_traceflag |= KTRFAC_ACTIVE;

	buflen = min(PAGE_SIZE, len + sizeof(struct ktr_genio));

	ktrinitheader(&kth, p, KTR_GENIO);
	ktp = malloc(buflen, M_TEMP, M_WAITOK);
	ktp->ktr_fd = fd;
	ktp->ktr_rw = rw;

	kth.ktr_buf = (caddr_t)ktp;

	cp = (caddr_t)((char *)ktp + sizeof(struct ktr_genio));
	buflen -= sizeof(struct ktr_genio);

	while (resid > 0) {
		if (curcpu()->ci_schedstate.spc_flags & SPCF_SHOULDYIELD)
			preempt(NULL);

		cnt = min(iov->iov_len, buflen);
		if (cnt > resid)
			cnt = resid;
		if (copyin(iov->iov_base, cp, cnt))
			break;

		kth.ktr_len = cnt + sizeof(struct ktr_genio);

		if (__predict_false(ktrwrite(p, v, &kth) != 0))
			break;

		iov->iov_base = (caddr_t)iov->iov_base + cnt;
		iov->iov_len -= cnt;

		if (iov->iov_len == 0)
			iov++;

		resid -= cnt;
	}

	free(ktp, M_TEMP);
	p->p_traceflag &= ~KTRFAC_ACTIVE;
}

void
ktrpsig(v, sig, action, mask, code)
	void *v;
	int sig;
	sig_t action;
	sigset_t *mask;
	int code;
{
	struct ktr_header kth;
	struct ktr_psig	kp;
	struct proc *p = curproc;	/* XXX */

	p->p_traceflag |= KTRFAC_ACTIVE;
	ktrinitheader(&kth, p, KTR_PSIG);
	kp.signo = (char)sig;
	kp.action = action;
	kp.mask = *mask;
	kp.code = code;
	kth.ktr_buf = (caddr_t)&kp;
	kth.ktr_len = sizeof(struct ktr_psig);

	(void) ktrwrite(p, v, &kth);
	p->p_traceflag &= ~KTRFAC_ACTIVE;
}

void
ktrcsw(v, out, user)
	void *v;
	int out, user;
{
	struct ktr_header kth;
	struct ktr_csw kc;
	struct proc *p = curproc;	/* XXX */

	p->p_traceflag |= KTRFAC_ACTIVE;
	ktrinitheader(&kth, p, KTR_CSW);
	kc.out = out;
	kc.user = user;
	kth.ktr_buf = (caddr_t)&kc;
	kth.ktr_len = sizeof(struct ktr_csw);

	(void) ktrwrite(p, v, &kth);
	p->p_traceflag &= ~KTRFAC_ACTIVE;
}

/* Interface and common routines */

/*
 * ktrace system call
 */
/* ARGSUSED */
int
sys_fktrace(curp, v, retval)
	struct proc *curp;
	void *v;
	register_t *retval;
{
	struct sys_fktrace_args /* {
		syscallarg(int) fd;
		syscallarg(int) ops;
		syscallarg(int) facs;
		syscallarg(int) pid;
	} */ *uap = v;
	struct file *fp = NULL;
	struct proc *p;
	struct filedesc *fdp = curp->p_fd;
	struct pgrp *pg;
	int facs;
	int ops;
	int descend;
	int ret = 0;
	int error = 0;

	if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
	    (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
	    (fp->f_flag & FWRITE) == 0)
		return (EBADF);

	ops = KTROP(SCARG(uap, ops)) | KTRFLAG_FD;
	descend = SCARG(uap, ops) & KTRFLAG_DESCEND;
	facs = SCARG(uap, facs) & ~((unsigned) KTRFAC_ROOT);
	curp->p_traceflag |= KTRFAC_ACTIVE;

	/*
	 * Clear all uses of the tracefile
	 */
	if (KTROP(ops) == KTROP_CLEARFILE) {
		proclist_lock_read();
		for (p = LIST_FIRST(&allproc); p != NULL;
		     p = LIST_NEXT(p, p_list)) {
			if (p->p_tracep == fp) {
				if (ktrcanset(curp, p))
					ktrderef(p);
				else
					error = EPERM;
			}
		}
		proclist_unlock_read();
		goto done;
	}
	/*
	 * need something to (un)trace (XXX - why is this here?)
	 */
	if (!facs) {
		error = EINVAL;
		goto done;
	}
	/* 
	 * do it
	 */
	if (SCARG(uap, pid) < 0) {
		/*
		 * by process group
		 */
		pg = pgfind(-SCARG(uap, pid));
		if (pg == NULL) {
			error = ESRCH;
			goto done;
		}
		for (p = LIST_FIRST(&pg->pg_members); p != NULL;
		     p = LIST_NEXT(p, p_pglist)) {
			if (descend)
				ret |= ktrsetchildren(curp, p, ops, facs, fp);
			else 
				ret |= ktrops(curp, p, ops, facs, fp);
		}
					
	} else {
		/*
		 * by pid
		 */
		p = pfind(SCARG(uap, pid));
		if (p == NULL) {
			error = ESRCH;
			goto done;
		}
		if (descend)
			ret |= ktrsetchildren(curp, p, ops, facs, fp);
		else
			ret |= ktrops(curp, p, ops, facs, fp);
	}
	if (!ret)
		error = EPERM;
done:
	curp->p_traceflag &= ~KTRFAC_ACTIVE;
	return (error);
}

/*
 * ktrace system call
 */
/* ARGSUSED */
int
sys_ktrace(curp, v, retval)
	struct proc *curp;
	void *v;
	register_t *retval;
{
	struct sys_ktrace_args /* {
		syscallarg(const char *) fname;
		syscallarg(int) ops;
		syscallarg(int) facs;
		syscallarg(int) pid;
	} */ *uap = v;
	struct vnode *vp = NULL;
	struct proc *p;
	struct pgrp *pg;
	int facs = SCARG(uap, facs) & ~((unsigned) KTRFAC_ROOT);
	int ops = KTROP(SCARG(uap, ops));
	int descend = SCARG(uap, ops) & KTRFLAG_DESCEND;
	int ret = 0;
	int error = 0;
	struct nameidata nd;

	curp->p_traceflag |= KTRFAC_ACTIVE;
	if (ops != KTROP_CLEAR) {
		/*
		 * an operation which requires a file argument.
		 */
		NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, fname),
		    curp);
		if ((error = vn_open(&nd, FREAD|FWRITE, 0)) != 0) {
			curp->p_traceflag &= ~KTRFAC_ACTIVE;
			return (error);
		}
		vp = nd.ni_vp;
		VOP_UNLOCK(vp, 0);
		if (vp->v_type != VREG) {
			(void) vn_close(vp, FREAD|FWRITE, curp->p_ucred, curp);
			curp->p_traceflag &= ~KTRFAC_ACTIVE;
			return (EACCES);
		}
	}
	/*
	 * Clear all uses of the tracefile
	 */
	if (KTROP(ops) == KTROP_CLEARFILE) {
		proclist_lock_read();
		for (p = LIST_FIRST(&allproc); p != NULL;
		     p = LIST_NEXT(p, p_list)) {
			if (p->p_tracep == vp &&
			    !ktrops(curp, p, KTROP_CLEAR, ~0, vp))
				error = EPERM;
		}
		proclist_unlock_read();
		goto done;
	}
	/*
	 * need something to (un)trace (XXX - why is this here?)
	 */
	if (!facs) {
		error = EINVAL;
		goto done;
	}
	/* 
	 * do it
	 */
	if (SCARG(uap, pid) < 0) {
		/*
		 * by process group
		 */
		pg = pgfind(-SCARG(uap, pid));
		if (pg == NULL) {
			error = ESRCH;
			goto done;
		}
		for (p = LIST_FIRST(&pg->pg_members); p != NULL;
		     p = LIST_NEXT(p, p_pglist)) {
			if (descend)
				ret |= ktrsetchildren(curp, p, ops, facs, vp);
			else 
				ret |= ktrops(curp, p, ops, facs, vp);
		}
					
	} else {
		/*
		 * by pid
		 */
		p = pfind(SCARG(uap, pid));
		if (p == NULL) {
			error = ESRCH;
			goto done;
		}
		if (descend)
			ret |= ktrsetchildren(curp, p, ops, facs, vp);
		else
			ret |= ktrops(curp, p, ops, facs, vp);
	}
	if (!ret)
		error = EPERM;
done:
	if (vp != NULL)
		(void) vn_close(vp, FWRITE, curp->p_ucred, curp);
	curp->p_traceflag &= ~KTRFAC_ACTIVE;
	return (error);
}

int
ktrops(curp, p, ops, facs, v)
	struct proc *p, *curp;
	int ops, facs;
	void *v;
{

	if (!ktrcanset(curp, p))
		return (0);
	if (KTROP(ops) == KTROP_SET) {
		if (p->p_tracep != v) { 
			/*
			 * if trace file already in use, relinquish
			 */
			ktrderef(p);
			if (ops & KTRFLAG_FD)
				p->p_traceflag = KTRFAC_FD;
			p->p_tracep = v;
			ktradref(p);
		}
		p->p_traceflag |= facs;
		if (curp->p_ucred->cr_uid == 0)
			p->p_traceflag |= KTRFAC_ROOT;
	} else {	
		/* KTROP_CLEAR */
		if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
			/* no more tracing */
			ktrderef(p);
		}
	}

	/*
	 * Emit an emulation record, every time there is a ktrace
	 * change/attach request. 
	 */
	if (KTRPOINT(p, KTR_EMUL))
		ktremul(p->p_tracep, p, p->p_emul->e_name);

	return (1);
}

int
ktrsetchildren(curp, top, ops, facs, v)
	struct proc *curp, *top;
	int ops, facs;
	void *v;
{
	struct proc *p;
	int ret = 0;

	p = top;
	for (;;) {
		ret |= ktrops(curp, p, ops, facs, v);
		/*
		 * If this process has children, descend to them next,
		 * otherwise do any siblings, and if done with this level,
		 * follow back up the tree (but not past top).
		 */
		if (LIST_FIRST(&p->p_children) != NULL)
			p = LIST_FIRST(&p->p_children);
		else for (;;) {
			if (p == top)
				return (ret);
			if (LIST_NEXT(p, p_sibling) != NULL) {
				p = LIST_NEXT(p, p_sibling);
				break;
			}
			p = p->p_pptr;
		}
	}
	/*NOTREACHED*/
}

int
ktrwrite(p, v, kth)
	struct proc *p;
	void *v;
	struct ktr_header *kth;
{
	struct uio auio;
	struct iovec aiov[2];
	int error;

	if (v == NULL)
		return (0);
	auio.uio_iov = &aiov[0];
	auio.uio_offset = 0;
	auio.uio_segflg = UIO_SYSSPACE;
	auio.uio_rw = UIO_WRITE;
	aiov[0].iov_base = (caddr_t)kth;
	aiov[0].iov_len = sizeof(struct ktr_header);
	auio.uio_resid = sizeof(struct ktr_header);
	auio.uio_iovcnt = 1;
	auio.uio_procp = (struct proc *)0;
	if (kth->ktr_len > 0) {
		auio.uio_iovcnt++;
		aiov[1].iov_base = kth->ktr_buf;
		aiov[1].iov_len = kth->ktr_len;
		auio.uio_resid += kth->ktr_len;
	}
	if (p->p_traceflag & KTRFAC_FD) {
		struct file *fp = v;

		FILE_USE(fp);
		error = (*fp->f_ops->fo_write)(fp, &fp->f_offset, &auio,
		    fp->f_cred, FOF_UPDATE_OFFSET);
		FILE_UNUSE(fp, NULL);
	}
	else {
		struct vnode *vp = v;

		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
		error = VOP_WRITE(vp, &auio, IO_UNIT|IO_APPEND, p->p_ucred);
		VOP_UNLOCK(vp, 0);
	}
	if (__predict_true(error == 0))
		return (0);
	/*
	 * If error encountered, give up tracing on this vnode.  Don't report
	 * EPIPE as this can easily happen with fktrace()/ktruss.
	 */
	if (error != EPIPE)
		log(LOG_NOTICE,
		    "ktrace write failed, errno %d, tracing stopped\n",
		    error);
	proclist_lock_read();
	for (p = LIST_FIRST(&allproc); p != NULL; p = LIST_NEXT(p, p_list)) {
		if (p->p_tracep == v)
			ktrderef(p);
	}
	proclist_unlock_read();

	return (error);
}

/*
 * Return true if caller has permission to set the ktracing state
 * of target.  Essentially, the target can't possess any
 * more permissions than the caller.  KTRFAC_ROOT signifies that
 * root previously set the tracing status on the target process, and 
 * so, only root may further change it.
 *
 * TODO: check groups.  use caller effective gid.
 */
int
ktrcanset(callp, targetp)
	struct proc *callp, *targetp;
{
	struct pcred *caller = callp->p_cred;
	struct pcred *target = targetp->p_cred;

	if ((caller->pc_ucred->cr_uid == target->p_ruid &&
	     target->p_ruid == target->p_svuid &&
	     caller->p_rgid == target->p_rgid &&	/* XXX */
	     target->p_rgid == target->p_svgid &&
	     (targetp->p_traceflag & KTRFAC_ROOT) == 0) ||
	     caller->pc_ucred->cr_uid == 0)
		return (1);

	return (0);
}

#endif