On 02/24/2014 10:07 AM, Vince Weaver wrote: >> >> Anyway I've attached the full tail end of the trace if you want to see >> everything that happens. > > and then I note there are *two* kernel page faults. > > perf_fuzzer-2979 [000] 161.475924: page_fault_kernel: > address=irq_stack_union ip=copy_user_generic_string error_code=0x0 > address=0x1 ip=0xffffffff812a7d9c error_code=0x0 > perf_fuzzer-2979 [000] 161.475924: function: > __do_page_fault > perf_fuzzer-2979 [000] 161.475924: function: > bad_area_nosemaphore > perf_fuzzer-2979 [000] 161.475925: function: > __bad_area_nosemaphore > perf_fuzzer-2979 [000] 161.475925: function: > no_context > perf_fuzzer-2979 [000] 161.475925: function: > fixup_exception > perf_fuzzer-2979 [000] 161.475926: function: > search_exception_tables > perf_fuzzer-2979 [000] 161.475926: function: > search_extable > perf_fuzzer-2979 [000] 161.475927: function: > copy_user_handle_tail > perf_fuzzer-2979 [000] 161.475927: function: > trace_do_page_fault > perf_fuzzer-2979 [000] 161.475928: page_fault_kernel: > address=irq_stack_union ip=copy_user_handle_tail error_code=0x0 > address=0x1 ip=0xffffffff812a92bb error_code=0x0 > perf_fuzzer-2979 [000] 161.475928: function: > __do_page_fault > perf_fuzzer-2979 [000] 161.475928: function: > bad_area_nosemaphore > perf_fuzzer-2979 [000] 161.475929: function: > __bad_area_nosemaphore > perf_fuzzer-2979 [000] 161.475929: function: > no_context > perf_fuzzer-2979 [000] 161.475929: function: > fixup_exception > perf_fuzzer-2979 [000] 161.475929: function: > search_exception_tables > perf_fuzzer-2979 [000] 161.475930: function: > search_extable > perf_fuzzer-2979 [000] 161.475931: function: > perf_output_begin > perf_fuzzer-2979 [000] 161.475931: function: > perf_output_copy > > That second one is in copy_user_handle_tail() >
Either way, it really seems like we have a case of CR2 leakage out of the NMI context. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/