int
ptrace_machdep_dorequest(struct lwp *l, struct lwp *lt,
int req, void *addr, int data)
{
struct uio uio;
struct iovec iov;
int write = 0;
switch (req) {
default:
return EINVAL;
#ifdef COMPAT_40
case PT___SETREGS40:
write = 1;
/* FALLTHROUGH*/
case PT___GETREGS40:
if (!process_validregs(lt))
return EINVAL;
iov.iov_base = addr;
iov.iov_len = sizeof(struct __reg40);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = 0;
uio.uio_resid = sizeof(struct __reg40);
uio.uio_rw = write ? UIO_WRITE : UIO_READ;
uio.uio_vmspace = l->l_proc->p_vmspace;
return process_machdep_doregs40(l, lt, &uio);
#endif /* COMPAT_40 */
}
}
/*
* Process debugging system call.
*/
int
sys_ptrace(struct lwp *l, const struct sys_ptrace_args *uap, register_t *retval)
{
/* {
syscallarg(int) req;
syscallarg(pid_t) pid;
syscallarg(void *) addr;
syscallarg(int) data;
} */
struct proc *p = l->l_proc;
struct lwp *lt;
struct proc *t; /* target process */
struct uio uio;
struct iovec iov;
struct ptrace_io_desc piod;
struct ptrace_lwpinfo pl;
struct vmspace *vm;
int error, write, tmp, req, pheld;
int signo;
ksiginfo_t ksi;
#ifdef COREDUMP
char *path;
#endif
error = 0;
req = SCARG(uap, req);
/*
* If attaching or detaching, we need to get a write hold on the
* proclist lock so that we can re-parent the target process.
*/
mutex_enter(proc_lock);
/* "A foolish consistency..." XXX */
if (req == PT_TRACE_ME) {
t = p;
mutex_enter(t->p_lock);
} else {
/* Find the process we're supposed to be operating on. */
if ((t = p_find(SCARG(uap, pid), PFIND_LOCKED)) == NULL) {
mutex_exit(proc_lock);
return (ESRCH);
}
/* XXX-elad */
mutex_enter(t->p_lock);
error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE,
t, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
if (error) {
mutex_exit(proc_lock);
mutex_exit(t->p_lock);
return (ESRCH);
}
}
/*
* Grab a reference on the process to prevent it from execing or
* exiting.
*/
if (!rw_tryenter(&t->p_reflock, RW_READER)) {
mutex_exit(proc_lock);
mutex_exit(t->p_lock);
return EBUSY;
}
/* 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 (t->p_pid == p->p_pid) {
error = EINVAL;
break;
}
/*
* (2) it's a system process
*/
if (t->p_flag & PK_SYSTEM) {
error = EPERM;
break;
}
/*
* (3) it's already being traced, or
*/
if (ISSET(t->p_slflag, PSL_TRACED)) {
error = EBUSY;
break;
}
/*
* (4) the tracer is chrooted, and its root directory is
* not at or above the root directory of the tracee
*/
mutex_exit(t->p_lock); /* XXXSMP */
tmp = proc_isunder(t, l);
mutex_enter(t->p_lock); /* XXXSMP */
if (!tmp) {
error = EPERM;
break;
}
break;
case PT_READ_I:
case PT_READ_D:
case PT_WRITE_I:
case PT_WRITE_D:
case PT_IO:
#ifdef PT_GETREGS
case PT_GETREGS:
#endif
#ifdef PT_SETREGS
case PT_SETREGS:
#endif
#ifdef PT_GETFPREGS
case PT_GETFPREGS:
#endif
#ifdef PT_SETFPREGS
case PT_SETFPREGS:
#endif
#ifdef __HAVE_PTRACE_MACHDEP
PTRACE_MACHDEP_REQUEST_CASES
#endif
/*
* You can't read/write the memory or registers of a process
* if the tracer is chrooted, and its root directory is not at
* or above the root directory of the tracee.
*/
mutex_exit(t->p_lock); /* XXXSMP */
tmp = proc_isunder(t, l);
mutex_enter(t->p_lock); /* XXXSMP */
if (!tmp) {
error = EPERM;
break;
}
/*FALLTHROUGH*/
case PT_CONTINUE:
case PT_KILL:
case PT_DETACH:
case PT_LWPINFO:
case PT_SYSCALL:
#ifdef COREDUMP
case PT_DUMPCORE:
#endif
#ifdef PT_STEP
case PT_STEP:
#endif
/*
* You can't do what you want to the process if:
* (1) It's not being traced at all,
*/
if (!ISSET(t->p_slflag, PSL_TRACED)) {
error = EPERM;
break;
}
/*
* (2) it's being traced by procfs (which has
* different signal delivery semantics),
*/
if (ISSET(t->p_slflag, PSL_FSTRACE)) {
uprintf("file system traced\n");
error = EBUSY;
break;
}
/*
* (3) it's not being traced by _you_, or
*/
if (t->p_pptr != p) {
uprintf("parent %d != %d\n", t->p_pptr->p_pid, p->p_pid);
error = EBUSY;
break;
}
/*
* (4) it's not currently stopped.
*/
if (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */) {
uprintf("stat %d flag %d\n", t->p_stat,
!t->p_waited);
error = EBUSY;
break;
}
break;
default: /* It was not a legal request. */
error = EINVAL;
break;
}
if (error == 0)
error = kauth_authorize_process(l->l_cred,
KAUTH_PROCESS_PTRACE, t, KAUTH_ARG(req),
NULL, NULL);
if (error != 0) {
mutex_exit(proc_lock);
mutex_exit(t->p_lock);
rw_exit(&t->p_reflock);
return error;
}
/* Do single-step fixup if needed. */
FIX_SSTEP(t);
/*
* XXX NJWLWP
*
* The entire ptrace interface needs work to be useful to a
* process with multiple LWPs. For the moment, we'll kluge
* this; memory access will be fine, but register access will
* be weird.
*/
lt = LIST_FIRST(&t->p_lwps);
KASSERT(lt != NULL);
lwp_addref(lt);
/*
* Which locks do we need held? XXX Ugly.
*/
switch (req) {
#ifdef PT_STEP
case PT_STEP:
#endif
case PT_CONTINUE:
case PT_DETACH:
case PT_KILL:
case PT_SYSCALL:
case PT_ATTACH:
case PT_TRACE_ME:
pheld = 1;
break;
default:
mutex_exit(proc_lock);
mutex_exit(t->p_lock);
pheld = 0;
break;
}
/* Now do the operation. */
write = 0;
*retval = 0;
tmp = 0;
switch (req) {
case PT_TRACE_ME:
/* Just set the trace flag. */
SET(t->p_slflag, PSL_TRACED);
t->p_opptr = t->p_pptr;
break;
case PT_WRITE_I: /* XXX no separate I and D spaces */
case PT_WRITE_D:
#if defined(__HAVE_RAS)
/*
* Can't write to a RAS
*/
if (ras_lookup(t, SCARG(uap, addr)) != (void *)-1) {
error = EACCES;
break;
}
#endif
write = 1;
tmp = SCARG(uap, data);
/* FALLTHROUGH */
case PT_READ_I: /* XXX no separate I and D spaces */
case PT_READ_D:
/* write = 0 done above. */
iov.iov_base = (void *)&tmp;
iov.iov_len = sizeof(tmp);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = (off_t)(unsigned long)SCARG(uap, addr);
uio.uio_resid = sizeof(tmp);
uio.uio_rw = write ? UIO_WRITE : UIO_READ;
UIO_SETUP_SYSSPACE(&uio);
error = process_domem(l, lt, &uio);
if (!write)
*retval = tmp;
break;
case PT_IO:
error = copyin(SCARG(uap, addr), &piod, sizeof(piod));
if (error)
break;
switch (piod.piod_op) {
case PIOD_READ_D:
case PIOD_READ_I:
uio.uio_rw = UIO_READ;
break;
case PIOD_WRITE_D:
case PIOD_WRITE_I:
/*
* Can't write to a RAS
*/
if (ras_lookup(t, SCARG(uap, addr)) != (void *)-1) {
return (EACCES);
}
uio.uio_rw = UIO_WRITE;
break;
default:
error = EINVAL;
break;
}
if (error)
break;
error = proc_vmspace_getref(l->l_proc, &vm);
if (error)
break;
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)(unsigned long)piod.piod_offs;
uio.uio_resid = piod.piod_len;
uio.uio_vmspace = vm;
error = process_domem(l, lt, &uio);
piod.piod_len -= uio.uio_resid;
(void) copyout(&piod, SCARG(uap, addr), sizeof(piod));
uvmspace_free(vm);
break;
#ifdef COREDUMP
case PT_DUMPCORE:
if ((path = SCARG(uap, addr)) != NULL) {
char *dst;
int len = SCARG(uap, data);
if (len < 0 || len >= MAXPATHLEN) {
error = EINVAL;
break;
}
dst = malloc(len + 1, M_TEMP, M_WAITOK);
if ((error = copyin(path, dst, len)) != 0) {
free(dst, M_TEMP);
break;
}
path = dst;
path[len] = '\0';
}
error = coredump(lt, path);
if (path)
free(path, M_TEMP);
break;
#endif
#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:
case PT_SYSCALL:
case PT_DETACH:
if (req == PT_SYSCALL) {
if (!ISSET(t->p_slflag, PSL_SYSCALL)) {
SET(t->p_slflag, PSL_SYSCALL);
#ifdef __HAVE_SYSCALL_INTERN
(*t->p_emul->e_syscall_intern)(t);
#endif
}
} else {
if (ISSET(t->p_slflag, PSL_SYSCALL)) {
CLR(t->p_slflag, PSL_SYSCALL);
#ifdef __HAVE_SYSCALL_INTERN
(*t->p_emul->e_syscall_intern)(t);
#endif
}
}
p->p_trace_enabled = trace_is_enabled(p);
/*
* 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."
*/
/* Check that the data is a valid signal number or zero. */
if (SCARG(uap, data) < 0 || SCARG(uap, data) >= NSIG) {
error = EINVAL;
break;
}
uvm_lwp_hold(lt);
/* If the address parameter is not (int *)1, set the pc. */
if ((int *)SCARG(uap, addr) != (int *)1)
if ((error = process_set_pc(lt, SCARG(uap, addr))) != 0) {
uvm_lwp_rele(lt);
break;
}
#ifdef PT_STEP
/*
* Arrange for a single-step, if that's requested and possible.
*/
error = process_sstep(lt, req == PT_STEP);
if (error) {
uvm_lwp_rele(lt);
break;
}
#endif
uvm_lwp_rele(lt);
if (req == PT_DETACH) {
CLR(t->p_slflag, PSL_TRACED|PSL_FSTRACE|PSL_SYSCALL);
/* give process back to original parent or init */
if (t->p_opptr != t->p_pptr) {
struct proc *pp = t->p_opptr;
proc_reparent(t, pp ? pp : initproc);
}
/* not being traced any more */
t->p_opptr = NULL;
}
signo = SCARG(uap, data);
sendsig:
/* Finally, deliver the requested signal (or none). */
if (t->p_stat == SSTOP) {
/*
* Unstop the process. If it needs to take a
* signal, make all efforts to ensure that at
* an LWP runs to see it.
*/
t->p_xstat = signo;
proc_unstop(t);
} else if (signo != 0) {
KSI_INIT_EMPTY(&ksi);
ksi.ksi_signo = signo;
kpsignal2(t, &ksi);
}
break;
case PT_KILL:
/* just send the process a KILL signal. */
signo = SIGKILL;
goto sendsig; /* in PT_CONTINUE, above. */
case PT_ATTACH:
/*
* 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.
*/
t->p_opptr = t->p_pptr;
if (t->p_pptr != p) {
struct proc *parent = t->p_pptr;
if (parent->p_lock < t->p_lock) {
if (!mutex_tryenter(parent->p_lock)) {
mutex_exit(t->p_lock);
mutex_enter(parent->p_lock);
}
} else if (parent->p_lock > t->p_lock) {
mutex_enter(parent->p_lock);
}
parent->p_slflag |= PSL_CHTRACED;
proc_reparent(t, p);
if (parent->p_lock != t->p_lock)
mutex_exit(parent->p_lock);
}
SET(t->p_slflag, PSL_TRACED);
signo = SIGSTOP;
goto sendsig;
case PT_LWPINFO:
if (SCARG(uap, data) != sizeof(pl)) {
error = EINVAL;
break;
}
error = copyin(SCARG(uap, addr), &pl, sizeof(pl));
if (error)
break;
tmp = pl.pl_lwpid;
lwp_delref(lt);
mutex_enter(t->p_lock);
if (tmp == 0)
lt = LIST_FIRST(&t->p_lwps);
else {
lt = lwp_find(t, tmp);
if (lt == NULL) {
mutex_exit(t->p_lock);
error = ESRCH;
break;
}
lt = LIST_NEXT(lt, l_sibling);
}
while (lt != NULL && lt->l_stat == LSZOMB)
lt = LIST_NEXT(lt, l_sibling);
pl.pl_lwpid = 0;
pl.pl_event = 0;
if (lt) {
lwp_addref(lt);
pl.pl_lwpid = lt->l_lid;
if (lt->l_lid == t->p_sigctx.ps_lwp)
pl.pl_event = PL_EVENT_SIGNAL;
}
mutex_exit(t->p_lock);
error = copyout(&pl, SCARG(uap, addr), sizeof(pl));
break;
#ifdef PT_SETREGS
case PT_SETREGS:
write = 1;
#endif
#ifdef PT_GETREGS
case PT_GETREGS:
/* write = 0 done above. */
#endif
#if defined(PT_SETREGS) || defined(PT_GETREGS)
tmp = SCARG(uap, data);
if (tmp != 0 && t->p_nlwps > 1) {
lwp_delref(lt);
mutex_enter(t->p_lock);
lt = lwp_find(t, tmp);
if (lt == NULL) {
mutex_exit(t->p_lock);
error = ESRCH;
break;
}
lwp_addref(lt);
mutex_exit(t->p_lock);
}
if (!process_validregs(lt))
error = EINVAL;
else {
error = proc_vmspace_getref(l->l_proc, &vm);
if (error)
break;
iov.iov_base = SCARG(uap, addr);
iov.iov_len = sizeof(struct reg);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = 0;
uio.uio_resid = sizeof(struct reg);
uio.uio_rw = write ? UIO_WRITE : UIO_READ;
uio.uio_vmspace = vm;
error = process_doregs(l, lt, &uio);
uvmspace_free(vm);
}
break;
#endif
#ifdef PT_SETFPREGS
case PT_SETFPREGS:
write = 1;
#endif
#ifdef PT_GETFPREGS
case PT_GETFPREGS:
/* write = 0 done above. */
#endif
#if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
tmp = SCARG(uap, data);
if (tmp != 0 && t->p_nlwps > 1) {
lwp_delref(lt);
mutex_enter(t->p_lock);
lt = lwp_find(t, tmp);
if (lt == NULL) {
mutex_exit(t->p_lock);
error = ESRCH;
break;
}
lwp_addref(lt);
mutex_exit(t->p_lock);
}
if (!process_validfpregs(lt))
error = EINVAL;
else {
error = proc_vmspace_getref(l->l_proc, &vm);
if (error)
break;
iov.iov_base = SCARG(uap, addr);
iov.iov_len = sizeof(struct fpreg);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = 0;
uio.uio_resid = sizeof(struct fpreg);
uio.uio_rw = write ? UIO_WRITE : UIO_READ;
uio.uio_vmspace = vm;
error = process_dofpregs(l, lt, &uio);
uvmspace_free(vm);
}
break;
#endif
#ifdef __HAVE_PTRACE_MACHDEP
PTRACE_MACHDEP_REQUEST_CASES
error = ptrace_machdep_dorequest(l, lt,
req, SCARG(uap, addr), SCARG(uap, data));
break;
#endif
}
if (pheld) {
mutex_exit(t->p_lock);
mutex_exit(proc_lock);
}
if (lt != NULL)
lwp_delref(lt);
rw_exit(&t->p_reflock);
return error;
}
