From: Stefan Hajnoczi <stefanha@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Kevin Wolf" <kwolf@redhat.com>,
"Peter Maydell" <peter.maydell@linaro.org>,
"Thomas Huth" <thuth@redhat.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
qemu-block@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>,
"Laurent Vivier" <lvivier@redhat.com>,
"Max Reitz" <mreitz@redhat.com>,
"Alexander Bulekov" <alxndr@bu.edu>,
"Bandan Das" <bsd@redhat.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Marc-André Lureau" <marcandre.lureau@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Fam Zheng" <fam@euphon.net>,
"Darren Kenny" <darren.kenny@oracle.com>,
"Richard Henderson" <rth@twiddle.net>
Subject: [PULL 23/31] main: keep rcu_atfork callback enabled for qtest
Date: Sat, 22 Feb 2020 08:50:22 +0000 [thread overview]
Message-ID: <20200222085030.1760640-24-stefanha@redhat.com> (raw)
In-Reply-To: <20200222085030.1760640-1-stefanha@redhat.com>
From: Alexander Bulekov <alxndr@bu.edu>
The qtest-based fuzzer makes use of forking to reset-state between
tests. Keep the callback enabled, so the call_rcu thread gets created
within the child process.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200220041118.23264-15-alxndr@bu.edu
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
softmmu/vl.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 080d3b5106..92c7b3a6e9 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -3782,7 +3782,17 @@ void qemu_init(int argc, char **argv, char **envp)
set_memory_options(&ram_slots, &maxram_size, machine_class);
os_daemonize();
- rcu_disable_atfork();
+
+ /*
+ * If QTest is enabled, keep the rcu_atfork enabled, since system processes
+ * may be forked testing purposes (e.g. fork-server based fuzzing) The fork
+ * should happen before a signle cpu instruction is executed, to prevent
+ * deadlocks. See commit 73c6e40, rcu: "completely disable pthread_atfork
+ * callbacks as soon as possible"
+ */
+ if (!qtest_enabled()) {
+ rcu_disable_atfork();
+ }
if (pid_file && !qemu_write_pidfile(pid_file, &err)) {
error_reportf_err(err, "cannot create PID file: ");
--
2.24.1
next prev parent reply other threads:[~2020-02-22 8:58 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-22 8:49 [PULL 00/31] Block patches Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 01/31] virtio: increase virtqueue size for virtio-scsi and virtio-blk Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 02/31] aio-posix: avoid reacquiring rcu_read_lock() when polling Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 03/31] rcu_queue: add QSLIST functions Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 04/31] util/async: make bh_aio_poll() O(1) Stefan Hajnoczi
2020-03-16 16:42 ` Marc-André Lureau
2020-02-22 8:50 ` [PULL 05/31] aio-posix: fix use after leaving scope in aio_poll() Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 06/31] aio-posix: don't pass ns timeout to epoll_wait() Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 07/31] qemu/queue.h: add QLIST_SAFE_REMOVE() Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 08/31] aio-posix: make AioHandler deletion O(1) Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 09/31] aio-posix: make AioHandler dispatch O(1) with epoll Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 10/31] softmmu: move vl.c to softmmu/ Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 11/31] softmmu: split off vl.c:main() into main.c Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 12/31] module: check module wasn't already initialized Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 13/31] fuzz: add FUZZ_TARGET module type Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 14/31] qtest: add qtest_server_send abstraction Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 15/31] libqtest: add a layer of abstraction to send/recv Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 16/31] libqtest: make bufwrite rely on the TransportOps Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 17/31] qtest: add in-process incoming command handler Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 18/31] libqos: rename i2c_send and i2c_recv Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 19/31] libqos: split qos-test and libqos makefile vars Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 20/31] libqos: move useful qos-test funcs to qos_external Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 21/31] fuzz: add fuzzer skeleton Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 22/31] exec: keep ram block across fork when using qtest Stefan Hajnoczi
2020-02-22 8:50 ` Stefan Hajnoczi [this message]
2020-02-22 8:50 ` [PULL 24/31] fuzz: support for fork-based fuzzing Stefan Hajnoczi
2020-02-22 11:34 ` Eric Blake
2020-02-24 11:35 ` Stefan Hajnoczi
2020-02-27 2:50 ` Alexander Bulekov
2020-02-22 8:50 ` [PULL 25/31] fuzz: add support for qos-assisted fuzz targets Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 26/31] fuzz: add target/fuzz makefile rules Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 27/31] fuzz: add configure flag --enable-fuzzing Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 28/31] fuzz: add i440fx fuzz targets Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 29/31] fuzz: add virtio-net fuzz target Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 30/31] fuzz: add virtio-scsi " Stefan Hajnoczi
2020-02-22 8:50 ` [PULL 31/31] fuzz: add documentation to docs/devel/ Stefan Hajnoczi
2020-02-22 9:13 ` [PULL 00/31] Block patches no-reply
2020-02-24 11:33 ` Stefan Hajnoczi
2020-02-24 12:47 ` Peter Maydell
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