632 lines
14 KiB
C
632 lines
14 KiB
C
/*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)kern_ktrace.c 8.2 (Berkeley) 9/23/93
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* $FreeBSD$
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*/
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#include "opt_ktrace.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/sysproto.h>
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#include <sys/kernel.h>
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#include <sys/proc.h>
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#include <sys/fcntl.h>
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#include <sys/namei.h>
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#include <sys/vnode.h>
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#include <sys/ktrace.h>
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#include <sys/malloc.h>
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#include <sys/sx.h>
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#include <sys/syslog.h>
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#include <sys/jail.h>
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static MALLOC_DEFINE(M_KTRACE, "KTRACE", "KTRACE");
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#ifdef KTRACE
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static struct ktr_header *ktrgetheader(int type);
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static void ktrwrite(struct vnode *, struct ktr_header *, struct uio *);
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static int ktrcanset(struct thread *, struct proc *);
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static int ktrsetchildren(struct thread *, struct proc *, int, int, struct vnode *);
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static int ktrops(struct thread *, struct proc *, int, int, struct vnode *);
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static struct ktr_header *
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ktrgetheader(type)
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int type;
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{
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register struct ktr_header *kth;
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struct proc *p = curproc; /* XXX */
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MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
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M_KTRACE, M_WAITOK);
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kth->ktr_type = type;
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microtime(&kth->ktr_time);
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kth->ktr_pid = p->p_pid;
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bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN + 1);
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return (kth);
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}
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/*
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* MPSAFE
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*/
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void
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ktrsyscall(vp, code, narg, args)
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struct vnode *vp;
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int code, narg;
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register_t args[];
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{
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struct ktr_header *kth;
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struct ktr_syscall *ktp;
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register int len = offsetof(struct ktr_syscall, ktr_args) +
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(narg * sizeof(register_t));
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struct proc *p = curproc; /* XXX */
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register_t *argp;
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int i;
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mtx_lock(&Giant);
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p->p_traceflag |= KTRFAC_ACTIVE;
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kth = ktrgetheader(KTR_SYSCALL);
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MALLOC(ktp, struct ktr_syscall *, len, M_KTRACE, M_WAITOK);
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ktp->ktr_code = code;
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ktp->ktr_narg = narg;
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argp = &ktp->ktr_args[0];
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for (i = 0; i < narg; i++)
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*argp++ = args[i];
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kth->ktr_buffer = (caddr_t)ktp;
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kth->ktr_len = len;
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ktrwrite(vp, kth, NULL);
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FREE(ktp, M_KTRACE);
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FREE(kth, M_KTRACE);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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mtx_unlock(&Giant);
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}
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/*
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* MPSAFE
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*/
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void
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ktrsysret(vp, code, error, retval)
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struct vnode *vp;
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int code, error;
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register_t retval;
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{
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struct ktr_header *kth;
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struct ktr_sysret ktp;
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struct proc *p = curproc; /* XXX */
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mtx_lock(&Giant);
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p->p_traceflag |= KTRFAC_ACTIVE;
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kth = ktrgetheader(KTR_SYSRET);
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ktp.ktr_code = code;
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ktp.ktr_error = error;
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ktp.ktr_retval = retval; /* what about val2 ? */
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kth->ktr_buffer = (caddr_t)&ktp;
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kth->ktr_len = sizeof(struct ktr_sysret);
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ktrwrite(vp, kth, NULL);
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FREE(kth, M_KTRACE);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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mtx_unlock(&Giant);
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}
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void
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ktrnamei(vp, path)
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struct vnode *vp;
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char *path;
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{
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struct ktr_header *kth;
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struct proc *p = curproc; /* XXX */
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/*
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* don't let p_tracep get ripped out from under us
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*/
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if (vp)
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VREF(vp);
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p->p_traceflag |= KTRFAC_ACTIVE;
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kth = ktrgetheader(KTR_NAMEI);
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kth->ktr_len = strlen(path);
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kth->ktr_buffer = path;
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ktrwrite(vp, kth, NULL);
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if (vp)
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vrele(vp);
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FREE(kth, M_KTRACE);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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void
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ktrgenio(vp, fd, rw, uio, error)
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struct vnode *vp;
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int fd;
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enum uio_rw rw;
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struct uio *uio;
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int error;
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{
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struct ktr_header *kth;
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struct ktr_genio ktg;
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struct proc *p = curproc; /* XXX */
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if (error)
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return;
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mtx_lock(&Giant);
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/*
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* don't let p_tracep get ripped out from under us
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*/
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if (vp)
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VREF(vp);
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p->p_traceflag |= KTRFAC_ACTIVE;
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kth = ktrgetheader(KTR_GENIO);
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ktg.ktr_fd = fd;
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ktg.ktr_rw = rw;
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kth->ktr_buffer = (caddr_t)&ktg;
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kth->ktr_len = sizeof(struct ktr_genio);
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uio->uio_offset = 0;
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uio->uio_rw = UIO_WRITE;
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ktrwrite(vp, kth, uio);
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if (vp)
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vrele(vp);
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FREE(kth, M_KTRACE);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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mtx_unlock(&Giant);
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}
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void
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ktrpsig(vp, sig, action, mask, code)
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struct vnode *vp;
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int sig;
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sig_t action;
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sigset_t *mask;
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int code;
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{
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struct ktr_header *kth;
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struct ktr_psig kp;
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struct proc *p = curproc; /* XXX */
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/*
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* don't let vp get ripped out from under us
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*/
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if (vp)
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VREF(vp);
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p->p_traceflag |= KTRFAC_ACTIVE;
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kth = ktrgetheader(KTR_PSIG);
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kp.signo = (char)sig;
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kp.action = action;
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kp.mask = *mask;
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kp.code = code;
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kth->ktr_buffer = (caddr_t)&kp;
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kth->ktr_len = sizeof (struct ktr_psig);
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ktrwrite(vp, kth, NULL);
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if (vp)
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vrele(vp);
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FREE(kth, M_KTRACE);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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void
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ktrcsw(vp, out, user)
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struct vnode *vp;
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int out, user;
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{
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struct ktr_header *kth;
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struct ktr_csw kc;
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struct proc *p = curproc; /* XXX */
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/*
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* don't let vp get ripped out from under us
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*/
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if (vp)
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VREF(vp);
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p->p_traceflag |= KTRFAC_ACTIVE;
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kth = ktrgetheader(KTR_CSW);
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kc.out = out;
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kc.user = user;
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kth->ktr_buffer = (caddr_t)&kc;
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kth->ktr_len = sizeof (struct ktr_csw);
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ktrwrite(vp, kth, NULL);
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if (vp)
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vrele(vp);
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FREE(kth, M_KTRACE);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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}
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#endif
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/* Interface and common routines */
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/*
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* ktrace system call
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*/
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#ifndef _SYS_SYSPROTO_H_
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struct ktrace_args {
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char *fname;
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int ops;
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int facs;
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int pid;
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};
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#endif
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/* ARGSUSED */
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int
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ktrace(td, uap)
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struct thread *td;
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register struct ktrace_args *uap;
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{
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#ifdef KTRACE
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struct proc *curp = td->td_proc;
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register struct vnode *vp = NULL;
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register struct proc *p;
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struct pgrp *pg;
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int facs = uap->facs & ~KTRFAC_ROOT;
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int ops = KTROP(uap->ops);
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int descend = uap->ops & KTRFLAG_DESCEND;
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int ret = 0;
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int flags, error = 0;
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struct nameidata nd;
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curp->p_traceflag |= KTRFAC_ACTIVE;
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if (ops != KTROP_CLEAR) {
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/*
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* an operation which requires a file argument.
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*/
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NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->fname, td);
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flags = FREAD | FWRITE | O_NOFOLLOW;
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error = vn_open(&nd, &flags, 0);
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if (error) {
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curp->p_traceflag &= ~KTRFAC_ACTIVE;
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return (error);
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}
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NDFREE(&nd, NDF_ONLY_PNBUF);
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vp = nd.ni_vp;
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VOP_UNLOCK(vp, 0, td);
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if (vp->v_type != VREG) {
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(void) vn_close(vp, FREAD|FWRITE, td->td_ucred, td);
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curp->p_traceflag &= ~KTRFAC_ACTIVE;
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return (EACCES);
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}
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}
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/*
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* Clear all uses of the tracefile.
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*/
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if (ops == KTROP_CLEARFILE) {
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sx_slock(&allproc_lock);
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LIST_FOREACH(p, &allproc, p_list) {
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PROC_LOCK(p);
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if (p->p_tracep == vp) {
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if (ktrcanset(td, p) && p->p_tracep == vp) {
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p->p_tracep = NULL;
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p->p_traceflag = 0;
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PROC_UNLOCK(p);
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(void) vn_close(vp, FREAD|FWRITE,
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td->td_ucred, td);
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} else {
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PROC_UNLOCK(p);
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error = EPERM;
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}
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} else
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PROC_UNLOCK(p);
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}
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sx_sunlock(&allproc_lock);
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goto done;
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}
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/*
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* need something to (un)trace (XXX - why is this here?)
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*/
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if (!facs) {
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error = EINVAL;
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goto done;
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}
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/*
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* do it
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*/
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if (uap->pid < 0) {
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/*
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* by process group
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*/
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sx_slock(&proctree_lock);
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pg = pgfind(-uap->pid);
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if (pg == NULL) {
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sx_sunlock(&proctree_lock);
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error = ESRCH;
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goto done;
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}
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/*
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* ktrops() may call vrele(). Lock pg_members
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* by the proctree_lock rather than pg_mtx.
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*/
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PGRP_UNLOCK(pg);
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LIST_FOREACH(p, &pg->pg_members, p_pglist)
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if (descend)
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ret |= ktrsetchildren(td, p, ops, facs, vp);
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else
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ret |= ktrops(td, p, ops, facs, vp);
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sx_sunlock(&proctree_lock);
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} else {
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/*
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* by pid
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*/
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p = pfind(uap->pid);
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if (p == NULL) {
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error = ESRCH;
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goto done;
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}
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PROC_UNLOCK(p);
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/* XXX: UNLOCK above has a race */
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if (descend)
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ret |= ktrsetchildren(td, p, ops, facs, vp);
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else
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ret |= ktrops(td, p, ops, facs, vp);
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}
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if (!ret)
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error = EPERM;
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done:
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if (vp != NULL)
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(void) vn_close(vp, FWRITE, td->td_ucred, td);
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curp->p_traceflag &= ~KTRFAC_ACTIVE;
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return (error);
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#else
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return ENOSYS;
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#endif
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}
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/*
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* utrace system call
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*/
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/* ARGSUSED */
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int
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utrace(td, uap)
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struct thread *td;
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register struct utrace_args *uap;
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{
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#ifdef KTRACE
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struct ktr_header *kth;
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struct proc *p = curproc; /* XXX */
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struct vnode *vp;
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register caddr_t cp;
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if (!KTRPOINT(p, KTR_USER))
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return (0);
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if (uap->len > KTR_USER_MAXLEN)
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return (EINVAL);
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p->p_traceflag |= KTRFAC_ACTIVE;
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if ((vp = p->p_tracep) != NULL)
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VREF(vp);
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kth = ktrgetheader(KTR_USER);
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MALLOC(cp, caddr_t, uap->len, M_KTRACE, M_WAITOK);
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if (!copyin(uap->addr, cp, uap->len)) {
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kth->ktr_buffer = cp;
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kth->ktr_len = uap->len;
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ktrwrite(vp, kth, NULL);
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}
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if (vp)
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vrele(vp);
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FREE(kth, M_KTRACE);
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FREE(cp, M_KTRACE);
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p->p_traceflag &= ~KTRFAC_ACTIVE;
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return (0);
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#else
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return (ENOSYS);
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#endif
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}
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#ifdef KTRACE
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static int
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ktrops(td, p, ops, facs, vp)
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struct thread *td;
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struct proc *p;
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int ops, facs;
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struct vnode *vp;
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{
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struct vnode *vtmp = NULL, *newvp = NULL;
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PROC_LOCK(p);
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if (!ktrcanset(td, p)) {
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PROC_UNLOCK(p);
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return (0);
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}
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if (ops == KTROP_SET) {
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if (p->p_tracep != vp) {
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struct vnode *vtmp;
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/*
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* if trace file already in use, relinquish below
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*/
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newvp = vp;
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vtmp = p->p_tracep;
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p->p_tracep = NULL;
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}
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p->p_traceflag |= facs;
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if (td->td_ucred->cr_uid == 0)
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p->p_traceflag |= KTRFAC_ROOT;
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} else {
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/* KTROP_CLEAR */
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if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
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struct vnode *vtmp;
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/* no more tracing */
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p->p_traceflag = 0;
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vtmp = p->p_tracep;
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p->p_tracep = NULL;
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}
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}
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PROC_UNLOCK(p);
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/* Release old trace file if requested. */
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if (vtmp != NULL)
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vrele(vtmp);
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/* Setup new trace file if requested. */
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/*
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* XXX: Doing this before the PROC_UNLOCK above would result in
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* fewer lock operations but would break old behavior where the
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* above vrele() would not be traced when changing trace files.
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*/
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if (newvp != NULL) {
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VREF(newvp);
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PROC_LOCK(p);
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p->p_tracep = newvp;
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PROC_UNLOCK(p);
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}
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return (1);
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}
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static int
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ktrsetchildren(td, top, ops, facs, vp)
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struct thread *td;
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struct proc *top;
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int ops, facs;
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struct vnode *vp;
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{
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register struct proc *p;
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register int ret = 0;
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p = top;
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sx_slock(&proctree_lock);
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for (;;) {
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ret |= ktrops(td, p, ops, facs, vp);
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/*
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* If this process has children, descend to them next,
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* otherwise do any siblings, and if done with this level,
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* follow back up the tree (but not past top).
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*/
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if (!LIST_EMPTY(&p->p_children))
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p = LIST_FIRST(&p->p_children);
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else for (;;) {
|
|
if (p == top) {
|
|
sx_sunlock(&proctree_lock);
|
|
return (ret);
|
|
}
|
|
if (LIST_NEXT(p, p_sibling)) {
|
|
p = LIST_NEXT(p, p_sibling);
|
|
break;
|
|
}
|
|
p = p->p_pptr;
|
|
}
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
static void
|
|
ktrwrite(vp, kth, uio)
|
|
struct vnode *vp;
|
|
register struct ktr_header *kth;
|
|
struct uio *uio;
|
|
{
|
|
struct uio auio;
|
|
struct iovec aiov[2];
|
|
struct thread *td = curthread; /* XXX */
|
|
struct proc *p = td->td_proc; /* XXX */
|
|
struct mount *mp;
|
|
int error;
|
|
|
|
if (vp == NULL)
|
|
return;
|
|
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_td = curthread;
|
|
if (kth->ktr_len > 0) {
|
|
auio.uio_iovcnt++;
|
|
aiov[1].iov_base = kth->ktr_buffer;
|
|
aiov[1].iov_len = kth->ktr_len;
|
|
auio.uio_resid += kth->ktr_len;
|
|
if (uio != NULL)
|
|
kth->ktr_len += uio->uio_resid;
|
|
}
|
|
vn_start_write(vp, &mp, V_WAIT);
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
(void)VOP_LEASE(vp, td, td->td_ucred, LEASE_WRITE);
|
|
error = VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, td->td_ucred);
|
|
if (error == 0 && uio != NULL) {
|
|
(void)VOP_LEASE(vp, td, td->td_ucred, LEASE_WRITE);
|
|
error = VOP_WRITE(vp, uio, IO_UNIT | IO_APPEND, td->td_ucred);
|
|
}
|
|
VOP_UNLOCK(vp, 0, td);
|
|
vn_finished_write(mp);
|
|
if (!error)
|
|
return;
|
|
/*
|
|
* If error encountered, give up tracing on this vnode. XXX what
|
|
* happens to the loop if vrele() blocks?
|
|
*/
|
|
log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
|
|
error);
|
|
sx_slock(&allproc_lock);
|
|
LIST_FOREACH(p, &allproc, p_list) {
|
|
if (p->p_tracep == vp) {
|
|
p->p_tracep = NULL;
|
|
p->p_traceflag = 0;
|
|
vrele(vp);
|
|
}
|
|
}
|
|
sx_sunlock(&allproc_lock);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static int
|
|
ktrcanset(td, targetp)
|
|
struct thread *td;
|
|
struct proc *targetp;
|
|
{
|
|
|
|
PROC_LOCK_ASSERT(targetp, MA_OWNED);
|
|
if (targetp->p_traceflag & KTRFAC_ROOT &&
|
|
suser_cred(td->td_ucred, PRISON_ROOT))
|
|
return (0);
|
|
|
|
if (p_candebug(td->td_proc, targetp) != 0)
|
|
return (0);
|
|
|
|
return (1);
|
|
}
|
|
|
|
#endif /* KTRACE */
|