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[PULL 23/31] main: keep rcu_atfork callback enabled for qtest
From: |
Stefan Hajnoczi |
Subject: |
[PULL 23/31] main: keep rcu_atfork callback enabled for qtest |
Date: |
Sat, 22 Feb 2020 08:50:22 +0000 |
From: Alexander Bulekov <address@hidden>
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 <address@hidden>
Reviewed-by: Darren Kenny <address@hidden>
Acked-by: Stefan Hajnoczi <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
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
- [PULL 13/31] fuzz: add FUZZ_TARGET module type, (continued)
- [PULL 13/31] fuzz: add FUZZ_TARGET module type, Stefan Hajnoczi, 2020/02/22
- [PULL 14/31] qtest: add qtest_server_send abstraction, Stefan Hajnoczi, 2020/02/22
- [PULL 15/31] libqtest: add a layer of abstraction to send/recv, Stefan Hajnoczi, 2020/02/22
- [PULL 16/31] libqtest: make bufwrite rely on the TransportOps, Stefan Hajnoczi, 2020/02/22
- [PULL 17/31] qtest: add in-process incoming command handler, Stefan Hajnoczi, 2020/02/22
- [PULL 18/31] libqos: rename i2c_send and i2c_recv, Stefan Hajnoczi, 2020/02/22
- [PULL 19/31] libqos: split qos-test and libqos makefile vars, Stefan Hajnoczi, 2020/02/22
- [PULL 21/31] fuzz: add fuzzer skeleton, Stefan Hajnoczi, 2020/02/22
- [PULL 20/31] libqos: move useful qos-test funcs to qos_external, Stefan Hajnoczi, 2020/02/22
- [PULL 22/31] exec: keep ram block across fork when using qtest, Stefan Hajnoczi, 2020/02/22
- [PULL 23/31] main: keep rcu_atfork callback enabled for qtest,
Stefan Hajnoczi <=
- [PULL 24/31] fuzz: support for fork-based fuzzing., Stefan Hajnoczi, 2020/02/22
- [PULL 25/31] fuzz: add support for qos-assisted fuzz targets, Stefan Hajnoczi, 2020/02/22
- [PULL 26/31] fuzz: add target/fuzz makefile rules, Stefan Hajnoczi, 2020/02/22
- [PULL 27/31] fuzz: add configure flag --enable-fuzzing, Stefan Hajnoczi, 2020/02/22
- [PULL 28/31] fuzz: add i440fx fuzz targets, Stefan Hajnoczi, 2020/02/22
- [PULL 29/31] fuzz: add virtio-net fuzz target, Stefan Hajnoczi, 2020/02/22
- [PULL 30/31] fuzz: add virtio-scsi fuzz target, Stefan Hajnoczi, 2020/02/22