From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C9ECC4332F for ; Wed, 2 Nov 2022 12:52:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231183AbiKBMwj (ORCPT ); Wed, 2 Nov 2022 08:52:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231171AbiKBMwf (ORCPT ); Wed, 2 Nov 2022 08:52:35 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05352240B5 for ; Wed, 2 Nov 2022 05:52:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=YtVLJDGnn7ITBTMOUDCPITBmCHvZxC85F8h8cyu+d2Y=; b=wStI0I+5aFJGZYgieIMHRamzlN cJkv1hLJsWQC+ELiG6ND3SV24GosCkHQwLhwwcWKeJDN9QG9s17YH+lTZ7TxTu2rUlJbbK7rGZpJQ ki2+vtvMbzI9xMPZIV01B9SJKr377vPE4EBaFZeW725TOZiIcr1akKi7yE4Gr73HYA6Le7Yhpv8En cer5fWFmOe9J/7YMoASt+1mGiT62hsKI3tqM5208K+RE6GZTmbJ1SObHfJaPLoXmC54t1k34ZYemz LDoz/EF/AeHXUiGKuBXOCIOxzHPPp3+n1Hf7R2SeWOl7TsP5GwImV5K14dW5q8M9ZwOGo41rQC686 fgRfTlHg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1oqDER-005WTr-On; Wed, 02 Nov 2022 12:52:35 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id A188630007E; Wed, 2 Nov 2022 13:52:29 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9346B20B1E7E2; Wed, 2 Nov 2022 13:52:29 +0100 (CET) Date: Wed, 2 Nov 2022 13:52:29 +0100 From: Peter Zijlstra To: Alexander Potapenko Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Dmitry Vyukov , Marco Elver Subject: Re: [PATCH 1/5] kmsan: core: kmsan_in_runtime() should return true in NMI context Message-ID: References: <20221102110611.1085175-1-glider@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221102110611.1085175-1-glider@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 02, 2022 at 12:06:07PM +0100, Alexander Potapenko wrote: > Without that, every call to __msan_poison_alloca() in NMI may end up > allocating memory, which is NMI-unsafe. > > Cc: Andrew Morton > Cc: Dmitry Vyukov > Cc: Marco Elver > Cc: Peter Zijlstra (Intel) > Link: https://lore.kernel.org/lkml/20221025221755.3810809-1-glider@google.com/ > Signed-off-by: Alexander Potapenko Acked-by: Peter Zijlstra (Intel) > --- > mm/kmsan/kmsan.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/kmsan/kmsan.h b/mm/kmsan/kmsan.h > index 961eb658020aa..3cd2050a33e6a 100644 > --- a/mm/kmsan/kmsan.h > +++ b/mm/kmsan/kmsan.h > @@ -125,6 +125,8 @@ static __always_inline bool kmsan_in_runtime(void) > { > if ((hardirq_count() >> HARDIRQ_SHIFT) > 1) > return true; > + if (in_nmi()) > + return true; > return kmsan_get_context()->kmsan_in_runtime; > } > > -- > 2.38.1.273.g43a17bfeac-goog >