in kernel/signal.c [307:315]
asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall)
{
if (test_thread_flag(TIF_SIGPENDING) ||
test_thread_flag(TIF_NOTIFY_SIGNAL))
do_signal(regs, in_syscall);
if (test_thread_flag(TIF_NOTIFY_RESUME))
tracehook_notify_resume(regs);
}