079b7badea
this is a low-functionality change that changes the kernel to access the main thread of a process via the linked list of threads rather than assuming that it is embedded in the process. It IS still embeded there but remove all teh code that assumes that in preparation for the next commit which will actually move it out. Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,
371 lines
9.4 KiB
C
371 lines
9.4 KiB
C
/*
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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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* $FreeBSD$
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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/lock.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/ptrace.h>
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#include <sys/sbuf.h>
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#include <sys/signalvar.h>
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#include <sys/sx.h>
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#include <sys/uio.h>
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#include <fs/pseudofs/pseudofs.h>
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#include <fs/procfs/procfs.h>
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#include <vm/vm.h>
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/*
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* True iff process (p) is in trace wait state
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* relative to process (curp)
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*/
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#define TRACE_WAIT_P(curp, p) \
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((p)->p_stat == SSTOP && \
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(p)->p_pptr == (curp) && \
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((p)->p_flag & P_TRACED))
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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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struct namemap {
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const char *nm_name;
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int nm_val;
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};
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static struct namemap 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 struct namemap 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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static int procfs_control __P((struct proc *curp, struct proc *p, int op));
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static int
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procfs_control(struct proc *curp, struct proc *p, int op)
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{
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int error = 0;
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/*
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* Authorization check: rely on normal debugging protection, except
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* allow processes to disengage debugging on a process onto which
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* they have previously attached, but no longer have permission to
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* debug.
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*/
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if (op != PROCFS_CTL_DETACH &&
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((error = p_candebug(curp, p))))
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return (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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if (op == PROCFS_CTL_ATTACH) {
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sx_xlock(&proctree_lock);
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PROC_LOCK(p);
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if (p->p_flag & P_TRACED) {
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error = EBUSY;
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goto out;
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}
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/* Can't trace yourself! */
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if (p->p_pid == curp->p_pid) {
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error = EINVAL;
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goto out;
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}
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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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p->p_flag |= P_TRACED;
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faultin(p);
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p->p_xstat = 0; /* XXX ? */
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if (p->p_pptr != curp) {
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p->p_oppid = p->p_pptr->p_pid;
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proc_reparent(p, curp);
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}
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psignal(p, SIGSTOP);
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out:
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PROC_UNLOCK(p);
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sx_xunlock(&proctree_lock);
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return (error);
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}
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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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switch (op) {
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case PROCFS_CTL_DETACH:
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case PROCFS_CTL_WAIT:
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break;
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default:
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PROC_LOCK(p);
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mtx_lock_spin(&sched_lock);
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if (!TRACE_WAIT_P(curp, p)) {
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mtx_unlock_spin(&sched_lock);
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PROC_UNLOCK(p);
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return (EBUSY);
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}
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mtx_unlock_spin(&sched_lock);
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PROC_UNLOCK(p);
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}
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#ifdef FIX_SSTEP
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/*
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* do single-step fixup if needed
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*/
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FIX_SSTEP(FIRST_THREAD_IN_PROC(p)); /* XXXKSE */
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#endif
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/*
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* Don't deliver any signal by default.
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* To continue with a signal, just send
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* the signal name to the ctl file
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*/
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PROC_LOCK(p);
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p->p_xstat = 0;
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switch (op) {
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/*
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* Detach. Cleans up the target process, reparent it if possible
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* and set it running once more.
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*/
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case PROCFS_CTL_DETACH:
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/* if not being traced, then this is a painless no-op */
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if ((p->p_flag & P_TRACED) == 0) {
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PROC_UNLOCK(p);
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return (0);
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}
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/* not being traced any more */
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p->p_flag &= ~P_TRACED;
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/* remove pending SIGTRAP, else the process will die */
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SIGDELSET(p->p_siglist, SIGTRAP);
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PROC_UNLOCK(p);
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/* give process back to original parent */
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sx_xlock(&proctree_lock);
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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_LOCK(p);
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if (pp)
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proc_reparent(p, pp);
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} else
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PROC_LOCK(p);
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p->p_oppid = 0;
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p->p_flag &= ~P_WAITED; /* XXX ? */
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PROC_UNLOCK(p);
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sx_xunlock(&proctree_lock);
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wakeup((caddr_t) curp); /* XXX for CTL_WAIT below ? */
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break;
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/*
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* Step. Let the target process execute a single instruction.
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* What does it mean to single step a threaded program?
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*/
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case PROCFS_CTL_STEP:
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PROC_UNLOCK(p);
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error = proc_sstep(FIRST_THREAD_IN_PROC(p)); /* XXXKSE */
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PRELE(p);
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if (error)
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return (error);
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break;
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/*
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* Run. Let the target process continue running until a breakpoint
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* or some other trap.
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*/
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case PROCFS_CTL_RUN:
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PROC_UNLOCK(p);
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break;
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/*
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* Wait for the target process to stop.
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* If the target is not being traced then just wait
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* to enter
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*/
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case PROCFS_CTL_WAIT:
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if (p->p_flag & P_TRACED) {
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mtx_lock_spin(&sched_lock);
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while (error == 0 &&
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(p->p_stat != SSTOP) &&
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(p->p_flag & P_TRACED) &&
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(p->p_pptr == curp)) {
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mtx_unlock_spin(&sched_lock);
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error = msleep((caddr_t) p, &p->p_mtx,
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PWAIT|PCATCH, "procfsx", 0);
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mtx_lock_spin(&sched_lock);
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}
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if (error == 0 && !TRACE_WAIT_P(curp, p))
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error = EBUSY;
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mtx_unlock_spin(&sched_lock);
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PROC_UNLOCK(p);
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} else {
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PROC_UNLOCK(p);
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mtx_lock_spin(&sched_lock);
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while (error == 0 && p->p_stat != SSTOP) {
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mtx_unlock_spin(&sched_lock);
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error = tsleep((caddr_t) p,
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PWAIT|PCATCH, "procfs", 0);
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mtx_lock_spin(&sched_lock);
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}
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mtx_unlock_spin(&sched_lock);
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}
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return (error);
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default:
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panic("procfs_control");
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}
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mtx_lock_spin(&sched_lock);
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if (p->p_stat == SSTOP)
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setrunnable(FIRST_THREAD_IN_PROC(p)); /* XXXKSE */
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mtx_unlock_spin(&sched_lock);
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return (0);
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}
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static struct namemap *
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findname(struct namemap *nm, char *buf, int buflen)
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{
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for (; nm->nm_name; nm++)
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if (bcmp(buf, nm->nm_name, buflen+1) == 0)
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return (nm);
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return (0);
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}
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int
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procfs_doprocctl(PFS_FILL_ARGS)
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{
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int error;
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struct namemap *nm;
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if (uio == NULL || uio->uio_rw != UIO_WRITE)
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return (EOPNOTSUPP);
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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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sbuf_trim(sb);
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sbuf_finish(sb);
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nm = findname(ctlnames, sbuf_data(sb), sbuf_len(sb));
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if (nm) {
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printf("procfs: got a %s command\n", sbuf_data(sb));
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error = procfs_control(td->td_proc, p, nm->nm_val);
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} else {
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nm = findname(signames, sbuf_data(sb), sbuf_len(sb));
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if (nm) {
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printf("procfs: got a sig%s\n", sbuf_data(sb));
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PROC_LOCK(p);
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mtx_lock_spin(&sched_lock);
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/* This is very broken XXXKSE */
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if (TRACE_WAIT_P(td->td_proc, p)) {
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p->p_xstat = nm->nm_val;
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#ifdef FIX_SSTEP
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FIX_SSTEP(FIRST_THREAD_IN_PROC(p)); /* XXXKSE */
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#endif
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setrunnable(FIRST_THREAD_IN_PROC(p)); /* XXXKSE */
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mtx_unlock_spin(&sched_lock);
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} else {
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mtx_unlock_spin(&sched_lock);
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psignal(p, nm->nm_val);
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}
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PROC_UNLOCK(p);
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error = 0;
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}
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}
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return (error);
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}
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