From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f199.google.com (mail-lj1-f199.google.com [209.85.208.199]) by kanga.kvack.org (Postfix) with ESMTP id 81BDE6B6EA7 for ; Tue, 4 Dec 2018 07:18:49 -0500 (EST) Received: by mail-lj1-f199.google.com with SMTP id e8-v6so4511590ljg.22 for ; Tue, 04 Dec 2018 04:18:49 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id o22-v6sor9778807lji.38.2018.12.04.04.18.47 for (Google Transport Security); Tue, 04 Dec 2018 04:18:47 -0800 (PST) From: Igor Stoppa Subject: [PATCH 5/6] __wr_after_init: test write rare functionality Date: Tue, 4 Dec 2018 14:18:04 +0200 Message-Id: <20181204121805.4621-6-igor.stoppa@huawei.com> In-Reply-To: <20181204121805.4621-1-igor.stoppa@huawei.com> References: <20181204121805.4621-1-igor.stoppa@huawei.com> Reply-To: Igor Stoppa MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Andy Lutomirski , Kees Cook , Matthew Wilcox Cc: igor.stoppa@huawei.com, Nadav Amit , Peter Zijlstra , Dave Hansen , linux-integrity@vger.kernel.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Set of test cases meant to confirm that the write rare functionality works as expected. Signed-off-by: Igor Stoppa CC: Andy Lutomirski CC: Nadav Amit CC: Matthew Wilcox CC: Peter Zijlstra CC: Kees Cook CC: Dave Hansen CC: linux-integrity@vger.kernel.org CC: kernel-hardening@lists.openwall.com CC: linux-mm@kvack.org CC: linux-kernel@vger.kernel.org --- include/linux/prmem.h | 7 ++- mm/Kconfig.debug | 9 +++ mm/Makefile | 1 + mm/test_write_rare.c | 135 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 149 insertions(+), 3 deletions(-) create mode 100644 mm/test_write_rare.c diff --git a/include/linux/prmem.h b/include/linux/prmem.h index b0131c1f5dc0..d2492ec24c8c 100644 --- a/include/linux/prmem.h +++ b/include/linux/prmem.h @@ -125,9 +125,10 @@ static inline void *wr_memcpy(void *p, const void *q, __kernel_size_t size) * * It is provided as macro, to match rcu_assign_pointer() */ -#define wr_rcu_assign_pointer(p, v) ({ \ - __wr_op((unsigned long)&p, v, sizeof(p), WR_RCU_ASSIGN_PTR); \ - p; \ +#define wr_rcu_assign_pointer(p, v) ({ \ + __wr_op((unsigned long)&p, (unsigned long)v, sizeof(p), \ + WR_RCU_ASSIGN_PTR); \ + p; \ }) #endif #endif diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 9a7b8b049d04..a26ecbd27aea 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -94,3 +94,12 @@ config DEBUG_RODATA_TEST depends on STRICT_KERNEL_RWX ---help--- This option enables a testcase for the setting rodata read-only. + +config DEBUG_PRMEM_TEST + tristate "Run self test for statically allocated protected memory" + depends on STRICT_KERNEL_RWX + select PRMEM + default n + help + Tries to verify that the protection for statically allocated memory + works correctly and that the memory is effectively protected. diff --git a/mm/Makefile b/mm/Makefile index ef3867c16ce0..8de1d468f4e7 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -59,6 +59,7 @@ obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o obj-$(CONFIG_SLOB) += slob.o obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o obj-$(CONFIG_PRMEM) += prmem.o +obj-$(CONFIG_DEBUG_PRMEM_TEST) += test_write_rare.o obj-$(CONFIG_KSM) += ksm.o obj-$(CONFIG_PAGE_POISONING) += page_poison.o obj-$(CONFIG_SLAB) += slab.o diff --git a/mm/test_write_rare.c b/mm/test_write_rare.c new file mode 100644 index 000000000000..240cc43793d1 --- /dev/null +++ b/mm/test_write_rare.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * test_write_rare.c + * + * (C) Copyright 2018 Huawei Technologies Co. Ltd. + * Author: Igor Stoppa + */ + +#include +#include +#include +#include +#include + +#ifdef pr_fmt +#undef pr_fmt +#endif + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +extern long __start_wr_after_init; +extern long __end_wr_after_init; + +static __wr_after_init int scalar = '0'; +static __wr_after_init u8 array[PAGE_SIZE * 3] __aligned(PAGE_SIZE); + +/* The section must occupy a non-zero number of whole pages */ +static bool test_alignment(void) +{ + unsigned long pstart = (unsigned long)&__start_wr_after_init; + unsigned long pend = (unsigned long)&__end_wr_after_init; + + if (WARN((pstart & ~PAGE_MASK) || (pend & ~PAGE_MASK) || + (pstart >= pend), "Boundaries test failed.")) + return false; + pr_info("Boundaries test passed."); + return true; +} + +static inline bool test_pattern(void) +{ + return (memtst(array, '0', PAGE_SIZE / 2) || + memtst(array + PAGE_SIZE / 2, '1', PAGE_SIZE * 3 / 4) || + memtst(array + PAGE_SIZE * 5 / 4, '0', PAGE_SIZE / 2) || + memtst(array + PAGE_SIZE * 7 / 4, '1', PAGE_SIZE * 3 / 4) || + memtst(array + PAGE_SIZE * 5 / 2, '0', PAGE_SIZE / 2)); +} + +static bool test_wr_memset(void) +{ + int new_val = '1'; + + wr_memset(&scalar, new_val, sizeof(scalar)); + if (WARN(memtst(&scalar, new_val, sizeof(scalar)), + "Scalar write rare memset test failed.")) + return false; + + pr_info("Scalar write rare memset test passed."); + + wr_memset(array, '0', PAGE_SIZE * 3); + if (WARN(memtst(array, '0', PAGE_SIZE * 3), + "Array write rare memset test failed.")) + return false; + + wr_memset(array + PAGE_SIZE / 2, '1', PAGE_SIZE * 2); + if (WARN(memtst(array + PAGE_SIZE / 2, '1', PAGE_SIZE * 2), + "Array write rare memset test failed.")) + return false; + + wr_memset(array + PAGE_SIZE * 5 / 4, '0', PAGE_SIZE / 2); + if (WARN(memtst(array + PAGE_SIZE * 5 / 4, '0', PAGE_SIZE / 2), + "Array write rare memset test failed.")) + return false; + + if (WARN(test_pattern(), "Array write rare memset test failed.")) + return false; + + pr_info("Array write rare memset test passed."); + return true; +} + +static u8 array_1[PAGE_SIZE * 2]; +static u8 array_2[PAGE_SIZE * 2]; + +static bool test_wr_memcpy(void) +{ + int new_val = 0x12345678; + + wr_assign(scalar, new_val); + if (WARN(memcmp(&scalar, &new_val, sizeof(scalar)), + "Scalar write rare memcpy test failed.")) + return false; + pr_info("Scalar write rare memcpy test passed."); + + wr_memset(array, '0', PAGE_SIZE * 3); + memset(array_1, '1', PAGE_SIZE * 2); + memset(array_2, '0', PAGE_SIZE * 2); + wr_memcpy(array + PAGE_SIZE / 2, array_1, PAGE_SIZE * 2); + wr_memcpy(array + PAGE_SIZE * 5 / 4, array_2, PAGE_SIZE / 2); + + if (WARN(test_pattern(), "Array write rare memcpy test failed.")) + return false; + + pr_info("Array write rare memcpy test passed."); + return true; +} + +static __wr_after_init int *dst; +static int reference = 0x54; + +static bool test_wr_rcu_assign_pointer(void) +{ + wr_rcu_assign_pointer(dst, &reference); + return dst == &reference; +} + +static int __init test_static_wr_init_module(void) +{ + pr_info("static write_rare test"); + if (WARN(!(test_alignment() && + test_wr_memset() && + test_wr_memcpy() && + test_wr_rcu_assign_pointer()), + "static rare-write test failed")) + return -EFAULT; + pr_info("static write_rare test passed"); + return 0; +} + +module_init(test_static_wr_init_module); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Igor Stoppa "); +MODULE_DESCRIPTION("Test module for static write rare."); -- 2.19.1