[PATCH 4/6] Pmalloc selftest

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * test_pmalloc.h
+ *
+ * (C) Copyright 2018 Huawei Technologies Co. Ltd.
+ * Author: Igor Stoppa <igor.stoppa@huawei.com>
+ */
+
+
+#ifndef __LINUX_TEST_PMALLOC_H
+#define __LINUX_TEST_PMALLOC_H
+
+
+#ifdef CONFIG_TEST_PROTECTABLE_MEMORY
+
+void test_pmalloc(void);
+
+#else
+
+static inline void test_pmalloc(void){};
+
+#endif
+
+#endif

@@ -90,6 +90,7 @@
 #include <linux/cache.h>
 #include <linux/rodata_test.h>
 #include <linux/jump_label.h>
+#include <linux/test_pmalloc.h>
 
 #include <asm/io.h>
 #include <asm/bugs.h>

@@ -661,6 +662,7 @@ asmlinkage __visible void __init start_kernel(void)
 	 */
 	mem_encrypt_init();
 
+	test_pmalloc();
 #ifdef CONFIG_BLK_DEV_INITRD
 	if (initrd_start && !initrd_below_start_ok &&
 	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {

@@ -766,3 +766,13 @@ config PROTECTABLE_MEMORY
     depends on MMU
     depends on ARCH_HAS_SET_MEMORY
     default y
+
+config TEST_PROTECTABLE_MEMORY
+	bool "Run self test for pmalloc memory allocator"
+        depends on MMU
+	depends on ARCH_HAS_SET_MEMORY
+	select PROTECTABLE_MEMORY
+	default n
+	help
+	  Tries to verify that pmalloc works correctly and that the memory
+	  is effectively protected.

@@ -66,6 +66,7 @@ obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
 obj-$(CONFIG_SLOB) += slob.o
 obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o
 obj-$(CONFIG_PROTECTABLE_MEMORY) += pmalloc.o
+obj-$(CONFIG_TEST_PROTECTABLE_MEMORY) += test_pmalloc.o
 obj-$(CONFIG_KSM) += ksm.o
 obj-$(CONFIG_PAGE_POISONING) += page_poison.o
 obj-$(CONFIG_SLAB) += slab.o

@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * test_pmalloc.c
+ *
+ * (C) Copyright 2018 Huawei Technologies Co. Ltd.
+ * Author: Igor Stoppa <igor.stoppa@huawei.com>
+ */
+
+#include <linux/pmalloc.h>
+#include <linux/mm.h>
+#include <linux/test_pmalloc.h>
+#include <linux/bug.h>
+
+#define SIZE_1 (PAGE_SIZE * 3)
+#define SIZE_2 1000
+
+
+/* wrapper for is_pmalloc_object() with messages */
+static inline bool validate_alloc(bool expected, void *addr,
+				  unsigned long size)
+{
+	bool test;
+
+	test = is_pmalloc_object(addr, size) > 0;
+	pr_notice("must be %s: %s",
+		  expected ? "ok" : "no", test ? "ok" : "no");
+	return test == expected;
+}
+
+
+#define is_alloc_ok(variable, size)	\
+	validate_alloc(true, variable, size)
+
+
+#define is_alloc_no(variable, size)	\
+	validate_alloc(false, variable, size)
+
+/* tests the basic life-cycle of a pool */
+static bool create_and_destroy_pool(void)
+{
+	static struct pmalloc_pool *pool;
+
+	pr_notice("Testing pool creation and destruction capability");
+
+	pool = pmalloc_create_pool();
+	if (WARN(!pool, "Cannot allocate memory for pmalloc selftest."))
+		return false;
+	pmalloc_destroy_pool(pool);
+	return true;
+}
+
+
+/*  verifies that it's possible to allocate from the pool */
+static bool test_alloc(void)
+{
+	static struct pmalloc_pool *pool;
+	static void *p;
+
+	pr_notice("Testing allocation capability");
+	pool = pmalloc_create_pool();
+	if (WARN(!pool, "Unable to allocate memory for pmalloc selftest."))
+		return false;
+	p = pmalloc(pool,  SIZE_1 - 1);
+	pmalloc_protect_pool(pool);
+	pmalloc_destroy_pool(pool);
+	if (WARN(!p, "Failed to allocate memory from the pool"))
+		return false;
+	return true;
+}
+
+
+/* tests the identification of pmalloc ranges */
+static bool test_is_pmalloc_object(void)
+{
+	struct pmalloc_pool *pool;
+	void *pmalloc_p;
+	void *vmalloc_p;
+	bool retval = false;
+
+	pr_notice("Test correctness of is_pmalloc_object()");
+
+	vmalloc_p = vmalloc(SIZE_1);
+	if (WARN(!vmalloc_p,
+		 "Unable to allocate memory for pmalloc selftest."))
+		return false;
+	pool = pmalloc_create_pool();
+	if (WARN(!pool, "Unable to allocate memory for pmalloc selftest."))
+		return false;
+	pmalloc_p = pmalloc(pool,  SIZE_1 - 1);
+	if (WARN(!pmalloc_p, "Failed to allocate memory from the pool"))
+		goto error;
+	if (WARN_ON(unlikely(!is_alloc_ok(pmalloc_p, 10))) ||
+	    WARN_ON(unlikely(!is_alloc_ok(pmalloc_p, SIZE_1))) ||
+	    WARN_ON(unlikely(!is_alloc_ok(pmalloc_p, PAGE_SIZE))) ||
+	    WARN_ON(unlikely(!is_alloc_no(pmalloc_p, SIZE_1 + 1))) ||
+	    WARN_ON(unlikely(!is_alloc_no(vmalloc_p, 10))))
+		goto error;
+	retval = true;
+error:
+	pmalloc_protect_pool(pool);
+	pmalloc_destroy_pool(pool);
+	return retval;
+}
+
+/* Test out of virtually contiguous memory */
+static void test_oovm(void)
+{
+	struct pmalloc_pool *pool;
+	int i;
+
+	pr_notice("Exhaust vmalloc memory with doubling allocations.");
+	pool = pmalloc_create_pool();
+	if (WARN(!pool, "Failed to create pool"))
+		return;
+	for (i = 1; i; i *= 2)
+		if (unlikely(!pzalloc(pool, i - 1)))
+			break;
+	pr_notice("vmalloc oom at %d allocation", i - 1);
+	pmalloc_protect_pool(pool);
+	pmalloc_destroy_pool(pool);
+}
+
+/**
+ * test_pmalloc()  -main entry point for running the test cases
+ */
+void test_pmalloc(void)
+{
+
+	pr_notice("pmalloc-selftest");
+
+	if (unlikely(!(create_and_destroy_pool() &&
+		       test_alloc() &&
+		       test_is_pmalloc_object())))
+		return;
+	test_oovm();
+}