proc0_post: Fix some locking issues

- Filter out PRS_NEW procs as rufetch() tries taking the thread lock
  which may not yet be initialized.
- Hold PROC_LOCK to ensure stability of iterating the threads.
- p_rux fields are protected by the process statlock as well.

MFC after:	2 weeks
Reviewed by:	kib
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D15809
This commit is contained in:
Bryan Drewery 2018-06-15 00:36:41 +00:00
parent 78bcf87e3e
commit 03bd1b693e
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=335183

View File

@ -618,17 +618,23 @@ proc0_post(void *dummy __unused)
*/
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
PROC_LOCK(p);
if (p->p_state == PRS_NEW) {
PROC_UNLOCK(p);
continue;
}
microuptime(&p->p_stats->p_start);
PROC_STATLOCK(p);
rufetch(p, &ru); /* Clears thread stats */
PROC_STATUNLOCK(p);
p->p_rux.rux_runtime = 0;
p->p_rux.rux_uticks = 0;
p->p_rux.rux_sticks = 0;
p->p_rux.rux_iticks = 0;
PROC_STATUNLOCK(p);
FOREACH_THREAD_IN_PROC(p, td) {
td->td_runtime = 0;
}
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
PCPU_SET(switchtime, cpu_ticks());