/* * 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); }