/*
* process pending MCE event from the mce event queue. This function will be
* called during syscall exit.
*/
static void machine_process_ue_event(struct work_struct *work)
{
int index;
struct machine_check_event *evt;
while (__this_cpu_read(mce_ue_count) > 0) {
index = __this_cpu_read(mce_ue_count) - 1;
evt = this_cpu_ptr(&mce_ue_event_queue[index]);
#ifdef CONFIG_MEMORY_FAILURE
/*
* This should probably queued elsewhere, but
* oh! well
*/
if (evt->error_type == MCE_ERROR_TYPE_UE) {
if (evt->u.ue_error.physical_address_provided) {
unsigned long pfn;
pfn = evt->u.ue_error.physical_address >>
PAGE_SHIFT;
memory_failure(pfn, 0);
} else
pr_warn("Failed to identify bad address from "
"where the uncorrectable error (UE) "
"was generated\n");
}
/* Forcibly offline a page, including killing processes. */
static ssize_t
store_hard_offline_page(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int ret;
u64 pfn;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (kstrtoull(buf, 0, &pfn) < 0)
return -EINVAL;
pfn >>= PAGE_SHIFT;
ret = memory_failure(pfn, 0, 0);
return ret ? ret : count;
}
static int hwpoison_inject(void *data, u64 val)
{
unsigned long pfn = val;
struct page *p;
struct page *hpage;
int err;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (!pfn_valid(pfn))
return -ENXIO;
p = pfn_to_page(pfn);
hpage = compound_head(p);
/*
* This implies unable to support free buddy pages.
*/
if (!get_page_unless_zero(hpage))
return 0;
if (!hwpoison_filter_enable)
goto inject;
if (!PageLRU(p) && !PageHuge(p))
shake_page(p, 0);
/*
* This implies unable to support non-LRU pages.
*/
if (!PageLRU(p) && !PageHuge(p))
return 0;
/*
* do a racy check with elevated page count, to make sure PG_hwpoison
* will only be set for the targeted owner (or on a free page).
* We temporarily take page lock for try_get_mem_cgroup_from_page().
* memory_failure() will redo the check reliably inside page lock.
*/
lock_page(hpage);
err = hwpoison_filter(hpage);
unlock_page(hpage);
if (err)
return 0;
inject:
printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn);
return memory_failure(pfn, 18, MF_COUNT_INCREASED);
}
