Hi Vegard, First, thanks for testing! * Vegard Nossum <vegard.nossum@xxxxxxxxx>: > > I got this crash: > > [ 279.029673] BUG: unable to handle kernel NULL pointer dereference > at 0000000000000008 [...] > It reproduces reliably if I do this: > > $ while true; do echo 1 > /sys/bus/pci/devices/0000\:00\:00.0/remove; done I was going to ask for lspci -v output so that I could see what device 0000:00:00.0 might be, but I was able to reproduce something similar on my machine. Can I ask why you're doing the above with a while loop? Just to torture the code? Or something else? I haven't started investigating too closely yet, but it looks like I need some locking in there. Thanks. /ac [root@tahitifp1 pci]# while true ; do echo 1 > devices/0000\:04\:00.0/remove ; done kobject: '0000:06:00.0' (e000000181703120): kobject_uevent_env ------------[ cut here ]------------ WARNING: at fs/sysfs/group.c:138 sysfs_remove_group+0x80/0x180() Hardware name: server BL860c sysfs group a000000101432580 not found for kobject '0000:06:00.0' Modules linked in: binfmt_misc dm_multipath pci_slot sg shpchp pci_hotplug dm_snapshot dm_zero dm_mirror dm_region_hash dm_log dm_mod uhci_hcd ohci_hcd ehci_hcd usbcore Call Trace: [<a0000001000146d0>] show_stack+0x50/0xa0 sp=e00000018131fae0 bsp=e000000181311228 [<a000000100014750>] dump_stack+0x30/0x60 sp=e00000018131fcb0 bsp=e000000181311210 [<a00000010009a0f0>] warn_slowpath+0x130/0x180 sp=e00000018131fcb0 bsp=e0000001813111a8 [<a0000001002336a0>] sysfs_remove_group+0x80/0x180 sp=e00000018131fdd0 bsp=e000000181311178 [<a000000100513410>] dpm_sysfs_remove+0x30/0x60 sp=e00000018131fdd0 bsp=e000000181311158 [<a0000001005041d0>] device_del+0x70/0x3a0 sp=e00000018131fdd0 bsp=e000000181311120 [<a0000001005045d0>] device_unregister+0xd0/0x100 sp=e00000018131fdd0 bsp=e000000181311100 [<a000000100409cd0>] pci_stop_dev+0x70/0x100 sp=e00000018131fdd0 bsp=e0000001813110d8 [<a000000100409f40>] pci_remove_bus_device+0x80/0x180 sp=e00000018131fdd0 bsp=e0000001813110a8 [<a00000010040a0a0>] pci_remove_behind_bridge+0x60/0xc0 sp=e00000018131fdd0 bsp=e000000181311080 [<a000000100409f00>] pci_remove_bus_device+0x40/0x180 sp=e00000018131fdd0 bsp=e000000181311050 [<a00000010040a0a0>] pci_remove_behind_bridge+0x60/0xc0 sp=e00000018131fdd0 bsp=e000000181311028 [<a000000100409f00>] pci_remove_bus_device+0x40/0x180 sp=e00000018131fdd0 bsp=e000000181310ff0 [<a000000100415bc0>] remove_callback+0x40/0xc0 sp=e00000018131fdd0 bsp=e000000181310fc8 [<a00000010022edb0>] sysfs_schedule_callback_work+0x50/0xc0 sp=e00000018131fdd0 bsp=e000000181310fa0 [<a0000001000c1150>] run_workqueue+0x1f0/0x340 sp=e00000018131fdd0 bsp=e000000181310f60 [<a0000001000c13e0>] worker_thread+0x140/0x180 sp=e00000018131fdd0 bsp=e000000181310f38 [<a0000001000c9ba0>] kthread+0xa0/0x120 sp=e00000018131fe30 bsp=e000000181310f08 [<a000000100016690>] kernel_thread_helper+0xd0/0x100 sp=e00000018131fe30 bsp=e000000181310ee0 [<a00000010000a4c0>] start_kernel_thread+0x20/0x40 sp=e00000018131fe30 bsp=e000000181310ee0 ---[ end trace 9397c0de832fd5ba ]--- Unable to handle kernel NULL pointer dereference (address 0000000000000020) events/4[32]: Oops 8813272891392 [1] Modules linked in: binfmt_misc dm_multipath pci_slot sg shpchp pci_hotplug dm_snapshot dm_zero dm_mirror dm_region_hash dm_log dm_mod uhci_hcd ohci_hcd ehci_hcd usbcore Pid: 32, CPU 4, comm: events/4 psr : 00001010085a6010 ifs : 800000000000038a ip : [<a0000001009059a0>] Tainted: G W (2.6.29-rc4) ip is at klist_put+0x40/0x160 unat: 0000000000000000 pfs : 000000000000038a rsc : 0000000000000003 rnat: e00000018131fcb0 bsps: 9397c0de832fd5ba pr : 0000000000005a41 ldrs: 0000000000000000 ccv : 0000000000000000 fpsr: 0009804c8a70433f csd : 0000000000000000 ssd : 0000000000000000 b0 : a000000100905990 b6 : a000000100044250 b7 : a00000010000cd10 f6 : 000000000000000000000 f7 : 1003e9e3779b97f4a7c16 f8 : 1003e0a00000010000a4c f9 : 1003e0000000000000056 f10 : 1003e000000000000025a f11 : 1003e6db6db6db6db6db7 r1 : a0000001016d1360 r2 : a0000001014f5f50 r3 : a0000001014f5188 r8 : 0000000000000000 r9 : 0000000000000000 r10 : 0000000000000200 r11 : 0000000000000000 r12 : e00000018131fdd0 r13 : e000000181310000 r14 : 0000000000000020 r15 : 0000000000000009 r16 : 0000000000000000 r17 : a0000001014f5f50 r18 : 0000000000000200 r19 : 000000000007aca1 r20 : fffffffffff7aca1 r21 : a0000001014f5f90 r22 : a0000001014f5f94 r23 : 000000000000000a r24 : 000000000000000a r25 : a000000102b76a98 r26 : 000000000007aca0 r27 : 00000010085a2010 r28 : 00000000000fffff r29 : a0000001014f4e58 r30 : 0000000000000000 r31 : a000000101409818 Call Trace: [<a0000001000146d0>] show_stack+0x50/0xa0 sp=e00000018131f9a0 bsp=e0000001813112c0 [<a000000100014fb0>] show_regs+0x830/0x860 sp=e00000018131fb70 bsp=e000000181311278 [<a000000100039bc0>] die+0x1c0/0x2c0 sp=e00000018131fb70 bsp=e000000181311230 [<a000000100063e50>] ia64_do_page_fault+0x830/0x960 sp=e00000018131fb70 bsp=e0000001813111c8 [<a00000010000c700>] ia64_native_leave_kernel+0x0/0x270 sp=e00000018131fc00 bsp=e0000001813111c8 [<a0000001009059a0>] klist_put+0x40/0x160 sp=e00000018131fdd0 bsp=e000000181311178 [<a000000100905af0>] klist_del+0x30/0x60 sp=e00000018131fdd0 bsp=e000000181311158 [<a0000001005041f0>] device_del+0x90/0x3a0 sp=e00000018131fdd0 bsp=e000000181311120 [<a0000001005045d0>] device_unregister+0xd0/0x100 sp=e00000018131fdd0 bsp=e000000181311100 [<a000000100409cd0>] pci_stop_dev+0x70/0x100 sp=e00000018131fdd0 bsp=e0000001813110d8 [<a000000100409f40>] pci_remove_bus_device+0x80/0x180 sp=e00000018131fdd0 bsp=e0000001813110a8 [<a00000010040a0a0>] pci_remove_behind_bridge+0x60/0xc0 sp=e00000018131fdd0 bsp=e000000181311080 [<a000000100409f00>] pci_remove_bus_device+0x40/0x180 sp=e00000018131fdd0 bsp=e000000181311050 [<a00000010040a0a0>] pci_remove_behind_bridge+0x60/0xc0 sp=e00000018131fdd0 bsp=e000000181311028 [<a000000100409f00>] pci_remove_bus_device+0x40/0x180 sp=e00000018131fdd0 bsp=e000000181310ff0 [<a000000100415bc0>] remove_callback+0x40/0xc0 sp=e00000018131fdd0 bsp=e000000181310fc8 [<a00000010022edb0>] sysfs_schedule_callback_work+0x50/0xc0 sp=e00000018131fdd0 bsp=e000000181310fa0 [<a0000001000c1150>] run_workqueue+0x1f0/0x340 sp=e00000018131fdd0 bsp=e000000181310f60 [<a0000001000c13e0>] worker_thread+0x140/0x180 sp=e00000018131fdd0 bsp=e000000181310f38 [<a0000001000c9ba0>] kthread+0xa0/0x120 sp=e00000018131fe30 bsp=e000000181310f08 [<a000000100016690>] kernel_thread_helper+0xd0/0x100 sp=e00000018131fe30 bsp=e000000181310ee0 [<a00000010000a4c0>] start_kernel_thread+0x20/0x40 sp=e00000018131fe30 bsp=e000000181310ee0 kobject: '0000:06:00.0' (e000000181703120): fill_kobj_path: path = '/devices/pci0000:03/0000:03:00.0/0000:04:00.0/0000:05:02.0/0000:06:00.0' -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html