Date: Sat, 13 Jun 2026 01:03:58 +0000 From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 53d691cacae6 - stable/15 - reap_kill_subtree_once: when proctree_lock is dropped, reaper might change Message-ID: <6a2cac7e.1eaf2.2767a78c@gitrepo.freebsd.org>
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The branch stable/15 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=53d691cacae602f96a80a656ec8f508b65ace81c commit 53d691cacae602f96a80a656ec8f508b65ace81c Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2026-06-05 23:57:16 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2026-06-13 00:58:38 +0000 reap_kill_subtree_once: when proctree_lock is dropped, reaper might change (cherry picked from commit 44970244e6d872103f36eae34218b672b69579dd) --- sys/kern/kern_procctl.c | 43 +++++++++++++++++++++++++++++-------------- 1 file changed, 29 insertions(+), 14 deletions(-) diff --git a/sys/kern/kern_procctl.c b/sys/kern/kern_procctl.c index 1ff1b15767b5..c8d14aa2f2f6 100644 --- a/sys/kern/kern_procctl.c +++ b/sys/kern/kern_procctl.c @@ -49,6 +49,7 @@ #include <vm/pmap.h> #include <vm/vm_map.h> #include <vm/vm_extern.h> +#include <vm/uma.h> static int protect_setchild(struct thread *td, struct proc *p, int flags) @@ -366,13 +367,7 @@ reap_kill_sched(struct reap_kill_tracker_head *tracker, struct proc *p2) { struct reap_kill_tracker *t; - PROC_LOCK(p2); - if ((p2->p_flag2 & P2_WEXIT) != 0) { - PROC_UNLOCK(p2); - return; - } - _PHOLD(p2); - PROC_UNLOCK(p2); + PROC_TREE_REF(p2); t = malloc(sizeof(struct reap_kill_tracker), M_TEMP, M_WAITOK); t->parent = p2; TAILQ_INSERT_TAIL(tracker, t, link); @@ -381,7 +376,7 @@ reap_kill_sched(struct reap_kill_tracker_head *tracker, struct proc *p2) static void reap_kill_sched_free(struct reap_kill_tracker *t) { - PRELE(t->parent); + PROC_TREE_UNREF(t->parent); free(t, M_TEMP); } @@ -416,16 +411,17 @@ reap_kill_children(struct thread *td, struct proc *reaper, } static bool -reap_kill_subtree_once(struct thread *td, struct proc *p, struct proc *reaper, +reap_kill_subtree_once(struct thread *td, struct proc *p, struct proc **reaperp, struct unrhdr *pids, struct reap_kill_proc_work *w) { struct reap_kill_tracker_head tracker; struct reap_kill_tracker *t; - struct proc *p2; + struct proc *p2, *reaper, *old_reaper; bool proctree_dropped, res; res = false; TAILQ_INIT(&tracker); + reaper = *reaperp; reap_kill_sched(&tracker, reaper); while ((t = TAILQ_FIRST(&tracker)) != NULL) { TAILQ_REMOVE(&tracker, t, link); @@ -483,8 +479,24 @@ again: } PROC_UNLOCK(p2); res = true; - if (proctree_dropped) + if (proctree_dropped) { + old_reaper = reaper; + reaper = get_reaper_or_p(p); + if (old_reaper != reaper) { + *reaperp = reaper; + PROC_TREE_REF(reaper); + PROC_TREE_UNREF(old_reaper); + reap_kill_sched(&tracker, reaper); + /* + * Already scheduled kill + * actions should be kept on + * the schedule, the processes + * are inherited by the new + * reaper. + */ + } goto again; + } } reap_kill_sched_free(t); } @@ -492,7 +504,7 @@ again: } static void -reap_kill_subtree(struct thread *td, struct proc *p, struct proc *reaper, +reap_kill_subtree(struct thread *td, struct proc *p, struct proc **reaperp, struct reap_kill_proc_work *w) { struct unrhdr pids; @@ -512,7 +524,7 @@ reap_kill_subtree(struct thread *td, struct proc *p, struct proc *reaper, goto out; } PROC_UNLOCK(td->td_proc); - while (reap_kill_subtree_once(td, p, reaper, &pids, w)) + while (reap_kill_subtree_once(td, p, reaperp, &pids, w)) ; ihandle = create_iter_unr(&pids); @@ -562,6 +574,7 @@ reap_kill(struct thread *td, struct proc *p, void *data) return (EINVAL); PROC_UNLOCK(p); reaper = get_reaper_or_p(p); + ksiginfo_init(&ksi); ksi.ksi_signo = rk->rk_sig; ksi.ksi_code = SI_USER; @@ -577,7 +590,9 @@ reap_kill(struct thread *td, struct proc *p, void *data) w.ksi = &ksi; w.rk = rk; w.error = &error; - reap_kill_subtree(td, p, reaper, &w); + PROC_TREE_REF(reaper); + reap_kill_subtree(td, p, &reaper, &w); + PROC_TREE_UNREF(reaper); crfree(w.cr); } PROC_LOCK(p);home | help
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