From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id 1EF4A6B000C for ; Sat, 10 Feb 2018 22:22:35 -0500 (EST) Received: by mail-wr0-f198.google.com with SMTP id i12so6811511wra.22 for ; Sat, 10 Feb 2018 19:22:35 -0800 (PST) Received: from huawei.com (lhrrgout.huawei.com. [194.213.3.17]) by mx.google.com with ESMTPS id l5si2145749edb.260.2018.02.10.19.22.33 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 10 Feb 2018 19:22:33 -0800 (PST) From: Igor Stoppa Subject: [PATCH 5/6] Pmalloc: self-test Date: Sun, 11 Feb 2018 05:19:19 +0200 Message-ID: <20180211031920.3424-6-igor.stoppa@huawei.com> In-Reply-To: <20180211031920.3424-1-igor.stoppa@huawei.com> References: <20180211031920.3424-1-igor.stoppa@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: willy@infradead.org, rdunlap@infradead.org, corbet@lwn.net, keescook@chromium.org, mhocko@kernel.org, labbott@redhat.com, jglisse@redhat.com, hch@infradead.org Cc: cl@linux.com, linux-security-module@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Igor Stoppa Add basic self-test functionality for pmalloc. Signed-off-by: Igor Stoppa --- mm/Kconfig | 9 ++++++++ mm/Makefile | 1 + mm/pmalloc-selftest.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++ mm/pmalloc-selftest.h | 24 ++++++++++++++++++++ mm/pmalloc.c | 2 ++ 5 files changed, 99 insertions(+) create mode 100644 mm/pmalloc-selftest.c create mode 100644 mm/pmalloc-selftest.h diff --git a/mm/Kconfig b/mm/Kconfig index be578fbdce6d..098aefef78b1 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 PROTECTABLE_MEMORY_SELFTEST + 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..f7bbbfde6967 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-$(CONFIG_PROTECTABLE_MEMORY_SELFTEST) += pmalloc-selftest.o obj-$(CONFIG_KSM) += ksm.o obj-$(CONFIG_PAGE_POISONING) += page_poison.o obj-$(CONFIG_SLAB) += slab.o diff --git a/mm/pmalloc-selftest.c b/mm/pmalloc-selftest.c new file mode 100644 index 000000000000..05acd62d23ec --- /dev/null +++ b/mm/pmalloc-selftest.c @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * pmalloc-selftest.c + * + * (C) Copyright 2018 Huawei Technologies Co. Ltd. + * Author: Igor Stoppa + */ + +#include +#include + +#include "pmalloc-selftest.h" + +#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 pmalloc_selftest(void) +{ + struct gen_pool *pool_unprot; + struct gen_pool *pool_prot; + void *var_prot, *var_unprot, *var_vmall; + + pr_notice("pmalloc self-test"); + pool_unprot = pmalloc_create_pool("unprotected", 0); + pool_prot = pmalloc_create_pool("protected", 0); + BUG_ON(!(pool_unprot && pool_prot)); + + 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. + */ + pmalloc_destroy_pool(pool_unprot); + + /* This must not cause WARNings */ + pmalloc_destroy_pool(pool_prot); +} diff --git a/mm/pmalloc-selftest.h b/mm/pmalloc-selftest.h new file mode 100644 index 000000000000..63e430de74f8 --- /dev/null +++ b/mm/pmalloc-selftest.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * pmalloc-selftest.h + * + * (C) Copyright 2018 Huawei Technologies Co. Ltd. + * Author: Igor Stoppa + */ + + +#ifndef __MM_PMALLOC_SELFTEST_H +#define __MM_PMALLOC_SELFTEST_H + + +#ifdef CONFIG_PROTECTABLE_MEMORY_SELFTEST + +void pmalloc_selftest(void); + +#else + +static inline void pmalloc_selftest(void){}; + +#endif + +#endif diff --git a/mm/pmalloc.c b/mm/pmalloc.c index e94bfb407c92..c9a472730afc 100644 --- a/mm/pmalloc.c +++ b/mm/pmalloc.c @@ -22,6 +22,7 @@ #include #include +#include "pmalloc-selftest.h" /* * pmalloc_data contains the data specific to a pmalloc pool, * in a format compatible with the design of gen_alloc. @@ -492,6 +493,7 @@ static int __init pmalloc_late_init(void) } } mutex_unlock(&pmalloc_mutex); + pmalloc_selftest(); return 0; } late_initcall(pmalloc_late_init); -- 2.14.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org