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 163F6C433EF for ; Wed, 20 Jul 2022 15:33:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237293AbiGTPdW (ORCPT ); Wed, 20 Jul 2022 11:33:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237358AbiGTPdR (ORCPT ); Wed, 20 Jul 2022 11:33:17 -0400 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C3E961DA5 for ; Wed, 20 Jul 2022 08:33:16 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id b6so10565901wmq.5 for ; Wed, 20 Jul 2022 08:33:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=+ITN8/NzMqMN7zHfyXAOzFRekORzcIckFhvH54+KYKA=; b=IenLWnEEs9XlqJG2dIci50Gy15R7Qnd+SkxKyc3Wl+ZY1jRDLUw324Px2VWmv6BWTq klvrupR+wkZ2uE+ktWw/E/MZsehPUA9xXH0lb3ZIz/8jGvF6av59PCYnc5mpGIMkPgn6 UU8m9zzN6CsMbYUw9XgvVv5J1c2JouJrPr80tGSuSBj6YfMDvoKDVPyfx12cpQ3+Hxne Nxi1BaodgAyIuxXt/EdoF/kW1WDrA0+eND1W2KqiQCmyIME0dVJLwIwARcoC8MdNzxbL Uje/Su6C7SDMC+f/R+xfRn8KNnewYX4fLONmv1pMQJ+TsK8NPHKcTqWMlR8vLNLwUp7k C40A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=+ITN8/NzMqMN7zHfyXAOzFRekORzcIckFhvH54+KYKA=; b=JTUj+wp815RUROW9WozKYqLFFqDv1QuDheaTchVrMTZs50ArnAwcFzJ2OR/8HLtau8 470y8xosvhBYdNjjS1+MGe3G/fuAAtC6YyJJ+uNLDR0pW+un3/0JU8iEid/AChNcJkV1 X+2AC1AMn+5hytn0TxA/tHQX1GbYZ6raX1ok6beJ368+PWm34EoW+LffSe5PSBiV0Mkr aJVzPqX+1uPbw5JWK0c+f4gXXCfrm+X/uZsRdEHrG26ilCeGNGVVHEX2FWf5JBYKdRjj 7SgNp/IEI3bWXYmissAOgITyLo6rMBpjNwyds/bTOknioSLJrmhi2mURnpRVrnBHa5Wi psIw== X-Gm-Message-State: AJIora+IFGftrXOjQxuA+Dct8MwCzP8zjJM86msFcj1oNMceJedVXJV8 jUN33/D2YGiHrKc5dqjwssukqA== X-Google-Smtp-Source: AGRyM1sd+rdWLzQsA2lQG5zNk6KUCSobzGcO7gB3VqchM9eamBm9L6oCUo0agfpc4MIGawpoudhbQg== X-Received: by 2002:a05:600c:2d09:b0:3a3:1062:ce61 with SMTP id x9-20020a05600c2d0900b003a31062ce61mr4439786wmf.138.1658331195186; Wed, 20 Jul 2022 08:33:15 -0700 (PDT) Received: from google.com (cpc155339-bagu17-2-0-cust87.1-3.cable.virginm.net. [86.27.177.88]) by smtp.gmail.com with ESMTPSA id m126-20020a1ca384000000b003a03e63e428sm3276117wme.36.2022.07.20.08.33.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Jul 2022 08:33:14 -0700 (PDT) Date: Wed, 20 Jul 2022 16:33:13 +0100 From: Lee Jones To: Will Deacon Cc: =?utf-8?B?aGFpYmluemhhbmco5byg5rW35paMKQ==?= , Catalin Marinas , Ard Biesheuvel , Martin Ma , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "hewenliang4@huawei.com" Subject: Re: [PATCH V2] arm64: fix oops in concurrently setting insn_emulation sysctls Message-ID: References: <9A004C03-250B-46C5-BF39-782D7551B00E@tencent.com> <20220720151344.GA16452@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220720151344.GA16452@willie-the-truck> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 20 Jul 2022, Will Deacon wrote: > On Wed, Jul 20, 2022 at 01:23:24PM +0100, Lee Jones wrote: > > On Sat, 02 Jul 2022, haibinzhang(张海斌) wrote: > > > > > How to reproduce: > > > launch two shell executions: > > > #!/bin/bash > > > while [ 1 ]; > > > do > > > echo 1 > /proc/sys/abi/swp > > > done > > > > > > Oops info: > > > Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 > > > Internal error: Oops: 96000006 [#1] SMP > > > Call trace: > > > update_insn_emulation_mode+0xc0/0x148 > > > emulation_proc_handler+0x64/0xb8 > > > proc_sys_call_handler+0x9c/0xf8 > > > proc_sys_write+0x18/0x20 > > > __vfs_write+0x20/0x48 > > > vfs_write+0xe4/0x1d0 > > > ksys_write+0x70/0xf8 > > > __arm64_sys_write+0x20/0x28 > > > el0_svc_common.constprop.0+0x7c/0x1c0 > > > el0_svc_handler+0x2c/0xa0 > > > el0_svc+0x8/0x200 > > > > > > emulation_proc_handler changes table->data for proc_dointvec_minmax > > > and so it isn't allowed to reenter before restoring table->data, > > > which isn't right now. > > > To fix this issue, keep the table->data as &insn->current_mode and > > > use container_of() to retrieve the insn pointer. Another mutex is > > > used to protect against the current_mode update but not for retrieving > > > insn_emulation as table->data is no longer changing. > > > > Looks as though this lost its Fixes tag during the rework. > > > > Fixes: 587064b610c7 ("arm64: Add framework for legacy instruction emulation") > > > > Will, are you able to add this retroactively? > > Sadly, this is now buried under some other patches so I'd have to rebase the > branch if I were to add this and I don't think it's worth it just to add a > tag. No worries. Just thought I'd ask. > On the plus side, the patch has a Link: tag to this thread, so the > Fixes tag is retrievable if you're determined enough. > > If somebody wants this for stable, then I suppose they'll have to send > a backport to make sure it doesn't get missed. I'll add it to my TODO. -- Lee Jones [李琼斯] Principal Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 26202C433EF for ; Wed, 20 Jul 2022 15:34:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ygrvsRuAYRe7pYrIzYIXXjF9FTQ+jPlhFYQIkIre9wY=; b=kbTkOUOJGev8XR looz5bgc8KTsiTg6082mIFZgJMBno5nVEmKbI9IDbDguhVmEU7ANARqz1o8YmbV+PkI05gQoK01ZM VEoWz1MGGu9VqWGZejxlS/hxf6ezkF/phUHpp8MB2JcrbqkWnXGJSCix72s7ys5gnhw1w7YagTGOE h2yHSr77OSpZOkrJzhOKt+hEL81R2TPeY56DcAjWqyd+m6kNybl97WFMTGikkvg7exnFL2BEqNJnX EVAi5HdYIg1DsKcfzmwCsUK8aLsX+MufsAcP4Vtn29IKlIgb8GNVx6cHYScru1GLWdNBrHzawFpEu ogW2TnbHIVz5ys+Jj56Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oEBhQ-007bxh-7f; Wed, 20 Jul 2022 15:33:20 +0000 Received: from mail-wm1-x333.google.com ([2a00:1450:4864:20::333]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oEBhM-007bvk-Ey for linux-arm-kernel@lists.infradead.org; Wed, 20 Jul 2022 15:33:17 +0000 Received: by mail-wm1-x333.google.com with SMTP id a11so4959542wmq.3 for ; Wed, 20 Jul 2022 08:33:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=+ITN8/NzMqMN7zHfyXAOzFRekORzcIckFhvH54+KYKA=; b=IenLWnEEs9XlqJG2dIci50Gy15R7Qnd+SkxKyc3Wl+ZY1jRDLUw324Px2VWmv6BWTq klvrupR+wkZ2uE+ktWw/E/MZsehPUA9xXH0lb3ZIz/8jGvF6av59PCYnc5mpGIMkPgn6 UU8m9zzN6CsMbYUw9XgvVv5J1c2JouJrPr80tGSuSBj6YfMDvoKDVPyfx12cpQ3+Hxne Nxi1BaodgAyIuxXt/EdoF/kW1WDrA0+eND1W2KqiQCmyIME0dVJLwIwARcoC8MdNzxbL Uje/Su6C7SDMC+f/R+xfRn8KNnewYX4fLONmv1pMQJ+TsK8NPHKcTqWMlR8vLNLwUp7k C40A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=+ITN8/NzMqMN7zHfyXAOzFRekORzcIckFhvH54+KYKA=; b=4YD1fVyoRJsumNJG2v5aHEGUJHLqDvo0thkQtHZBQeu6mYuehMnBnkkcCAmok3x9Bo qb2VGwZbNWaXbhozLJe6SMebyxMVjDE+EgalZ63XODekNhcc2IVp3yBSyIbPPO2FFU3L YS7uTLGhmFwlqOkUpQ1wmEGxnkuukeRHYsghy6CXxqj0vet0TRdS4i+zaMYhUMht8iFU AiSv3ehi29pjHegWNAh1AnOUcGpbtbD24dOqnjLgqGIYLdsjYKiQjBTkTG1JQG1G7RDI y/ApIQpoDjOod/b9o/Z5QMjTwfajVCf5fkrvYevnQDhWPNMaV4UQpHKp5hPD/4tGqtU4 vbTQ== X-Gm-Message-State: AJIora94V2LXod5UsJV/fmwutDR5pH8cWwQRZRAvLq90Za9tGflHz9Lc ytWCi933rxDHjTNmQiF0hQP6b8HEiEyEXg== X-Google-Smtp-Source: AGRyM1sd+rdWLzQsA2lQG5zNk6KUCSobzGcO7gB3VqchM9eamBm9L6oCUo0agfpc4MIGawpoudhbQg== X-Received: by 2002:a05:600c:2d09:b0:3a3:1062:ce61 with SMTP id x9-20020a05600c2d0900b003a31062ce61mr4439786wmf.138.1658331195186; Wed, 20 Jul 2022 08:33:15 -0700 (PDT) Received: from google.com (cpc155339-bagu17-2-0-cust87.1-3.cable.virginm.net. [86.27.177.88]) by smtp.gmail.com with ESMTPSA id m126-20020a1ca384000000b003a03e63e428sm3276117wme.36.2022.07.20.08.33.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Jul 2022 08:33:14 -0700 (PDT) Date: Wed, 20 Jul 2022 16:33:13 +0100 From: Lee Jones To: Will Deacon Cc: =?utf-8?B?aGFpYmluemhhbmco5byg5rW35paMKQ==?= , Catalin Marinas , Ard Biesheuvel , Martin Ma , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "hewenliang4@huawei.com" Subject: Re: [PATCH V2] arm64: fix oops in concurrently setting insn_emulation sysctls Message-ID: References: <9A004C03-250B-46C5-BF39-782D7551B00E@tencent.com> <20220720151344.GA16452@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220720151344.GA16452@willie-the-truck> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220720_083316_521575_22C0B7F3 X-CRM114-Status: GOOD ( 25.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gV2VkLCAyMCBKdWwgMjAyMiwgV2lsbCBEZWFjb24gd3JvdGU6Cgo+IE9uIFdlZCwgSnVsIDIw LCAyMDIyIGF0IDAxOjIzOjI0UE0gKzAxMDAsIExlZSBKb25lcyB3cm90ZToKPiA+IE9uIFNhdCwg MDIgSnVsIDIwMjIsIGhhaWJpbnpoYW5nKOW8oOa1t+aWjCkgd3JvdGU6Cj4gPiAKPiA+ID4gSG93 IHRvIHJlcHJvZHVjZToKPiA+ID4gICAgIGxhdW5jaCB0d28gc2hlbGwgZXhlY3V0aW9uczoKPiA+ ID4gICAgICAgICMhL2Jpbi9iYXNoCj4gPiA+ICAgICAgICB3aGlsZSBbIDEgXTsKPiA+ID4gICAg ICAgIGRvCj4gPiA+ICAgICAgICAgICAgZWNobyAxID4gL3Byb2Mvc3lzL2FiaS9zd3AKPiA+ID4g ICAgICAgIGRvbmUKPiA+ID4gCj4gPiA+IE9vcHMgaW5mbzoKPiA+ID4gICAgIFVuYWJsZSB0byBo YW5kbGUga2VybmVsIE5VTEwgcG9pbnRlciBkZXJlZmVyZW5jZSBhdCB2aXJ0dWFsIGFkZHJlc3Mg MDAwMDAwMDAwMDAwMDAxMAo+ID4gPiAgICAgSW50ZXJuYWwgZXJyb3I6IE9vcHM6IDk2MDAwMDA2 IFsjMV0gU01QCj4gPiA+ICAgICBDYWxsIHRyYWNlOgo+ID4gPiAgICAgdXBkYXRlX2luc25fZW11 bGF0aW9uX21vZGUrMHhjMC8weDE0OAo+ID4gPiAgICAgZW11bGF0aW9uX3Byb2NfaGFuZGxlcisw eDY0LzB4YjgKPiA+ID4gICAgIHByb2Nfc3lzX2NhbGxfaGFuZGxlcisweDljLzB4ZjgKPiA+ID4g ICAgIHByb2Nfc3lzX3dyaXRlKzB4MTgvMHgyMAo+ID4gPiAgICAgX192ZnNfd3JpdGUrMHgyMC8w eDQ4Cj4gPiA+ICAgICB2ZnNfd3JpdGUrMHhlNC8weDFkMAo+ID4gPiAgICAga3N5c193cml0ZSsw eDcwLzB4ZjgKPiA+ID4gICAgIF9fYXJtNjRfc3lzX3dyaXRlKzB4MjAvMHgyOAo+ID4gPiAgICAg ZWwwX3N2Y19jb21tb24uY29uc3Rwcm9wLjArMHg3Yy8weDFjMAo+ID4gPiAgICAgZWwwX3N2Y19o YW5kbGVyKzB4MmMvMHhhMAo+ID4gPiAgICAgZWwwX3N2YysweDgvMHgyMDAKPiA+ID4gCj4gPiA+ IGVtdWxhdGlvbl9wcm9jX2hhbmRsZXIgY2hhbmdlcyB0YWJsZS0+ZGF0YSBmb3IgcHJvY19kb2lu dHZlY19taW5tYXgKPiA+ID4gYW5kIHNvIGl0IGlzbid0IGFsbG93ZWQgdG8gcmVlbnRlciBiZWZv cmUgcmVzdG9yaW5nIHRhYmxlLT5kYXRhLAo+ID4gPiB3aGljaCBpc24ndCByaWdodCBub3cuCj4g PiA+IFRvIGZpeCB0aGlzIGlzc3VlLCBrZWVwIHRoZSB0YWJsZS0+ZGF0YSBhcyAmaW5zbi0+Y3Vy cmVudF9tb2RlIGFuZAo+ID4gPiB1c2UgY29udGFpbmVyX29mKCkgdG8gcmV0cmlldmUgdGhlIGlu c24gcG9pbnRlci4gQW5vdGhlciBtdXRleCBpcwo+ID4gPiB1c2VkIHRvIHByb3RlY3QgYWdhaW5z dCB0aGUgY3VycmVudF9tb2RlIHVwZGF0ZSBidXQgbm90IGZvciByZXRyaWV2aW5nCj4gPiA+IGlu c25fZW11bGF0aW9uIGFzIHRhYmxlLT5kYXRhIGlzIG5vIGxvbmdlciBjaGFuZ2luZy4KPiA+IAo+ ID4gTG9va3MgYXMgdGhvdWdoIHRoaXMgbG9zdCBpdHMgRml4ZXMgdGFnIGR1cmluZyB0aGUgcmV3 b3JrLgo+ID4gCj4gPiAgIEZpeGVzOiA1ODcwNjRiNjEwYzcgKCJhcm02NDogQWRkIGZyYW1ld29y ayBmb3IgbGVnYWN5IGluc3RydWN0aW9uIGVtdWxhdGlvbiIpCj4gPiAKPiA+IFdpbGwsIGFyZSB5 b3UgYWJsZSB0byBhZGQgdGhpcyByZXRyb2FjdGl2ZWx5Pwo+IAo+IFNhZGx5LCB0aGlzIGlzIG5v dyBidXJpZWQgdW5kZXIgc29tZSBvdGhlciBwYXRjaGVzIHNvIEknZCBoYXZlIHRvIHJlYmFzZSB0 aGUKPiBicmFuY2ggaWYgSSB3ZXJlIHRvIGFkZCB0aGlzIGFuZCBJIGRvbid0IHRoaW5rIGl0J3Mg d29ydGggaXQganVzdCB0byBhZGQgYQo+IHRhZy4KCk5vIHdvcnJpZXMuICBKdXN0IHRob3VnaHQg SSdkIGFzay4KCj4gT24gdGhlIHBsdXMgc2lkZSwgdGhlIHBhdGNoIGhhcyBhIExpbms6IHRhZyB0 byB0aGlzIHRocmVhZCwgc28gdGhlCj4gRml4ZXMgdGFnIGlzIHJldHJpZXZhYmxlIGlmIHlvdSdy ZSBkZXRlcm1pbmVkIGVub3VnaC4KPiAKPiBJZiBzb21lYm9keSB3YW50cyB0aGlzIGZvciBzdGFi bGUsIHRoZW4gSSBzdXBwb3NlIHRoZXknbGwgaGF2ZSB0byBzZW5kCj4gYSBiYWNrcG9ydCB0byBt YWtlIHN1cmUgaXQgZG9lc24ndCBnZXQgbWlzc2VkLgoKSSdsbCBhZGQgaXQgdG8gbXkgVE9ETy4K Ci0tIApMZWUgSm9uZXMgW+adjueQvOaWr10KUHJpbmNpcGFsIFRlY2huaWNhbCBMZWFkIC0gRGV2 ZWxvcGVyIFNlcnZpY2VzCkxpbmFyby5vcmcg4pSCIE9wZW4gc291cmNlIHNvZnR3YXJlIGZvciBB cm0gU29DcwpGb2xsb3cgTGluYXJvOiBGYWNlYm9vayB8IFR3aXR0ZXIgfCBCbG9nCgpfX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpsaW51eC1hcm0ta2VybmVs IG1haWxpbmcgbGlzdApsaW51eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDov L2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1hcm0ta2VybmVsCg==