I am backporting a driver called GTP from 4.9 Linux kernel to 3.18 version. I fixed the errors in the source code of the driver and compiled the kernel successfully. I am also using Ubuntu Server 14.04 to test the kernel with that driver. (There is also a netlink library (libgtpnl) to control the driver.
I do modprobe gtp and there is no problem. I use the library to control some functions of the driver, and there is no problem. However, strangely, when I enable forwarding: (echo 1 > /proc/sys/net/ipv4/ip_forward) The kernel somehow haults. I am also unable to do many network commands (ifconfig, iproute, etc)
the dmesg shows:
[ 33.032315] gtp: GTP module loaded (pdp ctx size 88 bytes)
[ 62.269996] general protection fault: 0000 [#1] SMP
[ 62.270028] Modules linked in: gtp(E) udp_tunnel(E) pci_stub(E) vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) nfnetlink_queue(E) nfnetlink_log(E) nfnetlink(E) coretemp(E) crct10dif_pclmul(E) ppdev(E) crc32_pclmul(E) ghash_clmulni_intel(E) vmw_balloon(E) btusb(E) bluetooth(E) aesni_intel(E) aes_x86_64(E) lrw(E) gf128mul(E) glue_helper(E) ablk_helper(E) cryptd(E) microcode(E) serio_raw(E) snd_ens1371(E) snd_ac97_codec(E) ac97_bus(E) gameport(E) snd_rawmidi(E) snd_seq_device(E) snd_pcm(E) snd_timer(E) snd(E) soundcore(E) vmwgfx(E) ttm(E) drm_kms_helper(E) drm(E) shpchp(E) vmw_vmci(E) i2c_piix4(E) parport_pc(E) mac_hid(E) lp(E) parport(E) hid_generic(E) usbhid(E) hid(E) psmouse(E) ahci(E) libahci(E) e1000(E) mptspi(E) mptscsih(E) mptbase(E) floppy(E) vmw_pvscsi(E) vmxnet3(E) pata_acpi(E)
[ 62.271080] CPU: 1 PID: 1323 Comm: bash Tainted: G OE 3.18.20-bondingv4 #7
[ 62.271121] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
[ 62.271293] task: ffff8800772c9920 ti: ffff880079390000 task.ti: ffff880079390000
[ 62.271329] RIP: 0010:[<ffffffff81669a5d>] [<ffffffff81669a5d>] dev_disable_lro+0x2d/0x130
[ 62.271465] RSP: 0018:ffff880079393df8 EFLAGS: 00010206
[ 62.271492] RAX: 0000000000200000 RBX: 0002000000000000 RCX: 0000000000000000
[ 62.271595] RDX: ffffffff81ce6d98 RSI: 0000000000000000 RDI: ffff8800795ed000
[ 62.271630] RBP: ffff880079393e18 R08: 0000000000000000 R09: ffff88007e4361a0
[ 62.271664] R10: ffffffff8165266f R11: ffffea0001dd5480 R12: ffffffff81ce2e00
[ 62.271703] R13: ffffffff81ce2ec8 R14: ffff880079393f50 R15: ffff8800795ed000
[ 62.271798] FS: 00007fcfa02e8740(0000) GS:ffff88007e420000(0000) knlGS:0000000000000000
[ 62.271838] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 62.271866] CR2: 00007ffe943a5ac8 CR3: 00000000782e6000 CR4: 00000000001407e0
[ 62.271964] Stack:
[ 62.271978] ffffffff81ce2e00 0000000000000001 ffffffff81ce2e00 ffffffff81ce2ec8
[ 62.272078] ffff880079393e68 ffffffff816da5a2 0000000000000000 0000000000000002
[ 62.272774] ffffffff81ce8b40 0000000000000001 ffffffffffffffea ffffffff81ce8b40
[ 62.273379] Call Trace:
[ 62.274042] [<ffffffff816da5a2>] devinet_sysctl_forward+0x1c2/0x1f0
[ 62.274940] [<ffffffff8124bf23>] proc_sys_call_handler+0xb3/0xc0
[ 62.275504] [<ffffffff8124bf44>] proc_sys_write+0x14/0x20
[ 62.276157] [<ffffffff811db457>] vfs_write+0xb7/0x1f0
[ 62.276795] [<ffffffff811dbed6>] SyS_write+0x46/0xb0
[ 62.277394] [<ffffffff81786914>] ? int_check_syscall_exit_work+0x34/0x3d
[ 62.278080] [<ffffffff8178668d>] system_call_fastpath+0x16/0x1b
[ 62.278753] Code: 44 00 00 55 48 89 e5 41 55 41 54 53 48 89 fb 48 83 ec 08 8b 87 0c 02 00 00 a8 01 75 39 a9 00 00 20 00 74 07 48 8b 9b f0 08 00 00 <48> 81 a3 e0 00 00 00 ff 7f ff ff 48 89 df e8 80 ff ff ff f6 83
[ 62.282203] RIP [<ffffffff81669a5d>] dev_disable_lro+0x2d/0x130
[ 62.282925] RSP <ffff880079393df8>
[ 62.283664] ---[ end trace f2a66d8a2b1df752 ]---
[ 62.289214] init: tty2 main process ended, respawning
There are some answers related to kernel taint as the driver seems have no license. But it has, I dont why the kernel didnt realize it. I couldn't find how the driver uses dev_disable_lro. I couldnt move through. Any help to identify my problem would be appreciated. Thanks
