/**
* mark_oom_victim - mark the given task as OOM victim
* @tsk: task to mark
*
* Has to be called with oom_lock held and never after
* oom has been disabled already.
*
* tsk->mm has to be non NULL and caller has to guarantee it is stable (either
* under task_lock or operate on the current).
*/
static void mark_oom_victim(struct task_struct *tsk)
{
struct mm_struct *mm = tsk->mm;
WARN_ON(oom_killer_disabled);
/* OOM killer might race with memcg OOM */
if (test_and_set_tsk_thread_flag(tsk, TIF_MEMDIE))
return;
/* oom_mm is bound to the signal struct life time. */
if (!cmpxchg(&tsk->signal->oom_mm, NULL, mm)) {
mmgrab(tsk->signal->oom_mm);
set_bit(MMF_OOM_VICTIM, &mm->flags);
}
/*
* Make sure that the task is woken up from uninterruptible sleep
* if it is frozen because OOM killer wouldn't be able to free
* any memory and livelock. freezing_slow_path will tell the freezer
* that TIF_MEMDIE tasks should be ignored.
*/
__thaw_task(tsk);
atomic_inc(&oom_victims);
trace_mark_victim(tsk->pid);
}
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;
}
void ocd_enable(struct task_struct *child)
{
u32 dc;
if (child)
pr_debug("ocd_enable: child=%s [%u]\n",
child->comm, child->pid);
else
pr_debug("ocd_enable (no child)\n");
if (!child || !test_and_set_tsk_thread_flag(child, TIF_DEBUG)) {
spin_lock(&ocd_lock);
ocd_count++;
dc = ocd_read(DC);
dc |= (1 << OCD_DC_MM_BIT) | (1 << OCD_DC_DBE_BIT);
ocd_write(DC, dc);
spin_unlock(&ocd_lock);
}
}
