Created attachment 101171 [details] Output from serial console showing oops. Booted 3.8.12 and it BUG-ged at a kobject_put: BUG: unable to handle kernel paging request at f86dd0d8 IP: [<c1125a8d>] kobject_put+0xa/0x50 *pde = 36aff067 *pte = 00000000 Oops: 0000 [#1] PREEMPT SMP Modules linked in: usbhid(+) videobuf2_core acpi_cpufreq(+) snd_rawmidi snd_hwdep snd_seq videodev mperf snd_seq_device snd_pcm snd_page_alloc snd_hrtimer firewire_ohci snd_timer firewire_core ppdev parport_pc snd i2c_i801 dcdbas parport soundcore crc_itu_t microcode psmouse floppy lpc_ich mfd_core pcspkr ehci_pci processor serio_raw nfsd auth_rpcgss binfmt_misc nfs_acl lockd sunrpc uinput ext3 mbcache jbd sr_mod cdrom sd_mod pata_acpi sata_sil radeon uhci_hcd ata_piix cfbfillrect libata ehci_hcd cfbimgblt cfbcopyarea i2c_algo_bit backlight scsi_mod drm_kms_helper usbcore intel_agp e1000 ttm usb_common drm intel_gtt agpgart button Pid: 1726, comm: systemd-udevd Not tainted 3.8.12 #1 Dell Computer Corporation Precision WorkStation 650 /0F1262 EIP: 0060:[<c1125a8d>] EFLAGS: 00010286 CPU: 0 EIP is at kobject_put+0xa/0x50 ... This might have happened once with an earlier kernel, and it hasn't happened again with this kernel. Rare race condition?
Created attachment 101191 [details] dmesg output from successful boot Hardware is 2 x Intel Xeon (Northwood) CPUs, 32 bit, 2 GB RAM.
Hi Chris, I saw a similar crash running 3.9 that emitted "mgag200: module is already loaded" (much like the "acpi_cpufreq: module is already loaded" from your attachment) before blowing up in load_module executing kobj code. This would occur in a low percentage of boots. I cherry picked commit 944a1fa01266aa9ace607f29551b73c41e9440e9 "module: don't unlink the module until we've removed all exposure" and haven't seen that crash since. Hope this helps, -- Joe
Commit a49b7e82cab0f9b41f483359be83f44fbb6b4979 "kobject: fix kset_find_obj() race with concurrent last kobject_put()" may also be good enough to dodge this crash. -- Joe