From patchwork Fri Feb 23 14:48:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Stoppa X-Patchwork-Id: 10237957 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 5086D602A0 for ; Fri, 23 Feb 2018 14:51:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4085A29666 for ; Fri, 23 Feb 2018 14:51:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 354CD2966E; Fri, 23 Feb 2018 14:51:59 +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 410D529666 for ; Fri, 23 Feb 2018 14:51:57 +0000 (UTC) Received: (qmail 32405 invoked by uid 550); 23 Feb 2018 14:51:56 -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 32380 invoked from network); 23 Feb 2018 14:51:55 -0000 From: Igor Stoppa To: , , , CC: , , , , , Igor Stoppa Subject: [PATCH 5/7] Pmalloc selftest Date: Fri, 23 Feb 2018 16:48:05 +0200 Message-ID: <20180223144807.1180-6-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180223144807.1180-1-igor.stoppa@huawei.com> References: <20180223144807.1180-1-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 | 9 +++++ mm/Makefile | 1 + mm/test_pmalloc.c | 79 ++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 115 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 bfccf1fd463c..a61e3a5fd321 100644 --- a/init/main.c +++ b/init/main.c @@ -90,6 +90,7 @@ #include #include #include +#include #include #include @@ -662,6 +663,7 @@ 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 be578fbdce6d..81dcc5345631 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -766,3 +766,12 @@ 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 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..5de21c462d3d --- /dev/null +++ b/mm/test_pmalloc.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * test_pmalloc.c + * + * (C) Copyright 2018 Huawei Technologies Co. Ltd. + * Author: Igor Stoppa + */ + +#include +#include +#include + +#define SIZE_1 (PAGE_SIZE * 3) +#define SIZE_2 1000 + +#define validate_alloc(expected, variable, size) \ + pr_notice("must be " expected ": %s", \ + is_pmalloc_object(variable, size) > 0 ? "ok" : "no") + +#define is_alloc_ok(variable, size) \ + validate_alloc("ok", variable, size) + +#define is_alloc_no(variable, size) \ + validate_alloc("no", 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; + + 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); + is_alloc_ok(var_unprot, 10); + is_alloc_ok(var_unprot, SIZE_1); + is_alloc_ok(var_unprot, PAGE_SIZE); + is_alloc_no(var_unprot, SIZE_1 + 1); + 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 + * 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."); +}