d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Properly reparent traced processes when the tracer dies.

Browse Source 
Previously they were uncoditionally reparented to init. In effect
it was possible that tracee was never returned to original parent.

Reviewed by:	kib
MFC after:	1 week
This commit is contained in:
mjg 2014-08-24 09:02:16 +00:00
parent 79d2bf4036
commit eda187d10a
1 changed files with 22 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
sys/kern/kern_exit.c
View File

@ -156,7 +156,8 @@ sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
void void
exit1(struct thread *td, int rv) exit1(struct thread *td, int rv)
{ {
struct proc *p, *nq, *q; struct proc *p, *nq, *q, *t;
struct thread *tdt;
struct vnode *ttyvp = NULL; struct vnode *ttyvp = NULL;
mtx_assert(&Giant, MA_NOTOWNED); mtx_assert(&Giant, MA_NOTOWNED);
@ -437,7 +438,9 @@ exit1(struct thread *td, int rv)
WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
/* /*
* Reparent all of our children to init. * Reparent all children processes:
* - traced ones to the original parent (or init if we are that parent)
* - the rest to init
*/ */
sx_xlock(&proctree_lock); sx_xlock(&proctree_lock);
q = LIST_FIRST(&p->p_children); q = LIST_FIRST(&p->p_children);
@ -446,15 +449,23 @@ exit1(struct thread *td, int rv)
for (; q != NULL; q = nq) { for (; q != NULL; q = nq) {
nq = LIST_NEXT(q, p_sibling); nq = LIST_NEXT(q, p_sibling);
PROC_LOCK(q); PROC_LOCK(q);
proc_reparent(q, initproc);
q->p_sigparent = SIGCHLD; q->p_sigparent = SIGCHLD;
/*
* Traced processes are killed
* since their existence means someone is screwing up.
*/
if (q->p_flag & P_TRACED) {
struct thread *temp;
if (!(q->p_flag & P_TRACED)) {
proc_reparent(q, initproc);
} else {
/*
* Traced processes are killed since their existence
* means someone is screwing up.
*/
t = proc_realparent(q);
if (t == p) {
proc_reparent(q, initproc);
} else {
PROC_LOCK(t);
proc_reparent(q, t);
PROC_UNLOCK(t);
}
/* /*
* Since q was found on our children list, the * Since q was found on our children list, the
* proc_reparent() call moved q to the orphan * proc_reparent() call moved q to the orphan
@ -463,8 +474,8 @@ exit1(struct thread *td, int rv)
*/ */
clear_orphan(q); clear_orphan(q);
q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
FOREACH_THREAD_IN_PROC(q, temp) FOREACH_THREAD_IN_PROC(q, tdt)
temp->td_dbgflags &= ~TDB_SUSPEND; tdt->td_dbgflags &= ~TDB_SUSPEND;
kern_psignal(q, SIGKILL); kern_psignal(q, SIGKILL);
} }
PROC_UNLOCK(q); PROC_UNLOCK(q);