Greetings, Today's mainline kernel Oops when running stack_grow_into_huge Machine: Power 8 bare-metal Kernel: 4.15.0 Config: attached gcc: 4.8.5 Test: libhugetlbfs stack_grow_into_huge (16M: 64) resulted in kernel Oops message and the bad address maps to: # gdb -batch vmlinux -ex 'list *(0xc000000000a15a18)' 0xc000000000a15a18 is in _raw_spin_lock (./arch/powerpc/include/asm/spinlock.h:82). 77 */ 78 static inline unsigned long __arch_spin_trylock(arch_spinlock_t *lock) 79 { 80 unsigned long tmp, token; 81 82 token = LOCK_TOKEN; 83 __asm__ __volatile__( 84 "1: " PPC_LWARX(%0,0,%2,1) "\n\ 85 cmpwi 0,%0,0\n\ 86 bne- 2f\n\ trace logs: ----------- stack_grow_into[71525]: unhandled signal 11 at 00007effefbc10f0 nip 0000000010001764 lr 000000001000173c code 1 Unable to handle kernel paging request for data at address 0xf000400000000030 Faulting instruction address: 0xc000000000a15a18 Oops: Kernel access of bad area, sig: 11 [#3] LE SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp tun bridge stp llc kvm_hv kvm iptable_filter vmx_crypto ipmi_powernv ipmi_devintf ipmi_msghandler powernv_rng leds_powernv led_class powernv_op_panel rng_core nfsd binfmt_misc ip_tables x_tables autofs4 CPU: 32 PID: 71525 Comm: stack_grow_into Tainted: G D 4.15.0-11704-ga2e5790-dirty #1 NIP: c000000000a15a18 LR: c00000000028a0a0 CTR: c000000000065880 REGS: c000000db6fd75e0 TRAP: 0300 Tainted: G D (4.15.0-11704-ga2e5790-dirty) MSR: 900000000280b033 CR: 28022888 XER: 00000000 CFAR: c00000000000884c DAR: f000400000000030 DSISR: 40000000 SOFTE: 0 GPR00: c00000000028a0a0 c000000db6fd7860 c0000000010e3300 f000400000000030 GPR04: 0000000000000001 0000000000000002 0000000000000000 0000000000000000 GPR08: c000000000000000 c100000000000000 0000000080000020 c0000007ec745468 GPR12: 0000000000002200 c00000000fd0c000 00007fc9a0000000 0000000000000001 GPR16: c00000052401fd80 0000000000000000 00000007fef60000 c000000000da54f8 GPR20: 0000000000000001 0000000000000000 0000000000000000 f000400000000000 GPR24: c0000007e9070d00 c100000000000000 c000000db6fd78b0 c0000007ec745100 GPR28: fe7fffffffffefff ffffffffffffffff c000000db6fd7a50 f000400000000030 NIP [c000000000a15a18] _raw_spin_lock+0x28/0xc0 LR [c00000000028a0a0] unmap_page_range+0x4b0/0xf70 Call Trace: [c000000db6fd7860] [c000000db6fd7890] 0xc000000db6fd7890 (unreliable) [c000000db6fd7890] [c00000000028a0a0] unmap_page_range+0x4b0/0xf70 [c000000db6fd79e0] [c00000000028aee4] unmap_vmas+0x74/0xf0 [c000000db6fd7a30] [c000000000298cfc] exit_mmap+0x9c/0x1c0 [c000000db6fd7af0] [c0000000000e9744] mmput+0x94/0x190 [c000000db6fd7b20] [c0000000000f33c0] do_exit+0x330/0xcc0 [c000000db6fd7be0] [c0000000000f3e0c] do_group_exit+0x5c/0xf0 [c000000db6fd7c20] [c0000000001031a8] get_signal+0x1f8/0x6f0 [c000000db6fd7d10] [c00000000001be98] do_signal+0x78/0x2e0 [c000000db6fd7e00] [c00000000001c294] do_notify_resume+0xd4/0xf0 [c000000db6fd7e30] [c00000000000bf44] ret_from_except_lite+0x70/0x74 Instruction dump: 990d028c 4bffffc8 3c4c006d 3842d910 7c0802a6 fbe1fff8 7c7f1b78 f8010010 f821ffd1 39400000 994d028c 814d0008 <7d201829> 2c090000 40c20010 7d40192d ---[ end trace b21abd323ba17f9e ]--- Fixing recursive fault but reboot is needed! -- Regard's Abdul Haleem IBM Linux Technology Centre