目前都是这么找： git grep SYSCALL_DEFINE | grep signal
系统调用的函数名本来是叫sys_xxx，现在都是用宏SYSCALL_DEFINE(XXX)，搞得无法找到sys_xxx了
比如找read系统调用： git grep SYSCALL_DEFINE | grep read
fs/read_write.c: SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)