/*
* Called immediately after a successful exec.
*/
void arch_setup_new_exec(void)
{
/* If cpuid was previously disabled for this task, re-enable it. */
if (test_thread_flag(TIF_NOCPUID))
enable_cpuid();
/*
* Don't inherit TIF_SSBD across exec boundary when
* PR_SPEC_DISABLE_NOEXEC is used.
*/
if (test_thread_flag(TIF_SSBD) &&
task_spec_ssb_noexec(current)) {
clear_thread_flag(TIF_SSBD);
task_clear_spec_ssb_disable(current);
task_clear_spec_ssb_noexec(current);
speculation_ctrl_update(task_thread_info(current)->flags);
}
}
static int ssb_prctl_set(struct task_struct *task, unsigned long ctrl)
{
bool update;
if (ssb_mode != SPEC_STORE_BYPASS_PRCTL &&
ssb_mode != SPEC_STORE_BYPASS_SECCOMP)
return -ENXIO;
switch (ctrl) {
case PR_SPEC_ENABLE:
/* If speculation is force disabled, enable is not allowed */
if (task_spec_ssb_force_disable(task))
return -EPERM;
task_clear_spec_ssb_disable(task);
update = test_and_clear_tsk_thread_flag(task, TIF_SSBD);
break;
case PR_SPEC_DISABLE:
task_set_spec_ssb_disable(task);
update = !test_and_set_tsk_thread_flag(task, TIF_SSBD);
break;
case PR_SPEC_FORCE_DISABLE:
task_set_spec_ssb_disable(task);
task_set_spec_ssb_force_disable(task);
update = !test_and_set_tsk_thread_flag(task, TIF_SSBD);
break;
default:
return -ERANGE;
}
/*
* If being set on non-current task, delay setting the CPU
* mitigation until it is next scheduled.
*/
if (task == current && update)
speculative_store_bypass_update_current();
return 0;
}
