From patchwork Wed Feb 28 20:06:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Stoppa X-Patchwork-Id: 10249579 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 210C660211 for ; Wed, 28 Feb 2018 20:11:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0F65B28B0C for ; Wed, 28 Feb 2018 20:11:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 03AC328DF3; Wed, 28 Feb 2018 20:11:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id D4F7B28B0C for ; Wed, 28 Feb 2018 20:11:01 +0000 (UTC) Received: (qmail 15420 invoked by uid 550); 28 Feb 2018 20:11:00 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 15391 invoked from network); 28 Feb 2018 20:10:59 -0000 From: Igor Stoppa To: , , , CC: , , , , , Igor Stoppa Subject: [PATCH 5/7] Pmalloc selftest Date: Wed, 28 Feb 2018 22:06:18 +0200 Message-ID: <20180228200620.30026-6-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180228200620.30026-1-igor.stoppa@huawei.com> References: <20180228200620.30026-1-igor.stoppa@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.122.225.51] X-CFilter-Loop: Reflected X-Virus-Scanned: ClamAV using ClamSMTP Add basic self-test functionality for pmalloc. The testing is introduced as early as possible, right after the main dependency, genalloc, has passed successfully, so that it can help diagnosing failures in pmalloc users. Signed-off-by: Igor Stoppa Reviewed-by: Jay Freyensee --- include/linux/test_pmalloc.h | 24 +++++++++++ init/main.c | 2 + mm/Kconfig | 10 +++++ mm/Makefile | 1 + mm/test_pmalloc.c | 100 +++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 137 insertions(+) create mode 100644 include/linux/test_pmalloc.h create mode 100644 mm/test_pmalloc.c diff --git a/include/linux/test_pmalloc.h b/include/linux/test_pmalloc.h new file mode 100644 index 000000000000..c7e2e451c17c --- /dev/null +++ b/include/linux/test_pmalloc.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * test_pmalloc.h + * + * (C) Copyright 2018 Huawei Technologies Co. Ltd. + * Author: Igor Stoppa + */ + + +#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 diff --git a/init/main.c b/init/main.c index 2bf1312fd2fe..ea44c940070a 100644 --- a/init/main.c +++ b/init/main.c @@ -91,6 +91,7 @@ #include #include #include +#include #include #include @@ -663,6 +664,7 @@ asmlinkage __visible void __init start_kernel(void) mem_encrypt_init(); test_genalloc(); + 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) { diff --git a/mm/Kconfig b/mm/Kconfig index 016d29b9400b..47b0843b02d2 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -767,3 +767,13 @@ config PROTECTABLE_MEMORY depends on ARCH_HAS_SET_MEMORY select GENERIC_ALLOCATOR 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. diff --git a/mm/Makefile b/mm/Makefile index 959fdbdac118..1de4be5fd0bc 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -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 diff --git a/mm/test_pmalloc.c b/mm/test_pmalloc.c new file mode 100644 index 000000000000..df7ecc91c6a4 --- /dev/null +++ b/mm/test_pmalloc.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * test_pmalloc.c + * + * (C) Copyright 2018 Huawei Technologies Co. Ltd. + * Author: Igor Stoppa + */ + +#include +#include +#include +#include + +#define SIZE_1 (PAGE_SIZE * 3) +#define SIZE_2 1000 + +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) + +void test_pmalloc(void) +{ + struct gen_pool *pool_unprot; + struct gen_pool *pool_prot; + void *var_prot, *var_unprot, *var_vmall; + + pr_notice("pmalloc-selftest"); + pool_unprot = pmalloc_create_pool("unprotected", 0); + if (unlikely(!pool_unprot)) + goto error; + pool_prot = pmalloc_create_pool("protected", 0); + if (unlikely(!(pool_prot))) + goto error_release; + + pr_notice("Testing allocation capability"); + var_unprot = pmalloc(pool_unprot, SIZE_1 - 1, GFP_KERNEL); + var_prot = pmalloc(pool_prot, SIZE_1, GFP_KERNEL); + *(int *)var_prot = 0; + var_vmall = vmalloc(SIZE_2); + + + pr_notice("Test correctness of is_pmalloc_object()"); + WARN_ON(unlikely(!is_alloc_ok(var_unprot, 10))); + WARN_ON(unlikely(!is_alloc_ok(var_unprot, SIZE_1))); + WARN_ON(unlikely(!is_alloc_ok(var_unprot, PAGE_SIZE))); + WARN_ON(unlikely(!is_alloc_no(var_unprot, SIZE_1 + 1))); + WARN_ON(unlikely(!is_alloc_no(var_vmall, 10))); + + + pfree(pool_unprot, var_unprot); + vfree(var_vmall); + + pmalloc_protect_pool(pool_prot); + + /* + * This will intentionally trigger a WARN, because the pool being + * allocated from is already protected. + */ + pr_notice("Test allocation from a protected pool." + "Expect WARN in pmalloc"); + if (unlikely(pmalloc(pool_prot, 10, GFP_KERNEL))) + WARN(true, "no memory from a protected pool"); + + /* + * This will intentionally trigger a WARN because the pool being + * destroyed is not protected, which is unusual and should happen + * on error paths only, where probably other warnings are already + * displayed. + */ + pr_notice("pmalloc-selftest:" + " Expect WARN in pmalloc_pool_set_protection below."); + pmalloc_destroy_pool(pool_unprot); + pr_notice("pmalloc-selftest:" + "Critical point for expected WARN passed."); + + /* This must not cause WARNings */ + pr_notice("pmalloc-selftest:" + "Expect no WARN below."); + pmalloc_destroy_pool(pool_prot); + pr_notice("pmalloc-selftest:" + "Critical point for unexpected WARN passed."); + return; +error_release: + pmalloc_destroy_pool(pool_unprot); +error: + WARN(true, "Unable to allocate memory for pmalloc selftest."); +}