git: 7326e8589cc2 - main - fsetown: Avoid process group lock recursion
Mark Johnston
markj at FreeBSD.org
Sat Aug 28 19:55:26 UTC 2021
The branch main has been updated by markj:
URL: https://cgit.FreeBSD.org/src/commit/?id=7326e8589cc21431d62f25802eac7c5dd6f74122
commit 7326e8589cc21431d62f25802eac7c5dd6f74122
Author: Mark Johnston <markj at FreeBSD.org>
AuthorDate: 2021-08-28 19:50:44 +0000
Commit: Mark Johnston <markj at FreeBSD.org>
CommitDate: 2021-08-28 19:50:44 +0000
fsetown: Avoid process group lock recursion
Restore the pre-1d874ba4f8ba behaviour of disassociating the current
SIGIO recipient before looking up the specified process or process
group. This avoids a lock recursion in the scenario where a process
group is configured to receive SIGIO for an fd when it has already been
so configured.
Reported by: pho
Tested by: pho
Reviewed by: kib
MFC after: 3 days
---
sys/kern/kern_descrip.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index f78e999ab3b5..ed7fe83cf02f 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -1158,14 +1158,12 @@ fsetown(pid_t pgid, struct sigio **sigiop)
sigio->sio_ucred = crhold(curthread->td_ucred);
sigio->sio_myref = sigiop;
- osigio = NULL;
ret = 0;
if (pgid > 0) {
ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc);
SIGIO_LOCK();
+ osigio = funsetown_locked(*sigiop);
if (ret == 0) {
- osigio = funsetown_locked(*sigiop);
-
PROC_LOCK(proc);
_PRELE(proc);
if ((proc->p_flag & P_WEXIT) != 0) {
@@ -1191,12 +1189,11 @@ fsetown(pid_t pgid, struct sigio **sigiop)
} else /* if (pgid < 0) */ {
sx_slock(&proctree_lock);
SIGIO_LOCK();
+ osigio = funsetown_locked(*sigiop);
pgrp = pgfind(-pgid);
if (pgrp == NULL) {
ret = ESRCH;
} else {
- osigio = funsetown_locked(*sigiop);
-
if (pgrp->pg_session != curthread->td_proc->p_session) {
/*
* Policy - Don't allow a process to FSETOWN a
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