From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f178.google.com (mail-pd0-f178.google.com [209.85.192.178]) by kanga.kvack.org (Postfix) with ESMTP id 3DF296B0099 for ; Mon, 6 Oct 2014 12:01:39 -0400 (EDT) Received: by mail-pd0-f178.google.com with SMTP id y10so3439226pdj.23 for ; Mon, 06 Oct 2014 09:01:38 -0700 (PDT) Received: from mailout3.w1.samsung.com (mailout3.w1.samsung.com. [210.118.77.13]) by mx.google.com with ESMTPS id b3si11062034pdc.11.2014.10.06.09.01.37 for (version=TLSv1 cipher=RC4-MD5 bits=128/128); Mon, 06 Oct 2014 09:01:37 -0700 (PDT) Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0ND1009NU5ZE8M80@mailout3.w1.samsung.com> for linux-mm@kvack.org; Mon, 06 Oct 2014 17:04:26 +0100 (BST) From: Andrey Ryabinin Subject: [RFC PATCH v4 13/13] kasan: introduce inline instrumentation Date: Mon, 06 Oct 2014 19:54:07 +0400 Message-id: <1412610847-27671-14-git-send-email-a.ryabinin@samsung.com> In-reply-to: <1412610847-27671-1-git-send-email-a.ryabinin@samsung.com> References: <1404905415-9046-1-git-send-email-a.ryabinin@samsung.com> <1412610847-27671-1-git-send-email-a.ryabinin@samsung.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: Andrey Ryabinin , Dmitry Vyukov , Konstantin Serebryany , Dmitry Chernenkov , Andrey Konovalov , Yuri Gribov , Konstantin Khlebnikov , Sasha Levin , Christoph Lameter , Joonsoo Kim , Andrew Morton , Dave Hansen , Andi Kleen , Vegard Nossum , "H. Peter Anvin" , Dave Jones , x86@kernel.org, linux-mm@kvack.org, Michal Marek This patch only demonstration how easy this could be achieved. GCC doesn't support this feature yet. Two patches required for this: https://gcc.gnu.org/ml/gcc-patches/2014-09/msg00452.html https://gcc.gnu.org/ml/gcc-patches/2014-09/msg00605.html In inline instrumentation mode compiler directly inserts code checking shadow memory instead of __asan_load/__asan_store calls. This is usually faster than outline. In some workloads inline is 2 times faster than outline instrumentation. The downside of inline instrumentation is bloated kernel's .text size: size noasan/vmlinux text data bss dec hex filename 11759720 1566560 946176 14272456 d9c7c8 noasan/vmlinux size outline/vmlinux text data bss dec hex filename 16553474 1602592 950272 19106338 1238a22 outline/vmlinux size inline/vmlinux text data bss dec hex filename 32064759 1598688 946176 34609623 21019d7 inline/vmlinux Signed-off-by: Andrey Ryabinin --- Makefile | 6 +++++- lib/Kconfig.kasan | 24 ++++++++++++++++++++++++ mm/kasan/kasan.c | 14 +------------- mm/kasan/kasan.h | 22 ++++++++++++++++++++++ mm/kasan/report.c | 37 +++++++++++++++++++++++++++++++++++++ 5 files changed, 89 insertions(+), 14 deletions(-) diff --git a/Makefile b/Makefile index 6f8be78..01cfa71 100644 --- a/Makefile +++ b/Makefile @@ -758,7 +758,11 @@ KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once) endif ifdef CONFIG_KASAN - ifeq ($(CFLAGS_KASAN),) +ifdef CONFIG_KASAN_INLINE +CFLAGS_KASAN += $(call cc-option, -fasan-shadow-offset=$(CONFIG_KASAN_SHADOW_OFFSET)) \ + $(call cc-option, --param asan-instrumentation-with-call-threshold=10000) +endif + ifeq ($(strip $(CFLAGS_KASAN)),) $(warning Cannot use CONFIG_KASAN: \ -fsanitize=kernel-address not supported by compiler) endif diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index 94293c8..ec5d680 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -27,4 +27,28 @@ config TEST_KASAN out of bounds accesses, use after free. It is useful for testing kernel debugging features like kernel address sanitizer. +choice + prompt "Instrumentation type" + depends on KASAN + default KASAN_INLINE if X86_64 + +config KASAN_OUTLINE + bool "Outline instrumentation" + help + Before every memory access compiler insert function call + __asan_load*/__asan_store*. These functions performs check + of shadow memory. This is slower than inline instrumentation, + however it doesn't bloat size of kernel's .text section so + much as inline does. + +config KASAN_INLINE + bool "Inline instrumentation" + help + Compiler directly inserts code checking shadow memory before + memory accesses. This is faster than outline (in some workloads + it gives about x2 boost over outline instrumentation), but + make kernel's .text size much bigger. + +endchoice + endif diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index d4552a2..6e34fdb 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -32,11 +32,6 @@ #include "kasan.h" #include "../slab.h" -static inline bool kasan_enabled(void) -{ - return !current->kasan_depth; -} - /* * Poisons the shadow memory for 'size' bytes starting from 'addr'. * Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE. @@ -250,14 +245,7 @@ static __always_inline void check_memory_region(unsigned long addr, if (likely(!memory_is_poisoned(addr, size))) return; - if (likely(!kasan_enabled())) - return; - - info.access_addr = addr; - info.access_size = size; - info.is_write = write; - info.ip = _RET_IP_; - kasan_report_error(&info); + kasan_report(addr, size, write); } void kasan_alloc_pages(struct page *page, unsigned int order) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index b70a3d1..049349b 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -29,4 +29,26 @@ static inline unsigned long kasan_shadow_to_mem(unsigned long shadow_addr) return (shadow_addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT; } +static inline bool kasan_enabled(void) +{ + return !current->kasan_depth; +} + +static __always_inline void kasan_report(unsigned long addr, + size_t size, + bool is_write) +{ + struct access_info info; + + if (likely(!kasan_enabled())) + return; + + info.access_addr = addr; + info.access_size = size; + info.is_write = is_write; + info.ip = _RET_IP_; + kasan_report_error(&info); +} + + #endif diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 03ce28e..39ec639 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -199,3 +199,40 @@ void kasan_report_user_access(struct access_info *info) "=================================\n"); spin_unlock_irqrestore(&report_lock, flags); } + +#define DEFINE_ASAN_REPORT_LOAD(size) \ +void __asan_report_recover_load##size(unsigned long addr) \ +{ \ + kasan_report(addr, size, false); \ +} \ +EXPORT_SYMBOL(__asan_report_recover_load##size) + +#define DEFINE_ASAN_REPORT_STORE(size) \ +void __asan_report_recover_store##size(unsigned long addr) \ +{ \ + kasan_report(addr, size, true); \ +} \ +EXPORT_SYMBOL(__asan_report_recover_store##size) + +DEFINE_ASAN_REPORT_LOAD(1); +DEFINE_ASAN_REPORT_LOAD(2); +DEFINE_ASAN_REPORT_LOAD(4); +DEFINE_ASAN_REPORT_LOAD(8); +DEFINE_ASAN_REPORT_LOAD(16); +DEFINE_ASAN_REPORT_STORE(1); +DEFINE_ASAN_REPORT_STORE(2); +DEFINE_ASAN_REPORT_STORE(4); +DEFINE_ASAN_REPORT_STORE(8); +DEFINE_ASAN_REPORT_STORE(16); + +void __asan_report_recover_load_n(unsigned long addr, size_t size) +{ + kasan_report(addr, size, false); +} +EXPORT_SYMBOL(__asan_report_recover_load_n); + +void __asan_report_recover_store_n(unsigned long addr, size_t size) +{ + kasan_report(addr, size, true); +} +EXPORT_SYMBOL(__asan_report_recover_store_n); -- 2.1.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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