/* * 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 * $FreeBSD$ */ #include #include #include #include #include #include #include #include #include #include #include /* * True iff process (p) is in trace wait state * relative to process (curp) */ #define TRACE_WAIT_P(curp, p) \ ((p)->p_stat == SSTOP && \ (p)->p_pptr == (curp) && \ ((p)->p_flag & P_TRACED)) #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 }, }; static int procfs_control __P((struct proc *curp, struct proc *p, int op)); static int procfs_control(curp, p, op) struct proc *curp; struct proc *p; int op; { int error = 0; /* * Authorization check: rely on normal debugging protection, except * allow processes to disengage debugging on a process onto which * they have previously attached, but no longer have permission to * debug. */ if (op != PROCFS_CTL_DETACH && ((error = p_candebug(curp, p)))) return (error); /* * Attach - attaches the target process for debugging * by the calling process. */ if (op == PROCFS_CTL_ATTACH) { sx_xlock(&proctree_lock); PROC_LOCK(p); if (p->p_flag & P_TRACED) { error = EBUSY; goto out; } /* Can't trace yourself! */ if (p->p_pid == curp->p_pid) { error = EINVAL; goto out; } /* * 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. */ p->p_flag |= P_TRACED; faultin(p); p->p_xstat = 0; /* XXX ? */ if (p->p_pptr != curp) { p->p_oppid = p->p_pptr->p_pid; proc_reparent(p, curp); } psignal(p, SIGSTOP); out: PROC_UNLOCK(p); sx_xunlock(&proctree_lock); return (error); } /* * 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. */ switch (op) { case PROCFS_CTL_DETACH: case PROCFS_CTL_WAIT: break; default: PROC_LOCK(p); mtx_lock_spin(&sched_lock); if (!TRACE_WAIT_P(curp, p)) { mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); return (EBUSY); } mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); } #ifdef FIX_SSTEP /* * do single-step fixup if needed */ FIX_SSTEP(&p->p_thread); /* XXXKSE */ #endif /* * Don't deliver any signal by default. * To continue with a signal, just send * the signal name to the ctl file */ PROC_LOCK(p); p->p_xstat = 0; switch (op) { /* * Detach. Cleans up the target process, reparent it if possible * and set it running once more. */ case PROCFS_CTL_DETACH: /* if not being traced, then this is a painless no-op */ if ((p->p_flag & P_TRACED) == 0) { PROC_UNLOCK(p); return (0); } /* not being traced any more */ p->p_flag &= ~P_TRACED; /* remove pending SIGTRAP, else the process will die */ SIGDELSET(p->p_siglist, SIGTRAP); PROC_UNLOCK(p); /* give process back to original parent */ sx_xlock(&proctree_lock); if (p->p_oppid != p->p_pptr->p_pid) { struct proc *pp; pp = pfind(p->p_oppid); PROC_LOCK(p); if (pp) proc_reparent(p, pp); } else PROC_LOCK(p); p->p_oppid = 0; p->p_flag &= ~P_WAITED; /* XXX ? */ PROC_UNLOCK(p); sx_xunlock(&proctree_lock); wakeup((caddr_t) curp); /* XXX for CTL_WAIT below ? */ break; /* * Step. Let the target process execute a single instruction. */ case PROCFS_CTL_STEP: _PHOLD(p); PROC_UNLOCK(p); error = proc_sstep(&p->p_thread); /* XXXKSE */ PRELE(p); if (error) return (error); break; /* * Run. Let the target process continue running until a breakpoint * or some other trap. */ case PROCFS_CTL_RUN: PROC_UNLOCK(p); break; /* * Wait for the target process to stop. * If the target is not being traced then just wait * to enter */ case PROCFS_CTL_WAIT: if (p->p_flag & P_TRACED) { mtx_lock_spin(&sched_lock); while (error == 0 && (p->p_stat != SSTOP) && (p->p_flag & P_TRACED) && (p->p_pptr == curp)) { mtx_unlock_spin(&sched_lock); error = msleep((caddr_t) p, &p->p_mtx, PWAIT|PCATCH, "procfsx", 0); mtx_lock_spin(&sched_lock); } if (error == 0 && !TRACE_WAIT_P(curp, p)) error = EBUSY; mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); } else { PROC_UNLOCK(p); mtx_lock_spin(&sched_lock); while (error == 0 && p->p_stat != SSTOP) { mtx_unlock_spin(&sched_lock); error = tsleep((caddr_t) p, PWAIT|PCATCH, "procfs", 0); mtx_lock_spin(&sched_lock); } mtx_unlock_spin(&sched_lock); } return (error); default: panic("procfs_control"); } mtx_lock_spin(&sched_lock); if (p->p_stat == SSTOP) setrunnable(&p->p_thread); /* XXXKSE */ mtx_unlock_spin(&sched_lock); return (0); } 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); } else { nm = vfs_findname(signames, msg, xlen); if (nm) { PROC_LOCK(p); mtx_lock_spin(&sched_lock); if (TRACE_WAIT_P(curp, p)) { p->p_xstat = nm->nm_val; #ifdef FIX_SSTEP FIX_SSTEP(&p->p_thread); /* XXXKSE */ #endif setrunnable(&p->p_thread); /* XXXKSE */ mtx_unlock_spin(&sched_lock); } else { mtx_unlock_spin(&sched_lock); psignal(p, nm->nm_val); } PROC_UNLOCK(p); error = 0; } } return (error); }