From 068a5ea02f62853116788a2c42d8851a94bb7567 Mon Sep 17 00:00:00 2001 From: "Emilio G. Cota" Date: Sun, 19 Aug 2018 05:13:35 -0400 Subject: qom: convert the CPU list to RCU Iterating over the list without using atomics is undefined behaviour, since the list can be modified concurrently by other threads (e.g. every time a new thread is created in user-mode). Fix it by implementing the CPU list as an RCU QTAILQ. This requires a little bit of extra work to traverse list in reverse order (see previous patch), but other than that the conversion is trivial. Signed-off-by: Emilio G. Cota Message-Id: <20180819091335.22863-12-cota@braap.org> Signed-off-by: Paolo Bonzini --- linux-user/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'linux-user/syscall.c') diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 202aa777ad..3c3c1aec48 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8157,7 +8157,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, TaskState *ts; /* Remove the CPU from the list. */ - QTAILQ_REMOVE(&cpus, cpu, node); + QTAILQ_REMOVE_RCU(&cpus, cpu, node); cpu_list_unlock(); -- cgit 1.4.1