On Fri, 2017-10-13 at 05:59:41 UTC, Anju T Sudhakar wrote: > Call trace observed with latest firmware, and upstream kernel. > > [ 14.499938] NIP [c0000000000f318c] init_imc_pmu+0x8c/0xcf0 > [ 14.499973] LR [c0000000000f33f8] init_imc_pmu+0x2f8/0xcf0 > [ 14.500007] Call Trace: > [ 14.500027] [c000003fed18f710] [c0000000000f33c8] init_imc_pmu+0x2c8/0xcf0 > (unreliable) > [ 14.500080] [c000003fed18f800] [c0000000000b5ec0] > opal_imc_counters_probe+0x300/0x400 > [ 14.500132] [c000003fed18f900] [c000000000807ef4] > platform_drv_probe+0x64/0x110 > [ 14.500185] [c000003fed18f980] [c000000000804b58] > driver_probe_device+0x3d8/0x580 > [ 14.500236] [c000003fed18fa10] [c000000000804e4c] > __driver_attach+0x14c/0x1a0 > [ 14.500302] [c000003fed18fa90] [c00000000080156c] > bus_for_each_dev+0x8c/0xf0 > [ 14.500353] [c000003fed18fae0] [c000000000803fa4] driver_attach+0x34/0x50 > [ 14.500397] [c000003fed18fb00] [c000000000803688] > bus_add_driver+0x298/0x350 > [ 14.500449] [c000003fed18fb90] [c00000000080605c] > driver_register+0x9c/0x180 > [ 14.500500] [c000003fed18fc00] [c000000000807dec] > __platform_driver_register+0x5c/0x70 > [ 14.500552] [c000003fed18fc20] [c00000000101cee0] > opal_imc_driver_init+0x2c/0x40 > [ 14.500603] [c000003fed18fc40] [c00000000000d084] > do_one_initcall+0x64/0x1d0 > [ 14.500654] [c000003fed18fd00] [c00000000100434c] > kernel_init_freeable+0x280/0x374 > [ 14.500705] [c000003fed18fdc0] [c00000000000d314] kernel_init+0x24/0x160 > [ 14.500750] [c000003fed18fe30] [c00000000000b4e8] > ret_from_kernel_thread+0x5c/0x74 > [ 14.500799] Instruction dump: > [ 14.500827] 4082024c 2f890002 419e054c 2e890003 41960094 2e890001 3ba0ffea > 419602d8 > [ 14.500884] 419e0290 2f890003 419e02a8 e93e0118 <e8690018> 2fa30000 > 419e0010 4827ba41 > [ 14.500945] ---[ end trace 27b734ad26f1add4 ]--- > [ 15.908719] > [ 16.908869] Kernel panic - not syncing: Attempted to kill init! > exitcode=0x00000007 > [ 16.908869] > [ 18.125813] ---[ end Kernel panic - not syncing: Attempted to kill init! > exitcode=0x00000007] > > While registering nest imc at init, cpu-hotplug callback > `nest_pmu_cpumask_init()` > makes an opal call to stop the engine. And if the OPAL call fails, > imc_common_cpuhp_mem_free() is invoked to cleanup memory and cpuhotplug setup. > > But when cleaning up the attribute group, we were dereferencing the attribute > element array without checking whether the backing element is not NULL. This > causes the kernel panic. > > Add a check for the backing element prior to dereferencing the attribute > element, > to handle the failing case gracefully. > > Signed-off-by: Anju T Sudhakar <a...@linux.vnet.ibm.com> > Reported-by: Pridhiviraj Paidipeddi <ppaid...@linux.vnet.ibm.com>
Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/0d8ba16278ec30a262d931875018ab cheers
