NetBSD-5.0.2/sys/miscfs/procfs/procfs_ctl.c
/* $NetBSD: procfs_ctl.c,v 1.45 2008/04/24 18:39:25 ad Exp $ */
/*
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)procfs_ctl.c 8.4 (Berkeley) 6/15/94
*/
/*
* Copyright (c) 1993 Jan-Simon Pendry
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)procfs_ctl.c 8.4 (Berkeley) 6/15/94
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: procfs_ctl.c,v 1.45 2008/04/24 18:39:25 ad Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/resource.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/kauth.h>
#include <uvm/uvm_extern.h>
#include <miscfs/procfs/procfs.h>
#define PROCFS_CTL_ATTACH 1
#define PROCFS_CTL_DETACH 2
#define PROCFS_CTL_STEP 3
#define PROCFS_CTL_RUN 4
#define PROCFS_CTL_WAIT 5
static const vfs_namemap_t ctlnames[] = {
/* special /proc commands */
{ "attach", PROCFS_CTL_ATTACH },
{ "detach", PROCFS_CTL_DETACH },
{ "step", PROCFS_CTL_STEP },
{ "run", PROCFS_CTL_RUN },
{ "wait", PROCFS_CTL_WAIT },
{ NULL, 0 },
};
static const vfs_namemap_t signames[] = {
/* regular signal names */
{ "hup", SIGHUP }, { "int", SIGINT },
{ "quit", SIGQUIT }, { "ill", SIGILL },
{ "trap", SIGTRAP }, { "abrt", SIGABRT },
{ "iot", SIGIOT }, { "emt", SIGEMT },
{ "fpe", SIGFPE }, { "kill", SIGKILL },
{ "bus", SIGBUS }, { "segv", SIGSEGV },
{ "sys", SIGSYS }, { "pipe", SIGPIPE },
{ "alrm", SIGALRM }, { "term", SIGTERM },
{ "urg", SIGURG }, { "stop", SIGSTOP },
{ "tstp", SIGTSTP }, { "cont", SIGCONT },
{ "chld", SIGCHLD }, { "ttin", SIGTTIN },
{ "ttou", SIGTTOU }, { "io", SIGIO },
{ "xcpu", SIGXCPU }, { "xfsz", SIGXFSZ },
{ "vtalrm", SIGVTALRM }, { "prof", SIGPROF },
{ "winch", SIGWINCH }, { "info", SIGINFO },
{ "usr1", SIGUSR1 }, { "usr2", SIGUSR2 },
{ NULL, 0 },
};
static int procfs_control(struct lwp *, struct lwp *, int, int,
struct pfsnode *);
int
procfs_control(curl, l, op, sig, pfs)
struct lwp *curl;
struct lwp *l;
int op, sig;
struct pfsnode *pfs;
{
struct proc *curp = curl->l_proc;
struct proc *p = l->l_proc;
int error = 0;
mutex_enter(proc_lock);
mutex_enter(p->p_lock);
switch (op) {
/*
* Attach - attaches the target process for debugging
* by the calling process.
*/
case PROCFS_CTL_ATTACH:
/*
* You can't attach to a process if:
* (1) it's the process that's doing the attaching,
*/
if (p->p_pid == curp->p_pid) {
error = EINVAL;
break;
}
/*
* (2) it's already being traced, or
*/
if (ISSET(p->p_slflag, PSL_TRACED)) {
error = EBUSY;
break;
}
/*
* (3) the security model prevents it.
*/
if ((error = kauth_authorize_process(curl->l_cred,
KAUTH_PROCESS_PROCFS, p, pfs,
KAUTH_ARG(KAUTH_REQ_PROCESS_PROCFS_CTL), NULL)) != 0)
break;
break;
/*
* Target process must be stopped, owned by (curp) and
* be set up for tracing (PSL_TRACED flag set).
* Allow DETACH to take place at any time for sanity.
* Allow WAIT any time, of course.
*
* Note that the semantics of DETACH are different here
* from ptrace(2).
*/
case PROCFS_CTL_DETACH:
case PROCFS_CTL_WAIT:
/*
* You can't do what you want to the process if:
* (1) It's not being traced at all,
*/
if (!ISSET(p->p_slflag, PSL_TRACED)) {
error = EPERM;
break;
}
/*
* (2) it's being traced by ptrace(2) (which has
* different signal delivery semantics), or
*/
if (!ISSET(p->p_slflag, PSL_FSTRACE)) {
error = EBUSY;
break;
}
/*
* (3) it's not being traced by _you_.
*/
if (p->p_pptr != curp)
error = EBUSY;
break;
default:
/*
* You can't do what you want to the process if:
* (1) It's not being traced at all,
*/
if (!ISSET(p->p_slflag, PSL_TRACED)) {
error = EPERM;
break;
}
/*
* (2) it's being traced by ptrace(2) (which has
* different signal delivery semantics),
*/
if (!ISSET(p->p_slflag, PSL_FSTRACE)) {
error = EBUSY;
break;
}
/*
* (3) it's not being traced by _you_, or
*/
if (p->p_pptr != curp) {
error = EBUSY;
break;
}
/*
* (4) it's not currently stopped.
*/
if (p->p_stat != SSTOP || !p->p_waited /* XXXSMP */)
error = EBUSY;
break;
}
if (error != 0) {
mutex_exit(p->p_lock);
mutex_exit(proc_lock);
return (error);
}
/* Do single-step fixup if needed. */
FIX_SSTEP(p);
switch (op) {
case PROCFS_CTL_ATTACH:
/*
* Go ahead and set the trace flag.
* Save the old parent (it's reset in
* _DETACH, and also in kern_exit.c:wait4()
* Reparent the process so that the tracing
* proc gets to see all the action.
* Stop the target.
*/
SET(p->p_slflag, PSL_TRACED|PSL_FSTRACE);
p->p_opptr = p->p_pptr;
if (p->p_pptr != curp) {
if (p->p_pptr->p_lock < p->p_lock) {
if (!mutex_tryenter(p->p_pptr->p_lock)) {
mutex_exit(p->p_lock);
mutex_enter(p->p_pptr->p_lock);
}
} else if (p->p_pptr->p_lock > p->p_lock) {
mutex_enter(p->p_pptr->p_lock);
}
p->p_pptr->p_slflag |= PSL_CHTRACED;
proc_reparent(p, curp);
if (p->p_pptr->p_lock != p->p_lock)
mutex_exit(p->p_pptr->p_lock);
}
sig = SIGSTOP;
goto sendsig;
#ifdef PT_STEP
case PROCFS_CTL_STEP:
/*
* Step. Let the target process execute a single instruction.
*/
#endif
case PROCFS_CTL_RUN:
case PROCFS_CTL_DETACH:
#ifdef PT_STEP
uvm_lwp_hold(l);
/* XXXAD locking? */
error = process_sstep(l, op == PROCFS_CTL_STEP);
uvm_lwp_rele(l);
if (error)
break;
#endif
if (op == PROCFS_CTL_DETACH) {
/* give process back to original parent */
if (p->p_opptr != p->p_pptr) {
struct proc *pp = p->p_opptr;
proc_reparent(p, pp ? pp : initproc);
}
/* not being traced any more */
p->p_opptr = NULL;
CLR(p->p_slflag, PSL_TRACED|PSL_FSTRACE);
p->p_waited = 0; /* XXXSMP */
}
sendsig:
/* Finally, deliver the requested signal (or none). */
lwp_lock(l);
if (l->l_stat == LSSTOP) {
p->p_xstat = sig;
/* setrunnable() will release the lock. */
setrunnable(l);
} else {
lwp_unlock(l);
if (sig != 0) {
mutex_exit(p->p_lock);
psignal(p, sig);
mutex_enter(p->p_lock);
}
}
mutex_exit(p->p_lock);
mutex_exit(proc_lock);
return (error);
case PROCFS_CTL_WAIT:
mutex_exit(p->p_lock);
mutex_exit(proc_lock);
/*
* Wait for the target process to stop.
* XXXSMP WTF is this?
*/
while (l->l_stat != LSSTOP && P_ZOMBIE(p)) {
error = tsleep(l, PWAIT|PCATCH, "procfsx", hz);
if (error)
break;
}
return (error);
default:
panic("procfs_ctl");
/* NOTREACHED */
}
mutex_exit(p->p_lock);
mutex_exit(proc_lock);
return (error);
}
int
procfs_doctl(
struct lwp *curl,
struct lwp *l,
struct pfsnode *pfs,
struct uio *uio
)
{
struct proc *p = l->l_proc;
char msg[PROCFS_CTLLEN+1];
const vfs_namemap_t *nm;
int error;
int xlen;
if (uio->uio_rw != UIO_WRITE)
return (EOPNOTSUPP);
xlen = PROCFS_CTLLEN;
error = vfs_getuserstr(uio, msg, &xlen);
if (error)
return (error);
/*
* Map signal names into signal generation
* or debug control. Unknown commands and/or signals
* return EOPNOTSUPP.
*
* Sending a signal while the process is being debugged
* also has the side effect of letting the target continue
* to run. There is no way to single-step a signal delivery.
*/
error = EOPNOTSUPP;
nm = vfs_findname(ctlnames, msg, xlen);
if (nm) {
error = procfs_control(curl, l, nm->nm_val, 0, pfs);
} else {
nm = vfs_findname(signames, msg, xlen);
if (nm) {
if (ISSET(p->p_slflag, PSL_TRACED) &&
p->p_pptr == p)
error = procfs_control(curl, l, PROCFS_CTL_RUN,
nm->nm_val, pfs);
else {
psignal(p, nm->nm_val);
error = 0;
}
}
}
return (error);
}