2 * Copyright (c) 1994, Sean Eric Fagan
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Sean Eric Fagan.
16 * 4. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * $FreeBSD: src/sys/kern/sys_process.c,v 1.51.2.6 2003/01/08 03:06:45 kan Exp $
32 * $DragonFly: src/sys/kern/sys_process.c,v 1.30 2007/02/19 01:14:23 corecode Exp $
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/sysproto.h>
40 #include <sys/vnode.h>
41 #include <sys/ptrace.h>
47 #include <vm/vm_map.h>
48 #include <vm/vm_page.h>
51 #include <vfs/procfs/procfs.h>
53 #include <sys/thread2.h>
54 #include <sys/spinlock2.h>
56 /* use the equivalent procfs code */
59 pread (struct proc *procp, unsigned int addr, unsigned int *retval) {
64 int page_offset; /* offset into page */
65 vm_offset_t pageno; /* page number */
66 vm_map_entry_t out_entry;
71 /* Map page into kernel space */
73 map = &procp->p_vmspace->vm_map;
75 page_offset = addr - trunc_page(addr);
76 pageno = trunc_page(addr);
79 rv = vm_map_lookup(&tmap, pageno, VM_PROT_READ, &out_entry,
80 &object, &pindex, &out_prot, &wired);
82 if (rv != KERN_SUCCESS)
85 vm_map_lookup_done (tmap, out_entry, 0);
87 /* Find space in kernel_map for the page we're interested in */
88 rv = vm_map_find (&kernel_map, object, IDX_TO_OFF(pindex),
92 VM_PROT_ALL, VM_PROT_ALL,
96 vm_object_reference XXX (object);
98 rv = vm_map_wire (&kernel_map, kva, kva + PAGE_SIZE, 0);
101 bcopy ((caddr_t)kva + page_offset,
102 retval, sizeof *retval);
104 vm_map_remove (&kernel_map, kva, kva + PAGE_SIZE);
111 pwrite (struct proc *procp, unsigned int addr, unsigned int datum) {
116 int page_offset; /* offset into page */
117 vm_offset_t pageno; /* page number */
118 vm_map_entry_t out_entry;
122 boolean_t fix_prot = 0;
124 /* Map page into kernel space */
126 map = &procp->p_vmspace->vm_map;
128 page_offset = addr - trunc_page(addr);
129 pageno = trunc_page(addr);
132 * Check the permissions for the area we're interested in.
135 if (vm_map_check_protection (map, pageno, pageno + PAGE_SIZE,
136 VM_PROT_WRITE, FALSE) == FALSE) {
138 * If the page was not writable, we make it so.
139 * XXX It is possible a page may *not* be read/executable,
140 * if a process changes that!
143 /* The page isn't writable, so let's try making it so... */
144 if ((rv = vm_map_protect (map, pageno, pageno + PAGE_SIZE,
145 VM_PROT_ALL, 0)) != KERN_SUCCESS)
146 return EFAULT; /* I guess... */
150 * Now we need to get the page. out_entry, out_prot, wired, and
151 * single_use aren't used. One would think the vm code would be
152 * a *bit* nicer... We use tmap because vm_map_lookup() can
153 * change the map argument.
157 rv = vm_map_lookup(&tmap, pageno, VM_PROT_WRITE, &out_entry,
158 &object, &pindex, &out_prot, &wired);
159 if (rv != KERN_SUCCESS)
163 * Okay, we've got the page. Let's release tmap.
165 vm_map_lookup_done (tmap, out_entry, 0);
168 * Fault the page in...
170 rv = vm_fault(map, pageno, VM_PROT_WRITE|VM_PROT_READ, FALSE);
171 if (rv != KERN_SUCCESS)
174 /* Find space in kernel_map for the page we're interested in */
175 rv = vm_map_find (&kernel_map, object, IDX_TO_OFF(pindex),
177 PAGE_SIZE, PAGE_SIZE,
178 0, VM_MAPTYPE_NORMAL,
179 VM_PROT_ALL, VM_PROT_ALL,
182 vm_object_reference XXX (object);
184 rv = vm_map_wire (&kernel_map, kva, kva + PAGE_SIZE, 0);
186 bcopy (&datum, (caddr_t)kva + page_offset, sizeof datum);
188 vm_map_remove (&kernel_map, kva, kva + PAGE_SIZE);
192 vm_map_protect (map, pageno, pageno + PAGE_SIZE,
193 VM_PROT_READ|VM_PROT_EXECUTE, 0);
199 * Process debugging system call.
204 sys_ptrace(struct ptrace_args *uap)
206 struct proc *p = curproc;
209 * XXX this obfuscation is to reduce stack usage, but the register
210 * structs may be too large to put on the stack anyway.
213 struct ptrace_io_desc piod;
230 error = copyin(uap->addr, &r.reg, sizeof r.reg);
233 error = copyin(uap->addr, &r.fpreg, sizeof r.fpreg);
237 error = copyin(uap->addr, &r.dbreg, sizeof r.dbreg);
241 error = copyin(uap->addr, &r.piod, sizeof r.piod);
249 error = kern_ptrace(p, uap->req, uap->pid, addr, uap->data,
250 &uap->sysmsg_result);
256 (void)copyout(&r.piod, uap->addr, sizeof r.piod);
259 error = copyout(&r.reg, uap->addr, sizeof r.reg);
262 error = copyout(&r.fpreg, uap->addr, sizeof r.fpreg);
266 error = copyout(&r.dbreg, uap->addr, sizeof r.dbreg);
275 kern_ptrace(struct proc *curp, int req, pid_t pid, void *addr,
282 struct ptrace_io_desc *piod;
287 lwkt_gettoken(&proc_token);
290 if (req == PT_TRACE_ME) {
294 if ((p = pfind(pid)) == NULL) {
295 lwkt_reltoken(&proc_token);
299 if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) {
301 lwkt_reltoken(&proc_token);
305 lwkt_gettoken(&p->p_token);
306 /* Can't trace a process that's currently exec'ing. */
307 if ((p->p_flags & P_INEXEC) != 0) {
308 lwkt_reltoken(&p->p_token);
310 lwkt_reltoken(&proc_token);
324 if (p->p_pid == curp->p_pid) {
325 lwkt_reltoken(&p->p_token);
327 lwkt_reltoken(&proc_token);
332 if (p->p_flags & P_TRACED) {
333 lwkt_reltoken(&p->p_token);
335 lwkt_reltoken(&proc_token);
339 if (curp->p_flags & P_TRACED)
340 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr)
342 lwkt_reltoken(&p->p_token);
344 lwkt_reltoken(&proc_token);
348 /* not owned by you, has done setuid (unless you're root) */
349 if ((p->p_ucred->cr_ruid != curp->p_ucred->cr_ruid) ||
350 (p->p_flags & P_SUGID)) {
351 if ((error = priv_check_cred(curp->p_ucred, PRIV_ROOT, 0)) != 0) {
352 lwkt_reltoken(&p->p_token);
354 lwkt_reltoken(&proc_token);
359 /* can't trace init when securelevel > 0 */
360 if (securelevel > 0 && p->p_pid == 1) {
361 lwkt_reltoken(&p->p_token);
363 lwkt_reltoken(&proc_token);
397 /* not being traced... */
398 if ((p->p_flags & P_TRACED) == 0) {
399 lwkt_reltoken(&p->p_token);
401 lwkt_reltoken(&proc_token);
405 /* not being traced by YOU */
406 if (p->p_pptr != curp) {
407 lwkt_reltoken(&p->p_token);
409 lwkt_reltoken(&proc_token);
413 /* not currently stopped */
414 if (p->p_stat != SSTOP ||
415 (p->p_flags & P_WAITED) == 0) {
416 lwkt_reltoken(&p->p_token);
418 lwkt_reltoken(&proc_token);
426 lwkt_reltoken(&p->p_token);
428 lwkt_reltoken(&proc_token);
433 lp = FIRST_LWP_IN_PROC(p);
436 * Single step fixup ala procfs
442 * Actually do the requests
449 /* set my trace flag and "owner" so it can read/write me */
450 p->p_flags |= P_TRACED;
451 p->p_oppid = p->p_pptr->p_pid;
452 lwkt_reltoken(&p->p_token);
454 lwkt_reltoken(&proc_token);
458 /* security check done above */
459 p->p_flags |= P_TRACED;
460 p->p_oppid = p->p_pptr->p_pid;
461 proc_reparent(p, curp);
463 goto sendsig; /* in PT_CONTINUE below */
468 /* Zero means do not send any signal */
469 if (data < 0 || data > _SIG_MAXSIG) {
470 lwkt_reltoken(&p->p_token);
472 lwkt_reltoken(&proc_token);
478 if (req == PT_STEP) {
479 if ((error = ptrace_single_step (lp))) {
481 lwkt_reltoken(&p->p_token);
483 lwkt_reltoken(&proc_token);
488 if (addr != (void *)1) {
489 if ((error = ptrace_set_pc (lp,
490 (u_long)(uintfptr_t)addr))) {
492 lwkt_reltoken(&p->p_token);
494 lwkt_reltoken(&proc_token);
500 if (req == PT_DETACH) {
501 /* reset process parent */
502 if (p->p_oppid != p->p_pptr->p_pid) {
505 pp = pfind(p->p_oppid);
507 proc_reparent(p, pp);
512 p->p_flags &= ~(P_TRACED | P_WAITED);
515 /* should we send SIGCHLD? */
520 * Deliver or queue signal. If the process is stopped
521 * force it to be SACTIVE again.
524 if (p->p_stat == SSTOP) {
531 lwkt_reltoken(&p->p_token);
533 lwkt_reltoken(&proc_token);
543 * NOTE! uio_offset represents the offset in the target
544 * process. The iov is in the current process (the guy
545 * making the ptrace call) so uio_td must be the current
546 * process (though for a SYSSPACE transfer it doesn't
550 /* write = 0 set above */
551 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
552 iov.iov_len = sizeof(int);
555 uio.uio_offset = (off_t)(uintptr_t)addr;
556 uio.uio_resid = sizeof(int);
557 uio.uio_segflg = UIO_SYSSPACE;
558 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
559 uio.uio_td = curthread;
560 error = procfs_domem(curp, lp, NULL, &uio);
561 if (uio.uio_resid != 0) {
563 * XXX procfs_domem() doesn't currently return ENOSPC,
564 * so I think write() can bogusly return 0.
565 * XXX what happens for short writes? We don't want
566 * to write partial data.
567 * XXX procfs_domem() returns EPERM for other invalid
568 * addresses. Convert this to EINVAL. Does this
569 * clobber returns of EPERM for other reasons?
571 if (error == 0 || error == ENOSPC || error == EPERM)
572 error = EINVAL; /* EOF */
576 lwkt_reltoken(&p->p_token);
578 lwkt_reltoken(&proc_token);
583 * NOTE! uio_offset represents the offset in the target
584 * process. The iov is in the current process (the guy
585 * making the ptrace call) so uio_td must be the current
589 iov.iov_base = piod->piod_addr;
590 iov.iov_len = piod->piod_len;
593 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
594 uio.uio_resid = piod->piod_len;
595 uio.uio_segflg = UIO_USERSPACE;
596 uio.uio_td = curthread;
597 switch (piod->piod_op) {
600 uio.uio_rw = UIO_READ;
604 uio.uio_rw = UIO_WRITE;
607 lwkt_reltoken(&p->p_token);
609 lwkt_reltoken(&proc_token);
612 error = procfs_domem(curp, lp, NULL, &uio);
613 piod->piod_len -= uio.uio_resid;
614 lwkt_reltoken(&p->p_token);
616 lwkt_reltoken(&proc_token);
621 goto sendsig; /* in PT_CONTINUE above */
627 #endif /* PT_SETREGS */
630 /* write = 0 above */
631 #endif /* PT_SETREGS */
632 #if defined(PT_SETREGS) || defined(PT_GETREGS)
633 if (!procfs_validregs(lp)) { /* no P_SYSTEM procs please */
634 lwkt_reltoken(&p->p_token);
636 lwkt_reltoken(&proc_token);
640 iov.iov_len = sizeof(struct reg);
644 uio.uio_resid = sizeof(struct reg);
645 uio.uio_segflg = UIO_SYSSPACE;
646 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
647 uio.uio_td = curthread;
648 t = procfs_doregs(curp, lp, NULL, &uio);
649 lwkt_reltoken(&p->p_token);
651 lwkt_reltoken(&proc_token);
654 #endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */
660 #endif /* PT_SETFPREGS */
663 /* write = 0 above */
664 #endif /* PT_SETFPREGS */
665 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
666 if (!procfs_validfpregs(lp)) { /* no P_SYSTEM procs please */
667 lwkt_reltoken(&p->p_token);
669 lwkt_reltoken(&proc_token);
673 iov.iov_len = sizeof(struct fpreg);
677 uio.uio_resid = sizeof(struct fpreg);
678 uio.uio_segflg = UIO_SYSSPACE;
679 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
680 uio.uio_td = curthread;
681 t = procfs_dofpregs(curp, lp, NULL, &uio);
682 lwkt_reltoken(&p->p_token);
684 lwkt_reltoken(&proc_token);
687 #endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */
693 #endif /* PT_SETDBREGS */
696 /* write = 0 above */
697 #endif /* PT_SETDBREGS */
698 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
699 if (!procfs_validdbregs(lp)) { /* no P_SYSTEM procs please */
700 lwkt_reltoken(&p->p_token);
702 lwkt_reltoken(&proc_token);
706 iov.iov_len = sizeof(struct dbreg);
710 uio.uio_resid = sizeof(struct dbreg);
711 uio.uio_segflg = UIO_SYSSPACE;
712 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
713 uio.uio_td = curthread;
714 t = procfs_dodbregs(curp, lp, NULL, &uio);
715 lwkt_reltoken(&p->p_token);
717 lwkt_reltoken(&proc_token);
720 #endif /* defined(PT_SETDBREGS) || defined(PT_GETDBREGS) */
726 lwkt_reltoken(&p->p_token);
728 lwkt_reltoken(&proc_token);
734 trace_req(struct proc *p)
742 * Stop a process because of a procfs event. Stay stopped until p->p_step
743 * is cleared (cleared by PIOCCONT in procfs).
748 stopevent(struct proc *p, unsigned int event, unsigned int val)
751 * Set event info. Recheck p_stops in case we are
752 * racing a close() on procfs.
754 spin_lock(&p->p_spin);
755 if ((p->p_stops & event) == 0) {
756 spin_unlock(&p->p_spin);
762 tsleep_interlock(&p->p_step, 0);
763 spin_unlock(&p->p_spin);
766 * Wakeup any PIOCWAITing procs and wait for p_step to
771 tsleep(&p->p_step, PINTERLOCKED, "stopevent", 0);
772 spin_lock(&p->p_spin);
773 if (p->p_step == 0) {
774 spin_unlock(&p->p_spin);
777 tsleep_interlock(&p->p_step, 0);
778 spin_unlock(&p->p_spin);