sys/compat/freebsd/freebsd_ptrace.c

   1 /*      $NetBSD: freebsd_ptrace.c,v 1.18 2008/11/12 12:36:10 ad Exp $   */
   2
   3 /*-
   4  * Copyright (c) 1982, 1986, 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  * (c) UNIX System Laboratories, Inc.
   7  * All or some portions of this file are derived from material licensed
   8  * to the University of California by American Telephone and Telegraph
   9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  10  * the permission of UNIX System Laboratories, Inc.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  *      from: @(#)sys_process.c 8.1 (Berkeley) 6/10/93
  37  */
  38
  39 /*-
  40  * Copyright (c) 1994 Christopher G. Demetriou.  All rights reserved.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  * 3. All advertising materials mentioning features or use of this software
  51  *    must display the following acknowledgement:
  52  *      This product includes software developed by the University of
  53  *      California, Berkeley and its contributors.
  54  * 4. Neither the name of the University nor the names of its contributors
  55  *    may be used to endorse or promote products derived from this software
  56  *    without specific prior written permission.
  57  *
  58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  68  * SUCH DAMAGE.
  69  *
  70  *      from: @(#)sys_process.c 8.1 (Berkeley) 6/10/93
  71  */
  72
  73 #include <sys/cdefs.h>
  74 __KERNEL_RCSID(0, "$NetBSD: freebsd_ptrace.c,v 1.18 2008/11/12 12:36:10 ad Exp $");
  75
  76 #include <sys/param.h>
  77 #include <sys/systm.h>
  78 #include <sys/proc.h>
  79 #include <sys/errno.h>
  80 #include <sys/ptrace.h>
  81 #include <sys/uio.h>
  82 #include <sys/mount.h>
  83 #include <sys/syscall.h>
  84 #include <sys/syscallargs.h>
  85
  86 #include <compat/sys/signal.h>
  87 #include <compat/sys/signalvar.h>
  88
  89 #include <machine/reg.h>
  90 #include <machine/freebsd_machdep.h>
  91
  92 #include <compat/common/compat_util.h>
  93 #include <compat/freebsd/freebsd_syscallargs.h>
  94 #include <compat/freebsd/freebsd_ptrace.h>
  95
  96 /*
  97  * Process debugging system call.
  98  */
  99 int
 100 freebsd_sys_ptrace(struct lwp *l, const struct freebsd_sys_ptrace_args *uap, register_t *retval)
 101 {
 102         /* {
 103                 syscallarg(int) req;
 104                 syscallarg(pid_t) pid;
 105                 syscallarg(void *) addr;
 106                 syscallarg(int) data;
 107         } */
 108         struct sys_ptrace_args npa;
 109         sy_call_t *fn = sysent[SYS_ptrace].sy_call;
 110
 111         switch (SCARG(uap, req)) {
 112 #ifdef PT_STEP
 113         case FREEBSD_PT_STEP:
 114                 SCARG(&npa, req) = PT_STEP;
 115                 SCARG(&npa, pid) = SCARG(uap, pid);
 116                 SCARG(&npa, addr) = SCARG(uap, addr);
 117                 SCARG(&npa, data) = SCARG(uap, data);
 118                 return (*fn)(l, &npa, retval);
 119 #endif
 120         case FREEBSD_PT_TRACE_ME:
 121         case FREEBSD_PT_READ_I:
 122         case FREEBSD_PT_READ_D:
 123         case FREEBSD_PT_WRITE_I:
 124         case FREEBSD_PT_WRITE_D:
 125         case FREEBSD_PT_CONTINUE:
 126         case FREEBSD_PT_KILL:
 127                 /* These requests are compatible with NetBSD */
 128                 return (*fn)(l, (const void *)uap, retval);
 129
 130 #if 0
 131 /*
 132  * XXX: I've commented out this code, it is broken on too many fronts to fix.
 133  *      1) It is doing an unlocked read-modify-write cycle on process that
 134  *         I assume might be running!
 135  *         and in code that might sleep (due to a pagefault), never mind
 136  *         what happens on an SMP system
 137  *      2) It accesses data in userspace without using copyin/out.
 138  *      3) It all looks like a nasty hack that isn't likely to work.
 139  *      4) It uses the stackgap.
 140  * dsl June 2007
 141  */
 142         case FREEBSD_PT_READ_U:
 143         case FREEBSD_PT_WRITE_U:
 144     {
 145         int error;
 146         struct {
 147                 struct reg regs;
 148                 struct fpreg fpregs;
 149         } *nrp;
 150         struct freebsd_ptrace_reg fr;
 151                 sg = stackgap_init(p, 0);
 152                 nrp = stackgap_alloc(p, &sg, sizeof(*nrp));
 153 #ifdef PT_GETREGS
 154                 SCARG(&npa, req) = PT_GETREGS;
 155                 SCARG(&npa, pid) = SCARG(uap, pid);
 156                 SCARG(&npa, addr) = (void *)&nrp->regs;
 157                 if ((error = (*fn)(l, &npa, retval)) != 0)
 158                         return error;
 159 #endif
 160 #ifdef PT_GETFPREGS
 161                 SCARG(&npa, req) = PT_GETFPREGS;
 162                 SCARG(&npa, pid) = SCARG(uap, pid);
 163                 SCARG(&npa, addr) = (void *)&nrp->fpregs;
 164                 if ((error = (*fn)(l, &npa, retval)) != 0)
 165                         return error;
 166 #endif
 167                 netbsd_to_freebsd_ptrace_regs(&nrp->regs, &nrp->fpregs, &fr);
 168                 switch (SCARG(uap, req)) {
 169                 case FREEBSD_PT_READ_U:
 170                         return freebsd_ptrace_getregs(&fr, SCARG(uap, addr),
 171                                                       retval);
 172
 173                 case FREEBSD_PT_WRITE_U:
 174                         error = freebsd_ptrace_setregs(&fr,
 175                             SCARG(uap, addr), SCARG(uap, data));
 176                         if (error)
 177                                 return error;
 178                         freebsd_to_netbsd_ptrace_regs(&fr,
 179                                                 &nrp->regs, &nrp->fpregs);
 180 #ifdef PT_SETREGS
 181                         SCARG(&npa, req) = PT_SETREGS;
 182                         SCARG(&npa, pid) = SCARG(uap, pid);
 183                         SCARG(&npa, addr) = (void *)&nrp->regs;
 184                         if ((error = (*fn)(l, &npa, retval)) != 0)
 185                                 return error;
 186 #endif
 187 #ifdef PT_SETFPREGS
 188                         SCARG(&npa, req) = PT_SETFPREGS;
 189                         SCARG(&npa, pid) = SCARG(uap, pid);
 190                         SCARG(&npa, addr) = (void *)&nrp->fpregs;
 191                         if ((error = (*fn)(l, &npa, retval)) != 0)
 192                                 return error;
 193 #endif
 194                         return 0;
 195                 }
 196     }
 197 #endif
 198
 199         default:                        /* It was not a legal request. */
 200                 return (EINVAL);
 201         }
 202
 203 #ifdef DIAGNOSTIC
 204         panic("freebsd_ptrace: impossible");
 205 #endif
 206 }