/* 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 (strict_strtoull(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;
int err;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (!hwpoison_filter_enable)
goto inject;
if (!pfn_valid(pfn))
return -ENXIO;
p = pfn_to_page(pfn);
/*
* This implies unable to support free buddy pages.
*/
if (!get_page_unless_zero(p))
return 0;
if (!PageLRU(p))
shake_page(p, 0);
/*
* This implies unable to support non-LRU pages.
*/
if (!PageLRU(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(p);
err = hwpoison_filter(p);
unlock_page(p);
if (err)
return 0;
inject:
printk(KERN_INFO "Injecting memory failure at pfn %lx\n", pfn);
return __memory_failure(pfn, 18, MF_COUNT_INCREASED);
}
