Excerpts from Paul Menzel's message of July 8, 2020 3:42 am: > Dear Nicholas, > > > Am 07.07.20 um 09:03 schrieb Nicholas Piggin: >> Excerpts from Paul Menzel's message of July 6, 2020 3:20 pm: > >>> Am 06.07.20 um 02:41 schrieb Nicholas Piggin: >>>> Excerpts from Paul Menzel's message of July 5, 2020 8:30 pm: >>> >>>>> Am 05.07.20 um 11:22 schrieb Paul Menzel: >>>>>> [ 572.253008] Oops: Exception in kernel mode, sig: 5 [#1] >>>>>> [ 572.253198] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV >>>>>> [ 572.253232] Modules linked in: tcp_diag inet_diag unix_diag >>>>>> xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 >>>>>> xt_tcpudp ip6table_mangle ip6table_nat iptable_mangle iptable_nat nf_nat >>>>>> nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink >>>>>> ip6table_filter ip6_tables iptable_filter bridge stp llc overlay xfs >>>>>> kvm_hv kvm binfmt_misc joydev uas usb_storage vmx_crypto bnx2x >>>>>> crct10dif_vpmsum ofpart cmdlinepart powernv_flash mtd mdio ibmpowernv >>>>>> at24 ipmi_powernv ipmi_devintf ipmi_msghandler opal_prd powernv_rng >>>>>> sch_fq_codel parport_pc ppdev lp nfsd parport auth_rpcgss nfs_acl lockd >>>>>> grace sunrpc ip_tables x_tables autofs4 btrfs blake2b_generic libcrc32c >>>>>> xor zstd_compress raid6_pq input_leds mac_hid hid_generic ast >>>>>> drm_vram_helper drm_ttm_helper i2c_algo_bit ttm drm_kms_helper >>>>>> syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci >>>>>> drm_panel_orientation_quirks libahci usbhid hid crc32c_vpmsum >>>>>> uio_pdrv_genirq uio >>>>>> [ 572.253639] CPU: 4 PID: 6728 Comm: Web Content Not tainted 5.8.0-rc3+ >>>>>> #1 >>>>>> [ 572.253659] NIP: c00000000000ff5c LR: c00000000001a8f8 CTR: >>>>>> c0000000001d5f00 >>>>>> [ 572.253835] REGS: c000007f31f0f420 TRAP: 1500 Not tainted >>>>>> (5.8.0-rc3+) >>>>>> [ 572.253854] MSR: 900000000290b033 >>>>>> <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 28c48482 XER: 20000000 >>>>>> [ 572.253888] CFAR: c00000000000fecc IRQMASK: 1 >>>>>> [ 572.253888] GPR00: c00000000001b228 c000007f31f0f6b0 c000000001f9a900 >>>>>> c000007f351544d0 >>>>>> [ 572.253888] GPR04: 0000000000000000 c000007f31f0fe90 c000007f351544f0 >>>>>> c000007f32e522b0 >>>>>> [ 572.253888] GPR08: 0000000000000000 0000000000002000 9000000000009033 >>>>>> c000007fbcd85800 >>>>>> [ 572.253888] GPR12: 0000000000008800 c000007fffffb680 0000000000000005 >>>>>> 0000000000000004 >>>>>> [ 572.253888] GPR16: c000007f35153800 c000007f35154130 0000000000000005 >>>>>> 0000000000000001 >>>>>> [ 572.253888] GPR20: 0000000000000024 c000007f32e51e68 c000007f35154028 >>>>>> 0000007fd8da0000 >>>>>> [ 572.253888] GPR24: 0000007fd8da0000 c000007f351544d0 c000007e9a4024d0 >>>>>> c000000001665f18 >>>>>> [ 572.253888] GPR28: c000007f351544d0 c000007f35153800 900000000290f033 >>>>>> c000007f35153800 >>>>>> [ 572.254079] NIP [c00000000000ff5c] save_fpu+0xa8/0x2ac >>>>>> [ 572.254098] LR [c00000000001a8f8] __giveup_fpu+0x28/0x80 >>>>>> [ 572.254114] Call Trace: >>>>>> [ 572.254128] [c000007f31f0f6b0] [c000007f35153980] 0xc000007f35153980 >>>>>> (unreliable) >>>>>> [ 572.254156] [c000007f31f0f6e0] [c00000000001b228] >>>>>> giveup_all+0x128/0x150 >>>>>> [ 572.254327] [c000007f31f0f710] [c00000000001c124] >>>>>> __switch_to+0x104/0x490 >>>>>> [ 572.254352] [c000007f31f0f770] [c0000000010d2e34] >>>>>> __schedule+0x2e4/0xa10 >>>>>> [ 572.254374] [c000007f31f0f840] [c0000000010d35d4] schedule+0x74/0x140 >>>>>> [ 572.254397] [c000007f31f0f870] [c0000000010d9478] >>>>>> schedule_timeout+0x358/0x5d0 >>>>>> [ 572.254424] [c000007f31f0f980] [c0000000010d5638] >>>>>> wait_for_completion+0xc8/0x210 >>>>>> [ 572.254451] [c000007f31f0fa00] [c000000000608ed4] >>>>>> do_coredump+0x3a4/0xd60 >>>>>> [ 572.254625] [c000007f31f0fba0] [c00000000018d1cc] >>>>>> get_signal+0x1dc/0xd00 >>>>>> [ 572.254648] [c000007f31f0fcc0] [c00000000001f088] >>>>>> do_notify_resume+0x158/0x450 >>>>>> [ 572.254672] [c000007f31f0fda0] [c000000000037d04] >>>>>> interrupt_exit_user_prepare+0x1c4/0x230 >>>>>> [ 572.254699] [c000007f31f0fe20] [c00000000000f2b4] >>>>>> interrupt_return+0x14/0x1c0 >>>>>> [ 572.254720] Instruction dump: >>>>>> [ 572.254882] dae60170 db060180 db260190 db4601a0 db6601b0 db8601c0 >>>>>> dba601d0 dbc601e0 >>>>>> [ 572.254912] dbe601f0 48000204 38800000 f0000250 <7c062798> f0000250 >>>>>> 38800010 f0210a50 >>>>>> [ 572.254946] ---[ end trace ba4452ee5c77d58e ]--- >>>>> >>>>> Please find all the messages attached. >>>> >>>> "Oops: Exception in kernel mode, sig: 5 [#1]" >>>> >>>> Unfortunately it's a very poor error message. I think it is a 0x1500 >>>> exception triggering in the kernel FP register saving. Do you have the >>>> CONFIG_PPC_DENORMALISATION config option set? >>> >>> Yes, as it’s set in the Ubuntu Linux kernel configuration, I have it set >>> too. >>> >>> $ grep DENORMALI /boot/config-* >>> /boot/config-4.15.0-23-generic:CONFIG_PPC_DENORMALISATION=y >>> /boot/config-5.4.0-40-generic:CONFIG_PPC_DENORMALISATION=y >>> /boot/config-5.7.0-rc5+:CONFIG_PPC_DENORMALISATION=y >>> /boot/config-5.8.0-rc3+:CONFIG_PPC_DENORMALISATION=y >> >> Ah thanks I was able to reproduce with a little denorm test case. >> >> The denorm interrupt handler got broken by some careless person. >> >> This patch should hopefully fix it for you? > > Yes, it does. Thank you. > >> --- >> arch/powerpc/kernel/exceptions-64s.S | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/powerpc/kernel/exceptions-64s.S >> b/arch/powerpc/kernel/exceptions-64s.S >> index fa080694e581..0fc8bad878b2 100644 >> --- a/arch/powerpc/kernel/exceptions-64s.S >> +++ b/arch/powerpc/kernel/exceptions-64s.S >> @@ -2551,7 +2551,7 @@ EXC_VIRT_NONE(0x5400, 0x100) >> INT_DEFINE_BEGIN(denorm_exception) >> IVEC=0x1500 >> IHSRR=1 >> - IBRANCH_COMMON=0 >> + IBRANCH_TO_COMMON=0 >> IKVM_REAL=1 >> INT_DEFINE_END(denorm_exception) > > Tested-by: Paul Menzel <pmen...@molgen.mpg.de>
Thanks for reporting and testing, sorry for breaking it for you! Thanks, Nick
