NetBSD/sys/miscfs/procfs/procfs_ctl.c

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/* $NetBSD: procfs_ctl.c,v 1.16 1997/04/28 04:49:34 mycroft Exp $ */
/*
* Copyright (c) 1993 Jan-Simon Pendry
* 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. 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/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>
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#include <sys/signalvar.h>
#include <sys/ptrace.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 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 },
{ 0 },
};
static 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 },
{ 0 },
};
int procfs_control __P((struct proc *, struct proc *, int, int));
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/* Macros to clear/set/test flags. */
#define SET(t, f) (t) |= (f)
#define CLR(t, f) (t) &= ~(f)
#define ISSET(t, f) ((t) & (f))
int
procfs_control(curp, p, op, sig)
struct proc *curp;
struct proc *p;
int op, sig;
{
int error;
/*
* Attach - attaches the target process for debugging
* by the calling process.
*/
switch (op) {
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)
return (EINVAL);
/*
* (2) it's already being traced, or
*/
if (ISSET(p->p_flag, P_TRACED))
return (EBUSY);
/*
* (3) it's not owned by you, or is set-id on exec
* (unless you're root), or...
*/
if ((p->p_cred->p_ruid != curp->p_cred->p_ruid ||
ISSET(p->p_flag, P_SUGID)) &&
(error = suser(curp->p_ucred, &curp->p_acflag)) != 0)
return (error);
/*
* (4) ...it's init, which controls the security level
* of the entire system, and the system was not
* compiled with permanently insecure mode turned
* on.
*/
if (p == initproc && securelevel > -1)
return (EPERM);
break;
/*
* Target process must be stopped, owned by (curp) and
* be set up for tracing (P_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_flag, P_TRACED))
return (EPERM);
/*
* (2) it's being traced by ptrace(2) (which has
* different signal delivery semantics), or
*/
if (!ISSET(p->p_flag, P_FSTRACE))
return (EBUSY);
/*
* (3) it's not being traced by _you_.
*/
if (p->p_pptr != curp)
return (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_flag, P_TRACED))
return (EPERM);
/*
* (2) it's being traced by ptrace(2) (which has
* different signal delivery semantics),
*/
if (!ISSET(p->p_flag, P_FSTRACE))
return (EBUSY);
/*
* (3) it's not being traced by _you_, or
*/
if (p->p_pptr != curp)
return (EBUSY);
/*
* (4) it's not currently stopped.
*/
if (p->p_stat != SSTOP || !ISSET(p->p_flag, P_WAITED))
return (EBUSY);
break;
}
/* 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_flag, P_TRACED|P_FSTRACE);
p->p_oppid = p->p_pptr->p_pid;
if (p->p_pptr != curp)
proc_reparent(p, curp);
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
PHOLD(p);
error = process_sstep(p, op == PROCFS_CTL_STEP);
PRELE(p);
if (error)
return (error);
#endif
if (op == PROCFS_CTL_DETACH) {
/* give process back to original parent */
if (p->p_oppid != p->p_pptr->p_pid) {
struct proc *pp;
pp = pfind(p->p_oppid);
proc_reparent(p, pp ? pp : initproc);
}
/* not being traced any more */
p->p_oppid = 0;
CLR(p->p_flag, P_TRACED|P_FSTRACE|P_WAITED);
}
sendsig:
/* Finally, deliver the requested signal (or none). */
if (p->p_stat == SSTOP) {
p->p_xstat = sig;
setrunnable(p);
} else {
if (sig != 0)
psignal(p, sig);
}
return (0);
case PROCFS_CTL_WAIT:
/*
* Wait for the target process to stop.
*/
while (p->p_stat != SSTOP && p->p_stat != SZOMB) {
error = tsleep(p, PWAIT|PCATCH, "procfsx", 0);
if (error)
return (error);
}
return (0);
}
panic("procfs_control");
}
int
procfs_doctl(curp, p, pfs, uio)
struct proc *curp;
struct pfsnode *pfs;
struct uio *uio;
struct proc *p;
{
int xlen;
int error;
char msg[PROCFS_CTLLEN+1];
vfs_namemap_t *nm;
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(curp, p, nm->nm_val, 0);
} else {
nm = vfs_findname(signames, msg, xlen);
if (nm) {
if (ISSET(p->p_flag, P_TRACED) &&
p->p_pptr == curp)
error = procfs_control(curp, p, PROCFS_CTL_RUN,
nm->nm_val);
else {
psignal(p, nm->nm_val);
error = 0;
}
}
}
return (error);
}