syscall_user_buffer
static struct syscall_user_buffer *syscall_buffer;
struct syscall_user_buffer *sbuf;
struct syscall_user_buffer *sbuf =
container_of(rcu, struct syscall_user_buffer, rcu);
struct syscall_user_buffer *sbuf = syscall_buffer;
struct syscall_user_buffer *sbuf,
struct syscall_user_buffer *sbuf;