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 X-Spam-Level: X-Spam-Status: No, score=-14.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47E7FC433E0 for ; Wed, 3 Feb 2021 18:38:48 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D6C7B64F65 for ; Wed, 3 Feb 2021 18:38:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D6C7B64F65 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4fVbTdYGiW7zs5Cj01TMBoFvJzcp4YZrwZaQfW89UmU=; b=o2AQSWzEHeUGMHD4ZOdIvtdm9 BT35lmbxQTCFkoOP7UzsN9zFe54w2ReXPlRuM2IgixR4hsK2R0kWNO1mxhheRIRaMMKDyAdhAhSYH cEgiKGMUXxPaXPG32tvwFBMl3eQf9P8cuJqQS1inFjBn63NS3zRr7OLRYLACgoFS+Mm/1idIwV1rK hIphzZI+o5WEleX8rozOhDUlqZVjEq6WUMjAj2Q6Z1TMldVJocgqf5SehzwXQumxCUPlDrfM1H/BD EHCQYFHw2vyOPC+8VWDPybqwWs8bgea1gRpMCwbp5N6j/SJ+u5Gwb2RJT3HVbhoSVyZ0BSgvOI5Md jSS76yIcw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l7N1y-0005ty-5S; Wed, 03 Feb 2021 18:37:34 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l7N1v-0005tW-N0; Wed, 03 Feb 2021 18:37:32 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id B185864E34; Wed, 3 Feb 2021 18:37:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612377450; bh=3giaFRH1j9PVmzyZwv3HjY0DTQs3tZkZzQ8m1nc4mNg=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=UKpOsqrXPhh2J4MabEYv9pDGdajv4XjOL7hpTw2yiP+4kYP4oJo8FVd0iHO6eLA+d uUxt+1U0/Y7RFnuzOGAQigFDWYuTKbC5dVhZk71coTGV5MT/IX8PoN+8XQMsXlEuy/ DSEFwVrLUmKKZtoy3KCaPhjNzA2hdantHnAHWC91GpHYfiYKawj/Hw/xGFrWs3qwSb buJ0AhEwkX3UXUOmaxEF+DNxV2KP7lfRUNJbTCxWYNp8/PqOoJJ3DZ0Gucefn8UIQl 2vNbkpA8mw7Z+kmelm61kFgflvIjghJU/9bNHmQ3YZZabrpJNCdv4T6b1Tuf/XUaJO fuCqWe4BgPnWg== Received: by mail-oi1-f172.google.com with SMTP id h6so925022oie.5; Wed, 03 Feb 2021 10:37:30 -0800 (PST) X-Gm-Message-State: AOAM531OxJnAocc7p89OyOoQoiXhhDR8CeTx1UQ5ZCNlx7CpxRD1oFjZ 5s/oWoH9Pxg10BVWr/1JPFNvYuUh4MOkTVDZT60= X-Google-Smtp-Source: ABdhPJwTcKGhhrhcSXeU83MadiHuFOevZ5EXyyScTqYjD6/o+QLIP4TAi8X/UM98hvguCOQr900onLCBTaId+ZK8RP4= X-Received: by 2002:aca:ea0b:: with SMTP id i11mr2899751oih.33.1612377449888; Wed, 03 Feb 2021 10:37:29 -0800 (PST) MIME-Version: 1.0 References: <20210109103252.812517-1-lecopzer@gmail.com> <20210109103252.812517-2-lecopzer@gmail.com> In-Reply-To: <20210109103252.812517-2-lecopzer@gmail.com> From: Ard Biesheuvel Date: Wed, 3 Feb 2021 19:37:18 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 1/4] arm64: kasan: don't populate vmalloc area for CONFIG_KASAN_VMALLOC To: Lecopzer Chen X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210203_133731_912858_5B66701D X-CRM114-Status: GOOD ( 20.93 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lecopzer Chen , Catalin Marinas , "Gustavo A. R. Silva" , Linux Memory Management List , Tyler Hicks , Alexander Potapenko , Vincenzo Frascino , Will Deacon , yj.chiang@mediatek.com, kasan-dev , Linux ARM , Andrey Ryabinin , Guenter Roeck , Andrey Konovalov , Mark Brown , linux-mediatek@lists.infradead.org, Dan Williams , Dmitry Vyukov , Linux Kernel Mailing List , Andrew Morton , Robin Murphy , Mike Rapoport Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, 9 Jan 2021 at 11:33, Lecopzer Chen wrote: > > Linux support KAsan for VMALLOC since commit 3c5c3cfb9ef4da9 > ("kasan: support backing vmalloc space with real shadow memory") > > Like how the MODULES_VADDR does now, just not to early populate > the VMALLOC_START between VMALLOC_END. > similarly, the kernel code mapping is now in the VMALLOC area and > should keep these area populated. > > Signed-off-by: Lecopzer Chen This commit log text is a bit hard to follow. You are saying that the vmalloc region is *not* backed with zero shadow or any default mapping at all, right, and everything gets allocated on demand, just like is the case for modules? > --- > arch/arm64/mm/kasan_init.c | 23 ++++++++++++++++++----- > 1 file changed, 18 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c > index d8e66c78440e..39b218a64279 100644 > --- a/arch/arm64/mm/kasan_init.c > +++ b/arch/arm64/mm/kasan_init.c > @@ -214,6 +214,7 @@ static void __init kasan_init_shadow(void) > { > u64 kimg_shadow_start, kimg_shadow_end; > u64 mod_shadow_start, mod_shadow_end; > + u64 vmalloc_shadow_start, vmalloc_shadow_end; > phys_addr_t pa_start, pa_end; > u64 i; > > @@ -223,6 +224,9 @@ static void __init kasan_init_shadow(void) > mod_shadow_start = (u64)kasan_mem_to_shadow((void *)MODULES_VADDR); > mod_shadow_end = (u64)kasan_mem_to_shadow((void *)MODULES_END); > > + vmalloc_shadow_start = (u64)kasan_mem_to_shadow((void *)VMALLOC_START); > + vmalloc_shadow_end = (u64)kasan_mem_to_shadow((void *)VMALLOC_END); > + This and the below seems overly complicated, given that VMALLOC_START == MODULES_END. Can we simplify this? > /* > * We are going to perform proper setup of shadow memory. > * At first we should unmap early shadow (clear_pgds() call below). > @@ -241,12 +245,21 @@ static void __init kasan_init_shadow(void) > > kasan_populate_early_shadow(kasan_mem_to_shadow((void *)PAGE_END), > (void *)mod_shadow_start); > - kasan_populate_early_shadow((void *)kimg_shadow_end, > - (void *)KASAN_SHADOW_END); > + if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) { > + kasan_populate_early_shadow((void *)vmalloc_shadow_end, > + (void *)KASAN_SHADOW_END); > + if (vmalloc_shadow_start > mod_shadow_end) > + kasan_populate_early_shadow((void *)mod_shadow_end, > + (void *)vmalloc_shadow_start); > + > + } else { > + kasan_populate_early_shadow((void *)kimg_shadow_end, > + (void *)KASAN_SHADOW_END); > + if (kimg_shadow_start > mod_shadow_end) > + kasan_populate_early_shadow((void *)mod_shadow_end, > + (void *)kimg_shadow_start); > + } > > - if (kimg_shadow_start > mod_shadow_end) > - kasan_populate_early_shadow((void *)mod_shadow_end, > - (void *)kimg_shadow_start); > > for_each_mem_range(i, &pa_start, &pa_end) { > void *start = (void *)__phys_to_virt(pa_start); > -- > 2.25.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel