From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benoit Pradelle Subject: Kernel taint on setspeed Date: Mon, 20 Jan 2014 15:08:36 +0100 Message-ID: <52DD2DE4.6080002@uvsq.fr> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Sender: cpufreq-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: cpufreq@vger.kernel.org Hi all, On Linux 3.12.6 over an Intel x86 processor (with intel_pstate=disable), I am trying to change the frequency with the following command sequence: echo "userspace" | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor echo "3000000" | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_setspeed It used to work well on older kernels, but since a recent (unknown) kernel version, the last command occasionaly never returns but I got the following log: [344746.428121] ------------[ cut here ]------------ [344746.428132] WARNING: CPU: 7 PID: 1882 at /build/linux-xS3nxO/linux-3.12.6/drivers/cpufreq/cpufreq_governor.c:203 cpufreq_governor_dbs+0x6a2/0x710() [344746.428134] Modules linked in: msr cpufreq_userspace nfsv3 parport_pc ppdev lp parport bnep rfcomm bluetooth ip6table_filter ip6_tables iptable_filter ip_tables x_tables autofs4 tun pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) binfmt_misc uinput nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc fuse loop joydev hid_generic usbhid hid snd_hda_codec_hdmi x86_pkg_temp_thermal snd_hda_codec_realtek snd_hda_intel snd_hda_codec intel_powerclamp snd_hwdep coretemp kvm_intel kvm crc32_pclmul nvidia(PO) snd_pcm iTCO_wdt iTCO_vendor_support snd_page_alloc crc32c_intel ghash_clmulni_intel hp_wmi sparse_keymap evdev rfkill acpi_cpufreq processor psmouse snd_seq snd_seq_device snd_timer snd mei_me aesni_intel wmi pcspkr i2c_i801 serio_raw aes_x86_64 ablk_helper cryptd lrw gf128mul soundcore mei glue_helper lpc_ich mfd_core i2c_core button ext4 crc16 mbcache jbd2 sg sd_mod sr_mod crc_t10dif crct10dif_common cdrom xhci_hcd ahci libahci ehci_pci ehci_hcd libata scsi_mod e1000e usbcore usb_common ptp pps_core thermal fan thermal_sys [344746.428213] CPU: 7 PID: 1882 Comm: tee Tainted: P O 3.12-1-amd64 #1 Debian 3.12.6-2 [344746.428215] Hardware name: Hewlett-Packard HP Z220 CMT Workstation/1790, BIOS K51 v01.14 09/27/2012 [344746.428217] 0000000000000009 ffffffff8148c9d5 0000000000000000 ffffffff8105b572 [344746.428221] 0000000000000000 ffff880037046a00 0000000000000007 0000000000000002 [344746.428224] ffffffff81881fe0 ffffffff81376732 ffffffff8148f559 ffff88033449dd00 [344746.428228] Call Trace: [344746.428237] [] ? dump_stack+0x41/0x51 [344746.428245] [] ? warn_slowpath_common+0x72/0x90 [344746.428248] [] ? cpufreq_governor_dbs+0x6a2/0x710 [344746.428253] [] ? mutex_lock+0x9/0x30 [344746.428261] [] ? acpi_processor_ppc_notifier+0xc0/0xc4 [processor] [344746.428267] [] ? notifier_call_chain+0x44/0x70 [344746.428274] [] ? __cpufreq_governor+0xf4/0x280 [344746.428277] [] ? __cpufreq_set_policy+0x129/0x1f0 [344746.428280] [] ? store_scaling_governor+0xd5/0x1e0 [344746.428284] [] ? cpufreq_update_policy+0x110/0x110 [344746.428287] [] ? store+0x72/0xb0 [344746.428292] [] ? sysfs_write_file+0xb9/0x140 [344746.428297] [] ? vfs_write+0xb3/0x1e0 [344746.428301] [] ? SyS_write+0x43/0xa0 [344746.428305] [] ? system_call_fastpath+0x16/0x1b [344746.428307] ---[ end trace 42394bba698a65fd ]--- [344746.428314] BUG: unable to handle kernel NULL pointer dereference at (null) [344746.428317] IP: [] cpufreq_governor_dbs+0x4f/0x710 [344746.428321] PGD 3be4fe067 PUD 35dc6a067 PMD 0 [344746.428325] Oops: 0000 [#1] SMP [344746.428327] Modules linked in: msr cpufreq_userspace nfsv3 parport_pc ppdev lp parport bnep rfcomm bluetooth ip6table_filter ip6_tables iptable_filter ip_tables x_tables autofs4 tun pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) binfmt_misc uinput nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc fuse loop joydev hid_generic usbhid hid snd_hda_codec_hdmi x86_pkg_temp_thermal snd_hda_codec_realtek snd_hda_intel snd_hda_codec intel_powerclamp snd_hwdep coretemp kvm_intel kvm crc32_pclmul nvidia(PO) snd_pcm iTCO_wdt iTCO_vendor_support snd_page_alloc crc32c_intel ghash_clmulni_intel hp_wmi sparse_keymap evdev rfkill acpi_cpufreq processor psmouse snd_seq snd_seq_device snd_timer snd mei_me aesni_intel wmi pcspkr i2c_i801 serio_raw aes_x86_64 ablk_helper cryptd lrw gf128mul soundcore mei glue_helper lpc_ich mfd_core i2c_core button ext4 crc16 mbcache jbd2 sg sd_mod sr_mod crc_t10dif crct10dif_common cdrom xhci_hcd ahci libahci ehci_pci ehci_hcd libata scsi_mod e1000e usbcore usb_common ptp pps_core thermal fan thermal_sys [344746.428386] CPU: 7 PID: 1882 Comm: tee Tainted: P W O 3.12-1-amd64 #1 Debian 3.12.6-2 [344746.428388] Hardware name: Hewlett-Packard HP Z220 CMT Workstation/1790, BIOS K51 v01.14 09/27/2012 [344746.428390] task: ffff8803a3f03080 ti: ffff88033449c000 task.ti: ffff88033449c000 [344746.428391] RIP: 0010:[] [] cpufreq_governor_dbs+0x4f/0x710 [344746.428395] RSP: 0018:ffff88033449dc50 EFLAGS: 00010293 [344746.428397] RAX: 0000000000000024 RBX: 0000000000000000 RCX: 0000000000000006 [344746.428398] RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000009 [344746.428400] RBP: ffff880037046a00 R08: 000000000000000a R09: 0000000000000376 [344746.428402] R10: 0000000000000000 R11: ffff88033449d986 R12: 0000000000000007 [344746.428403] R13: 0000000000000002 R14: ffffffff81881fe0 R15: ffff88040cba16d8 [344746.428406] FS: 00007f4067ae6700(0000) GS:ffff88041ddc0000(0000) knlGS:0000000000000000 [344746.428407] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [344746.428409] CR2: 0000000000000000 CR3: 000000035dc7d000 CR4: 00000000001407e0 [344746.428411] Stack: [344746.428412] ffffffff8148f559 ffff88033449dd00 ffffffffa02d600f 00000000fffffffe [344746.428415] ffffffff81495c64 ffffffff81881be0 0000000000000000 ffff880037046a00 [344746.428419] 0000000000000002 ffffffff81881d00 ffff8803df64b000 000000000000000a [344746.428422] Call Trace: [344746.428425] [] ? mutex_lock+0x9/0x30 [344746.428432] [] ? acpi_processor_ppc_notifier+0xc0/0xc4 [processor] [344746.428436] [] ? notifier_call_chain+0x44/0x70 [344746.428440] [] ? __cpufreq_governor+0xf4/0x280 [344746.428443] [] ? __cpufreq_set_policy+0x129/0x1f0 [344746.428446] [] ? store_scaling_governor+0xd5/0x1e0 [344746.428449] [] ? cpufreq_update_policy+0x110/0x110 [344746.428452] [] ? store+0x72/0xb0 [344746.428456] [] ? sysfs_write_file+0xb9/0x140 [344746.428459] [] ? vfs_write+0xb3/0x1e0 [344746.428463] [] ? SyS_write+0x43/0xa0 [344746.428466] [] ? system_call_fastpath+0x16/0x1b [344746.428468] Code: c0 0f 84 55 02 00 00 48 8b 9d b0 00 00 00 48 85 db 0f 84 4c 06 00 00 41 83 fd 04 0f 84 7b 02 00 00 41 83 fd 05 0f 84 41 02 00 00 <48> 8b 03 44 89 e7 ff 50 20 48 89 44 24 08 48 8b 03 83 38 01 0f [344746.428500] RIP [] cpufreq_governor_dbs+0x4f/0x710 [344746.428503] RSP [344746.428504] CR2: 0000000000000000 [344746.428507] ---[ end trace 42394bba698a65fe ]--- Can anyone help with that? Cheers, Benoit.