From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yang Yingliang Subject: Re: [PATCH] net: sched: tbf: fix an oops when a GSO packet cannot be enqueued Date: Sat, 23 Nov 2013 16:08:47 +0800 Message-ID: <5290628F.6080604@huawei.com> References: <1385112446-15564-1-git-send-email-yangyingliang@huawei.com> <1385131801.10637.84.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: , , , , To: Eric Dumazet Return-path: Received: from szxga02-in.huawei.com ([119.145.14.65]:43396 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750925Ab3KWIMI (ORCPT ); Sat, 23 Nov 2013 03:12:08 -0500 In-Reply-To: <1385131801.10637.84.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: On 2013/11/22 22:50, Eric Dumazet wrote: > On Fri, 2013-11-22 at 17:27 +0800, Yang Yingliang wrote: >> It seems commit e43ac79a4b("sch_tbf: segment too big GSO packets") >> introduce this oops. >> >> When GSO mode is on, use the following command: >> tc qdisc add dev eth0 root handle 1: tbf latency 50ms burst 1KB rate 50mbit mtu 1KB >> iperf -c host -t 30 > > I think your patch is not needed, the stack trace point to a different > spot. > > The issue should be fixed by : > > http://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=9d8506cc2d7ea1f911c72c100193a3677f6668c3 > > Could you check again ? > > Thanks I've applied this patch, but it's oops too. I think it's not the same problem. In this problem, when the segs is not enqueued, we do nothing to the segs.I think it causes the problem. If I am wrong, please point out. Thanks! Here is the call trace after applying the above patch: BTW, the call trace is not always same no matter the above patch is applied. [ 355.298416] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 355.391292] IP: [] __skb_recv_datagram+0x259/0x500 [ 355.466628] PGD 20312fc067 PUD 2030ed9067 PMD 0 [ 355.521336] Oops: 0002 [#1] SMP [ 355.559528] Modules linked in: sch_tbf(O) tun ip6table_filter ip6_tables iptable_filter ip_tables x_tables edd af_packet bridge stp llc microcode fuse loop dm_mod igb dca i2c_algo_bit i2c_i801 ptp serio_raw sg ehci_pci ipv6 kvm_intel i2c_core kvm iTCO_wdt iTCO_vendor_support lpc_ich mfd_core hid_generic mptctl pps_core pcspkr button ext3 jbd mbcache usbhid hid uhci_hcd ehci_hcd usbcore sd_mod usb_common crc_t10dif crct10dif_common processor thermal_sys hwmon scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh_rdac scsi_dh ata_generic ata_piix libata mptsas mptscsih mptbase scsi_transport_sas scsi_mod [ 356.186224] CPU: 9 PID: 10073 Comm: acc-snf Tainted: G O 3.12.0-rc6-0.7-default+ #8 [ 356.287345] Hardware name: Huawei Technologies Co., Ltd. Tecal XH620 /BC21THSA , BIOS TTSAV020 12/02/2011 [ 356.424571] task: ffff881fbd4e0380 ti: ffff881fbf028000 task.ti: ffff881fbf028000 [ 356.513306] RIP: 0010:[] [] __skb_recv_datagram+0x259/0x500 [ 356.617524] RSP: 0018:ffff881fbf029b68 EFLAGS: 00210046 [ 356.680466] RAX: 0000000000000000 RBX: ffff881fbd0e1b70 RCX: 0000000000200296 [ 356.765074] RDX: 0000000000000000 RSI: 0000000000200296 RDI: ffff881fbbc6f0a4 [ 356.849683] RBP: ffff881fbf029c48 R08: ffff881fbf029cb4 R09: ffff88203eb24840 [ 356.934291] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 357.018900] R13: ffff881fbbc6f000 R14: ffff881fbbc6f090 R15: ffff881fbf029c64 [ 357.103508] FS: 0000000000000000(0000) GS:ffff88203f320000(0063) knlGS:00000000f7320b70 [ 357.199465] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 357.267566] CR2: 0000000000000008 CR3: 0000001fbb973000 CR4: 00000000000027e0 [ 357.352175] Stack: [ 357.375911] 0000000000200286 ffff881fbf029c00 ffff881fbf028010 ffff881fbd4e0380 [ 357.463640] ffff881fbf028010 ffff881fbbc6f1b8 ffff881fbf029cb4 ffff881fbf029c60 [ 357.551369] ffff881f80000020 7fffffffffffffff ffff881fbbc6f0a4 ffff881fbbc6f0cc [ 357.639099] Call Trace: [ 357.667998] [] ? skb_release_data+0xaa/0xe0 [ 357.737135] [] skb_recv_datagram+0x32/0x40 [ 357.805237] [] packet_recvmsg+0x66/0x360 [af_packet] [ 357.883662] [] sock_recvmsg+0xac/0xe0 [ 357.946613] [] ? compat_core_sys_select+0x24d/0x260 [ 358.024001] [] SyS_recvfrom+0xbe/0x120 [ 358.087976] [] ? compat_sock_ioctl+0x88/0xb0 [ 358.158145] [] ? compat_sys_ioctl+0x7c/0x1380 [ 358.229344] [] ? ktime_get_ts+0x53/0x100 [ 358.295387] [] compat_sys_socketcall+0x150/0x240 [ 358.369685] [] sysenter_dispatch+0x7/0x1a [ 358.436756] Code: 00 48 89 8d 68 ff ff ff e9 38 fe ff ff 41 83 ad a0 00 00 00 01 48 8b 13 48 8b 43 08 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 <48> 89 42 08 48 89 10 48 8b bd 70 ff ff ff e8 04 f9 0b 00 48 8b [ 358.661068] RIP [] __skb_recv_datagram+0x259/0x500 ------------------------------cut here------------------------------------- Regards, Yang > > > >