From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f51.google.com (mail-pa0-f51.google.com [209.85.220.51]) by kanga.kvack.org (Postfix) with ESMTP id D85576B0032 for ; Fri, 30 Jan 2015 18:27:58 -0500 (EST) Received: by mail-pa0-f51.google.com with SMTP id fb1so58038131pad.10 for ; Fri, 30 Jan 2015 15:27:58 -0800 (PST) Received: from mail-pa0-x229.google.com (mail-pa0-x229.google.com. [2607:f8b0:400e:c03::229]) by mx.google.com with ESMTPS id be6si15278934pbd.160.2015.01.30.15.27.57 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 30 Jan 2015 15:27:57 -0800 (PST) Received: by mail-pa0-f41.google.com with SMTP id kq14so57979553pab.0 for ; Fri, 30 Jan 2015 15:27:57 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20150130133723.26e6e7f2b8e489a8640abd05@linux-foundation.org> References: <1404905415-9046-1-git-send-email-a.ryabinin@samsung.com> <1422544321-24232-1-git-send-email-a.ryabinin@samsung.com> <1422544321-24232-3-git-send-email-a.ryabinin@samsung.com> <20150129151224.4e7947af78605c199763102c@linux-foundation.org> <54CBAE2E.2030106@samsung.com> <20150130133723.26e6e7f2b8e489a8640abd05@linux-foundation.org> Date: Sat, 31 Jan 2015 03:27:57 +0400 Message-ID: Subject: Re: [PATCH v10 02/17] x86_64: add KASan support From: Andrey Ryabinin Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Andrey Ryabinin , LKML , Dmitry Vyukov , Konstantin Serebryany , Dmitry Chernenkov , Andrey Konovalov , Yuri Gribov , Konstantin Khlebnikov , Sasha Levin , Christoph Lameter , Joonsoo Kim , Dave Hansen , Andi Kleen , "x86@kernel.org" , "linux-mm@kvack.org" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Jonathan Corbet , Andy Lutomirski , "open list:DOCUMENTATION" 2015-01-31 0:37 GMT+03:00 Andrew Morton : > On Fri, 30 Jan 2015 19:15:42 +0300 Andrey Ryabinin wrote: > >> >> --- a/lib/Kconfig.kasan >> >> +++ b/lib/Kconfig.kasan >> >> @@ -5,6 +5,7 @@ if HAVE_ARCH_KASAN >> >> >> >> config KASAN >> >> bool "AddressSanitizer: runtime memory debugger" >> >> + depends on !MEMORY_HOTPLUG >> >> help >> >> Enables address sanitizer - runtime memory debugger, >> >> designed to find out-of-bounds accesses and use-after-free bugs. >> > >> > That's a significant restriction. It has obvious runtime implications. >> > It also means that `make allmodconfig' and `make allyesconfig' don't >> > enable kasan, so compile coverage will be impacted. >> > >> > This wasn't changelogged. What's the reasoning and what has to be done >> > to fix it? >> > >> >> Yes, this is runtime dependency. Hot adding memory won't work. >> Since we don't have shadow for hotplugged memory, kernel will crash on the first access to it. >> To fix this we need to allocate shadow for new memory. >> >> Perhaps it would be better to have a runtime warning instead of Kconfig dependecy? > > Is there a plan to get mem-hotplug working with kasan, btw? It doesn't > strike me as very important/urgent. Please add a sentence about this > to the changelog as well. > I don't have a strict plan for this. I could work on this, but not now -- 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