sys/vfs/procfs/procfs_regs.c

   1 /*
   2  * Copyright (c) 1993 Jan-Simon Pendry
   3  * Copyright (c) 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to Berkeley by
   7  * Jan-Simon Pendry.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed by the University of
  20  *      California, Berkeley and its contributors.
  21  * 4. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  *      @(#)procfs_regs.c       8.4 (Berkeley) 6/15/94
  38  *
  39  * From:
  40  * $FreeBSD: src/sys/miscfs/procfs/procfs_regs.c,v 1.10.2.3 2002/01/22 17:22:59 nectar Exp $
  41  * $DragonFly: src/sys/vfs/procfs/procfs_regs.c,v 1.11 2007/02/19 01:14:24 corecode Exp $
  42  */
  43
  44 #include <sys/param.h>
  45 #include <sys/proc.h>
  46 #include <sys/priv.h>
  47 #include <sys/vnode.h>
  48 #include <sys/reg.h>
  49 #include <vfs/procfs/procfs.h>
  50 #include <vm/vm.h>
  51 #include <vm/vm_extern.h>
  52
  53 int
  54 procfs_doregs(struct proc *curp, struct lwp *lp, struct pfsnode *pfs,
  55               struct uio *uio)
  56 {
  57         struct proc *p = lp->lwp_proc;
  58         int error;
  59         struct reg r;
  60         char *kv;
  61         int kl;
  62
  63         /* Can't trace a process that's currently exec'ing. */
  64         if ((p->p_flag & P_INEXEC) != 0)
  65                 return EAGAIN;
  66         if (!CHECKIO(curp, p) || p_trespass(curp->p_ucred, p->p_ucred))
  67                 return EPERM;
  68         kl = sizeof(r);
  69         kv = (char *) &r;
  70
  71         kv += uio->uio_offset;
  72         kl -= uio->uio_offset;
  73         if (kl > uio->uio_resid)
  74                 kl = uio->uio_resid;
  75
  76         LWPHOLD(lp);
  77
  78         error = procfs_read_regs(lp, &r);
  79         if (error == 0)
  80                 error = uiomove_frombuf(&r, sizeof(r), uio);
  81         if (error == 0 && uio->uio_rw == UIO_WRITE) {
  82                 if (p->p_stat != SSTOP)
  83                         error = EBUSY;
  84                 else
  85                         error = procfs_write_regs(lp, &r);
  86         }
  87         LWPRELE(lp);
  88
  89         uio->uio_offset = 0;
  90         return (error);
  91 }
  92
  93 int
  94 procfs_validregs(struct lwp *lp)
  95 {
  96         return ((lp->lwp_proc->p_flag & P_SYSTEM) == 0);
  97 }