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-rw-r--r--Documentation/vm/hwpoison.txt3
-rw-r--r--mm/hwpoison-inject.c41
-rw-r--r--mm/internal.h2
3 files changed, 43 insertions, 3 deletions
diff --git a/Documentation/vm/hwpoison.txt b/Documentation/vm/hwpoison.txt
index fdf580464324..4ef7bb30d15c 100644
--- a/Documentation/vm/hwpoison.txt
+++ b/Documentation/vm/hwpoison.txt
@@ -103,7 +103,8 @@ hwpoison-inject module through debugfs
corrupt-pfn
-Inject hwpoison fault at PFN echoed into this file.
+Inject hwpoison fault at PFN echoed into this file. This does
+some early filtering to avoid corrupted unintended pages in test suites.
unpoison-pfn
diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
index ac692a9b766c..2b6b3200fa65 100644
--- a/mm/hwpoison-inject.c
+++ b/mm/hwpoison-inject.c
@@ -3,16 +3,53 @@
#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;
static int hwpoison_inject(void *data, u64 val)
{
+ unsigned long pfn = val;
+ struct page *p;
+ int err;
+
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- printk(KERN_INFO "Injecting memory failure at pfn %Lx\n", val);
- return __memory_failure(val, 18, 0);
+
+ 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);
+ /*
+ * 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;
+
+ 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)
diff --git a/mm/internal.h b/mm/internal.h
index 814da335f050..04bbce8b8ba6 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -251,5 +251,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
#define ZONE_RECLAIM_SUCCESS 1
#endif
+extern int hwpoison_filter(struct page *p);
+
extern u32 hwpoison_filter_dev_major;
extern u32 hwpoison_filter_dev_minor;