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| author | kib <kib@FreeBSD.org> | 2015-01-05 03:27:09 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2015-01-05 03:27:09 +0000 |
| commit | 5777edec4a4de6b756dc614129b8c3ac1605481d (patch) | |
| tree | 6960c9f306d6b65c6d55b3a1dab46a3fe4eb9100 /sys/kern/kern_fork.c | |
| parent | 6e9fd215c729431fe469e85f7af8fc605988227d (diff) | |
| download | FreeBSD-src-5777edec4a4de6b756dc614129b8c3ac1605481d.zip FreeBSD-src-5777edec4a4de6b756dc614129b8c3ac1605481d.tar.gz | |
Merge reaper facility.
MFC r270443 (by mjg):
Properly reparent traced processes when the tracer dies.
MFC r273452 (by mjg):
Plug unnecessary PRS_NEW check in kern_procctl.
MFC 275800:
Add a facility for non-init process to declare itself the reaper of
the orphaned descendants.
MFC r275821:
Add missed break.
MFC r275846 (by mckusick):
Add some additional clarification and fix a few gammer nits.
MFC r275847 (by bdrewery):
Bump Dd for r275846.
Diffstat (limited to 'sys/kern/kern_fork.c')
| -rw-r--r-- | sys/kern/kern_fork.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c index d3a7741..2a83327 100644 --- a/sys/kern/kern_fork.c +++ b/sys/kern/kern_fork.c @@ -267,11 +267,21 @@ retry: * Scan the active and zombie procs to check whether this pid * is in use. Remember the lowest pid that's greater * than trypid, so we can avoid checking for a while. + * + * Avoid reuse of the process group id, session id or + * the reaper subtree id. Note that for process group + * and sessions, the amount of reserved pids is + * limited by process limit. For the subtree ids, the + * id is kept reserved only while there is a + * non-reaped process in the subtree, so amount of + * reserved pids is limited by process limit times + * two. */ p = LIST_FIRST(&allproc); again: for (; p != NULL; p = LIST_NEXT(p, p_list)) { while (p->p_pid == trypid || + p->p_reapsubtree == trypid || (p->p_pgrp != NULL && (p->p_pgrp->pg_id == trypid || (p->p_session != NULL && @@ -618,12 +628,22 @@ do_fork(struct thread *td, int flags, struct proc *p2, struct thread *td2, * of init. This effectively disassociates the child from the * parent. */ - if (flags & RFNOWAIT) - pptr = initproc; - else + if ((flags & RFNOWAIT) != 0) { + pptr = p1->p_reaper; + p2->p_reaper = pptr; + } else { + p2->p_reaper = (p1->p_treeflag & P_TREE_REAPER) != 0 ? + p1 : p1->p_reaper; pptr = p1; + } p2->p_pptr = pptr; LIST_INSERT_HEAD(&pptr->p_children, p2, p_sibling); + LIST_INIT(&p2->p_reaplist); + LIST_INSERT_HEAD(&p2->p_reaper->p_reaplist, p2, p_reapsibling); + if (p2->p_reaper == p1) + p2->p_reapsubtree = p2->p_pid; + else + p2->p_reapsubtree = p1->p_reapsubtree; sx_xunlock(&proctree_lock); /* Inform accounting that we have forked. */ |
