28d3ae407e
This is an automated DistroBaker update from upstream sources. If you do not know what this is about or would like to opt out, contact the OSCI team. Source: https://src.fedoraproject.org/rpms/device-mapper-multipath.git#26a2cd7a3e189bf91263d17bc8a8c449cc043fb0
99 lines
3.1 KiB
Diff
99 lines
3.1 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
|
From: Martin Wilck <mwilck@suse.com>
|
|
Date: Wed, 23 Sep 2020 18:02:39 +0200
|
|
Subject: [PATCH] multipathd: Fix liburcu memory leak
|
|
|
|
Fix this leak in multipathd, reported by valgrind, that messes up
|
|
multipathd's otherwise clean leak report:
|
|
|
|
==23823== 336 bytes in 1 blocks are possibly lost in loss record 3 of 3
|
|
==23823== at 0x483AB65: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
|
|
==23823== by 0x4012F16: _dl_allocate_tls (in /lib64/ld-2.31.so)
|
|
==23823== by 0x493BB8E: pthread_create@@GLIBC_2.2.5 (in /lib64/libpthread-2.31.so)
|
|
==23823== by 0x492A9A9: call_rcu_data_init (urcu-call-rcu-impl.h:437)
|
|
==23823== by 0x492AD2F: UnknownInlinedFun (urcu-call-rcu-impl.h:492)
|
|
==23823== by 0x492AD2F: create_call_rcu_data_memb (urcu-call-rcu-impl.h:504)
|
|
==23823== by 0x1164E3: child.constprop.0.isra.0 (main.c:2915)
|
|
==23823== by 0x10F50C: main (main.c:3335)
|
|
==23823==
|
|
==23823== LEAK SUMMARY:
|
|
==23823== definitely lost: 0 bytes in 0 blocks
|
|
==23823== indirectly lost: 0 bytes in 0 blocks
|
|
==23823== possibly lost: 336 bytes in 1 blocks
|
|
|
|
The problem is caused by using liburcu's default RCU call handler,
|
|
which liburcu refuses to stop/join. See comments in the code.
|
|
|
|
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
|
|
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
|
|
---
|
|
multipathd/main.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
|
|
1 file changed, 44 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/multipathd/main.c b/multipathd/main.c
|
|
index c5c374b7..ce14bb66 100644
|
|
--- a/multipathd/main.c
|
|
+++ b/multipathd/main.c
|
|
@@ -2889,6 +2889,48 @@ set_oom_adj (void)
|
|
condlog(0, "couldn't adjust oom score");
|
|
}
|
|
|
|
+/*
|
|
+ * Use a non-default call_rcu_data for child().
|
|
+ *
|
|
+ * We do this to avoid a memory leak from liburcu.
|
|
+ * liburcu never frees the default rcu handler (see comments on
|
|
+ * call_rcu_data_free() in urcu-call-rcu-impl.h), its thread
|
|
+ * can't be joined with pthread_join(), leaving a memory leak.
|
|
+ *
|
|
+ * Therefore we create our own, which can be destroyed and joined.
|
|
+ */
|
|
+static struct call_rcu_data *setup_rcu(void)
|
|
+{
|
|
+ struct call_rcu_data *crdp;
|
|
+
|
|
+ rcu_init();
|
|
+ rcu_register_thread();
|
|
+ crdp = create_call_rcu_data(0UL, -1);
|
|
+ if (crdp != NULL)
|
|
+ set_thread_call_rcu_data(crdp);
|
|
+ return crdp;
|
|
+}
|
|
+
|
|
+static struct call_rcu_data *mp_rcu_data;
|
|
+
|
|
+static void cleanup_rcu(void)
|
|
+{
|
|
+ pthread_t rcu_thread;
|
|
+
|
|
+ /* Wait for any pending RCU calls */
|
|
+ rcu_barrier();
|
|
+ if (mp_rcu_data != NULL) {
|
|
+ rcu_thread = get_call_rcu_thread(mp_rcu_data);
|
|
+ /* detach this thread from the RCU thread */
|
|
+ set_thread_call_rcu_data(NULL);
|
|
+ synchronize_rcu();
|
|
+ /* tell RCU thread to exit */
|
|
+ call_rcu_data_free(mp_rcu_data);
|
|
+ pthread_join(rcu_thread, NULL);
|
|
+ }
|
|
+ rcu_unregister_thread();
|
|
+}
|
|
+
|
|
static int
|
|
child (__attribute__((unused)) void *param)
|
|
{
|
|
@@ -2906,7 +2948,8 @@ child (__attribute__((unused)) void *param)
|
|
|
|
mlockall(MCL_CURRENT | MCL_FUTURE);
|
|
signal_init();
|
|
- rcu_init();
|
|
+ mp_rcu_data = setup_rcu();
|
|
+ atexit(cleanup_rcu);
|
|
|
|
setup_thread_attr(&misc_attr, 64 * 1024, 0);
|
|
setup_thread_attr(&uevent_attr, DEFAULT_UEVENT_STACKSIZE * 1024, 0);
|
|
--
|
|
2.17.2
|
|
|