arch_prctl_spec_ctrl_get
switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_INDIRECT_BRANCH)) {
int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which);
error = arch_prctl_spec_ctrl_get(me, arg2);