int
process_domem(struct proc *curp, struct proc *p, struct uio *uio, int req)
{
struct vmspace *vm;
int error;
vaddr_t addr;
vsize_t len;
len = uio->uio_resid;
if (len == 0)
return (0);
if ((error = process_checkioperm(curp, p->p_p)) != 0)
return (error);
/* XXXCDC: how should locking work here? */
if ((p->p_p->ps_flags & PS_EXITING) || (p->p_vmspace->vm_refcnt < 1))
return(EFAULT);
addr = uio->uio_offset;
vm = p->p_vmspace;
vm->vm_refcnt++;
error = uvm_io(&vm->vm_map, uio,
(req == PT_WRITE_I) ? UVM_IO_FIXPROT : 0);
uvmspace_free(vm);
if (error == 0 && req == PT_WRITE_I)
pmap_proc_iflush(p, addr, len);
return (error);
}
/*
* set things up for doing i/o on
* the pfsnode (vp). (vp) is locked
* on entry, and should be left locked
* on exit.
*
* for procfs we don't need to do anything
* in particular for i/o. all that is done
* is to support exclusive open on process
* memory images.
*/
int
procfs_open(void *v)
{
struct vop_open_args *ap = v;
struct pfsnode *pfs = VTOPFS(ap->a_vp);
struct proc *p1 = ap->a_p; /* tracer */
struct proc *p2; /* traced */
int error;
if ((p2 = pfind(pfs->pfs_pid)) == 0)
return (ENOENT); /* was ESRCH, jsp */
switch (pfs->pfs_type) {
case Pmem:
if (((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL)) ||
((pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE)))
return (EBUSY);
if ((error = process_checkioperm(p1, p2)) != 0)
return (error);
if (ap->a_mode & FWRITE)
pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL);
return (0);
default:
break;
}
return (0);
}
/*
* Process debugging system call.
*/
int
sys_ptrace(struct proc *p, void *v, register_t *retval)
{
struct sys_ptrace_args /* {
syscallarg(int) req;
syscallarg(pid_t) pid;
syscallarg(caddr_t) addr;
syscallarg(int) data;
} */ *uap = v;
struct proc *t; /* target thread */
struct process *tr; /* target process */
struct uio uio;
struct iovec iov;
struct ptrace_io_desc piod;
struct ptrace_event pe;
struct ptrace_thread_state pts;
struct reg *regs;
#if defined (PT_SETFPREGS) || defined (PT_GETFPREGS)
struct fpreg *fpregs;
#endif
#if defined (PT_SETXMMREGS) || defined (PT_GETXMMREGS)
struct xmmregs *xmmregs;
#endif
#ifdef PT_WCOOKIE
register_t wcookie;
#endif
int error, write;
int temp;
int req = SCARG(uap, req);
int s;
/* "A foolish consistency..." XXX */
switch (req) {
case PT_TRACE_ME:
t = p;
break;
/* calls that only operate on the PID */
case PT_READ_I:
case PT_READ_D:
case PT_WRITE_I:
case PT_WRITE_D:
case PT_KILL:
case PT_ATTACH:
case PT_IO:
case PT_SET_EVENT_MASK:
case PT_GET_EVENT_MASK:
case PT_GET_PROCESS_STATE:
case PT_GET_THREAD_FIRST:
case PT_GET_THREAD_NEXT:
default:
/* Find the process we're supposed to be operating on. */
if ((t = pfind(SCARG(uap, pid))) == NULL)
return (ESRCH);
if (t->p_flag & P_THREAD)
return (ESRCH);
break;
/* calls that accept a PID or a thread ID */
case PT_CONTINUE:
case PT_DETACH:
#ifdef PT_STEP
case PT_STEP:
#endif
case PT_GETREGS:
case PT_SETREGS:
#ifdef PT_GETFPREGS
case PT_GETFPREGS:
#endif
#ifdef PT_SETFPREGS
case PT_SETFPREGS:
#endif
#ifdef PT_GETXMMREGS
case PT_GETXMMREGS:
#endif
#ifdef PT_SETXMMREGS
case PT_SETXMMREGS:
#endif
if (SCARG(uap, pid) > THREAD_PID_OFFSET) {
t = pfind(SCARG(uap, pid) - THREAD_PID_OFFSET);
if (t == NULL)
return (ESRCH);
} else {
if ((t = pfind(SCARG(uap, pid))) == NULL)
return (ESRCH);
if (t->p_flag & P_THREAD)
return (ESRCH);
}
break;
}
tr = t->p_p;
if ((tr->ps_flags & PS_INEXEC) != 0)
return (EAGAIN);
/* Make sure we can operate on it. */
switch (req) {
case PT_TRACE_ME:
/* Saying that you're being traced is always legal. */
break;
case PT_ATTACH:
/*
* You can't attach to a process if:
* (1) it's the process that's doing the attaching,
*/
if (tr == p->p_p)
return (EINVAL);
/*
* (2) it's a system process
*/
if (ISSET(tr->ps_flags, PS_SYSTEM))
return (EPERM);
/*
* (3) it's already being traced, or
*/
if (ISSET(tr->ps_flags, PS_TRACED))
return (EBUSY);
/*
* (4) it's not owned by you, or the last exec
* gave us setuid/setgid privs (unless
* you're root), or...
*
* [Note: once PS_SUGID or PS_SUGIDEXEC gets set in
* execve(), they stay set until the process does
* another execve(). Hence this prevents a setuid
* process which revokes its special privileges using
* setuid() from being traced. This is good security.]
*/
if ((tr->ps_ucred->cr_ruid != p->p_ucred->cr_ruid ||
ISSET(tr->ps_flags, PS_SUGIDEXEC | PS_SUGID)) &&
(error = suser(p, 0)) != 0)
return (error);
/*
* (4.5) it's not a child of the tracing process.
*/
if (global_ptrace == 0 && !inferior(tr, p->p_p) &&
(error = suser(p, 0)) != 0)
return (error);
/*
* (5) ...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 ((tr->ps_pid == 1) && (securelevel > -1))
return (EPERM);
/*
* (6) it's an ancestor of the current process and
* not init (because that would create a loop in
* the process graph).
*/
if (tr->ps_pid != 1 && inferior(p->p_p, tr))
return (EINVAL);
break;
case PT_READ_I:
case PT_READ_D:
case PT_WRITE_I:
case PT_WRITE_D:
case PT_IO:
case PT_CONTINUE:
case PT_KILL:
case PT_DETACH:
#ifdef PT_STEP
case PT_STEP:
#endif
case PT_SET_EVENT_MASK:
case PT_GET_EVENT_MASK:
case PT_GET_PROCESS_STATE:
case PT_GETREGS:
case PT_SETREGS:
#ifdef PT_GETFPREGS
case PT_GETFPREGS:
#endif
#ifdef PT_SETFPREGS
case PT_SETFPREGS:
#endif
#ifdef PT_GETXMMREGS
case PT_GETXMMREGS:
#endif
#ifdef PT_SETXMMREGS
case PT_SETXMMREGS:
#endif
#ifdef PT_WCOOKIE
case PT_WCOOKIE:
#endif
/*
* You can't do what you want to the process if:
* (1) It's not being traced at all,
*/
if (!ISSET(tr->ps_flags, PS_TRACED))
return (EPERM);
/*
* (2) it's not being traced by _you_, or
*/
if (tr->ps_pptr != p->p_p)
return (EBUSY);
/*
* (3) it's not currently stopped.
*/
if (t->p_stat != SSTOP || !ISSET(tr->ps_flags, PS_WAITED))
return (EBUSY);
break;
case PT_GET_THREAD_FIRST:
case PT_GET_THREAD_NEXT:
/*
* You can't do what you want to the process if:
* (1) It's not being traced at all,
*/
if (!ISSET(tr->ps_flags, PS_TRACED))
return (EPERM);
/*
* (2) it's not being traced by _you_, or
*/
if (tr->ps_pptr != p->p_p)
return (EBUSY);
/*
* Do the work here because the request isn't actually
* associated with 't'
*/
if (SCARG(uap, data) != sizeof(pts))
return (EINVAL);
if (req == PT_GET_THREAD_NEXT) {
error = copyin(SCARG(uap, addr), &pts, sizeof(pts));
if (error)
return (error);
t = pfind(pts.pts_tid - THREAD_PID_OFFSET);
if (t == NULL || ISSET(t->p_flag, P_WEXIT))
return (ESRCH);
if (t->p_p != tr)
return (EINVAL);
t = TAILQ_NEXT(t, p_thr_link);
} else {
t = TAILQ_FIRST(&tr->ps_threads);
}
if (t == NULL)
pts.pts_tid = -1;
else
pts.pts_tid = t->p_pid + THREAD_PID_OFFSET;
return (copyout(&pts, SCARG(uap, addr), sizeof(pts)));
default: /* It was not a legal request. */
return (EINVAL);
}
/* Do single-step fixup if needed. */
FIX_SSTEP(t);
/* Now do the operation. */
write = 0;
*retval = 0;
switch (req) {
case PT_TRACE_ME:
/* Just set the trace flag. */
atomic_setbits_int(&tr->ps_flags, PS_TRACED);
tr->ps_oppid = tr->ps_pptr->ps_pid;
if (tr->ps_ptstat == NULL)
tr->ps_ptstat = malloc(sizeof(*tr->ps_ptstat),
M_SUBPROC, M_WAITOK);
memset(tr->ps_ptstat, 0, sizeof(*tr->ps_ptstat));
return (0);
case PT_WRITE_I: /* XXX no separate I and D spaces */
case PT_WRITE_D:
write = 1;
temp = SCARG(uap, data);
case PT_READ_I: /* XXX no separate I and D spaces */
case PT_READ_D:
/* write = 0 done above. */
iov.iov_base = (caddr_t)&temp;
iov.iov_len = sizeof(int);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = (off_t)(vaddr_t)SCARG(uap, addr);
uio.uio_resid = sizeof(int);
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_rw = write ? UIO_WRITE : UIO_READ;
uio.uio_procp = p;
error = process_domem(p, t, &uio, write ? PT_WRITE_I :
PT_READ_I);
if (write == 0)
*retval = temp;
return (error);
case PT_IO:
error = copyin(SCARG(uap, addr), &piod, sizeof(piod));
if (error)
return (error);
iov.iov_base = piod.piod_addr;
iov.iov_len = piod.piod_len;
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = (off_t)(vaddr_t)piod.piod_offs;
uio.uio_resid = piod.piod_len;
uio.uio_segflg = UIO_USERSPACE;
uio.uio_procp = p;
switch (piod.piod_op) {
case PIOD_READ_I:
req = PT_READ_I;
uio.uio_rw = UIO_READ;
break;
case PIOD_READ_D:
req = PT_READ_D;
uio.uio_rw = UIO_READ;
break;
case PIOD_WRITE_I:
req = PT_WRITE_I;
uio.uio_rw = UIO_WRITE;
break;
case PIOD_WRITE_D:
req = PT_WRITE_D;
uio.uio_rw = UIO_WRITE;
break;
case PIOD_READ_AUXV:
req = PT_READ_D;
uio.uio_rw = UIO_READ;
temp = tr->ps_emul->e_arglen * sizeof(char *);
if (uio.uio_offset > temp)
return (EIO);
if (uio.uio_resid > temp - uio.uio_offset)
uio.uio_resid = temp - uio.uio_offset;
piod.piod_len = iov.iov_len = uio.uio_resid;
error = process_auxv_offset(p, t, &uio);
if (error)
return (error);
break;
default:
return (EINVAL);
}
error = process_domem(p, t, &uio, req);
piod.piod_len -= uio.uio_resid;
(void) copyout(&piod, SCARG(uap, addr), sizeof(piod));
return (error);
#ifdef PT_STEP
case PT_STEP:
/*
* From the 4.4BSD PRM:
* "Execution continues as in request PT_CONTINUE; however
* as soon as possible after execution of at least one
* instruction, execution stops again. [ ... ]"
*/
#endif
case PT_CONTINUE:
/*
* From the 4.4BSD PRM:
* "The data argument is taken as a signal number and the
* child's execution continues at location addr as if it
* incurred that signal. Normally the signal number will
* be either 0 to indicate that the signal that caused the
* stop should be ignored, or that value fetched out of
* the process's image indicating which signal caused
* the stop. If addr is (int *)1 then execution continues
* from where it stopped."
*/
if (SCARG(uap, pid) < THREAD_PID_OFFSET && tr->ps_single)
t = tr->ps_single;
/* Check that the data is a valid signal number or zero. */
if (SCARG(uap, data) < 0 || SCARG(uap, data) >= NSIG)
return (EINVAL);
/* If the address parameter is not (int *)1, set the pc. */
if ((int *)SCARG(uap, addr) != (int *)1)
if ((error = process_set_pc(t, SCARG(uap, addr))) != 0)
goto relebad;
#ifdef PT_STEP
/*
* Arrange for a single-step, if that's requested and possible.
*/
error = process_sstep(t, req == PT_STEP);
if (error)
goto relebad;
#endif
goto sendsig;
case PT_DETACH:
/*
* From the 4.4BSD PRM:
* "The data argument is taken as a signal number and the
* child's execution continues at location addr as if it
* incurred that signal. Normally the signal number will
* be either 0 to indicate that the signal that caused the
* stop should be ignored, or that value fetched out of
* the process's image indicating which signal caused
* the stop. If addr is (int *)1 then execution continues
* from where it stopped."
*/
if (SCARG(uap, pid) < THREAD_PID_OFFSET && tr->ps_single)
t = tr->ps_single;
/* Check that the data is a valid signal number or zero. */
if (SCARG(uap, data) < 0 || SCARG(uap, data) >= NSIG)
return (EINVAL);
#ifdef PT_STEP
/*
* Arrange for a single-step, if that's requested and possible.
*/
error = process_sstep(t, req == PT_STEP);
if (error)
goto relebad;
#endif
/* give process back to original parent or init */
if (tr->ps_oppid != tr->ps_pptr->ps_pid) {
struct process *ppr;
ppr = prfind(tr->ps_oppid);
proc_reparent(tr, ppr ? ppr : initprocess);
}
/* not being traced any more */
tr->ps_oppid = 0;
atomic_clearbits_int(&tr->ps_flags, PS_TRACED|PS_WAITED);
sendsig:
memset(tr->ps_ptstat, 0, sizeof(*tr->ps_ptstat));
/* Finally, deliver the requested signal (or none). */
if (t->p_stat == SSTOP) {
t->p_xstat = SCARG(uap, data);
SCHED_LOCK(s);
setrunnable(t);
SCHED_UNLOCK(s);
} else {
if (SCARG(uap, data) != 0)
psignal(t, SCARG(uap, data));
}
return (0);
relebad:
return (error);
case PT_KILL:
if (SCARG(uap, pid) < THREAD_PID_OFFSET && tr->ps_single)
t = tr->ps_single;
/* just send the process a KILL signal. */
SCARG(uap, data) = SIGKILL;
goto sendsig; /* in PT_CONTINUE, above. */
case PT_ATTACH:
/*
* As was done in procfs:
* 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.
*/
atomic_setbits_int(&tr->ps_flags, PS_TRACED);
tr->ps_oppid = tr->ps_pptr->ps_pid;
if (tr->ps_pptr != p->p_p)
proc_reparent(tr, p->p_p);
if (tr->ps_ptstat == NULL)
tr->ps_ptstat = malloc(sizeof(*tr->ps_ptstat),
M_SUBPROC, M_WAITOK);
SCARG(uap, data) = SIGSTOP;
goto sendsig;
case PT_GET_EVENT_MASK:
if (SCARG(uap, data) != sizeof(pe))
return (EINVAL);
memset(&pe, 0, sizeof(pe));
pe.pe_set_event = tr->ps_ptmask;
return (copyout(&pe, SCARG(uap, addr), sizeof(pe)));
case PT_SET_EVENT_MASK:
if (SCARG(uap, data) != sizeof(pe))
return (EINVAL);
if ((error = copyin(SCARG(uap, addr), &pe, sizeof(pe))))
return (error);
tr->ps_ptmask = pe.pe_set_event;
return (0);
case PT_GET_PROCESS_STATE:
if (SCARG(uap, data) != sizeof(*tr->ps_ptstat))
return (EINVAL);
if (tr->ps_single)
tr->ps_ptstat->pe_tid =
tr->ps_single->p_pid + THREAD_PID_OFFSET;
return (copyout(tr->ps_ptstat, SCARG(uap, addr),
sizeof(*tr->ps_ptstat)));
case PT_SETREGS:
KASSERT((p->p_flag & P_SYSTEM) == 0);
if ((error = process_checkioperm(p, tr)) != 0)
return (error);
regs = malloc(sizeof(*regs), M_TEMP, M_WAITOK);
error = copyin(SCARG(uap, addr), regs, sizeof(*regs));
if (error == 0) {
error = process_write_regs(t, regs);
}
free(regs, M_TEMP, sizeof(*regs));
return (error);
case PT_GETREGS:
KASSERT((p->p_flag & P_SYSTEM) == 0);
if ((error = process_checkioperm(p, tr)) != 0)
return (error);
regs = malloc(sizeof(*regs), M_TEMP, M_WAITOK);
error = process_read_regs(t, regs);
if (error == 0)
error = copyout(regs,
SCARG(uap, addr), sizeof (*regs));
free(regs, M_TEMP, sizeof(*regs));
return (error);
#ifdef PT_SETFPREGS
case PT_SETFPREGS:
KASSERT((p->p_flag & P_SYSTEM) == 0);
if ((error = process_checkioperm(p, tr)) != 0)
return (error);
fpregs = malloc(sizeof(*fpregs), M_TEMP, M_WAITOK);
error = copyin(SCARG(uap, addr), fpregs, sizeof(*fpregs));
if (error == 0) {
error = process_write_fpregs(t, fpregs);
}
free(fpregs, M_TEMP, sizeof(*fpregs));
return (error);
#endif
#ifdef PT_GETFPREGS
case PT_GETFPREGS:
KASSERT((p->p_flag & P_SYSTEM) == 0);
if ((error = process_checkioperm(p, tr)) != 0)
return (error);
fpregs = malloc(sizeof(*fpregs), M_TEMP, M_WAITOK);
error = process_read_fpregs(t, fpregs);
if (error == 0)
error = copyout(fpregs,
SCARG(uap, addr), sizeof(*fpregs));
free(fpregs, M_TEMP, sizeof(*fpregs));
return (error);
#endif
#ifdef PT_SETXMMREGS
case PT_SETXMMREGS:
KASSERT((p->p_flag & P_SYSTEM) == 0);
if ((error = process_checkioperm(p, tr)) != 0)
return (error);
xmmregs = malloc(sizeof(*xmmregs), M_TEMP, M_WAITOK);
error = copyin(SCARG(uap, addr), xmmregs, sizeof(*xmmregs));
if (error == 0) {
error = process_write_xmmregs(t, xmmregs);
}
free(xmmregs, M_TEMP, sizeof(*xmmregs));
return (error);
#endif
#ifdef PT_GETXMMREGS
case PT_GETXMMREGS:
KASSERT((p->p_flag & P_SYSTEM) == 0);
if ((error = process_checkioperm(p, tr)) != 0)
return (error);
xmmregs = malloc(sizeof(*xmmregs), M_TEMP, M_WAITOK);
error = process_read_xmmregs(t, xmmregs);
if (error == 0)
error = copyout(xmmregs,
SCARG(uap, addr), sizeof(*xmmregs));
free(xmmregs, M_TEMP, sizeof(*xmmregs));
return (error);
#endif
#ifdef PT_WCOOKIE
case PT_WCOOKIE:
wcookie = process_get_wcookie (t);
return (copyout(&wcookie, SCARG(uap, addr),
sizeof (register_t)));
#endif
}
#ifdef DIAGNOSTIC
panic("ptrace: impossible");
#endif
return 0;
}