On Wed, 2 Jan 2013, Dave Jones wrote: > We've had a increased number of reports in the last six months or so > from Fedora users getting corrupted page tables. > At first I wrote it off to bad hardware, but they started happening frequently > enough that I began to wonder if it was a real problem. > > The only common thing I could think of was that now that gnome-shell is > our default desktop, we're making a lot more use of DRI than we used to. > > To test a hypothesis, I played a whole lot of quake3 over the holidays, > and was finally able to make it happen too. > > After playing the game for a few hours, I exited it, and all was well. > But when I then went to shut down the laptop, I saw this.. > > [52460.280346] BUG: Bad page map in process panel-6-systray > pte:ffff8800b665a0e8 pmd:b6659067
A virtual address in place of a page table entry: almost the virtual address of the page table itself. > [52460.280848] addr:00000038bf3fd000 vm_flags:00000070 anon_vma: > (null) mapping:ffff88011052fd98 index:1fd > [52460.281547] vma->vm_ops->fault: filemap_fault+0x0/0x470 > [52460.281878] vma->vm_file->f_op->mmap: btrfs_file_mmap+0x0/0x60 [btrfs] > [52460.282286] Modules linked in: iptable_mangle bridge stp llc > ip6table_filter ip6_tables dm_crypt xfs snd_hda_codec_hdmi arc4 iwldvm > mac80211 c > oretemp crc32c_intel snd_hda_codec_realtek ghash_clmulni_intel snd_hda_intel > snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm iwlwifi thinkpad_acpi > snd_page_alloc btusb > iTCO_wdt microcode tpm_tis vhost_net iTCO_vendor_support cfg80211 snd_timer > bluetooth snd e1000e tpm pcspkr tun macvtap lpc_ich soundcore tpm_bios rfkill > wmi hwmon mfd_core me > i macvlan kvm_intel kvm nfsd auth_rpcgss nfs_acl lockd sunrpc btrfs libcrc32c > zlib_deflate i915 i2c_algo_bit drm_kms_helper drm sdhci_pci sdhci led_class > mmc_core i2c_core vid > eo > [52460.286556] Pid: 1317, comm: panel-6-systray Not tainted 3.7.0+ #15 > [52460.286926] Call Trace: > [52460.287086] [<ffffffff8114c662>] print_bad_pte+0x1e2/0x250 > [52460.287445] [<ffffffff8114ea1d>] unmap_single_vma+0x5dd/0x8a0 > [52460.287804] [<ffffffff8114f541>] unmap_vmas+0x51/0xa0 > [52460.288087] [<ffffffff81158628>] exit_mmap+0x98/0x170 > [52460.288388] [<ffffffff81047808>] mmput+0x78/0xe0 > [52460.288651] [<ffffffff8104ffae>] do_exit+0x24e/0xa30 > [52460.288944] [<ffffffff8119394e>] ? ____fput+0xe/0x10 > [52460.289268] [<ffffffff8106af3c>] ? task_work_run+0xac/0xe0 > [52460.289608] [<ffffffff8105081f>] do_group_exit+0x3f/0xa0 > [52460.289937] [<ffffffff81050897>] sys_exit_group+0x17/0x20 > [52460.290288] [<ffffffff815f5699>] system_call_fastpath+0x16/0x1b > [52460.290652] Disabling lock debugging due to kernel taint > [52460.290972] BUG: Bad page map in process panel-6-systray > pte:ffffffff81033f52 pmd:b6659067 I wonder what's at virtual address ffffffff81033f52... > [52460.291477] addr:00000038bf3fe000 vm_flags:00000070 anon_vma: > (null) mapping:ffff88011052fd98 index:1fe > [52460.292083] vma->vm_ops->fault: filemap_fault+0x0/0x470 > [52460.292427] vma->vm_file->f_op->mmap: btrfs_file_mmap+0x0/0x60 [btrfs] > [52460.292816] Modules linked in: iptable_mangle bridge stp llc > ip6table_filter ip6_tables dm_crypt xfs snd_hda_codec_hdmi arc4 iwldvm > mac80211 c > oretemp crc32c_intel snd_hda_codec_realtek ghash_clmulni_intel snd_hda_intel > snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm iwlwifi thinkpad_acpi > snd_page_alloc btusb > iTCO_wdt microcode tpm_tis vhost_net iTCO_vendor_support cfg80211 snd_timer > bluetooth snd e1000e tpm pcspkr tun macvtap lpc_ich soundcore tpm_bios rfkill > wmi hwmon mfd_core me > i macvlan kvm_intel kvm nfsd auth_rpcgss nfs_acl lockd sunrpc btrfs libcrc32c > zlib_deflate i915 i2c_algo_bit drm_kms_helper drm sdhci_pci sdhci led_class > mmc_core i2c_core vid > eo > [52460.297010] Pid: 1317, comm: panel-6-systray Tainted: G B 3.7.0+ > #15 > [52460.297455] Call Trace: > [52460.297617] [<ffffffff8114c662>] print_bad_pte+0x1e2/0x250 > [52460.297954] [<ffffffff81033f52>] ? __change_page_attr_set_clr+0x772/0xc00 > [52460.298383] [<ffffffff81033f52>] ? __change_page_attr_set_clr+0x772/0xc00 ... oh, thank you, it's __change_page_attr_set_clr+0x772 ;) It looks rather as if panel-6-systray's kernel stack is on one of its userspace page tables. Hugh > [52460.298796] [<ffffffff8114db8d>] vm_normal_page+0x6d/0x90 > [52460.299143] [<ffffffff8114e90f>] unmap_single_vma+0x4cf/0x8a0 > [52460.299497] [<ffffffff8114f541>] unmap_vmas+0x51/0xa0 > [52460.299810] [<ffffffff81158628>] exit_mmap+0x98/0x170 > [52460.300142] [<ffffffff81047808>] mmput+0x78/0xe0 > [52460.300432] [<ffffffff8104ffae>] do_exit+0x24e/0xa30 > [52460.300738] [<ffffffff8119394e>] ? ____fput+0xe/0x10 > [52460.301041] [<ffffffff8106af3c>] ? task_work_run+0xac/0xe0 > [52460.301363] [<ffffffff8105081f>] do_group_exit+0x3f/0xa0 > [52460.301669] [<ffffffff81050897>] sys_exit_group+0x17/0x20 > [52460.301974] [<ffffffff815f5699>] system_call_fastpath+0x16/0x1b > > > It's falling over in btrfs's mmap op, but I think it's just the victim here, > of something else corrupting what had been mmaped in the panel process. > > Daniel, can you think of additional sanity checks that could be added to > the i915 driver ? (Even if at the expense of speed: a CONFIG_DEBUG option > to prove correctness would be very worthwhile imo) > > Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
