1 files changed, 47 insertions, 0 deletions
diff --git a/lib/test_free_pages.c b/lib/test_free_pages.c
new file mode 100644
index 000000000000..9ebf6f5549f3
--- /dev/null
+++ b/lib/test_free_pages.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * test_free_pages.c: Check that free_pages() doesn't leak memory
+ * Copyright (c) 2020 Oracle
+ * Author: Matthew Wilcox <willy@infradead.org>
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+
+static void test_free_pages(gfp_t gfp)
+{
+	unsigned int i;
+
+	for (i = 0; i < 1000 * 1000; i++) {
+		unsigned long addr = __get_free_pages(gfp, 3);
+		struct page *page = virt_to_page((void *)addr);
+
+		/* Simulate page cache getting a speculative reference */
+		get_page(page);
+		free_pages(addr, 3);
+		put_page(page);
+	}
+}
+
+static int m_in(void)
+{
+	pr_info("Testing with GFP_KERNEL\n");
+	test_free_pages(GFP_KERNEL);
+	pr_info("Testing with GFP_KERNEL | __GFP_COMP\n");
+	test_free_pages(GFP_KERNEL | __GFP_COMP);
+	pr_info("Test completed\n");
+
+	return 0;
+}
+
+static void m_ex(void)
+{
+}
+
+module_init(m_in);
+module_exit(m_ex);
+MODULE_AUTHOR("Matthew Wilcox <willy@infradead.org>");
+MODULE_LICENSE("GPL");