From 4daea938130b4a219e01d678e9499f0bdb715f82 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Fri, 1 Jan 2021 00:29:40 +0200 Subject: Lock proctree in around fill_kinfo_proc(). Proctree lock is needed for correct calculation and collection of the job-control related data in kinfo_proc. There was even an XXX comment about it. Satisfy locking and lock ordering requirements by taking proctree lock around pass over each bucket in proc_iterate(), and in sysctl_kern_proc() and note_procstat_proc() for individual process reporting. Reviewed by: jilles Tested by: pho MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D27871 --- sys/kern/kern_proc.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'sys/kern/kern_proc.c') diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c index fab1df795799..c63d136a3046 100644 --- a/sys/kern/kern_proc.c +++ b/sys/kern/kern_proc.c @@ -1653,6 +1653,7 @@ proc_iterate(int (*cb)(struct proc *, void *), void *cbarg) int error, i, j; for (i = 0; i < pidhashlock + 1; i++) { + sx_slock(&proctree_lock); sx_slock(&pidhashtbl_lock[i]); for (j = i; j <= pidhash; j += pidhashlock + 1) { LIST_FOREACH(p, &pidhashtbl[j], p_hash) { @@ -1662,11 +1663,13 @@ proc_iterate(int (*cb)(struct proc *, void *), void *cbarg) PROC_LOCK_ASSERT(p, MA_NOTOWNED); if (error != 0) { sx_sunlock(&pidhashtbl_lock[i]); + sx_sunlock(&proctree_lock); return (error); } } } sx_sunlock(&pidhashtbl_lock[i]); + sx_sunlock(&proctree_lock); } return (0); } @@ -1792,9 +1795,11 @@ sysctl_kern_proc(SYSCTL_HANDLER_ARGS) error = sysctl_wire_old_buffer(req, 0); if (error) return (error); + sx_slock(&proctree_lock); error = pget((pid_t)name[0], PGET_CANSEE, &p); if (error == 0) error = sysctl_out_proc(p, req, flags); + sx_sunlock(&proctree_lock); return (error); } -- cgit v1.2.3