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[209.132.180.67]) by mx.google.com with ESMTP id n3si4819366plk.108.2019.03.07.12.33.53; Thu, 07 Mar 2019 12:34:09 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=HxeY3u5R; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726241AbfCGUde (ORCPT + 99 others); Thu, 7 Mar 2019 15:33:34 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:37798 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726166AbfCGUde (ORCPT ); Thu, 7 Mar 2019 15:33:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=fkYaEH8Lve4sR/la9f9snjahXKQZ/tlT69AaKb0XkEw=; b=HxeY3u5RbjH0XvRTaiKF7GPlA JOgZjD+37kRedW1+359cNSZDkKp4moPVQdeVhfvkrT8pOHWaE8krfKdrit7lnNxWsZOlcXjWNLjKe pBq1lEkMeQOizjyDa14ZTlYe9VLrvedbRMQY97WwGy2Bym5Tx7WL94RFunkqeTqPPwyN55OIpX4mS tpiBy0bmOq1zcT2IA16autCOjsO672ukIgK21uZ9+nEVC0rhZLXN2v7CV+Q3cq/bQxJyutNnLe+aN XXXTFT4gdcBKto4UvJThSZzgQjhWTIKOAJHDDDo9bGg11ijlJ0sqlZ1sxJts3iuRSTBKyOxVYvlG2 OFJDqdMQw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1h1zhg-0007XV-KZ; Thu, 07 Mar 2019 20:33:20 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 29D3020297BBE; Thu, 7 Mar 2019 21:33:18 +0100 (CET) Date: Thu, 7 Mar 2019 21:33:18 +0100 From: Peter Zijlstra To: Andrey Ryabinin Cc: Linus Torvalds , Thomas Gleixner , Peter Anvin , Julien Thierry , Will Deacon , Andy Lutomirski , Ingo Molnar , Catalin Marinas , James Morse , valentin.schneider@arm.com, Brian Gerst , Josh Poimboeuf , Andrew Lutomirski , Borislav Petkov , Denys Vlasenko , Linux List Kernel Mailing , Dmitry Vyukov , Steven Rostedt Subject: Re: [PATCH 18/20] objtool: Add UACCESS validation Message-ID: <20190307203318.GM32477@hirez.programming.kicks-ass.net> References: <20190307114511.870090179@infradead.org> <20190307115200.697533978@infradead.org> <20190307174135.GJ32477@hirez.programming.kicks-ass.net> <6a4875bd-2b22-91e4-cbe2-b01c12786a1b@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6a4875bd-2b22-91e4-cbe2-b01c12786a1b@virtuozzo.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 07, 2019 at 11:15:42PM +0300, Andrey Ryabinin wrote: > > > On 3/7/19 8:41 PM, Peter Zijlstra wrote: > > On Thu, Mar 07, 2019 at 08:33:26AM -0800, Linus Torvalds wrote: > >> On Thu, Mar 7, 2019 at 3:52 AM Peter Zijlstra wrote: > >>> > >>> XXX: are we sure we want __memset marked AC-safe? > >> > >> It's certainly one of the safer functions to call with AC set, but it > >> sounds wrong anyway. It's not like it's likely to leak kernel data > >> (most memset's are with 0, and even the non-zero ones I can't imagine > >> are sensitive - more like poison values etc). > >> > >> What's the call site that made you go "just add __memset() to the list"? > > > > __asan_{,un}poinson_stack_memory() > > These two can be called only with CONFIG_KASAN_EXTRA=y which > was removed very recently, so it should be safe to delete these functions. Ooh shiny. Clearly my tree still has them; what commit do I need to look for?