Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / mm / hwpoison-inject.c

diff --git a/kernel/mm/hwpoison-inject.c b/kernel/mm/hwpoison-inject.c
new file mode 100644 (file)
index 0000000..4ca5fe0
--- /dev/null
+++ b/kernel/mm/hwpoison-inject.c
@@ -0,0 +1,144 @@
+/* Inject a hwpoison memory failure on a arbitrary pfn */
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include <linux/hugetlb.h>
+#include "internal.h"
+
+static struct dentry *hwpoison_dir;
+
+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(hpage) && !PageHuge(p))
+               shake_page(hpage, 0);
+       /*
+        * This implies unable to support non-LRU pages.
+        */
+       if (!PageLRU(hpage) && !PageHuge(p))
+               goto put_out;
+
+       /*
+        * 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)
+               goto put_out;
+
+inject:
+       pr_info("Injecting memory failure at pfn %#lx\n", pfn);
+       return memory_failure(pfn, 18, MF_COUNT_INCREASED);
+put_out:
+       put_page(hpage);
+       return 0;
+}
+
+static int hwpoison_unpoison(void *data, u64 val)
+{
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       return unpoison_memory(val);
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
+DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
+
+static void pfn_inject_exit(void)
+{
+       debugfs_remove_recursive(hwpoison_dir);
+}
+
+static int pfn_inject_init(void)
+{
+       struct dentry *dentry;
+
+       hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
+       if (hwpoison_dir == NULL)
+               return -ENOMEM;
+
+       /*
+        * Note that the below poison/unpoison interfaces do not involve
+        * hardware status change, hence do not require hardware support.
+        * They are mainly for testing hwpoison in software level.
+        */
+       dentry = debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir,
+                                         NULL, &hwpoison_fops);
+       if (!dentry)
+               goto fail;
+
+       dentry = debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir,
+                                    NULL, &unpoison_fops);
+       if (!dentry)
+               goto fail;
+
+       dentry = debugfs_create_u32("corrupt-filter-enable", 0600,
+                                   hwpoison_dir, &hwpoison_filter_enable);
+       if (!dentry)
+               goto fail;
+
+       dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600,
+                                   hwpoison_dir, &hwpoison_filter_dev_major);
+       if (!dentry)
+               goto fail;
+
+       dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600,
+                                   hwpoison_dir, &hwpoison_filter_dev_minor);
+       if (!dentry)
+               goto fail;
+
+       dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600,
+                                   hwpoison_dir, &hwpoison_filter_flags_mask);
+       if (!dentry)
+               goto fail;
+
+       dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600,
+                                   hwpoison_dir, &hwpoison_filter_flags_value);
+       if (!dentry)
+               goto fail;
+
+#ifdef CONFIG_MEMCG_SWAP
+       dentry = debugfs_create_u64("corrupt-filter-memcg", 0600,
+                                   hwpoison_dir, &hwpoison_filter_memcg);
+       if (!dentry)
+               goto fail;
+#endif
+
+       return 0;
+fail:
+       pfn_inject_exit();
+       return -ENOMEM;
+}
+
+module_init(pfn_inject_init);
+module_exit(pfn_inject_exit);
+MODULE_LICENSE("GPL");