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=-11.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=ham 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 C75FFC282F6 for ; Mon, 21 Jan 2019 08:30:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EA582084A for ; Mon, 21 Jan 2019 08:30:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="irk0kpYT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729393AbfAUIal (ORCPT ); Mon, 21 Jan 2019 03:30:41 -0500 Received: from mail-io1-f68.google.com ([209.85.166.68]:42829 "EHLO mail-io1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728554AbfAUIal (ORCPT ); Mon, 21 Jan 2019 03:30:41 -0500 Received: by mail-io1-f68.google.com with SMTP id x6so15743044ioa.9 for ; Mon, 21 Jan 2019 00:30:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=Ww085OACm4i7mqE67ZdIQ/eDnX5lMbW7fzlbmIgXAEk=; b=irk0kpYTWl+fMLn717tgCoPUMr7EWiqL5y7s82Xc9j0VPLy6PAEnLNMuGjDMoFV0Yy 2s6vFd/lJb8XWemgbmryxsgj9dEtQNcd32fDPLB1HsPt+SCVEUwFg4/boDUMEJovqRzI tq52Q6C+gt6cf5wqYzISfoTdLLYBN02u3ujIZskb8jftLw92rTGZZjnJz1hsV9wXrDwk QqRqk/lF7M+Uqv3JWbLC6qUiCXDAOeAg6XTvtuBeOl8E/SF/msImGHKEtZ9pK7L5/RlO LT2jzgZDAGSaMmD8El1xkmk10aw+dR7ee7ENpuhltHJDDXl+vMsj0KbQTq6Ym/yi89P7 X1ng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=Ww085OACm4i7mqE67ZdIQ/eDnX5lMbW7fzlbmIgXAEk=; b=if8Yt9QWU7nf1/HvRVHy8CYywuUfDR9VyZllUyVROqfMG5Cp08VFc/cjgRzWU55YTE TtyJm5iMh9ADyYXRyOSp2sMeX5FwvTvUG8pWCD2hb97sreZ9EN2lCO9HQ8k9N8Y+5TsO 8iyaHxExPoE/E6VwoChpquu8T2Kz+CgIV9SH2FbIqujStAQQDW78YWQAst3+6ziHzPGq UDYXJHK14V2XvCm7n8MO2SQtAvb2kSTtzDPKDKpsv0TaYCeGRxrqQ/Wq1AICr14ZTo0Z 3GcVNN+icB4i5sgZClXqeNptnMq7CUjx6P3XMB5A9NPNBqag3/+Sjf3p7Q9c3qXuDvwi zs3g== X-Gm-Message-State: AJcUukeXuC5HIPu/E01H/VkhNeANIMtew3IG77gbMBL+kxlX61UgiXZz k1lQHp64w6i2c1Jz8f2Qym9ICKvrYrI/OfZBJENVdw== X-Google-Smtp-Source: ALg8bN6pVSUQAGPoALJVcBXrooWWBo6DjGveKj9PCGXAw/Gya0V/2bdBH5M4qgvqAI4lru73E5WrUgt3rKufK0pKDe8= X-Received: by 2002:a5d:8491:: with SMTP id t17mr16024815iom.11.1548059439657; Mon, 21 Jan 2019 00:30:39 -0800 (PST) MIME-Version: 1.0 References: <935f9f83393affb5d55323b126468ecb90373b88.1547289808.git.christophe.leroy@c-s.fr> <8d433501-a5a7-8e3b-03f7-ccdd0f8622e1@c-s.fr> In-Reply-To: <8d433501-a5a7-8e3b-03f7-ccdd0f8622e1@c-s.fr> From: Dmitry Vyukov Date: Mon, 21 Jan 2019 09:30:27 +0100 Message-ID: Subject: Re: [PATCH v3 3/3] powerpc/32: Add KASAN support To: Christophe Leroy Cc: Andrey Ryabinin , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Nicholas Piggin , "Aneesh Kumar K.V" , Alexander Potapenko , LKML , linuxppc-dev@lists.ozlabs.org, kasan-dev , Linux-MM Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 21, 2019 at 8:17 AM Christophe Leroy wrote: > > > > Le 15/01/2019 =C3=A0 18:23, Andrey Ryabinin a =C3=A9crit : > > > > > > On 1/12/19 2:16 PM, Christophe Leroy wrote: > > > >> +KASAN_SANITIZE_early_32.o :=3D n > >> +KASAN_SANITIZE_cputable.o :=3D n > >> +KASAN_SANITIZE_prom_init.o :=3D n > >> + > > > > Usually it's also good idea to disable branch profiling - define DISABL= E_BRANCH_PROFILING > > either in top of these files or via Makefile. Branch profiling redefine= s if() statement and calls > > instrumented ftrace_likely_update in every if(). > > > > > > > >> diff --git a/arch/powerpc/mm/kasan_init.c b/arch/powerpc/mm/kasan_init= .c > >> new file mode 100644 > >> index 000000000000..3edc9c2d2f3e > > > >> +void __init kasan_init(void) > >> +{ > >> + struct memblock_region *reg; > >> + > >> + for_each_memblock(memory, reg) > >> + kasan_init_region(reg); > >> + > >> + pr_info("KASAN init done\n"); > > > > Without "init_task.kasan_depth =3D 0;" kasan will not repot bugs. > > > > There is test_kasan module. Make sure that it produce reports. > > > > Thanks for the review. > > Now I get the following very early in boot, what does that mean ? This looks like an instrumented memset call before kasan shadow is mapped, or kasan shadow is not zeros. Does this happen before or after mapping of kasan_early_shadow_page? This version seems to miss what x86 code has to clear the early shadow: /* * kasan_early_shadow_page has been used as early shadow memory, thus * it may contain some garbage. Now we can clear and write protect it, * since after the TLB flush no one should write to it. */ memset(kasan_early_shadow_page, 0, PAGE_SIZE); > [ 0.000000] KASAN init done > [ 0.000000] > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > [ 0.000000] BUG: KASAN: unknown-crash in memblock_alloc_try_nid+0xd8/0= xf0 > [ 0.000000] Write of size 68 at addr c7ff5a90 by task swapper/0 > [ 0.000000] > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted > 5.0.0-rc2-s3k-dev-00559-g88aa407c4bce #772 > [ 0.000000] Call Trace: > [ 0.000000] [c094ded0] [c016c7e4] > print_address_description+0x1a0/0x2b8 (unreliable) > [ 0.000000] [c094df00] [c016caa0] kasan_report+0xe4/0x168 > [ 0.000000] [c094df40] [c016b464] memset+0x2c/0x4c > [ 0.000000] [c094df60] [c08731f0] memblock_alloc_try_nid+0xd8/0xf0 > [ 0.000000] [c094df90] [c0861f20] mmu_context_init+0x58/0xa0 > [ 0.000000] [c094dfb0] [c085ca70] start_kernel+0x54/0x400 > [ 0.000000] [c094dff0] [c0002258] start_here+0x44/0x9c > [ 0.000000] > [ 0.000000] > [ 0.000000] Memory state around the buggy address: > [ 0.000000] c7ff5980: e2 a1 87 81 bd d4 a5 b5 f8 8d 89 e7 72 bc 20 24 > [ 0.000000] c7ff5a00: e7 b9 c1 c7 17 e9 b4 bd a4 d0 e7 a0 11 15 a5 b5 > [ 0.000000] >c7ff5a80: b5 e1 83 a5 2d 65 31 3f f3 e5 a7 ef 34 b5 69 b5 > [ 0.000000] ^ > [ 0.000000] c7ff5b00: 21 a5 c1 c1 b4 bf 2d e5 e5 c3 f5 91 e3 b8 a1 34 > [ 0.000000] c7ff5b80: ad ef 23 87 3d a6 ad b5 c3 c3 80 b7 ac b1 1f 37 > [ 0.000000] > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > [ 0.000000] Disabling lock debugging due to kernel taint > [ 0.000000] MMU: Allocated 76 bytes of context maps for 16 contexts > [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 817= 6 > [ 0.000000] Kernel command line: console=3DttyCPM0,115200N8 > ip=3D192.168.2.7:192.168.2.2::255.0.0.0:vgoip:eth0:off kgdboc=3DttyCPM0 > [ 0.000000] Dentry cache hash table entries: 16384 (order: 2, 65536 > bytes) > [ 0.000000] Inode-cache hash table entries: 8192 (order: 1, 32768 byte= s) > [ 0.000000] Memory: 99904K/131072K available (7376K kernel code, 528K > rwdata, 1168K rodata, 576K init, 4623K bss, 31168K reserved, 0K > cma-reserved) > [ 0.000000] Kernel virtual memory layout: > [ 0.000000] * 0xffefc000..0xffffc000 : fixmap > [ 0.000000] * 0xf7c00000..0xffc00000 : kasan shadow mem > [ 0.000000] * 0xf7a00000..0xf7c00000 : consistent mem > [ 0.000000] * 0xf7a00000..0xf7a00000 : early ioremap > [ 0.000000] * 0xc9000000..0xf7a00000 : vmalloc & ioremap > > > Christophe