** Description changed: I was trying to attach gdb to chromium-browser, by passing the PID to - gdb (gdb -p $PID). The first attempt as non-root user crashed gdb, then - I tried running it as root (sudo gdb -p $PID). gdb got stuck at - "Attaching to process ..." and I got this message: + gdb (gdb -p $PID). The first attempt as non-root user crashed gdb and I + got this message: ------------[ cut here ]------------ kernel BUG at /build/linux-lts-wily-Vv6Eyd/linux-lts-wily-4.2.0/mm/memory.c:3146! invalid opcode: 0000 [#1] SMP Modules linked in: vboxpci(OE) vboxnetadp(OE) r8168(OE) vboxnetflt(OE) vboxdrv(OE) ib_cm ib_sa ib_mad ib_core ib_addr libfc qla2xxx scsi_transport_fc configfs pci_stub drbg ansi_cprng ctr ccm dm_crypt ip6table_filter ip6_tables iptable_filter ip_tables x_tables binfmt_misc uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media arc4 hp_wmi sparse_keymap rtsx_pci_ms memstick dm_multipath scsi_dh snd_hda_codec_idt ath9k snd_hda_codec_generic ath9k_common snd_hda_codec_hdmi joydev ath9k_hw input_leds snd_hda_intel serio_raw ath snd_hda_codec snd_hda_core snd_hwdep k10temp snd_pcm_oss mac80211 snd_mixer_oss snd_pcm snd_seq_midi i2c_piix4 snd_seq_midi_event snd_rawmidi cfg80211 snd_seq snd_seq_device snd_timer snd soundcore shpchp parport_pc hp_accel lis3lv02d ppdev input_polldev mac_hid cpuid msr ircomm_tty ircomm irda crc_ccitt lp parport btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq raid1 raid0 multipath linear pata_acpi rtsx_pci_sdmmc amdkfd amd_iommu_v2 radeon i2c_algo_bit ttm drm_kms_helper psmouse ahci drm pata_atiixp libahci rtsx_pci wmi video [last unloaded: vboxpci] CPU: 3 PID: 25702 Comm: gdb Tainted: G OE 4.2.0-27-generic #32~14.04.1-Ubuntu Hardware name: Hewlett-Packard HP Pavilion dv6 Notebook PC/3590, BIOS F.21 09/13/2011 task: ffff8800cb54d780 ti: ffff88000a8f0000 task.ti: ffff88000a8f0000 RIP: 0010:[<ffffffff811a6a90>] [<ffffffff811a6a90>] handle_mm_fault+0x17e0/0x1840 RSP: 0018:ffff88000a8f3bb8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00003ffffffff000 RDX: ffff8801697c04f8 RSI: 0000000000000120 RDI: 00000001697c0067 RBP: ffff88000a8f3c78 R08: 00000001edddb120 R09: 0000000000000120 R10: 0000000000000001 R11: ffff8800000004f8 R12: ffff88003265bc00 R13: ffff880007a18808 R14: 00007f856029fe68 R15: ffff8800aa3843c0 FS: 00007f3d95334740(0000) GS:ffff88020ed80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002b69528 CR3: 000000012a9ad000 CR4: 00000000000006e0 Stack: 0000001600000000 ffff880000000016 ffffea0005a5f030 ffffffff817b0e73 ffff88003265bc00 00007f856029fe68 0000001700000000 ffff8800000004f8 ffff880000000000 0000000000000017 00007f856029fe68 ffff88003265bc00 Call Trace: [<ffffffff817b0e73>] ? follow_page_pte+0xae/0x307 [<ffffffff811a070e>] ? follow_page_mask+0x1ce/0x320 [<ffffffff811a095b>] __get_user_pages+0xfb/0x5b0 [<ffffffff811a1222>] get_user_pages+0x52/0x60 [<ffffffff811a16a7>] __access_remote_vm+0xb7/0x1c0 [<ffffffff811a7620>] access_process_vm+0x50/0x70 [<ffffffff81081aa9>] ptrace_request+0x2c9/0x5a0 [<ffffffff817ae9da>] ? queued_spin_lock_slowpath+0xb/0xf [<ffffffff810a0efa>] ? wait_task_inactive+0xea/0x1e0 [<ffffffff811eb508>] ? vfs_write+0x148/0x190 [<ffffffff81022f51>] arch_ptrace+0x261/0x2b0 [<ffffffff81080a2f>] ? ptrace_check_attach+0x5f/0x140 [<ffffffff81081726>] SyS_ptrace+0xa6/0x110 [<ffffffff817bc3b2>] entry_SYSCALL_64_fastpath+0x16/0x75 Code: d8 50 a8 81 e8 92 0f ed ff 4c 8b 9d 78 ff ff ff e9 fa ee ff ff 48 8b 7d 98 89 45 80 e8 2a dd fd ff 8b 45 80 89 c3 e9 ba eb ff ff <0f> 0b c7 45 80 01 00 00 00 e9 a5 f7 ff ff 4c 89 c7 48 89 95 68 RIP [<ffffffff811a6a90>] handle_mm_fault+0x17e0/0x1840 RSP <ffff88000a8f3bb8> ---[ end trace c5ec208e5d4b9c66 ]--- - Then, I tried killing gdb as root from another terminal, by running - "killall gdb", but killall got stuck, too. pidof and ps also got - stuck... + Then I tried running it as root (sudo gdb -p $PID). gdb got stuck at + "Attaching to process ...". I tried killing gdb as root from another + terminal, by running "killall gdb", but killall got stuck, too. pidof + and ps also got stuck... This is the line referenced in the error message: http://lxr.free- electrons.com/source/mm/memory.c?v=4.2#L3146 , I'm not sure if Ubuntu runs a modified version of this file, though. Also, I'm not sure if this affects Wily (I guess it does) or if this has been patched upstream. There is a similar bug report here: https://bugzilla.redhat.com/show_bug.cgi?id=1296505 , but it doesn't involve gdb. Should I report this bug upstream? My system is: $ lsb_release -a LSB Version: core-2.0-amd64:core-2.0-noarch:core-3.0-amd64:core-3.0-noarch:core-3.1-amd64:core-3.1-noarch:core-3.2-amd64:core-3.2-noarch:core-4.0-amd64:core-4.0-noarch:core-4.1-amd64:core-4.1-noarch:security-4.0-amd64:security-4.0-noarch:security-4.1-amd64:security-4.1-noarch Distributor ID: Ubuntu Description: Ubuntu 14.04.3 LTS Release: 14.04 Codename: trusty $ uname -r 4.2.0-27-generic $ dpkg -l | grep linux-image-generic ii linux-image-generic-lts-wily 4.2.0.27.21 amd64 Generic Linux kernel image
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1545401 Title: "kernel BUG at /build/linux-lts-wily-Vv6Eyd/linux-lts- wily-4.2.0/mm/memory.c:3146!" when starting gdb as root, gdb freezes To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-wily/+bug/1545401/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
