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 $
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #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>
50 #include <vfs/procfs/procfs.h>
52 #include <sys/thread2.h>
53 #include <sys/spinlock2.h>
55 /* use the equivalent procfs code */
58 pread (struct proc *procp, unsigned int addr, unsigned int *retval)
65 int page_offset; /* offset into page */
66 vm_offset_t pageno; /* page number */
67 vm_map_entry_t out_entry;
73 /* Map page into kernel space */
75 map = &procp->p_vmspace->vm_map;
77 page_offset = addr - trunc_page(addr);
78 pageno = trunc_page(addr);
81 rv = vm_map_lookup(&tmap, pageno, VM_PROT_READ, &out_entry,
82 &ba, &pindex, &pcount, &out_prot, &wflags);
89 if (rv != KERN_SUCCESS)
92 vm_map_lookup_done (tmap, out_entry, 0);
94 /* Find space in kernel_map for the page we're interested in */
95 rv = vm_map_find (&kernel_map, object, NULL,
96 IDX_TO_OFF(pindex), &kva, PAGE_SIZE,
98 VM_MAPTYPE_NORMAL, VM_SUBSYS_PROC,
99 VM_PROT_ALL, VM_PROT_ALL, 0);
102 vm_object_reference XXX (object);
104 rv = vm_map_wire (&kernel_map, kva, kva + PAGE_SIZE, 0);
107 bcopy ((caddr_t)kva + page_offset,
108 retval, sizeof *retval);
110 vm_map_remove (&kernel_map, kva, kva + PAGE_SIZE);
117 pwrite (struct proc *procp, unsigned int addr, unsigned int datum)
124 int page_offset; /* offset into page */
125 vm_offset_t pageno; /* page number */
126 vm_map_entry_t out_entry;
131 boolean_t fix_prot = 0;
133 /* Map page into kernel space */
135 map = &procp->p_vmspace->vm_map;
137 page_offset = addr - trunc_page(addr);
138 pageno = trunc_page(addr);
141 * Check the permissions for the area we're interested in.
144 if (vm_map_check_protection (map, pageno, pageno + PAGE_SIZE,
145 VM_PROT_WRITE, FALSE) == FALSE) {
147 * If the page was not writable, we make it so.
148 * XXX It is possible a page may *not* be read/executable,
149 * if a process changes that!
152 /* The page isn't writable, so let's try making it so... */
153 if ((rv = vm_map_protect (map, pageno, pageno + PAGE_SIZE,
154 VM_PROT_ALL, 0)) != KERN_SUCCESS)
155 return EFAULT; /* I guess... */
159 * Now we need to get the page. out_entry, out_prot, wflags, and
160 * single_use aren't used. One would think the vm code would be
161 * a *bit* nicer... We use tmap because vm_map_lookup() can
162 * change the map argument.
166 rv = vm_map_lookup(&tmap, pageno, VM_PROT_WRITE, &out_entry,
167 &ba, &pindex, &pcount, &out_prot, &wflags);
173 if (rv != KERN_SUCCESS)
177 * Okay, we've got the page. Let's release tmap.
179 vm_map_lookup_done (tmap, out_entry, 0);
182 * Fault the page in...
184 rv = vm_fault(map, pageno, VM_PROT_WRITE|VM_PROT_READ, FALSE);
185 if (rv != KERN_SUCCESS)
188 /* Find space in kernel_map for the page we're interested in */
189 rv = vm_map_find (&kernel_map, object, NULL,
190 IDX_TO_OFF(pindex), &kva, PAGE_SIZE,
192 VM_MAPTYPE_NORMAL, VM_SUBSYS_PROC,
193 VM_PROT_ALL, VM_PROT_ALL, 0);
195 vm_object_reference XXX (object);
197 rv = vm_map_wire (&kernel_map, kva, kva + PAGE_SIZE, 0);
199 bcopy (&datum, (caddr_t)kva + page_offset, sizeof datum);
201 vm_map_remove (&kernel_map, kva, kva + PAGE_SIZE);
205 vm_map_protect (map, pageno, pageno + PAGE_SIZE,
206 VM_PROT_READ|VM_PROT_EXECUTE, 0);
212 * Process debugging system call.
217 sys_ptrace(struct ptrace_args *uap)
219 struct proc *p = curproc;
222 * XXX this obfuscation is to reduce stack usage, but the register
223 * structs may be too large to put on the stack anyway.
226 struct ptrace_io_desc piod;
243 error = copyin(uap->addr, &r.reg, sizeof r.reg);
246 error = copyin(uap->addr, &r.fpreg, sizeof r.fpreg);
250 error = copyin(uap->addr, &r.dbreg, sizeof r.dbreg);
254 error = copyin(uap->addr, &r.piod, sizeof r.piod);
262 error = kern_ptrace(p, uap->req, uap->pid, addr, uap->data,
263 &uap->sysmsg_result);
269 (void)copyout(&r.piod, uap->addr, sizeof r.piod);
272 error = copyout(&r.reg, uap->addr, sizeof r.reg);
275 error = copyout(&r.fpreg, uap->addr, sizeof r.fpreg);
279 error = copyout(&r.dbreg, uap->addr, sizeof r.dbreg);
288 kern_ptrace(struct proc *curp, int req, pid_t pid, void *addr,
295 struct ptrace_io_desc *piod;
301 if (req == PT_TRACE_ME) {
305 if ((p = pfind(pid)) == NULL)
308 if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) {
312 if (p->p_flags & P_SYSTEM) {
317 lwkt_gettoken(&p->p_token);
318 /* Can't trace a process that's currently exec'ing. */
319 if ((p->p_flags & P_INEXEC) != 0) {
320 lwkt_reltoken(&p->p_token);
335 if (p->p_pid == curp->p_pid) {
336 lwkt_reltoken(&p->p_token);
342 if (p->p_flags & P_TRACED) {
343 lwkt_reltoken(&p->p_token);
348 if (curp->p_flags & P_TRACED)
349 for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr)
351 lwkt_reltoken(&p->p_token);
356 /* not owned by you, has done setuid (unless you're root) */
357 if ((p->p_ucred->cr_ruid != curp->p_ucred->cr_ruid) ||
358 (p->p_flags & P_SUGID)) {
359 if ((error = priv_check_cred(curp->p_ucred, PRIV_ROOT, 0)) != 0) {
360 lwkt_reltoken(&p->p_token);
366 /* can't trace init when securelevel > 0 */
367 if (securelevel > 0 && p->p_pid == 1) {
368 lwkt_reltoken(&p->p_token);
403 /* not being traced... */
404 if ((p->p_flags & P_TRACED) == 0) {
405 lwkt_reltoken(&p->p_token);
410 /* not being traced by YOU */
411 if (p->p_pptr != curp) {
412 lwkt_reltoken(&p->p_token);
417 /* not currently stopped */
418 if (p->p_stat != SSTOP ||
419 (p->p_flags & P_WAITED) == 0) {
420 lwkt_reltoken(&p->p_token);
429 lwkt_reltoken(&p->p_token);
435 lp = FIRST_LWP_IN_PROC(p);
437 lwkt_reltoken(&p->p_token);
444 * Single step fixup ala procfs
450 * Actually do the requests
457 /* set my trace flag and "owner" so it can read/write me */
458 p->p_flags |= P_TRACED;
459 p->p_oppid = p->p_pptr->p_pid;
460 lwkt_reltoken(&p->p_token);
465 /* security check done above */
466 p->p_flags |= P_TRACED;
467 p->p_oppid = p->p_pptr->p_pid;
468 proc_reparent(p, curp);
470 goto sendsig; /* in PT_CONTINUE below */
475 /* Zero means do not send any signal */
476 if (data < 0 || data > _SIG_MAXSIG) {
477 lwkt_reltoken(&p->p_token);
484 if (req == PT_STEP) {
485 if ((error = ptrace_single_step (lp))) {
487 lwkt_reltoken(&p->p_token);
493 if (addr != (void *)1) {
494 if ((error = ptrace_set_pc (lp, (u_long)addr))) {
496 lwkt_reltoken(&p->p_token);
503 if (req == PT_DETACH) {
504 /* reset process parent */
505 if (p->p_oppid != p->p_pptr->p_pid) {
508 pp = pfind(p->p_oppid);
510 proc_reparent(p, pp);
515 p->p_flags &= ~(P_TRACED | P_WAITED);
518 /* should we send SIGCHLD? */
523 * Deliver or queue signal. If the process is stopped
524 * force it to be SACTIVE again.
527 if (p->p_stat == SSTOP) {
529 proc_unstop(p, SSTOP);
534 lwkt_reltoken(&p->p_token);
545 * NOTE! uio_offset represents the offset in the target
546 * process. The iov is in the current process (the guy
547 * making the ptrace call) so uio_td must be the current
548 * process (though for a SYSSPACE transfer it doesn't
552 /* write = 0 set above */
553 iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp;
554 iov.iov_len = sizeof(int);
557 uio.uio_offset = (off_t)(uintptr_t)addr;
558 uio.uio_resid = sizeof(int);
559 uio.uio_segflg = UIO_SYSSPACE;
560 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
561 uio.uio_td = curthread;
562 error = procfs_domem(curp, lp, NULL, &uio);
563 if (uio.uio_resid != 0) {
565 * XXX procfs_domem() doesn't currently return ENOSPC,
566 * so I think write() can bogusly return 0.
567 * XXX what happens for short writes? We don't want
568 * to write partial data.
569 * XXX procfs_domem() returns EPERM for other invalid
570 * addresses. Convert this to EINVAL. Does this
571 * clobber returns of EPERM for other reasons?
573 if (error == 0 || error == ENOSPC || error == EPERM)
574 error = EINVAL; /* EOF */
578 lwkt_reltoken(&p->p_token);
584 * NOTE! uio_offset represents the offset in the target
585 * process. The iov is in the current process (the guy
586 * making the ptrace call) so uio_td must be the current
590 iov.iov_base = piod->piod_addr;
591 iov.iov_len = piod->piod_len;
594 uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
595 uio.uio_resid = piod->piod_len;
596 uio.uio_segflg = UIO_USERSPACE;
597 uio.uio_td = curthread;
598 switch (piod->piod_op) {
601 uio.uio_rw = UIO_READ;
605 uio.uio_rw = UIO_WRITE;
608 lwkt_reltoken(&p->p_token);
612 error = procfs_domem(curp, lp, NULL, &uio);
613 piod->piod_len -= uio.uio_resid;
614 lwkt_reltoken(&p->p_token);
620 goto sendsig; /* in PT_CONTINUE above */
626 #endif /* PT_SETREGS */
629 /* write = 0 above */
630 #endif /* PT_SETREGS */
631 #if defined(PT_SETREGS) || defined(PT_GETREGS)
632 if (!procfs_validregs(lp)) {
633 lwkt_reltoken(&p->p_token);
638 iov.iov_len = sizeof(struct reg);
642 uio.uio_resid = sizeof(struct reg);
643 uio.uio_segflg = UIO_SYSSPACE;
644 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
645 uio.uio_td = curthread;
646 t = procfs_doregs(curp, lp, NULL, &uio);
647 lwkt_reltoken(&p->p_token);
651 #endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */
657 #endif /* PT_SETFPREGS */
660 /* write = 0 above */
661 #endif /* PT_SETFPREGS */
662 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
663 if (!procfs_validfpregs(lp)) {
664 lwkt_reltoken(&p->p_token);
669 iov.iov_len = sizeof(struct fpreg);
673 uio.uio_resid = sizeof(struct fpreg);
674 uio.uio_segflg = UIO_SYSSPACE;
675 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
676 uio.uio_td = curthread;
677 t = procfs_dofpregs(curp, lp, NULL, &uio);
678 lwkt_reltoken(&p->p_token);
682 #endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */
688 #endif /* PT_SETDBREGS */
691 /* write = 0 above */
692 #endif /* PT_SETDBREGS */
693 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
694 if (!procfs_validdbregs(lp)) {
695 lwkt_reltoken(&p->p_token);
700 iov.iov_len = sizeof(struct dbreg);
704 uio.uio_resid = sizeof(struct dbreg);
705 uio.uio_segflg = UIO_SYSSPACE;
706 uio.uio_rw = write ? UIO_WRITE : UIO_READ;
707 uio.uio_td = curthread;
708 t = procfs_dodbregs(curp, lp, NULL, &uio);
709 lwkt_reltoken(&p->p_token);
713 #endif /* defined(PT_SETDBREGS) || defined(PT_GETDBREGS) */
719 lwkt_reltoken(&p->p_token);
726 trace_req(struct proc *p)
734 * Stop a process because of a procfs event. Stay stopped until p->p_step
735 * is cleared (cleared by PIOCCONT in procfs).
740 stopevent(struct proc *p, unsigned int event, unsigned int val)
743 * Set event info. Recheck p_stops in case we are
744 * racing a close() on procfs.
746 spin_lock(&p->p_spin);
747 if ((p->p_stops & event) == 0) {
748 spin_unlock(&p->p_spin);
754 tsleep_interlock(&p->p_step, 0);
755 spin_unlock(&p->p_spin);
758 * Wakeup any PIOCWAITing procs and wait for p_step to
763 tsleep(&p->p_step, PINTERLOCKED, "stopevent", 0);
764 spin_lock(&p->p_spin);
765 if (p->p_step == 0) {
766 spin_unlock(&p->p_spin);
769 tsleep_interlock(&p->p_step, 0);
770 spin_unlock(&p->p_spin);