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=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 8D164C3A59B for ; Mon, 19 Aug 2019 08:43:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49212206DF for ; Mon, 19 Aug 2019 08:43:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="jIcYdSUC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727263AbfHSIna (ORCPT ); Mon, 19 Aug 2019 04:43:30 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:42940 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725536AbfHSIn3 (ORCPT ); Mon, 19 Aug 2019 04:43:29 -0400 Received: by mail-wr1-f65.google.com with SMTP id b16so7783812wrq.9 for ; Mon, 19 Aug 2019 01:43:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:openpgp:autocrypt:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=sp6JOe2UVBs6PLytrxxuOCrhswEeaqVUNhszYrb2k9w=; b=jIcYdSUCecb2h/hqtX52oMRLGd/EW3h/SFIaR/b2ltMRaY9loJSNOfbnTEifkE42n9 b1bx4Cso0ouoo1qZCWdlxyNxF2VqvrziE08WNlHivn+zmwLd3OIWc06uNAFzjDiDNtMx ry9KJBiUEsy9sarx8TSV8x4IfbnvJx4cO1YWLjLxC0XGIMTpfEJru7PNkK1j7tT/Chow szn9e7YZWJ1gQPXBAWRg6yBFwjPktJ8Y3jOmKmHj809M53mWASMs4AeHRMwQI/BB8q/l 0yFFtH0FrmGTaGxdTAWAb69ZBiIyz1XFbJjtuVT0U6tB5NbVl4RwHZBTsJt86fQyCSFj dwZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:autocrypt :organization:message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=sp6JOe2UVBs6PLytrxxuOCrhswEeaqVUNhszYrb2k9w=; b=LE9I/HlcavTjR5sIJYPuLkOCl8s6CeQ+ZYQdRzwio2m4iih9a6VirlyQbXA1s4yPR8 Fy7bCZv93IXW0vgVsEWrhE108+BXkAxQgSb5If17RPoMSxf/dlE2l+NLp9aAsiRf46lQ XV/sOQ+vPRr1rHuQ3rvlwfhbjaXb4tFd1Mgy/DNpWqYz+vxSpE4viUqmPCHGHOI+GFZ3 KIn0rxLBig0ql9SWHBOJap+KmOGsVo+SsISgiPxHsrxYhopL41IxSj9UDy5/n1Utru+w PL0JZ+O+Ic2GL/mZIAEiirFgI9IO8L4+LFgJc/zjvTlWyBxXXExdVFdWCONq1T2yd2QL 3APw== X-Gm-Message-State: APjAAAUzc7TCKiIUrfIZDxmSjFN9e+hiPxNT6bLhDv6KDTB6AJukVzMy b30WjG7DCSmz3lxqjgwwacChOQ== X-Google-Smtp-Source: APXvYqxDb8PeVkwCL6tuUvNTdOWkLbDqOokiYbzIrTc/Mo09U6geHqQzuP7uJFnNxGErnDlHxUSk0A== X-Received: by 2002:a5d:4f91:: with SMTP id d17mr25585376wru.74.1566204206351; Mon, 19 Aug 2019 01:43:26 -0700 (PDT) Received: from [10.1.2.12] (lmontsouris-657-1-212-31.w90-63.abo.wanadoo.fr. [90.63.244.31]) by smtp.gmail.com with ESMTPSA id r15sm25195629wrj.68.2019.08.19.01.43.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 19 Aug 2019 01:43:25 -0700 (PDT) Subject: Re: [PATCH RFC v1] clk: Fix potential NULL dereference in clk_fetch_parent_index() To: Stephen Boyd , Martin Blumenstingl Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, mturquette@baylibre.com, "open list:ARM/Amlogic Meson..." References: <20190815223155.21384-1-martin.blumenstingl@googlemail.com> <20190815232951.AA402206C2@mail.kernel.org> <20190816173147.ED6022086C@mail.kernel.org> From: Neil Armstrong Openpgp: preference=signencrypt Autocrypt: addr=narmstrong@baylibre.com; prefer-encrypt=mutual; keydata= mQENBE1ZBs8BCAD78xVLsXPwV/2qQx2FaO/7mhWL0Qodw8UcQJnkrWmgTFRobtTWxuRx8WWP GTjuhvbleoQ5Cxjr+v+1ARGCH46MxFP5DwauzPekwJUD5QKZlaw/bURTLmS2id5wWi3lqVH4 BVF2WzvGyyeV1o4RTCYDnZ9VLLylJ9bneEaIs/7cjCEbipGGFlfIML3sfqnIvMAxIMZrvcl9 qPV2k+KQ7q+aXavU5W+yLNn7QtXUB530Zlk/d2ETgzQ5FLYYnUDAaRl+8JUTjc0CNOTpCeik 80TZcE6f8M76Xa6yU8VcNko94Ck7iB4vj70q76P/J7kt98hklrr85/3NU3oti3nrIHmHABEB AAG0KE5laWwgQXJtc3Ryb25nIDxuYXJtc3Ryb25nQGJheWxpYnJlLmNvbT6JATsEEwEKACUC GyMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheABQJXDO2CAhkBAAoJEBaat7Gkz/iubGIH/iyk RqvgB62oKOFlgOTYCMkYpm2aAOZZLf6VKHKc7DoVwuUkjHfIRXdslbrxi4pk5VKU6ZP9AKsN NtMZntB8WrBTtkAZfZbTF7850uwd3eU5cN/7N1Q6g0JQihE7w4GlIkEpQ8vwSg5W7hkx3yQ6 2YzrUZh/b7QThXbNZ7xOeSEms014QXazx8+txR7jrGF3dYxBsCkotO/8DNtZ1R+aUvRfpKg5 ZgABTC0LmAQnuUUf2PHcKFAHZo5KrdO+tyfL+LgTUXIXkK+tenkLsAJ0cagz1EZ5gntuheLD YJuzS4zN+1Asmb9kVKxhjSQOcIh6g2tw7vaYJgL/OzJtZi6JlIW5AQ0ETVkGzwEIALyKDN/O GURaHBVzwjgYq+ZtifvekdrSNl8TIDH8g1xicBYpQTbPn6bbSZbdvfeQPNCcD4/EhXZuhQXM coJsQQQnO4vwVULmPGgtGf8PVc7dxKOeta+qUh6+SRh3vIcAUFHDT3f/Zdspz+e2E0hPV2hi SvICLk11qO6cyJE13zeNFoeY3ggrKY+IzbFomIZY4yG6xI99NIPEVE9lNBXBKIlewIyVlkOa YvJWSV+p5gdJXOvScNN1epm5YHmf9aE2ZjnqZGoMMtsyw18YoX9BqMFInxqYQQ3j/HpVgTSv mo5ea5qQDDUaCsaTf8UeDcwYOtgI8iL4oHcsGtUXoUk33HEAEQEAAYkBHwQYAQIACQUCTVkG zwIbDAAKCRAWmrexpM/4rrXiB/sGbkQ6itMrAIfnM7IbRuiSZS1unlySUVYu3SD6YBYnNi3G 5EpbwfBNuT3H8//rVvtOFK4OD8cRYkxXRQmTvqa33eDIHu/zr1HMKErm+2SD6PO9umRef8V8 2o2oaCLvf4WeIssFjwB0b6a12opuRP7yo3E3gTCSKmbUuLv1CtxKQF+fUV1cVaTPMyT25Od+ RC1K+iOR0F54oUJvJeq7fUzbn/KdlhA8XPGzwGRy4zcsPWvwnXgfe5tk680fEKZVwOZKIEuJ C3v+/yZpQzDvGYJvbyix0lHnrCzq43WefRHI5XTTQbM0WUIBIcGmq38+OgUsMYu4NzLu7uZF Acmp6h8guQINBFYnf6QBEADQ+wBYa+X2n/xIQz/RUoGHf84Jm+yTqRT43t7sO48/cBW9vAn9 GNwnJ3HRJWKATW0ZXrCr40ES/JqM1fUTfiFDB3VMdWpEfwOAT1zXS+0rX8yljgsWR1UvqyEP 3xN0M/40Zk+rdmZKaZS8VQaXbveaiWMEmY7sBV3QvgOzB7UF2It1HwoCon5Y+PvyE3CguhBd 9iq5iEampkMIkbA3FFCpQFI5Ai3BywkLzbA3ZtnMXR8Qt9gFZtyXvFQrB+/6hDzEPnBGZOOx zkd/iIX59SxBuS38LMlhPPycbFNmtauOC0DNpXCv9ACgC9tFw3exER/xQgSpDVc4vrL2Cacr wmQp1k9E0W+9pk/l8S1jcHx03hgCxPtQLOIyEu9iIJb27TjcXNjiInd7Uea195NldIrndD+x 58/yU3X70qVY+eWbqzpdlwF1KRm6uV0ZOQhEhbi0FfKKgsYFgBIBchGqSOBsCbL35f9hK/JC 6LnGDtSHeJs+jd9/qJj4WqF3x8i0sncQ/gszSajdhnWrxraG3b7/9ldMLpKo/OoihfLaCxtv xYmtw8TGhlMaiOxjDrohmY1z7f3rf6njskoIXUO0nabun1nPAiV1dpjleg60s3OmVQeEpr3a K7gR1ljkemJzM9NUoRROPaT7nMlNYQL+IwuthJd6XQqwzp1jRTGG26J97wARAQABiQM+BBgB AgAJBQJWJ3+kAhsCAikJEBaat7Gkz/iuwV0gBBkBAgAGBQJWJ3+kAAoJEHfc29rIyEnRk6MQ AJDo0nxsadLpYB26FALZsWlN74rnFXth5dQVQ7SkipmyFWZhFL8fQ9OiIoxWhM6rSg9+C1w+ n45eByMg2b8H3mmQmyWztdI95OxSREKwbaXVapCcZnv52JRjlc3DoiiHqTZML5x1Z7lQ1T3F 8o9sKrbFO1WQw1+Nc91+MU0MGN0jtfZ0Tvn/ouEZrSXCE4K3oDGtj3AdC764yZVq6CPigCgs 6Ex80k6QlzCdVP3RKsnPO2xQXXPgyJPJlpD8bHHHW7OLfoR9DaBNympfcbQJeekQrTvyoASw EOTPKE6CVWrcQIztUp0WFTdRGgMK0cZB3Xfe6sOp24PQTHAKGtjTHNP/THomkH24Fum9K3iM /4Wh4V2eqGEgpdeSp5K+LdaNyNgaqzMOtt4HYk86LYLSHfFXywdlbGrY9+TqiJ+ZVW4trmui NIJCOku8SYansq34QzYM0x3UFRwff+45zNBEVzctSnremg1mVgrzOfXU8rt+4N1b2MxorPF8 619aCwVP7U16qNSBaqiAJr4e5SNEnoAq18+1Gp8QsFG0ARY8xp+qaKBByWES7lRi3QbqAKZf yOHS6gmYo9gBmuAhc65/VtHMJtxwjpUeN4Bcs9HUpDMDVHdfeRa73wM+wY5potfQ5zkSp0Jp bxnv/cRBH6+c43stTffprd//4Hgz+nJcCgZKtCYIAPkUxABC85ID2CidzbraErVACmRoizhT KR2OiqSLW2x4xdmSiFNcIWkWJB6Qdri0Fzs2dHe8etD1HYaht1ZhZ810s7QOL7JwypO8dscN KTEkyoTGn6cWj0CX+PeP4xp8AR8ot4d0BhtUY34UPzjE1/xyrQFAdnLd0PP4wXxdIUuRs0+n WLY9Aou/vC1LAdlaGsoTVzJ2gX4fkKQIWhX0WVk41BSFeDKQ3RQ2pnuzwedLO94Bf6X0G48O VsbXrP9BZ6snXyHfebPnno/te5XRqZTL9aJOytB/1iUna+1MAwBxGFPvqeEUUyT+gx1l3Acl ZaTUOEkgIor5losDrePdPgE= Organization: Baylibre Message-ID: <3653ea15-e223-e7f9-1871-f7c8aa84bf5d@baylibre.com> Date: Mon, 19 Aug 2019 10:43:25 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190816173147.ED6022086C@mail.kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org Hi, On 16/08/2019 19:31, Stephen Boyd wrote: > Quoting Martin Blumenstingl (2019-08-15 23:48:08) >>>> I have seen the original crash when I was testing an MMC driver which >>>> is not upstream yet on v5.3-rc4. I'm not sure whether this fix is >>>> "correct" (it fixes the crash for me) or where to point the Fixes tag >>>> to, it may be one of: >>>> - fc0c209c147f ("clk: Allow parents to be specified without string names") >>>> - 1a079560b145 ("clk: Cache core in clk_fetch_parent_index() without names") >>>> >>>> This is meant to be applied on top of v5.3-rc4. >>>> >>> >>> Ah ok. I thought that strcmp() would ignore NULL arguments, but >>> apparently not. I can apply this to clk-fixes. >> at least ARM [0] and the generic [1] implementations don't >> >> I did not bisect this so do you have any suggestion for a Fixes tag? I >> mentioned two candidates above, but I'm not sure which one to use >> just let me know, then I'll resend with the fixes tag so you can take >> it through clk-fixes >> >> > > I added the fixes tag for the first one, where it was broken, i.e. > fc0c209c147f. Thanks. > For the record, this also fixes the Amlogic Meson GXBB/GXL when AO-CEC driver is enabled : [ 7.790319] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 7.790324] Mem abort info: [ 7.790326] ESR = 0x96000007 [ 7.790330] Exception class = DABT (current EL), IL = 32 bits [ 7.790331] SET = 0, FnV = 0 [ 7.790333] EA = 0, S1PTW = 0 [ 7.790334] Data abort info: [ 7.790336] ISV = 0, ISS = 0x00000007 [ 7.790337] CM = 0, WnR = 0 [ 7.790341] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000364b7000 [ 7.790343] [0000000000000000] pgd=00000000364f5003, pud=00000000364f6003, pmd=00000000364f7003, pte=0000000000000000 [ 7.790350] Internal error: Oops: 96000007 [#1] SMP [ 7.790461] Modules linked in: ao_cec(+) [ 7.793569] CPU: 1 PID: 398 Comm: systemd-udevd Not tainted 5.3.0-rc5 #1 [ 7.800199] Hardware name: Libre Computer Board AML-S905X-CC (DT) [ 7.806233] pstate: 40000005 (nZcv daif -PAN -UAO) [ 7.810985] pc : __pi_strcmp+0x1c/0x154 [ 7.814775] lr : clk_fetch_parent_index.part.43+0xe4/0x120 [ 7.820203] sp : ffff0000113d3770 [ 7.823481] x29: ffff0000113d3770 x28: ffff00001136f000 [ 7.828741] x27: 0000000000000100 x26: ffff000010130648 [ 7.834012] x25: ffff000008943100 x24: 0000000000008000 [ 7.839273] x23: ffff80007c15cc00 x22: ffff80007c15cd00 [ 7.844525] x21: ffff80007c15ca00 x20: 0000000000000000 [ 7.849791] x19: 0000000000000000 x18: 0000000000000001 [ 7.855048] x17: 0000000000000000 x16: 0000000000000000 [ 7.860316] x15: ffffffffffffffff x14: ffffffffffffffff [ 7.865578] x13: 0000000000000028 x12: 0101010101010101 [ 7.870831] x11: 0000000000000004 x10: 0101010101010101 [ 7.876092] x9 : ffffffffffffffff x8 : 7f7f7f7f7f7f7f7f [ 7.881354] x7 : 0000000000000000 x6 : 0d0d0206ebadf2e1 [ 7.886615] x5 : 61722d6b06020d0d x4 : 8080808000000000 [ 7.891876] x3 : 36c6f636b2d72610 x2 : 00006b32335f6f61 [ 7.897137] x1 : 0000000000000000 x0 : ffff000010b147f0 [ 7.902405] Call trace: [ 7.904825] __pi_strcmp+0x1c/0x154 [ 7.908269] clk_calc_new_rates+0x208/0x260 [ 7.912419] clk_calc_new_rates+0x10c/0x260 [ 7.916556] clk_core_set_rate_nolock+0xe8/0x1e8 [ 7.921129] clk_set_rate+0x34/0xa0 [ 7.924583] meson_ao_cec_probe+0x19c/0x278 [ao_cec] [ 7.929498] platform_drv_probe+0x50/0xa0 [ 7.933461] really_probe+0xec/0x3d0 [ 7.936989] driver_probe_device+0xdc/0x130 [ 7.941128] device_driver_attach+0x6c/0x78 [ 7.945267] __driver_attach+0x9c/0x168 [ 7.949065] bus_for_each_dev+0x70/0xc0 [ 7.952860] driver_attach+0x20/0x28 [ 7.956394] bus_add_driver+0x190/0x220 [ 7.960190] driver_register+0x60/0x110 [ 7.963987] __platform_driver_register+0x44/0x50 [ 7.968646] meson_ao_cec_driver_init+0x1c/0x1000 [ao_cec] [ 7.974079] do_one_initcall+0x74/0x1b0 [ 7.977873] do_init_module+0x50/0x208 [ 7.981581] load_module+0x1dc4/0x2350 [ 7.985288] __se_sys_finit_module+0x9c/0xf8 [ 7.989515] __arm64_sys_finit_module+0x18/0x20 [ 7.994001] el0_svc_common.constprop.0+0x7c/0xe8 [ 7.998658] el0_svc_compat_handler+0x18/0x20 [ 8.002970] el0_svc_compat+0x8/0x10 [ 8.006510] Code: 540002e1 f2400807 54000141 f8408402 (f8408423) [ 8.012543] ---[ end trace e915b8961764bcd0 ]--- Neil