I just encontered a kernel bug (see below) on v3.14.19 and can also reproduce it on v3.14.22. It hits a BUG() in fs/locks.c, line 2247. This BUG() is removed and replaced in v3.15 with a WARN(), see commit 8c3cac5e6a85f03602ffe09c44f14418699e31ec. To trigger this bug, I start a userspace program under gdb. The program throws an exception while holding a fcntl lock, which is then catched by gdb. When quitting gdb in this state, sometimes the kernel BUG is triggered. As underlying filesystem I use ceph. As this BUG() easily triggered from user-space and seems to be unneccessary under this condition, could this patch be considered for stable? Markus ---------------------------- 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.189655] ------------[ cut here ]------------ 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.189754] kernel BUG at fs/locks.c:2247! 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.189843] invalid opcode: 0000 [#1] SMP 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.190031] Modules linked in: isofs nls_cp437 vfat fat loop fuse nls_utf8 cifs cbc ceph libceph rpcsec_gss_krb5 nfsv4 ipmi_watchdog nfs w83627ehf adm1026 w83795 w83793 hwmon_vid jc42 8021q garp stp mrp llc autofs4 bonding ipt_MASQUERADE xt_nat iptable_nat nf_nat_ipv4 nf_nat xt_LOG xt_comment xt_limit nf_conntrack_ipv4 nf_defrag_ipv4 xt_tcpudp xt_multiport xt_conntrack nf_conntrack xt_hashlimit iptable_filter ip_tables x_tables af_packet zfs(PO) zunicode(PO) zavl(PO) zcommon(PO) znvpair(P O) spl(O) ipmi_si ipmi_devintf ipmi_msghandler syscopyarea sysfillrect sysimgblt ttm kvm_amd kvm drm_kms_helper drm amd64_edac_mod psmouse edac_mce_amd microcode sp5100_tco edac_core pcspkr evdev k10temp i2c_piix4 arcmsr acpi_cpufreq rtc_cmos processor button thermal_sys xfs hid_generic usbhid hid raid1 md_mod sr_mod cdrom sd_mod ata_generic ohci_pci ahci pata_atiixp libahci ehci_pci ohci_hcd ehci_hcd libata usbcore usb_common ipv6 dm_mirror dm_region_hash dm_log dm_mod unix 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.195763] CPU: 2 PID: 8031 Comm: moldyn2 Tainted: P O 3.14.19-gentoo #2 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.195890] Hardware name: Supermicro H8SGL/H8SGL, BIOS 1.0c 09/03/10 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.196013] task: ffff880106676300 ti: ffff8803483c2000 task.ti: ffff8803483c2000 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.196139] RIP: 0010:[<ffffffff8113531a>] [<ffffffff8113531a>] locks_remove_flock+0xf5/0x117 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.196318] RSP: 0018:ffff8803483c3bc8 EFLAGS: 00010246 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.196410] RAX: 0000000000000081 RBX: ffff88007c508b00 RCX: 000000000000001a 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.196533] RDX: 000000000000001a RSI: 0000000000000082 RDI: ffff8801ee629eb8 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.196658] RBP: ffff8803483c3ca0 R08: ffff8803483c3ab0 R09: 0000000000000000 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.196782] R10: ffff880295e51472 R11: 000000000000b8d3 R12: ffff8801ee629e38 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.196905] R13: ffff8801ee629f78 R14: ffff8805cd6a70c0 R15: ffff88007c508b10 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.197029] FS: 00007ffff7faa880(0000) GS:ffff88040fc80000(0000) knlGS:0000000000000000 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.197154] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.197249] CR2: 00002af2b8a18000 CR3: 000000000180b000 CR4: 00000000000007e0 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.197372] Stack: 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.197452] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.197762] 0000000000000000 0000000000000000 0000000200000002 0000000000001f5f 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.198075] ffff8807e419e680 0000000000000000 0000000000000000 0000000000000000 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.198387] Call Trace: 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.198474] [<ffffffff810ff4fa>] fput+0xa3/0x1bb 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.198565] [<ffffffff810ff63e>] __fput+0x9/0xb 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.198656] [<ffffffff8104e6f3>] task_work_run+0x7d/0x96 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.198750] [<ffffffff8103b0ea>] do_exit+0x3f8/0x92d 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.198843] [<ffffffff813c5ff2>] ? __schedule+0x3bc/0x545 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.198936] [<ffffffff8103b688>] do_group_exit+0x3d/0xab 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.199029] [<ffffffff81044db2>] get_signal_to_deliver+0x4aa/0x4c9 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.199125] [<ffffffff81001d6f>] do_signal+0x43/0x4fc 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.199217] [<ffffffff810a60ed>] ? acct_account_cputime+0x17/0x19 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.199315] [<ffffffff8105d4d0>] ? account_user_time+0x41/0x46 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.199409] [<ffffffff8105d82c>] ? vtime_account_user+0x41/0x46 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.199505] [<ffffffff81002250>] do_notify_resume+0x28/0x78 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.199599] [<ffffffff813c8e74>] paranoid_userspace+0x3f/0x42 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.199692] Code: 31 48 39 58 60 75 26 8b 40 30 a8 02 74 0a 4c 89 ef e8 d6 e6 ff ff eb e0 a8 24 74 0f be 02 00 00 00 4c 89 ef e8 57 e7 ff ff eb cd <0f> 0b 49 89 c5 eb c6 66 41 83 84 24 80 00 00 00 01 48 81 c4 c0 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.202947] RIP [<ffffffff8113531a>] locks_remove_flock+0xf5/0x117 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.203090] RSP <ffff8803483c3bc8> 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.203192] ---[ end trace e1a1532c01988e14 ]--- 2014-11-28T15:53:09+01:00 bagheera2 kernel: [5546503.203284] Fixing recursive fault but reboot is needed! -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html