1 files changed, 91 insertions, 0 deletions

diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
index 7ecaa1900137..a11222572f97 100644
--- a/mm/hwpoison-inject.c
+++ b/mm/hwpoison-inject.c
@@ -7,8 +7,96 @@
 #include <linux/swap.h>
 #include <linux/pagemap.h>
 #include <linux/hugetlb.h>
+#include <linux/page-flags.h>
+#include <linux/memcontrol.h>
 #include "internal.h"
 
+static u32 hwpoison_filter_enable;
+static u32 hwpoison_filter_dev_major = ~0U;
+static u32 hwpoison_filter_dev_minor = ~0U;
+static u64 hwpoison_filter_flags_mask;
+static u64 hwpoison_filter_flags_value;
+
+static int hwpoison_filter_dev(struct page *p)
+{
+	struct folio *folio = page_folio(p);
+	struct address_space *mapping;
+	dev_t dev;
+
+	if (hwpoison_filter_dev_major == ~0U &&
+	    hwpoison_filter_dev_minor == ~0U)
+		return 0;
+
+	mapping = folio_mapping(folio);
+	if (mapping == NULL || mapping->host == NULL)
+		return -EINVAL;
+
+	dev = mapping->host->i_sb->s_dev;
+	if (hwpoison_filter_dev_major != ~0U &&
+	    hwpoison_filter_dev_major != MAJOR(dev))
+		return -EINVAL;
+	if (hwpoison_filter_dev_minor != ~0U &&
+	    hwpoison_filter_dev_minor != MINOR(dev))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int hwpoison_filter_flags(struct page *p)
+{
+	if (!hwpoison_filter_flags_mask)
+		return 0;
+
+	if ((stable_page_flags(p) & hwpoison_filter_flags_mask) ==
+				    hwpoison_filter_flags_value)
+		return 0;
+	else
+		return -EINVAL;
+}
+
+/*
+ * This allows stress tests to limit test scope to a collection of tasks
+ * by putting them under some memcg. This prevents killing unrelated/important
+ * processes such as /sbin/init. Note that the target task may share clean
+ * pages with init (eg. libc text), which is harmless. If the target task
+ * share _dirty_ pages with another task B, the test scheme must make sure B
+ * is also included in the memcg. At last, due to race conditions this filter
+ * can only guarantee that the page either belongs to the memcg tasks, or is
+ * a freed page.
+ */
+#ifdef CONFIG_MEMCG
+static u64 hwpoison_filter_memcg;
+static int hwpoison_filter_task(struct page *p)
+{
+	if (!hwpoison_filter_memcg)
+		return 0;
+
+	if (page_cgroup_ino(p) != hwpoison_filter_memcg)
+		return -EINVAL;
+
+	return 0;
+}
+#else
+static int hwpoison_filter_task(struct page *p) { return 0; }
+#endif
+
+static int hwpoison_filter(struct page *p)
+{
+	if (!hwpoison_filter_enable)
+		return 0;
+
+	if (hwpoison_filter_dev(p))
+		return -EINVAL;
+
+	if (hwpoison_filter_flags(p))
+		return -EINVAL;
+
+	if (hwpoison_filter_task(p))
+		return -EINVAL;
+
+	return 0;
+}
+
 static struct dentry *hwpoison_dir;
 
 static int hwpoison_inject(void *data, u64 val)
@@ -67,6 +155,7 @@ DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
 static void __exit pfn_inject_exit(void)
 {
 	hwpoison_filter_enable = 0;
+	hwpoison_filter_unregister();
 	debugfs_remove_recursive(hwpoison_dir);
 }
 
@@ -105,6 +194,8 @@ static int __init pfn_inject_init(void)
 			   &hwpoison_filter_memcg);
 #endif
 
+	hwpoison_filter_register(hwpoison_filter);
+
 	return 0;
 }