From: David Lamparter <equinox@opensourcerouting.org>
Date: Sat, 5 Mar 2022 18:39:53 +0000 (+0100)
Subject: lib: fix log target removal when singlethreaded
X-Git-Tag: pim6-testing-20220430~244^2~6
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=d03440cab78605dcc21427127afdf78860d9916b;p=matthieu%2Ffrr.git

lib: fix log target removal when singlethreaded

While running singlethreaded, the RCU code is "dormant" and rcu_free is
an immediate operation.  This results in the log target loop accessing
free'd memory if a log target removes itself while a message is printed
(which is likely to happen on e.g. error conditions.)

Just use frr_each_safe to avoid this issue.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
---

diff --git a/lib/zlog.c b/lib/zlog.c
index 85606d2624..e0bb34a258 100644
--- a/lib/zlog.c
+++ b/lib/zlog.c
@@ -401,7 +401,7 @@ void zlog_tls_buffer_flush(void)
 		return;
 
 	rcu_read_lock();
-	frr_each (zlog_targets, &zlog_targets, zt) {
+	frr_each_safe (zlog_targets, &zlog_targets, zt) {
 		if (!zt->logfn)
 			continue;
 
@@ -431,7 +431,7 @@ static void vzlog_notls(const struct xref_logmsg *xref, int prio,
 	msg->stackbufsz = sizeof(stackbuf);
 
 	rcu_read_lock();
-	frr_each (zlog_targets, &zlog_targets, zt) {
+	frr_each_safe (zlog_targets, &zlog_targets, zt) {
 		if (prio > zt->prio_min)
 			continue;
 		if (!zt->logfn)