Fix a race, described below
lkvm stop ... handle_stop
kvm_cpu__reboot
kvm_cmd_run_exit
vcpus exit
...
dev_exit
...
ioport__unregister
..serial...
kvm__pause --> br_write_lock
pthread_kill
But the thread is already dead above.
We mark the cpus as dying so that kvm_pause does nothing.
This should not break any semantics
Signed-off-by: Balbir Singh <bsingharora@xxxxxxxxx>
Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
---
builtin-run.c | 3 +++
kvm.c | 5 +++++
2 files changed, 8 insertions(+)
diff --git a/builtin-run.c b/builtin-run.c
index 17b1428..cdc7158 100644
--- a/builtin-run.c
+++ b/builtin-run.c
@@ -58,6 +58,7 @@ __thread struct kvm_cpu *current_kvm_cpu;
static int kvm_run_wrapper;
bool do_debug_print = false;
+int kvm_cmd_exit;
static const char * const run_usage[] = {
"lkvm run [<options>] [<kernel image>]",
@@ -648,6 +649,7 @@ static void kvm_cmd_run_exit(struct kvm *kvm, int guest_ret)
{
compat__print_all_messages();
+ kvm_cmd_exit = 1;
init_list__exit(kvm);
if (guest_ret == 0 && do_debug_print)
@@ -659,6 +661,7 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
int ret = -EFAULT;
struct kvm *kvm;
+ kvm_cmd_exit = 0;
kvm = kvm_cmd_run_init(argc, argv);
if (IS_ERR(kvm))
return PTR_ERR(kvm);
diff --git a/kvm.c b/kvm.c
index 1081072..53cf0e2 100644
--- a/kvm.c
+++ b/kvm.c
@@ -33,6 +33,8 @@
#define DEFINE_KVM_EXIT_REASON(reason) [reason] = #reason
+extern int kvm_cmd_exit;
+
const char *kvm_exit_reasons[] = {
DEFINE_KVM_EXIT_REASON(KVM_EXIT_UNKNOWN),
DEFINE_KVM_EXIT_REASON(KVM_EXIT_EXCEPTION),
@@ -435,6 +437,9 @@ void kvm__pause(struct kvm *kvm)
if (!kvm->cpus[0] || kvm->cpus[0]->thread == 0)
return;
+ if (kvm_cmd_exit)
+ return;
+
mutex_lock(&pause_lock);
pause_event = eventfd(0, 0);
--
2.5.5
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