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 860F3C433FE for ; Wed, 2 Nov 2022 11:06:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230336AbiKBLGh (ORCPT ); Wed, 2 Nov 2022 07:06:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230370AbiKBLGd (ORCPT ); Wed, 2 Nov 2022 07:06:33 -0400 Received: from mail-wr1-x44a.google.com (mail-wr1-x44a.google.com [IPv6:2a00:1450:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2826529C83 for ; Wed, 2 Nov 2022 04:06:25 -0700 (PDT) Received: by mail-wr1-x44a.google.com with SMTP id d23-20020adfa417000000b002364a31b7c9so4682909wra.15 for ; Wed, 02 Nov 2022 04:06:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=WrClR7h0c/XU2pAfJHOZckEycFJJtsgVk0eEUZJfByQ=; b=p8C9AfvzfTHb4amAZyR7Huo6iTM2OmZ596wuVutv4RMIjPVHhzGcRhijW0Wdzbgz/4 mg8h+O0U7SL3esE9xQvb/5kztONm+5qgbpw+tJlE//0bLZKuFkjRAzzQj+0wx1PDrFL6 Gauls6F4ST7RPiHkY++x7dd+3pFWOzDJv/RKpYF7ClI+YHFIqhcGVGIZOl7rqs/xFadg JoL4S1a87PsVKKh6JjnOfr+h9u34ulSYmsJAwMO91rHcN2Iy4iWb7e3lSQdY6fNFQ1ky oJ0NvFIbyshMi4t2Q/NN65+FNBXzM8tc6cSwn+oFCnYObruLNwf8GKhvRyngWCXgMNCu nieA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=WrClR7h0c/XU2pAfJHOZckEycFJJtsgVk0eEUZJfByQ=; b=Fkj0wGbRuEOzGfSMKkuwKKydff6CpzFQgzN+ABOsco+lsN+/OBObvfeE/pQVFWvRm4 5y4Lhw0/ItsNDIHDyQNaW8MHSV6tEjgWhrhKjtjRfDGhFZjGyTFnvB5VeaUEfVrv+D4p 5QmPyO8NucyM61/YSccjz/RNvxCn8pWywjUAgBzygJycqxHysH5ukGgGG9W/EWrA5Kzy 8iUIARPwoKBLu1YmPhkhl4pM6+eXOVmAcgd6AWoVcxvzMTPxEcApc4vp0SghGeWMBY94 FzP1GxPtJaxXuxCU2HArjkqkq7vif0hrQDg9X9WcHl3SpWBLjASbdj935PeAHs69AAqh 9ufg== X-Gm-Message-State: ACrzQf1L0yr2EGljHpuQwcsMlyfb7UEpVyBGqZJ2EaG08L6Z/TK4HRQJ +cpdUGfYE/AdNKOpAtIv3lvFYwZtG7A= X-Google-Smtp-Source: AMsMyM74mWMhrgnaynccgvDcG2odp7kJoqQH6hJmlTrNDoPthPuQMBlGWcgbtLnfVHNrarTgP4wSHzfbzMc= X-Received: from glider.muc.corp.google.com ([2a00:79e0:9c:201:7f41:af20:8:a96d]) (user=glider job=sendgmr) by 2002:adf:dd91:0:b0:236:a261:6930 with SMTP id x17-20020adfdd91000000b00236a2616930mr14444934wrl.551.1667387183641; Wed, 02 Nov 2022 04:06:23 -0700 (PDT) Date: Wed, 2 Nov 2022 12:06:10 +0100 In-Reply-To: <20221102110611.1085175-1-glider@google.com> Mime-Version: 1.0 References: <20221102110611.1085175-1-glider@google.com> X-Mailer: git-send-email 2.38.1.273.g43a17bfeac-goog Message-ID: <20221102110611.1085175-4-glider@google.com> Subject: [PATCH 4/5] kmsan: make sure PREEMPT_RT is off From: Alexander Potapenko To: glider@google.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Dmitry Vyukov , Marco Elver , Peter Zijlstra Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As pointed out by Peter Zijlstra, __msan_poison_alloca() does not play well with IRQ code when PREEMPT_RT is on, because in that mode even GFP_ATOMIC allocations cannot be performed. Fixing this would require making stackdepot completely lockless, which is quite challenging and may be excessive for the time being. Instead, make sure KMSAN is incompatible with PREEMPT_RT, like other debug configs are. 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 --- lib/Kconfig.kmsan | 1 + 1 file changed, 1 insertion(+) diff --git a/lib/Kconfig.kmsan b/lib/Kconfig.kmsan index b2489dd6503fa..ef2c8f256c57d 100644 --- a/lib/Kconfig.kmsan +++ b/lib/Kconfig.kmsan @@ -12,6 +12,7 @@ config KMSAN bool "KMSAN: detector of uninitialized values use" depends on HAVE_ARCH_KMSAN && HAVE_KMSAN_COMPILER depends on SLUB && DEBUG_KERNEL && !KASAN && !KCSAN + depends on !PREEMPT_RT select STACKDEPOT select STACKDEPOT_ALWAYS_INIT help -- 2.38.1.273.g43a17bfeac-goog