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Tue, 28 Jan 2020 00:05:17 +0000 Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 00S05EZp020295 for ; Tue, 28 Jan 2020 00:05:14 GMT Received: from bostrovs-us.us.oracle.com (/10.152.32.65) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 27 Jan 2020 16:05:14 -0800 To: xen-devel@lists.xenproject.org References: <20200127213722.GC2995@mail-itl> From: Boris Ostrovsky Autocrypt: addr=boris.ostrovsky@oracle.com; keydata= xsFNBFH8CgsBEAC0KiOi9siOvlXatK2xX99e/J3OvApoYWjieVQ9232Eb7GzCWrItCzP8FUV PQg8rMsSd0OzIvvjbEAvaWLlbs8wa3MtVLysHY/DfqRK9Zvr/RgrsYC6ukOB7igy2PGqZd+M MDnSmVzik0sPvB6xPV7QyFsykEgpnHbvdZAUy/vyys8xgT0PVYR5hyvhyf6VIfGuvqIsvJw5 C8+P71CHI+U/IhsKrLrsiYHpAhQkw+Zvyeml6XSi5w4LXDbF+3oholKYCkPwxmGdK8MUIdkM d7iYdKqiP4W6FKQou/lC3jvOceGupEoDV9botSWEIIlKdtm6C4GfL45RD8V4B9iy24JHPlom woVWc0xBZboQguhauQqrBFooHO3roEeM1pxXjLUbDtH4t3SAI3gt4dpSyT3EvzhyNQVVIxj2 FXnIChrYxR6S0ijSqUKO0cAduenhBrpYbz9qFcB/GyxD+ZWY7OgQKHUZMWapx5bHGQ8bUZz2 SfjZwK+GETGhfkvNMf6zXbZkDq4kKB/ywaKvVPodS1Poa44+B9sxbUp1jMfFtlOJ3AYB0WDS Op3d7F2ry20CIf1Ifh0nIxkQPkTX7aX5rI92oZeu5u038dHUu/dO2EcuCjl1eDMGm5PLHDSP 0QUw5xzk1Y8MG1JQ56PtqReO33inBXG63yTIikJmUXFTw6lLJwARAQABzTNCb3JpcyBPc3Ry b3Zza3kgKFdvcmspIDxib3Jpcy5vc3Ryb3Zza3lAb3JhY2xlLmNvbT7CwXgEEwECACIFAlH8 CgsCGwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEIredpCGysGyasEP/j5xApopUf4g 9Fl3UxZuBx+oduuw3JHqgbGZ2siA3EA4bKwtKq8eT7ekpApn4c0HA8TWTDtgZtLSV5IdH+9z JimBDrhLkDI3Zsx2CafL4pMJvpUavhc5mEU8myp4dWCuIylHiWG65agvUeFZYK4P33fGqoaS VGx3tsQIAr7MsQxilMfRiTEoYH0WWthhE0YVQzV6kx4wj4yLGYPPBtFqnrapKKC8yFTpgjaK jImqWhU9CSUAXdNEs/oKVR1XlkDpMCFDl88vKAuJwugnixjbPFTVPyoC7+4Bm/FnL3iwlJVE qIGQRspt09r+datFzPqSbp5Fo/9m4JSvgtPp2X2+gIGgLPWp2ft1NXHHVWP19sPgEsEJXSr9 tskM8ScxEkqAUuDs6+x/ISX8wa5Pvmo65drN+JWA8EqKOHQG6LUsUdJolFM2i4Z0k40BnFU/ kjTARjrXW94LwokVy4x+ZYgImrnKWeKac6fMfMwH2aKpCQLlVxdO4qvJkv92SzZz4538az1T m+3ekJAimou89cXwXHCFb5WqJcyjDfdQF857vTn1z4qu7udYCuuV/4xDEhslUq1+GcNDjAhB nNYPzD+SvhWEsrjuXv+fDONdJtmLUpKs4Jtak3smGGhZsqpcNv8nQzUGDQZjuCSmDqW8vn2o hWwveNeRTkxh+2x1Qb3GT46uzsFNBFH8CgsBEADGC/yx5ctcLQlB9hbq7KNqCDyZNoYu1HAB Hal3MuxPfoGKObEktawQPQaSTB5vNlDxKihezLnlT/PKjcXC2R1OjSDinlu5XNGc6mnky03q yymUPyiMtWhBBftezTRxWRslPaFWlg/h/Y1iDuOcklhpr7K1h1jRPCrf1yIoxbIpDbffnuyz kuto4AahRvBU4Js4sU7f/btU+h+e0AcLVzIhTVPIz7PM+Gk2LNzZ3/on4dnEc/qd+ZZFlOQ4 KDN/hPqlwA/YJsKzAPX51L6Vv344pqTm6Z0f9M7YALB/11FO2nBB7zw7HAUYqJeHutCwxm7i BDNt0g9fhviNcJzagqJ1R7aPjtjBoYvKkbwNu5sWDpQ4idnsnck4YT6ctzN4I+6lfkU8zMzC gM2R4qqUXmxFIS4Bee+gnJi0Pc3KcBYBZsDK44FtM//5Cp9DrxRQOh19kNHBlxkmEb8kL/pw XIDcEq8MXzPBbxwHKJ3QRWRe5jPNpf8HCjnZz0XyJV0/4M1JvOua7IZftOttQ6KnM4m6WNIZ 2ydg7dBhDa6iv1oKdL7wdp/rCulVWn8R7+3cRK95SnWiJ0qKDlMbIN8oGMhHdin8cSRYdmHK kTnvSGJNlkis5a+048o0C6jI3LozQYD/W9wq7MvgChgVQw1iEOB4u/3FXDEGulRVko6xCBU4 SQARAQABwsFfBBgBAgAJBQJR/AoLAhsMAAoJEIredpCGysGyfvMQAIywR6jTqix6/fL0Ip8G jpt3uk//QNxGJE3ZkUNLX6N786vnEJvc1beCu6EwqD1ezG9fJKMl7F3SEgpYaiKEcHfoKGdh 30B3Hsq44vOoxR6zxw2B/giADjhmWTP5tWQ9548N4VhIZMYQMQCkdqaueSL+8asp8tBNP+TJ PAIIANYvJaD8xA7sYUXGTzOXDh2THWSvmEWWmzok8er/u6ZKdS1YmZkUy8cfzrll/9hiGCTj u3qcaOM6i/m4hqtvsI1cOORMVwjJF4+IkC5ZBoeRs/xW5zIBdSUoC8L+OCyj5JETWTt40+lu qoqAF/AEGsNZTrwHJYu9rbHH260C0KYCNqmxDdcROUqIzJdzDKOrDmebkEVnxVeLJBIhYZUd t3Iq9hdjpU50TA6sQ3mZxzBdfRgg+vaj2DsJqI5Xla9QGKD+xNT6v14cZuIMZzO7w0DoojM4 ByrabFsOQxGvE0w9Dch2BDSI2Xyk1zjPKxG1VNBQVx3flH37QDWpL2zlJikW29Ws86PHdthh Fm5PY8YtX576DchSP6qJC57/eAAe/9ztZdVAdesQwGb9hZHJc75B+VNm4xrh/PJO6c1THqdQ 19WVJ+7rDx3PhVncGlbAOiiiE3NOFPJ1OQYxPKtpBUukAlOTnkKE6QcA4zckFepUkfmBV1wM Jg6OxFYd01z+a+oL Message-ID: Date: Mon, 27 Jan 2020 19:05:23 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9513 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001270187 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9513 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001270187 Subject: Re: [Xen-devel] Linux 5.5 fails to boot in VM X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============0113311045674523017==" Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" This is a multi-part message in MIME format. --===============0113311045674523017== Content-Type: multipart/alternative; boundary="------------6782CCBDA15BD1766381A1E7" Content-Language: en-US This is a multi-part message in MIME format. --------------6782CCBDA15BD1766381A1E7 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 1/27/20 6:29 PM, Boris Ostrovsky wrote: > > > On 1/27/20 4:37 PM, Marek Marczykowski-G=C3=B3recki wrote: >> On Mon, Jan 27, 2020 at 03:45:11PM +0100, J=C3=BCrgen Gro=C3=9F wrote:= >>> On 27.01.20 14:16, Ilpo J=C3=A4rvinen wrote: >>>> Hi, >>>> >>>> I've noted that 5.5-rcs and now 5.5-based kernel fails to boot in VM= =2E >>>> 5.4 based kernels worked fine and there seems to have been some chan= ges in >>>> drivers/xen post-5.4 so perhaps they broke something? >>> I can't reproduce your problem. Just booted a VM with kernel 5.5 as >>> PV- and as HVM-guest without any problems. >> It looks like an issue with gntdev driver, so reproducing it require a= ny >> userspace that actually makes use of it. Any idea what recent change >> could cause that? >> >>>> Loading Linux 5.5.0-accecn30 ... >>>> >>>> .[5;22H [ initrd.img-5.5.0-acc 16.52MiB 100% 10.23MiB/s ].[5= ;1HSetting up swapspace version 1, size =3D 1073737728 bytes >>>> /dev/xvda3: clean, 852118/1294896 files, 3076785/5190907 blocks >>>> [ 2.730931] BUG: kernel NULL pointer dereference, address: 000000= 00000003b0 >>>> [ 2.730959] #PF: supervisor read access in kernel mode >>>> [ 2.730966] #PF: error_code(0x0000) - not-present page >>>> [ 2.730973] PGD 0 P4D 0 >>>> [ 2.730978] Oops: 0000 [#1] SMP PTI >>>> [ 2.730985] CPU: 1 PID: 402 Comm: qubesdb-daemon Tainted: G = O 5.5.0-accecn30 #31 >>>> [ 2.731000] RIP: 0010:mmu_interval_read_begin+0x24/0xc0 > > > > > This looks like it could well be > d3eeb1d77c5d0af9df442db63722928238310a86. Can you revert it and see if > it makes a difference? > > (+Jason) > > -boris > > > > >>>> [ 2.731008] Code: e9 51 66 e1 ff 90 0f 1f 44 00 00 41 54 49 89 fc= 55 53 48 83 ec 30 65 48 8b 04 25 28 00 00 00 48 89 44 24 28 31 c0 48 8b = 47 38 <48> 8b a8 b0 03 00 00 48 8d 5d 0c 48 89 df e8 49 27 6f 00 4d 8b 64= >>>> [ 2.731030] RSP: 0018:ffff9873001e7d20 EFLAGS: 00010246 >>>> [ 2.731037] RAX: 0000000000000000 RBX: ffff8a4e94712500 RCX: 0000= 000000000000 I am pretty sure it is. RAX=3D0 most likely means that map->notifier is NULL (assuming your compiler generates code similar to mine). I believe you at least need diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 4fc83e3f..d35cf0b 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -1016,7 +1016,8 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * and we are holding it = now, there is no need for the notifier_range =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * locking pattern. =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 */ -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 mmu_interval_read_begin(&map->notif= ier); +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if (use_ptemod) +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0 mmu_interval_read_begin(&map->notifier); =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if (use_ptemod) { =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0 map->pages_vm_start =3D vma->vm_start; and maybe more.=C2=A0 Give that a try. -boris >>>> [ 2.731047] RDX: ffff8a4ef53add00 RSI: 0000000000000000 RDI: ffff= 8a4e94712500 >>>> [ 2.731057] RBP: ffff8a4e0bf7a640 R08: 00007bc5c0573000 R09: 0000= 000000000008 >>>> [ 2.731066] R10: ffff8a4ec756c190 R11: 00007bc5c05a2000 R12: ffff= 8a4e94712500 >>>> [ 2.731076] R13: ffff8a4ed3ab9d50 R14: 0000000000000000 R15: 0000= 000000000001 >>>> [ 2.731086] FS: 00007bc5c00dc7c0(0000) GS:ffff8a4ef5d00000(0000)= knlGS:0000000000000000 >>>> [ 2.731097] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>> [ 2.731105] CR2: 00000000000003b0 CR3: 000000008148e004 CR4: 0000= 0000003606e0 >>>> [ 2.731116] Call Trace: >>>> [ 2.731123] ? vma_merge+0xef/0x370 >>>> [ 2.731132] gntdev_mmap+0x153/0x30e [xen_gntdev] >>>> [ 2.731139] mmap_region+0x3d9/0x660 >>>> [ 2.731146] do_mmap+0x372/0x520 >>>> [ 2.731153] vm_mmap_pgoff+0xd2/0x120 >>>> [ 2.731160] ksys_mmap_pgoff+0x1b8/0x270 >>>> [ 2.731167] ? ksys_ioctl+0x60/0x90 >>>> [ 2.731174] do_syscall_64+0x5b/0x180 >>>> [ 2.731182] entry_SYSCALL_64_after_hwframe+0x44/0xa9 >>>> [ 2.731191] RIP: 0033:0x7bc5c03e8133 >>>> [ 2.731196] Code: 54 41 89 d4 55 48 89 fd 53 4c 89 cb 48 85 ff 74= 56 49 89 d9 45 89 f8 45 89 f2 44 89 e2 4c 89 ee 48 89 ef b8 09 00 00 00 = 0f 05 <48> 3d 00 f0 ff ff 77 7d 5b 5d 41 5c 41 5d 41 5e 41 5f c3 66 2e 0f= >>>> [ 2.731219] RSP: 002b:00007ffcbccc89b8 EFLAGS: 00000246 ORIG_RAX:= 0000000000000009 >>>> [ 2.731230] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000= 7bc5c03e8133 >>>> [ 2.731243] RDX: 0000000000000003 RSI: 0000000000001000 RDI: 0000= 000000000000 >>>> [ 2.731252] RBP: 0000000000000000 R08: 0000000000000007 R09: 0000= 000000000000 >>>> [ 2.731263] R10: 0000000000000001 R11: 0000000000000246 R12: 0000= 000000000003 >>>> [ 2.731273] R13: 0000000000001000 R14: 0000000000000001 R15: 0000= 000000000007 >>>> [ 2.731284] Modules linked in: xen_netback u2mfn(O) xen_gntdev xe= n_gntalloc xen_blkback xen_evtchn parport_pc ppdev xenfs xen_privcmd lp p= arport ip_tables xen_netfront xen_blkfront crc32c_intel >>>> [ 2.731309] CR2: 00000000000003b0 >>>> [ 2.731315] fbcon: Taking over console >>>> [ 2.731321] ---[ end trace 5ec57aa3f3a40247 ]--- >>>> [ 2.731329] RIP: 0010:mmu_interval_read_begin+0x24/0xc0 >>>> [ 2.731336] Code: e9 51 66 e1 ff 90 0f 1f 44 00 00 41 54 49 89 fc= 55 53 48 83 ec 30 65 48 8b 04 25 28 00 00 00 48 89 44 24 28 31 c0 48 8b = 47 38 <48> 8b a8 b0 03 00 00 48 8d 5d 0c 48 89 df e8 49 27 6f 00 4d 8b 64= >>>> [ 2.731358] RSP: 0018:ffff9873001e7d20 EFLAGS: 00010246 >>>> [ 2.731365] RAX: 0000000000000000 RBX: ffff8a4e94712500 RCX: 0000= 000000000000 >>>> [ 2.731375] RDX: ffff8a4ef53add00 RSI: 0000000000000000 RDI: ffff= 8a4e94712500 >>>> [ 2.731385] RBP: ffff8a4e0bf7a640 R08: 00007bc5c0573000 R09: 0000= 000000000008 >>>> [ 2.731395] R10: ffff8a4ec756c190 R11: 00007bc5c05a2000 R12: ffff= 8a4e94712500 >>>> [ 2.731405] R13: ffff8a4ed3ab9d50 R14: 0000000000000000 R15: 0000= 000000000001 >>>> [ 2.731415] FS: 00007bc5c00dc7c0(0000) GS:ffff8a4ef5d00000(0000)= knlGS:0000000000000000 >>>> [ 2.731427] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>> [ 2.731436] CR2: 00000000000003b0 CR3: 000000008148e004 CR4: 0000= 0000003606e0 >>>> [ 2.731446] Kernel panic - not syncing: Fatal exception >>>> [ 2.731527] Kernel Offset: 0x2a000000 from 0xffffffff81000000 (re= location range: 0xffffffff80000000-0xffffffffbfffffff) >>>> >>>> -- >>>> i. >>>> >>>> _______________________________________________ >>>> Xen-devel mailing list >>>> Xen-devel@lists.xenproject.org >>>> https://lists.xenproject.org/mailman/listinfo/xen-devel >>>> >>> _______________________________________________ >>> Xen-devel mailing list >>> Xen-devel@lists.xenproject.org >>> https://lists.xenproject.org/mailman/listinfo/xen-devel >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xenproject.org >> https://lists.xenproject.org/mailman/listinfo/xen-devel > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xenproject.org > https://lists.xenproject.org/mailman/listinfo/xen-devel --------------6782CCBDA15BD1766381A1E7 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit

On 1/27/20 6:29 PM, Boris Ostrovsky wrote:


On 1/27/20 4:37 PM, Marek Marczykowski-Górecki wrote:
On Mon, Jan 27, 2020 at 03:45:11PM +0100, Jürgen Groß wrote:

On 27.01.20 14:16, Ilpo Järvinen wrote:

Hi,

I've noted that 5.5-rcs and now 5.5-based kernel fails to boot in VM.
5.4 based kernels worked fine and there seems to have been some changes in
drivers/xen post-5.4 so perhaps they broke something?

I can't reproduce your problem. Just booted a VM with kernel 5.5 as
PV- and as HVM-guest without any problems.

It looks like an issue with gntdev driver, so reproducing it require any
userspace that actually makes use of it. Any idea what recent change
could cause that?


Loading Linux 5.5.0-accecn30 ...

.[5;22H      [ initrd.img-5.5.0-acc  16.52MiB  100%  10.23MiB/s ].[5;1HSetting up swapspace version 1, size = 1073737728 bytes
/dev/xvda3: clean, 852118/1294896 files, 3076785/5190907 blocks
[    2.730931] BUG: kernel NULL pointer dereference, address: 00000000000003b0
[    2.730959] #PF: supervisor read access in kernel mode
[    2.730966] #PF: error_code(0x0000) - not-present page
[    2.730973] PGD 0 P4D 0
[    2.730978] Oops: 0000 [#1] SMP PTI
[    2.730985] CPU: 1 PID: 402 Comm: qubesdb-daemon Tainted: G           O      5.5.0-accecn30 #31
[    2.731000] RIP: 0010:mmu_interval_read_begin+0x24/0xc0




This looks like it could well be d3eeb1d77c5d0af9df442db63722928238310a86. Can you revert it and see if it makes a difference?

(+Jason)

-boris




[    2.731008] Code: e9 51 66 e1 ff 90 0f 1f 44 00 00 41 54 49 89 fc 55 53 48 83 ec 30 65 48 8b 04 25 28 00 00 00 48 89 44 24 28 31 c0 48 8b 47 38 <48> 8b a8 b0 03 00 00 48 8d 5d 0c 48 89 df e8 49 27 6f 00 4d 8b 64
[    2.731030] RSP: 0018:ffff9873001e7d20 EFLAGS: 00010246
[    2.731037] RAX: 0000000000000000 RBX: ffff8a4e94712500 RCX: 0000000000000000


I am pretty sure it is.

RAX=0 most likely means that map->notifier is NULL (assuming your compiler generates code similar to mine).

I believe you at least need


diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 4fc83e3f..d35cf0b 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -1016,7 +1016,8 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
         * and we are holding it now, there is no need for the notifier_range
         * locking pattern.
         */
-       mmu_interval_read_begin(&map->notifier);
+       if (use_ptemod)
+               mmu_interval_read_begin(&map->notifier);
 
        if (use_ptemod) {
                map->pages_vm_start = vma->vm_start;


and maybe more.  Give that a try.


-boris


[    2.731047] RDX: ffff8a4ef53add00 RSI: 0000000000000000 RDI: ffff8a4e94712500
[    2.731057] RBP: ffff8a4e0bf7a640 R08: 00007bc5c0573000 R09: 0000000000000008
[    2.731066] R10: ffff8a4ec756c190 R11: 00007bc5c05a2000 R12: ffff8a4e94712500
[    2.731076] R13: ffff8a4ed3ab9d50 R14: 0000000000000000 R15: 0000000000000001
[    2.731086] FS:  00007bc5c00dc7c0(0000) GS:ffff8a4ef5d00000(0000) knlGS:0000000000000000
[    2.731097] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.731105] CR2: 00000000000003b0 CR3: 000000008148e004 CR4: 00000000003606e0
[    2.731116] Call Trace:
[    2.731123]  ? vma_merge+0xef/0x370
[    2.731132]  gntdev_mmap+0x153/0x30e [xen_gntdev]
[    2.731139]  mmap_region+0x3d9/0x660
[    2.731146]  do_mmap+0x372/0x520
[    2.731153]  vm_mmap_pgoff+0xd2/0x120
[    2.731160]  ksys_mmap_pgoff+0x1b8/0x270
[    2.731167]  ? ksys_ioctl+0x60/0x90
[    2.731174]  do_syscall_64+0x5b/0x180
[    2.731182]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[    2.731191] RIP: 0033:0x7bc5c03e8133
[    2.731196] Code: 54 41 89 d4 55 48 89 fd 53 4c 89 cb 48 85 ff 74 56 49 89 d9 45 89 f8 45 89 f2 44 89 e2 4c 89 ee 48 89 ef b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7d 5b 5d 41 5c 41 5d 41 5e 41 5f c3 66 2e 0f
[    2.731219] RSP: 002b:00007ffcbccc89b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
[    2.731230] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007bc5c03e8133
[    2.731243] RDX: 0000000000000003 RSI: 0000000000001000 RDI: 0000000000000000
[    2.731252] RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
[    2.731263] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000003
[    2.731273] R13: 0000000000001000 R14: 0000000000000001 R15: 0000000000000007
[    2.731284] Modules linked in: xen_netback u2mfn(O) xen_gntdev xen_gntalloc xen_blkback xen_evtchn parport_pc ppdev xenfs xen_privcmd lp parport ip_tables xen_netfront xen_blkfront crc32c_intel
[    2.731309] CR2: 00000000000003b0
[    2.731315] fbcon: Taking over console
[    2.731321] ---[ end trace 5ec57aa3f3a40247 ]---
[    2.731329] RIP: 0010:mmu_interval_read_begin+0x24/0xc0
[    2.731336] Code: e9 51 66 e1 ff 90 0f 1f 44 00 00 41 54 49 89 fc 55 53 48 83 ec 30 65 48 8b 04 25 28 00 00 00 48 89 44 24 28 31 c0 48 8b 47 38 <48> 8b a8 b0 03 00 00 48 8d 5d 0c 48 89 df e8 49 27 6f 00 4d 8b 64
[    2.731358] RSP: 0018:ffff9873001e7d20 EFLAGS: 00010246
[    2.731365] RAX: 0000000000000000 RBX: ffff8a4e94712500 RCX: 0000000000000000
[    2.731375] RDX: ffff8a4ef53add00 RSI: 0000000000000000 RDI: ffff8a4e94712500
[    2.731385] RBP: ffff8a4e0bf7a640 R08: 00007bc5c0573000 R09: 0000000000000008
[    2.731395] R10: ffff8a4ec756c190 R11: 00007bc5c05a2000 R12: ffff8a4e94712500
[    2.731405] R13: ffff8a4ed3ab9d50 R14: 0000000000000000 R15: 0000000000000001
[    2.731415] FS:  00007bc5c00dc7c0(0000) GS:ffff8a4ef5d00000(0000) knlGS:0000000000000000
[    2.731427] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.731436] CR2: 00000000000003b0 CR3: 000000008148e004 CR4: 00000000003606e0
[    2.731446] Kernel panic - not syncing: Fatal exception
[    2.731527] Kernel Offset: 0x2a000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)

--
  i.

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