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-rw-r--r--mm/hwpoison-inject.c113
1 files changed, 105 insertions, 8 deletions
diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
index e1d8513..10ea719 100644
--- a/mm/hwpoison-inject.c
+++ b/mm/hwpoison-inject.c
@@ -3,18 +3,68 @@
#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include "internal.h"
-static struct dentry *hwpoison_dir, *corrupt_pfn;
+static struct dentry *hwpoison_dir;
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);
+}
+
+static int hwpoison_unpoison(void *data, u64 val)
+{
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- printk(KERN_INFO "Injecting memory failure at pfn %Lx\n", val);
- return __memory_failure(val, 18, 0);
+
+ 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)
{
@@ -24,16 +74,63 @@ static void pfn_inject_exit(void)
static int pfn_inject_init(void)
{
+ struct dentry *dentry;
+
hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
if (hwpoison_dir == NULL)
return -ENOMEM;
- corrupt_pfn = debugfs_create_file("corrupt-pfn", 0600, hwpoison_dir,
+
+ /*
+ * 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", 0600, hwpoison_dir,
NULL, &hwpoison_fops);
- if (corrupt_pfn == NULL) {
- pfn_inject_exit();
- return -ENOMEM;
- }
+ if (!dentry)
+ goto fail;
+
+ dentry = debugfs_create_file("unpoison-pfn", 0600, 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_CGROUP_MEM_RES_CTLR_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);
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