From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Benc Subject: Re: [net-next:master 1179/1189] include/linux/compiler.h:447:38: error: call to '__compiletime_assert_243' declared with attribute error: BUILD_BUG_ON failed: offsetof(struct dst_entry, __refcnt) & 63 Date: Fri, 21 Aug 2015 16:48:55 +0200 Message-ID: <20150821164855.5b0341ca@griffin> References: <201508211329.x7P0JrxH%fengguang.wu@intel.com> <20150820.232650.1503466109554752010.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: fengguang.wu@intel.com, kbuild-all@01.org, netdev@vger.kernel.org To: David Miller Return-path: Received: from mx1.redhat.com ([209.132.183.28]:45352 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751955AbbHUOs7 (ORCPT ); Fri, 21 Aug 2015 10:48:59 -0400 In-Reply-To: <20150820.232650.1503466109554752010.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 20 Aug 2015 23:26:50 -0700 (PDT), David Miller wrote: > Yeah, I should have predicted this would happen on 32-bit builds when I saw > the adjustment of __pad_to_align_refcnt[] for 64-bit. > > Jiri, you might not have any reasonable options to fix this I'm afraid. Still working on this, the patch I sent should at least relieve the pressure (but of course, I'll understand if you revert the whole set). I'm currently fighting with vxlan triggering null pointer dereference in include/net/netns/generic.h:41, seems that net->gen is NULL. This is with commit 938049e18dca, i.e. before my lwtunnel ipv6 patchset. Pasting the trace below in case anyone has an idea. CONFIG_NET_NS is enabled. When adding debug printk to vxlan_init_net (before the call to net_generic), the issue disappears. Smells like a race. I'm not sure how much time I will have during the weekend. Jiri [ 26.102174] BUG: unable to handle kernel NULL pointer dereference at 00000010 [ 26.109299] IP: [] vxlan_init_net+0x14/0x50 [vxlan] [ 26.115032] *pdpt = 0000000033b48001 *pde = 0000000000000000 [ 26.120770] Oops: 0000 [#1] SMP [ 26.124000] Modules linked in: vxlan(+) tg3(+) ip6_udp_tunnel snd_pcm udp_tunnel snd_timer hp_wmi sparse_keymap snd ptp coretemp rfkill pps_core gpio_ich iTCO_wdt mdio dca iTCO_vendor_support ppdev kvm_intel kvm soundcore lpc_ich mfd_core pcspkr crc32_pclmul floppy parport_pc i7core_edac parport edac_core acpi_cpufreq xfs libcrc32c nouveau video mxm_wmi i2c_algo_bit drm_kms_helper ttm drm mptsas scsi_transport_sas firewire_ohci mptscsih crc32c_intel serio_raw firewire_core mptbase crc_itu_t wmi [ 26.168070] CPU: 0 PID: 370 Comm: systemd-udevd Not tainted 4.2.0-rc6+ #1 [ 26.174829] Hardware name: Hewlett-Packard HP Z800 Workstation/0AECh, BIOS 786G5 v03.54 11/02/2011 [ 26.183750] task: f4ec45c0 ti: f4a82000 task.ti: f4a82000 [ 26.189125] EIP: 0060:[] EFLAGS: 00010282 CPU: 0 [ 26.194588] EIP is at vxlan_init_net+0x14/0x50 [vxlan] [ 26.199703] EAX: 00000000 EBX: f8509000 ECX: 00000002 EDX: 00000002 [ 26.205942] ESI: f6583000 EDI: c0df7900 EBP: f4a83d74 ESP: f4a83d74 [ 26.212182] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 [ 26.217557] CR0: 80050033 CR2: 00000010 CR3: 34a3f4a0 CR4: 000006f0 [ 26.223797] Stack: [ 26.225797] f4a83d94 c09beab1 00000000 f6aed2c0 00000002 f8509000 c0df7900 f8509000 [ 26.233576] f4a83db4 c09bedb4 f4a83d9c f4a83d9c 3cd52c75 f8509000 c0d72780 f8091000 [ 26.241355] f4a83dc0 c09bee51 f4f08960 f4a83dcc f8091040 f4f08960 f4a83e48 c040211a [ 26.249133] Call Trace: [ 26.251568] [] ops_init+0x31/0x130 [ 26.255905] [] register_pernet_operations+0xe4/0x160 [ 26.261798] [] ? 0xf8091000 [ 26.265530] [] register_pernet_subsys+0x21/0x40 [ 26.270993] [] vxlan_init_module+0x40/0x1000 [vxlan] [ 26.276889] [] do_one_initcall+0xaa/0x200 [ 26.281829] [] ? 0xf8091000 [ 26.285562] [] ? kmem_cache_alloc_trace+0x175/0x1f0 [ 26.291369] [] ? do_init_module+0x21/0x1b5 [ 26.296398] [] ? do_init_module+0x21/0x1b5 [ 26.301428] [] do_init_module+0x50/0x1b5 [ 26.306285] [] load_module+0x1dbb/0x23c0 [ 26.311143] [] ? copy_module_from_fd.isra.48+0xf9/0x190 [ 26.317297] [] SyS_finit_module+0xa5/0xf0 [ 26.322240] [] ? vm_mmap_pgoff+0x9b/0xc0 [ 26.327097] [] sysenter_do_call+0x12/0x12 [ 26.332038] Code: c0 00 00 00 5d c3 90 55 89 e5 66 66 66 66 90 8b 80 18 05 00 00 5d c3 55 89 e5 66 66 66 66 90 8b 15 4c 94 50 f8 8b 80 98 0c 00 00 <8b> 54 90 08 89 12 89 52 04 8d 42 08 c7 82 08 04 00 00 00 00 00 [ 26.351295] EIP: [] vxlan_init_net+0x14/0x50 [vxlan] SS:ESP 0068:f4a83d74 [ 26.358938] CR2: 0000000000000010 [ 26.362259] ---[ end trace 3aa9af5192e30e1f ]--- -- Jiri Benc