sys/vfs/procfs/procfs_dbregs.c

   1 /*-
   2  * Copyright (c) 1999 Brian Scott Dean, brdean@unx.sas.com.
   3  *                    All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Jan-Simon Pendry under the following copyrights and conditions:
   7  *
   8  * Copyright (c) 1993 Jan-Simon Pendry
   9  * Copyright (c) 1993
  10  *      The Regents of the University of California.  All rights reserved.
  11  *
  12  * This code is derived from software contributed to Berkeley by
  13  * Jan-Simon Pendry.
  14  *
  15  * Redistribution and use in source and binary forms, with or without
  16  * modification, are permitted provided that the following conditions
  17  * are met:
  18  * 1. Redistributions of source code must retain the above copyright
  19  *    notice, this list of conditions and the following disclaimer.
  20  * 2. Redistributions in binary form must reproduce the above copyright
  21  *    notice, this list of conditions and the following disclaimer in the
  22  *    documentation and/or other materials provided with the distribution.
  23  * 3. All advertising materials mentioning features or use of this software
  24  *    must display the following acknowledgement:
  25  *      This product includes software developed by the University of
  26  *      California, Berkeley and its contributors.
  27  * 4. Neither the name of the University nor the names of its contributors
  28  *    may be used to endorse or promote products derived from this software
  29  *    without specific prior written permission.
  30  *
  31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  41  * SUCH DAMAGE.
  42  *
  43  * $FreeBSD: src/sys/miscfs/procfs/procfs_dbregs.c,v 1.4.2.3 2002/01/22 17:22:59 nectar Exp $
  44  * $DragonFly: src/sys/vfs/procfs/procfs_dbregs.c,v 1.10 2007/02/19 01:14:24 corecode Exp $
  45  */
  46
  47 #include <sys/param.h>
  48 #include <sys/proc.h>
  49 #include <sys/priv.h>
  50 #include <sys/vnode.h>
  51 #include <sys/reg.h>
  52 #include <vfs/procfs/procfs.h>
  53 #include <vm/vm.h>
  54
  55 int
  56 procfs_dodbregs(struct proc *curp, struct lwp *lp, struct pfsnode *pfs,
  57                 struct uio *uio)
  58 {
  59         struct proc *p = lp->lwp_proc;
  60         int error;
  61         struct dbreg r;
  62         char *kv;
  63         int kl;
  64
  65         /* Can't trace a process that's currently exec'ing. */
  66         if ((p->p_flag & P_INEXEC) != 0)
  67                 return EAGAIN;
  68         if (!CHECKIO(curp, p) || p_trespass(curp->p_ucred, p->p_ucred))
  69                 return (EPERM);
  70         kl = sizeof(r);
  71         kv = (char *) &r;
  72
  73         kv += uio->uio_offset;
  74         kl -= uio->uio_offset;
  75         if (kl > uio->uio_resid)
  76                 kl = uio->uio_resid;
  77
  78         LWPHOLD(lp);
  79         error = procfs_read_dbregs(lp, &r);
  80         if (error == 0)
  81                 error = uiomove_frombuf(&r, sizeof(r), uio);
  82         if (error == 0 && uio->uio_rw == UIO_WRITE) {
  83                 if (lp->lwp_stat != LSSTOP)
  84                         error = EBUSY;
  85                 else
  86                         error = procfs_write_dbregs(lp, &r);
  87         }
  88         LWPRELE(lp);
  89
  90         uio->uio_offset = 0;
  91         return (error);
  92 }
  93
  94 int
  95 procfs_validdbregs(struct lwp *lp)
  96 {
  97         return ((lp->lwp_proc->p_flag & P_SYSTEM) == 0);
  98 }