701f15db33
* Never send a SIGCHLD to the parent if P_FSTRACE is set. * Do not permit mixing ptrace(2) and procfs; only permit using the one that was attached.
333 lines
8.6 KiB
C
333 lines
8.6 KiB
C
/* $NetBSD: procfs_ctl.c,v 1.16 1997/04/28 04:49:34 mycroft Exp $ */
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/*
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* Copyright (c) 1993 Jan-Simon Pendry
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* Copyright (c) 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Jan-Simon Pendry.
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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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* @(#)procfs_ctl.c 8.4 (Berkeley) 6/15/94
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/time.h>
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#include <sys/kernel.h>
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#include <sys/proc.h>
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#include <sys/vnode.h>
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#include <sys/ioctl.h>
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#include <sys/tty.h>
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#include <sys/resource.h>
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#include <sys/resourcevar.h>
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#include <sys/signalvar.h>
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#include <sys/ptrace.h>
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#include <miscfs/procfs/procfs.h>
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#define PROCFS_CTL_ATTACH 1
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#define PROCFS_CTL_DETACH 2
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#define PROCFS_CTL_STEP 3
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#define PROCFS_CTL_RUN 4
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#define PROCFS_CTL_WAIT 5
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static vfs_namemap_t ctlnames[] = {
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/* special /proc commands */
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{ "attach", PROCFS_CTL_ATTACH },
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{ "detach", PROCFS_CTL_DETACH },
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{ "step", PROCFS_CTL_STEP },
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{ "run", PROCFS_CTL_RUN },
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{ "wait", PROCFS_CTL_WAIT },
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{ 0 },
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};
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static vfs_namemap_t signames[] = {
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/* regular signal names */
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{ "hup", SIGHUP }, { "int", SIGINT },
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{ "quit", SIGQUIT }, { "ill", SIGILL },
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{ "trap", SIGTRAP }, { "abrt", SIGABRT },
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{ "iot", SIGIOT }, { "emt", SIGEMT },
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{ "fpe", SIGFPE }, { "kill", SIGKILL },
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{ "bus", SIGBUS }, { "segv", SIGSEGV },
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{ "sys", SIGSYS }, { "pipe", SIGPIPE },
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{ "alrm", SIGALRM }, { "term", SIGTERM },
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{ "urg", SIGURG }, { "stop", SIGSTOP },
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{ "tstp", SIGTSTP }, { "cont", SIGCONT },
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{ "chld", SIGCHLD }, { "ttin", SIGTTIN },
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{ "ttou", SIGTTOU }, { "io", SIGIO },
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{ "xcpu", SIGXCPU }, { "xfsz", SIGXFSZ },
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{ "vtalrm", SIGVTALRM }, { "prof", SIGPROF },
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{ "winch", SIGWINCH }, { "info", SIGINFO },
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{ "usr1", SIGUSR1 }, { "usr2", SIGUSR2 },
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{ 0 },
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};
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int procfs_control __P((struct proc *, struct proc *, int, int));
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/* Macros to clear/set/test flags. */
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#define SET(t, f) (t) |= (f)
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#define CLR(t, f) (t) &= ~(f)
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#define ISSET(t, f) ((t) & (f))
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int
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procfs_control(curp, p, op, sig)
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struct proc *curp;
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struct proc *p;
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int op, sig;
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{
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int error;
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/*
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* Attach - attaches the target process for debugging
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* by the calling process.
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*/
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switch (op) {
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case PROCFS_CTL_ATTACH:
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/*
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* You can't attach to a process if:
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* (1) it's the process that's doing the attaching,
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*/
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if (p->p_pid == curp->p_pid)
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return (EINVAL);
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/*
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* (2) it's already being traced, or
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*/
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if (ISSET(p->p_flag, P_TRACED))
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return (EBUSY);
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/*
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* (3) it's not owned by you, or is set-id on exec
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* (unless you're root), or...
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*/
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if ((p->p_cred->p_ruid != curp->p_cred->p_ruid ||
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ISSET(p->p_flag, P_SUGID)) &&
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(error = suser(curp->p_ucred, &curp->p_acflag)) != 0)
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return (error);
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/*
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* (4) ...it's init, which controls the security level
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* of the entire system, and the system was not
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* compiled with permanently insecure mode turned
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* on.
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*/
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if (p == initproc && securelevel > -1)
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return (EPERM);
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break;
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/*
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* Target process must be stopped, owned by (curp) and
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* be set up for tracing (P_TRACED flag set).
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* Allow DETACH to take place at any time for sanity.
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* Allow WAIT any time, of course.
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*
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* Note that the semantics of DETACH are different here
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* from ptrace(2).
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*/
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case PROCFS_CTL_DETACH:
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case PROCFS_CTL_WAIT:
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/*
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* You can't do what you want to the process if:
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* (1) It's not being traced at all,
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*/
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if (!ISSET(p->p_flag, P_TRACED))
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return (EPERM);
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/*
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* (2) it's being traced by ptrace(2) (which has
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* different signal delivery semantics), or
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*/
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if (!ISSET(p->p_flag, P_FSTRACE))
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return (EBUSY);
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/*
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* (3) it's not being traced by _you_.
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*/
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if (p->p_pptr != curp)
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return (EBUSY);
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break;
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default:
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/*
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* You can't do what you want to the process if:
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* (1) It's not being traced at all,
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*/
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if (!ISSET(p->p_flag, P_TRACED))
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return (EPERM);
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/*
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* (2) it's being traced by ptrace(2) (which has
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* different signal delivery semantics),
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*/
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if (!ISSET(p->p_flag, P_FSTRACE))
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return (EBUSY);
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/*
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* (3) it's not being traced by _you_, or
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*/
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if (p->p_pptr != curp)
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return (EBUSY);
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/*
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* (4) it's not currently stopped.
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*/
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if (p->p_stat != SSTOP || !ISSET(p->p_flag, P_WAITED))
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return (EBUSY);
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break;
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}
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/* Do single-step fixup if needed. */
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FIX_SSTEP(p);
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switch (op) {
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case PROCFS_CTL_ATTACH:
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/*
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* Go ahead and set the trace flag.
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* Save the old parent (it's reset in
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* _DETACH, and also in kern_exit.c:wait4()
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* Reparent the process so that the tracing
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* proc gets to see all the action.
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* Stop the target.
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*/
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SET(p->p_flag, P_TRACED|P_FSTRACE);
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p->p_oppid = p->p_pptr->p_pid;
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if (p->p_pptr != curp)
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proc_reparent(p, curp);
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sig = SIGSTOP;
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goto sendsig;
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#ifdef PT_STEP
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case PROCFS_CTL_STEP:
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/*
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* Step. Let the target process execute a single instruction.
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*/
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#endif
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case PROCFS_CTL_RUN:
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case PROCFS_CTL_DETACH:
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#ifdef PT_STEP
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PHOLD(p);
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error = process_sstep(p, op == PROCFS_CTL_STEP);
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PRELE(p);
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if (error)
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return (error);
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#endif
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if (op == PROCFS_CTL_DETACH) {
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/* give process back to original parent */
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if (p->p_oppid != p->p_pptr->p_pid) {
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struct proc *pp;
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pp = pfind(p->p_oppid);
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proc_reparent(p, pp ? pp : initproc);
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}
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/* not being traced any more */
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p->p_oppid = 0;
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CLR(p->p_flag, P_TRACED|P_FSTRACE|P_WAITED);
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}
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sendsig:
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/* Finally, deliver the requested signal (or none). */
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if (p->p_stat == SSTOP) {
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p->p_xstat = sig;
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setrunnable(p);
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} else {
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if (sig != 0)
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psignal(p, sig);
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}
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return (0);
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case PROCFS_CTL_WAIT:
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/*
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* Wait for the target process to stop.
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*/
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while (p->p_stat != SSTOP && p->p_stat != SZOMB) {
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error = tsleep(p, PWAIT|PCATCH, "procfsx", 0);
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if (error)
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return (error);
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}
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return (0);
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}
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panic("procfs_control");
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}
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int
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procfs_doctl(curp, p, pfs, uio)
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struct proc *curp;
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struct pfsnode *pfs;
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struct uio *uio;
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struct proc *p;
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{
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int xlen;
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int error;
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char msg[PROCFS_CTLLEN+1];
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vfs_namemap_t *nm;
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if (uio->uio_rw != UIO_WRITE)
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return (EOPNOTSUPP);
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xlen = PROCFS_CTLLEN;
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error = vfs_getuserstr(uio, msg, &xlen);
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if (error)
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return (error);
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/*
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* Map signal names into signal generation
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* or debug control. Unknown commands and/or signals
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* return EOPNOTSUPP.
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*
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* Sending a signal while the process is being debugged
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* also has the side effect of letting the target continue
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* to run. There is no way to single-step a signal delivery.
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*/
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error = EOPNOTSUPP;
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nm = vfs_findname(ctlnames, msg, xlen);
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if (nm) {
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error = procfs_control(curp, p, nm->nm_val, 0);
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} else {
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nm = vfs_findname(signames, msg, xlen);
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if (nm) {
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if (ISSET(p->p_flag, P_TRACED) &&
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p->p_pptr == curp)
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error = procfs_control(curp, p, PROCFS_CTL_RUN,
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nm->nm_val);
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else {
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psignal(p, nm->nm_val);
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error = 0;
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}
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}
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}
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return (error);
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}
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