On Fri, 15 Sep 2017, kernel test robot wrote: > [ 0.035023] CPU: Intel Common KVM processor (family: 0xf, model: 0x6, > stepping: 0x1) > [ 0.042302] Performance Events: unsupported Netburst CPU model 6 no PMU > driver, software events only.
Cute. So there is no supported PMU, but for some unknown reason the lockup detector can create an event, otherwise the perf availaibility check in lockup_detector_init() would fail .... Peter??? > [ 0.051650] BUG: unable to handle kernel NULL pointer dereference at > 0000000000000208 > [ 0.052000] IP: perf_event_release_kernel+0x14/0x1ed > [ 0.052000] PGD 0 P4D 0 > [ 0.052000] Oops: 0000 [#1] > [ 0.052000] CPU: 0 PID: 1 Comm: swapper Not tainted 4.13.0-11828-gd57108d > #1 > [ 0.052000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > 1.9.3-20161025_171302-gandalf 04/01/2014 > [ 0.052000] task: ffff88001e532000 task.stack: ffffc90000008000 > [ 0.052000] RIP: 0010:perf_event_release_kernel+0x14/0x1ed > [ 0.052000] RSP: 0000:ffffc9000000be38 EFLAGS: 00010292 > [ 0.052000] RAX: 0000000000000001 RBX: 0000000000000000 RCX: > 000000000313fa45 > [ 0.052000] RDX: 0000000000000001 RSI: ffffffff828265e0 RDI: > 0000000000000000 > [ 0.052000] RBP: ffffc9000000beb8 R08: ffffc9000000bdc8 R09: > 0000000000000000 > [ 0.052000] R10: ffff88001e532000 R11: ffffc9000000bd68 R12: > 0000000000000000 > [ 0.052000] R13: 0000000000000000 R14: 0000000000000000 R15: > 0000000000000000 > [ 0.052000] FS: 0000000000000000(0000) GS:ffffffff8262f000(0000) > knlGS:0000000000000000 > [ 0.052000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 0.052000] CR2: 0000000000000208 CR3: 0000000002618000 CR4: > 00000000000006b0 > [ 0.052000] Call Trace: > [ 0.052000] ? trace_hardirqs_on_caller+0x162/0x198 > [ 0.052000] hardlockup_detector_perf_cleanup+0x20/0x2d > [ 0.052000] __lockup_detector_cleanup+0x2c/0x2e > [ 0.052000] softlockup_update_smpboot_threads+0x48/0x4a > [ 0.052000] softlockup_reconfigure_threads+0x21/0x5a > [ 0.052000] lockup_detector_init+0x75/0x83 > [ 0.052000] kernel_init_freeable+0x67/0xf0 > [ 0.052000] ? rest_init+0x13a/0x13a > [ 0.052000] kernel_init+0xe/0xf8 > [ 0.052000] ret_from_fork+0x2a/0x40 > [ 0.052000] Code: df e8 0c b2 ff ff 4c 89 e7 e8 89 13 bd 00 41 5b 5b 41 5c > 41 5d c9 c3 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 89 fb 48 83 ec 58 <48> > 83 bf 08 02 00 00 00 75 14 f6 87 8c 00 00 00 03 0f 84 9b 01 > [ 0.052000] RIP: perf_event_release_kernel+0x14/0x1ed RSP: ffffc9000000be38 > [ 0.052000] CR2: 0000000000000208 > [ 0.052000] ---[ end trace ed0d2c92e47d08db ]--- > [ 0.052000] Kernel panic - not syncing: Fatal exception
