linux-user: call cpu_copy under clone_lock

cpu_copy adds newly created CPU object to container/machine/unattached,
but does it w/o proper locking. As a result when multiple threads create
threads rapidly QEMU may abort with the following message:

  GLib-CRITICAL **: g_hash_table_iter_next: assertion
  'ri->version == ri->hash_table->version' failed

  ERROR:qemu/qom/object.c:1663:object_get_canonical_path_component:
  code should not be reached

E.g. this issue is observed when running glibc test nptl/tst-eintr1.
Move cpu_copy invocation under clone_lock to fix that.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov 2018-03-30 06:19:58 -07:00
parent 4a6bf7adb9
commit 73a988d957

View File

@ -6346,6 +6346,10 @@ static int do_fork(CPUArchState *env, unsigned int flags, abi_ulong newsp,
ts = g_new0(TaskState, 1);
init_task_state(ts);
/* Grab a mutex so that thread setup appears atomic. */
pthread_mutex_lock(&clone_lock);
/* we create a new CPU instance. */
new_env = cpu_copy(env);
/* Init regs that differ from the parent. */
@ -6364,9 +6368,6 @@ static int do_fork(CPUArchState *env, unsigned int flags, abi_ulong newsp,
cpu_set_tls (new_env, newtls);
}
/* Grab a mutex so that thread setup appears atomic. */
pthread_mutex_lock(&clone_lock);
memset(&info, 0, sizeof(info));
pthread_mutex_init(&info.mutex, NULL);
pthread_mutex_lock(&info.mutex);