4 files changed, 70 insertions, 0 deletions

diff --git a/Documentation/vm/hwpoison.txt b/Documentation/vm/hwpoison.txt
index f454d3cd4d6..989e5afe740 100644
--- a/Documentation/vm/hwpoison.txt
+++ b/Documentation/vm/hwpoison.txt
@@ -123,6 +123,22 @@ Only handle memory failures to pages associated with the file system defined
 by block device major/minor.  -1U is the wildcard value.
 This should be only used for testing with artificial injection.
 
+corrupt-filter-memcg
+
+Limit injection to pages owned by memgroup. Specified by inode number
+of the memcg.
+
+Example:
+        mkdir /cgroup/hwpoison
+
+        usemem -m 100 -s 1000 &
+        echo `jobs -p` > /cgroup/hwpoison/tasks
+
+        memcg_ino=$(ls -id /cgroup/hwpoison | cut -f1 -d' ')
+        echo $memcg_ino > /debug/hwpoison/corrupt-filter-memcg
+
+        page-types -p `pidof init`   --hwpoison  # shall do nothing
+        page-types -p `pidof usemem` --hwpoison  # poison its pages
 
 corrupt-filter-flags-mask
 corrupt-filter-flags-value
diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
index c4dfd89f654..c838735ac31 100644
--- a/mm/hwpoison-inject.c
+++ b/mm/hwpoison-inject.c
@@ -112,6 +112,13 @@ static int pfn_inject_init(void)
         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();
diff --git a/mm/internal.h b/mm/internal.h
index b2027c73119..5a6761bea6a 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -257,3 +257,4 @@ extern u32 hwpoison_filter_dev_major;
 extern u32 hwpoison_filter_dev_minor;
 extern u64 hwpoison_filter_flags_mask;
 extern u64 hwpoison_filter_flags_value;
+extern u64 hwpoison_filter_memcg;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 22d2b2028e5..117ef159846 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -100,6 +100,49 @@ static int hwpoison_filter_flags(struct page *p)
                 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_CGROUP_MEM_RES_CTLR_SWAP
+u64 hwpoison_filter_memcg;
+EXPORT_SYMBOL_GPL(hwpoison_filter_memcg);
+static int hwpoison_filter_task(struct page *p)
+{
+        struct mem_cgroup *mem;
+        struct cgroup_subsys_state *css;
+        unsigned long ino;
+
+        if (!hwpoison_filter_memcg)
+                return 0;
+
+        mem = try_get_mem_cgroup_from_page(p);
+        if (!mem)
+                return -EINVAL;
+
+        css = mem_cgroup_css(mem);
+        /* root_mem_cgroup has NULL dentries */
+        if (!css->cgroup->dentry)
+                return -EINVAL;
+
+        ino = css->cgroup->dentry->d_inode->i_ino;
+        css_put(css);
+
+        if (ino != hwpoison_filter_memcg)
+                return -EINVAL;
+
+        return 0;
+}
+#else
+static int hwpoison_filter_task(struct page *p) { return 0; }
+#endif
+
 int hwpoison_filter(struct page *p)
 {
         if (hwpoison_filter_dev(p))
@@ -108,6 +151,9 @@ int hwpoison_filter(struct page *p)
         if (hwpoison_filter_flags(p))
                 return -EINVAL;
 
+        if (hwpoison_filter_task(p))
+                return -EINVAL;
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(hwpoison_filter);