From 73a988d957b9142e0a005f4dc87944574f02de51 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Fri, 30 Mar 2018 06:19:58 -0700 Subject: 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 Signed-off-by: Max Filippov --- linux-user/syscall.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'linux-user') diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 889abbda1e..18ea79140f 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -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); -- cgit v1.2.3