On Sat, Sep 10, 2016 7:28 PM, Borislav Petkov wrote: > > ffffffff8143ef50 <acpi_ns_walk_namespace>: > ffffffff8143ef50: e8 6b 16 42 00 callq ffffffff818605c0 <__fentry__> > ffffffff8143ef55: 55 push %rbp > ffffffff8143ef56: 48 89 e5 mov %rsp,%rbp > ffffffff8143ef59: 41 57 push %r15 > ffffffff8143ef5b: 41 56 push %r14 > ffffffff8143ef5d: 49 89 f6 mov %rsi,%r14 > ffffffff8143ef60: 41 55 push %r13 > ffffffff8143ef62: 41 54 push %r12 > ffffffff8143ef64: 41 89 cc mov %ecx,%r12d > ffffffff8143ef67: 53 push %rbx > ffffffff8143ef68: bb 01 00 00 00 mov $0x1,%ebx > ffffffff8143ef6d: 48 83 ec 28 sub $0x28,%rsp > ffffffff8143ef71: 48 83 fe ff cmp $0xffffffffffffffff,%rsi > ffffffff8143ef75: 89 7d d0 mov %edi,-0x30(%rbp) > ffffffff8143ef78: 4c 0f 44 35 58 7b 99 cmove 0x1997b58(%rip),%r14 # ffffffff82dd6ad8 <acpi_gbl_root_node> > ffffffff8143ef7f: 01 > ffffffff8143ef80: 89 55 c8 mov %edx,-0x38(%rbp) > ffffffff8143ef83: 45 31 ff xor %r15d,%r15d > ffffffff8143ef86: 41 83 e4 01 and $0x1,%r12d > ffffffff8143ef8a: 89 4d cc mov %ecx,-0x34(%rbp) > ffffffff8143ef8d: 4d 8b 6e 18 mov 0x18(%r14),%r13 <--- > faulting insn. > ffffffff8143ef91: 4c 89 45 c0 mov %r8,-0x40(%rbp) > ffffffff8143ef95: 4c 89 4d b8 mov %r9,-0x48(%rbp) > ffffffff8143ef99: c7 45 d4 00 00 00 00 movl $0x0,-0x2c(%rbp) > ffffffff8143efa0: 4d 85 ed test %r13,%r13 Thanks for the analysis. Looks like acpi_gbl_root_node == 0. It is initialized earlier than where we call acpi_ioapic_add(). start_kernel() ->acpi_early_init() ->acpi_initialize_subsystem() ->acpi_ns_root_initialize() -> acpi_gbl_root_node = ... But acpi_gbl_root_node can be 0 if acpi_disabled == 1. Do you somehow have acpi turned off (!CONFIG_ACPI or booting with acpi=off)? Thanks Rui -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
