bsd/miscfs/procfs/procfs_ctl.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*      $NetBSD: procfs_ctl.c,v 1.12 1994/06/29 06:34:46 cgd Exp $      */
  23
  24 /*
  25  * Copyright (c) 1993 Jan-Simon Pendry
  26  * Copyright (c) 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * This code is derived from software contributed to Berkeley by
  30  * Jan-Simon Pendry.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)procfs_ctl.c        8.4 (Berkeley) 6/15/94
  61  */
  62
  63 #include <sys/param.h>
  64 #include <sys/systm.h>
  65 #include <sys/time.h>
  66 #include <sys/kernel.h>
  67 #include <sys/proc.h>
  68 #include <sys/vnode.h>
  69 #include <sys/ioctl.h>
  70 #include <sys/tty.h>
  71 #include <sys/resource.h>
  72 #include <sys/resourcevar.h>
  73 #include <sys/ptrace.h>
  74 #include <miscfs/procfs/procfs.h>
  75
  76 /*
  77  * True iff process (p) is in trace wait state
  78  * relative to process (curp)
  79  */
  80 #define TRACE_WAIT_P(curp, p) \
  81         ((p)->p_stat == SSTOP && \
  82          (p)->p_pptr == (curp) && \
  83          ((p)->p_flag & P_TRACED))
  84
  85 #define PROCFS_CTL_ATTACH       1
  86 #define PROCFS_CTL_DETACH       2
  87 #define PROCFS_CTL_STEP         3
  88 #define PROCFS_CTL_RUN          4
  89 #define PROCFS_CTL_WAIT         5
  90
  91 static vfs_namemap_t ctlnames[] = {
  92         /* special /proc commands */
  93         { "attach",     PROCFS_CTL_ATTACH },
  94         { "detach",     PROCFS_CTL_DETACH },
  95         { "step",       PROCFS_CTL_STEP },
  96         { "run",        PROCFS_CTL_RUN },
  97         { "wait",       PROCFS_CTL_WAIT },
  98         { 0 },
  99 };
 100
 101 static vfs_namemap_t signames[] = {
 102         /* regular signal names */
 103         { "hup",        SIGHUP },       { "int",        SIGINT },
 104         { "quit",       SIGQUIT },      { "ill",        SIGILL },
 105         { "trap",       SIGTRAP },      { "abrt",       SIGABRT },
 106         { "iot",        SIGIOT },       { "emt",        SIGEMT },
 107         { "fpe",        SIGFPE },       { "kill",       SIGKILL },
 108         { "bus",        SIGBUS },       { "segv",       SIGSEGV },
 109         { "sys",        SIGSYS },       { "pipe",       SIGPIPE },
 110         { "alrm",       SIGALRM },      { "term",       SIGTERM },
 111         { "urg",        SIGURG },       { "stop",       SIGSTOP },
 112         { "tstp",       SIGTSTP },      { "cont",       SIGCONT },
 113         { "chld",       SIGCHLD },      { "ttin",       SIGTTIN },
 114         { "ttou",       SIGTTOU },      { "io",         SIGIO },
 115         { "xcpu",       SIGXCPU },      { "xfsz",       SIGXFSZ },
 116         { "vtalrm",     SIGVTALRM },    { "prof",       SIGPROF },
 117         { "winch",      SIGWINCH },     { "info",       SIGINFO },
 118         { "usr1",       SIGUSR1 },      { "usr2",       SIGUSR2 },
 119         { 0 },
 120 };
 121
 122 static int
 123 procfs_control(curp, p, op)
 124         struct proc *curp;
 125         struct proc *p;
 126         int op;
 127 {
 128         int error;
 129
 130         /*
 131          * Attach - attaches the target process for debugging
 132          * by the calling process.
 133          */
 134         if (op == PROCFS_CTL_ATTACH) {
 135                 /* check whether already being traced */
 136                 if (p->p_flag & P_TRACED)
 137                         return (EBUSY);
 138
 139                 /* can't trace yourself! */
 140                 if (p->p_pid == curp->p_pid)
 141                         return (EINVAL);
 142
 143                 /*
 144                  * Go ahead and set the trace flag.
 145                  * Save the old parent (it's reset in
 146                  *   _DETACH, and also in kern_exit.c:wait4()
 147                  * Reparent the process so that the tracing
 148                  *   proc gets to see all the action.
 149                  * Stop the target.
 150                  */
 151                 p->p_flag |= P_TRACED;
 152                 p->p_xstat = 0;         /* XXX ? */
 153                 if (p->p_pptr != curp) {
 154                         p->p_oppid = p->p_pptr->p_pid;
 155                         proc_reparent(p, curp);
 156                 }
 157                 psignal(p, SIGSTOP);
 158                 return (0);
 159         }
 160
 161         /*
 162          * Target process must be stopped, owned by (curp) and
 163          * be set up for tracing (P_TRACED flag set).
 164          * Allow DETACH to take place at any time for sanity.
 165          * Allow WAIT any time, of course.
 166          */
 167         switch (op) {
 168         case PROCFS_CTL_DETACH:
 169         case PROCFS_CTL_WAIT:
 170                 break;
 171
 172         default:
 173                 if (!TRACE_WAIT_P(curp, p))
 174                         return (EBUSY);
 175         }
 176
 177         /*
 178          * do single-step fixup if needed
 179          */
 180         FIX_SSTEP(p);
 181
 182         /*
 183          * Don't deliver any signal by default.
 184          * To continue with a signal, just send
 185          * the signal name to the ctl file
 186          */
 187         p->p_xstat = 0;
 188
 189         switch (op) {
 190         /*
 191          * Detach.  Cleans up the target process, reparent it if possible
 192          * and set it running once more.
 193          */
 194         case PROCFS_CTL_DETACH:
 195                 /* if not being traced, then this is a painless no-op */
 196                 if ((p->p_flag & P_TRACED) == 0)
 197                         return (0);
 198
 199                 /* not being traced any more */
 200                 p->p_flag &= ~P_TRACED;
 201
 202                 /* give process back to original parent */
 203                 if (p->p_oppid != p->p_pptr->p_pid) {
 204                         struct proc *pp;
 205
 206                         pp = pfind(p->p_oppid);
 207                         if (pp)
 208                                 proc_reparent(p, pp);
 209                 }
 210
 211                 p->p_oppid = 0;
 212                 p->p_flag &= ~P_WAITED; /* XXX ? */
 213                 wakeup((caddr_t) curp); /* XXX for CTL_WAIT below ? */
 214
 215                 break;
 216
 217         /*
 218          * Step.  Let the target process execute a single instruction.
 219          */
 220         case PROCFS_CTL_STEP:
 221                 if (error = process_sstep(p, 1))
 222                         return (error);
 223                 break;
 224
 225         /*
 226          * Run.  Let the target process continue running until a breakpoint
 227          * or some other trap.
 228          */
 229         case PROCFS_CTL_RUN:
 230                 break;
 231
 232         /*
 233          * Wait for the target process to stop.
 234          * If the target is not being traced then just wait
 235          * to enter
 236          */
 237         case PROCFS_CTL_WAIT:
 238                 error = 0;
 239                 if (p->p_flag & P_TRACED) {
 240                         while (error == 0 &&
 241                                         (p->p_stat != SSTOP) &&
 242                                         (p->p_flag & P_TRACED) &&
 243                                         (p->p_pptr == curp)) {
 244                                 error = tsleep((caddr_t) p,
 245                                                 PWAIT|PCATCH, "procfsx", 0);
 246                         }
 247                         if (error == 0 && !TRACE_WAIT_P(curp, p))
 248                                 error = EBUSY;
 249                 } else {
 250                         while (error == 0 && p->p_stat != SSTOP) {
 251                                 error = tsleep((caddr_t) p,
 252                                                 PWAIT|PCATCH, "procfs", 0);
 253                         }
 254                 }
 255                 return (error);
 256
 257         default:
 258                 panic("procfs_control");
 259         }
 260
 261         if (p->p_stat == SSTOP)
 262                 setrunnable(p);
 263         return (0);
 264 }
 265
 266 int
 267 procfs_doctl(curp, p, pfs, uio)
 268         struct proc *curp;
 269         struct pfsnode *pfs;
 270         struct uio *uio;
 271         struct proc *p;
 272 {
 273         int xlen;
 274         int error;
 275         char msg[PROCFS_CTLLEN+1];
 276         vfs_namemap_t *nm;
 277
 278         if (uio->uio_rw != UIO_WRITE)
 279                 return (EOPNOTSUPP);
 280
 281         xlen = PROCFS_CTLLEN;
 282         error = vfs_getuserstr(uio, msg, &xlen);
 283         if (error)
 284                 return (error);
 285
 286         /*
 287          * Map signal names into signal generation
 288          * or debug control.  Unknown commands and/or signals
 289          * return EOPNOTSUPP.
 290          *
 291          * Sending a signal while the process is being debugged
 292          * also has the side effect of letting the target continue
 293          * to run.  There is no way to single-step a signal delivery.
 294          */
 295         error = EOPNOTSUPP;
 296
 297         nm = vfs_findname(ctlnames, msg, xlen);
 298         if (nm) {
 299                 error = procfs_control(curp, p, nm->nm_val);
 300         } else {
 301                 nm = vfs_findname(signames, msg, xlen);
 302                 if (nm) {
 303                         if (TRACE_WAIT_P(curp, p)) {
 304                                 p->p_xstat = nm->nm_val;
 305                                 FIX_SSTEP(p);
 306                                 setrunnable(p);
 307                         } else {
 308                                 psignal(p, nm->nm_val);
 309                         }
 310                         error = 0;
 311                 }
 312         }
 313
 314         return (error);
 315 }