So the perf_fuzzer caught this after about a week of fuzzing on a Haswell machine running a recent git kernel (pre 4.1-rc1 though).
We've seen this BUG before and various fixes were applied but apparently it wasn't enough. Sadly it doesn't seem to be reproducible. validate_group() -> x86_pmu.schedule_events() -> ???? -> variable_test_bit() (hard to tell which test bit with all the inlining going on). Vince [428232.701319] BUG: unable to handle kernel NULL pointer dereference at (null) [428232.710197] IP: [<ffffffff8102b3e2>] x86_schedule_events+0x112/0x250 [428232.717470] PGD cdf50067 PUD c610c067 PMD 0 [428232.722557] Oops: 0000 [#1] SMP [428232.726490] Modules linked in: fuse x86_pkg_temp_thermal intel_powerclamp intel_rapl iosf_mbi coretemp kvm crct10dif_pclmul snd_hda_codec_hdmi crc32_pclmul ghash_clmulni_intel snd_hda_codec_realtek aesni_intel snd_hda_codec_generic aes_x86_64 i915 snd_hda_intel snd_hda_controller snd_hda_codec snd_hda_core snd_hwdep lrw snd_pcm gf128mul iTCO_wdt iTCO_vendor_support drm_kms_helper glue_helper snd_timer ppdev evdev drm ablk_helper snd cryptd mei_me soundcore xhci_pci tpm_tis psmouse xhci_hcd mei serio_raw lpc_ich tpm mfd_core parport_pc pcspkr parport wmi i2c_algo_bit battery i2c_i801 button processor video sg sr_mod sd_mod cdrom ahci libahci libata ehci_pci ehci_hcd e1000e usbcore ptp crc32c_intel fan scsi_mod pps_core usb_common thermal thermal_sys [428232.800929] CPU: 0 PID: 31352 Comm: perf_fuzzer Tainted: G W 4.0.0+ #136 [428232.809912] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS FBKT72AUS 01/26/2014 [428232.818447] task: ffff8800cef88bd0 ti: ffff8800c56b0000 task.ti: ffff8800c56b0000 [428232.827119] RIP: 0010:[<ffffffff8102b3e2>] [<ffffffff8102b3e2>] x86_schedule_events+0x112/0x250 [428232.837221] RSP: 0018:ffff8800c56b3cb8 EFLAGS: 00010246 [428232.843575] RAX: 0000000000000000 RBX: ffff8800c54d5000 RCX: 00000000001001b7 [428232.851871] RDX: 0000000000000000 RSI: ffff8800c42e8000 RDI: 0000000000000000 [428232.860128] RBP: ffff8800c56b3d18 R08: 0000000000000000 R09: ffff8800c54d5724 [428232.868362] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000004 [428232.876655] R13: ffff8800366ec000 R14: 0000000000000002 R15: 0000000000000004 [428232.884987] FS: 00007f560c527700(0000) GS:ffff88011ea00000(0000) knlGS:0000000000000000 [428232.894338] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [428232.901173] CR2: 0000000000000000 CR3: 00000000c469b000 CR4: 00000000001407f0 [428232.909498] DR0: 0000000000000000 DR1: 0000000002d54000 DR2: 0000000002b4f000 [428232.917831] DR3: 00000000033d8000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 [428232.926129] Stack: [428232.928950] 0000000000000001 0000000000000000 00000002fffffff4 0000000000000002 [428232.937669] fffffffffffffff4 0000000000000000 ffff8800c56b3d18 ffff8800366ec000 [428232.946332] 0000000000000000 ffff8800c54d5000 ffff8800c42e8000 ffffffff81c1cfc0 [428232.955038] Call Trace: [428232.958326] [<ffffffff8102a75e>] x86_pmu_event_init+0x12e/0x3d0 [428232.965464] [<ffffffff81160030>] ? perf_event_ctx_lock_nested+0x20/0x110 [428232.973486] [<ffffffff8116023d>] perf_try_init_event+0x4d/0xb0 [428232.980501] [<ffffffff811683af>] perf_init_event+0x13f/0x170 [428232.987355] [<ffffffff81168275>] ? perf_init_event+0x5/0x170 [428232.994194] [<ffffffff8116882b>] perf_event_alloc+0x44b/0x6d0 [428233.001145] [<ffffffff81168ea3>] SYSC_perf_event_open+0x3f3/0xde0 [428233.008400] [<ffffffff81169d5e>] SyS_perf_event_open+0xe/0x10 [428233.015325] [<ffffffff816dd632>] system_call_fastpath+0x16/0x7a [428233.022430] Code: a0 8d 78 01 74 31 48 8b b4 c3 28 05 00 00 48 83 c0 01 48 63 96 5c 01 00 00 4c 8b 86 98 01 00 00 83 fa ff 0f 84 b4 00 00 00 89 c7 <49> 0f a3 10 45 19 c0 45 85 c0 75 a2 45 31 f6 3b 7d b4 0f 85 9a [428233.044645] RIP [<ffffffff8102b3e2>] x86_schedule_events+0x112/0x250 [428233.052293] RSP <ffff8800c56b3cb8> [428233.056712] CR2: 0000000000000000 [428233.061189] [drm:intel_crtc_set_config [i915]] *ERROR* failed to restore config after modeset failure [428233.076847] ---[ end trace 5679ca0875946dbb ]--- -- 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/
