From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f54.google.com (mail-pa0-f54.google.com [209.85.220.54]) by kanga.kvack.org (Postfix) with ESMTP id 06D066B00CF for ; Mon, 24 Nov 2014 13:02:50 -0500 (EST) Received: by mail-pa0-f54.google.com with SMTP id fb1so9936594pad.41 for ; Mon, 24 Nov 2014 10:02:49 -0800 (PST) Received: from mailout4.w1.samsung.com (mailout4.w1.samsung.com. [210.118.77.14]) by mx.google.com with ESMTPS id kj8si22569609pdb.175.2014.11.24.10.02.46 for (version=TLSv1 cipher=RC4-MD5 bits=128/128); Mon, 24 Nov 2014 10:02:47 -0800 (PST) Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout4.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NFK001LX294DR00@mailout4.w1.samsung.com> for linux-mm@kvack.org; Mon, 24 Nov 2014 18:05:28 +0000 (GMT) From: Andrey Ryabinin Subject: [PATCH v7 07/12] mm: slub: introduce metadata_access_enable()/metadata_access_disable() Date: Mon, 24 Nov 2014 21:02:20 +0300 Message-id: <1416852146-9781-8-git-send-email-a.ryabinin@samsung.com> In-reply-to: <1416852146-9781-1-git-send-email-a.ryabinin@samsung.com> References: <1404905415-9046-1-git-send-email-a.ryabinin@samsung.com> <1416852146-9781-1-git-send-email-a.ryabinin@samsung.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Andrey Ryabinin , Dmitry Vyukov , Konstantin Serebryany , Dmitry Chernenkov , Andrey Konovalov , Yuri Gribov , Konstantin Khlebnikov , Sasha Levin , Christoph Lameter , Joonsoo Kim , Dave Hansen , Andi Kleen , Vegard Nossum , "H. Peter Anvin" , Dave Jones , x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Pekka Enberg , David Rientjes Wrap access to object's metadata in external functions with metadata_access_enable()/metadata_access_disable() function calls. This hooks separates payload accesses from metadata accesses which might be useful for different checkers (e.g. KASan). Signed-off-by: Andrey Ryabinin --- mm/slub.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/mm/slub.c b/mm/slub.c index 0c01584..88ad8b8 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -467,13 +467,23 @@ static int slub_debug; static char *slub_debug_slabs; static int disable_higher_order_debug; +static inline void metadata_access_enable(void) +{ +} + +static inline void metadata_access_disable(void) +{ +} + /* * Object debugging */ static void print_section(char *text, u8 *addr, unsigned int length) { + metadata_access_enable(); print_hex_dump(KERN_ERR, text, DUMP_PREFIX_ADDRESS, 16, 1, addr, length, 1); + metadata_access_disable(); } static struct track *get_track(struct kmem_cache *s, void *object, @@ -503,7 +513,9 @@ static void set_track(struct kmem_cache *s, void *object, trace.max_entries = TRACK_ADDRS_COUNT; trace.entries = p->addrs; trace.skip = 3; + metadata_access_enable(); save_stack_trace(&trace); + metadata_access_disable(); /* See rant in lockdep.c */ if (trace.nr_entries != 0 && @@ -677,7 +689,9 @@ static int check_bytes_and_report(struct kmem_cache *s, struct page *page, u8 *fault; u8 *end; + metadata_access_enable(); fault = memchr_inv(start, value, bytes); + metadata_access_disable(); if (!fault) return 1; @@ -770,7 +784,9 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page) if (!remainder) return 1; + metadata_access_enable(); fault = memchr_inv(end - remainder, POISON_INUSE, remainder); + metadata_access_disable(); if (!fault) return 1; while (end > fault && end[-1] == POISON_INUSE) -- 2.1.3 -- 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