Re: perf_fuzzer compiled for x32 causes reboot

From: Vince Weaver
Date: Fri Feb 28 2014 - 10:05:29 EST


On Fri, 28 Feb 2014, Steven Rostedt wrote:

> Interesting. Are you doing a perf function trace?
>
> And just in case, can you add this patch and make sure the copy is
> called by NMI.

199.900682: function: trace_do_page_fault
199.900683: page_fault_user: address=__per_cpu_end ip=__per_cpu_end error_code=0x6
199.900683: function: perf_swevent_get_recursion_context
199.900684: function: perf_tp_event
199.900684: function: perf_swevent_event
199.900684: function: perf_swevent_overflow
199.900684: function: __perf_event_overflow
199.900685: function: perf_prepare_sample
199.900685: function: __perf_event_header__init_id
199.900685: function: task_tgid_nr_ns
199.900685: function: perf_event_tid
199.900686: function: __task_pid_nr_ns
199.900686: function: perf_callchain
199.900687: function: copy_from_user_nmi
199.900687: function: trace_do_page_fault
199.900687: page_fault_kernel: address=irq_stack_union ip=copy_user_generic_string error_code=0x0
199.900688: function: __do_page_fault
199.900688: function: bad_area_nosemaphore
199.900688: function: __bad_area_nosemaphore
199.900689: function: no_context
199.900689: function: fixup_exception
199.900689: function: search_exception_tables
199.900689: function: search_extable
199.900691: function: copy_user_handle_tail
199.900691: function: trace_do_page_fault
199.900691: page_fault_kernel: address=irq_stack_union ip=copy_user_handle_tail error_code=0x0
199.900691: function: __do_page_fault
199.900692: function: bad_area_nosemaphore
199.900692: function: __bad_area_nosemaphore
199.900692: function: no_context
199.900692: function: fixup_exception
199.900692: function: search_exception_tables
199.900692: function: search_extable
199.900693: function: save_stack_trace
199.900693: function: dump_trace
199.900694: function: print_context_stack
199.900694: function: __kernel_text_address
199.900694: function: is_module_text_address
199.900695: function: __module_text_address
199.900695: function: __module_address
199.900695: function: __kernel_text_address
199.900695: function: is_module_text_address
199.900696: function: __module_text_address
199.900696: function: __module_address
...
199.900705: function: __kernel_text_address
199.900809: kernel_stack: <stack trace>
=> perf_callchain (ffffffff810d35a2)
=> perf_prepare_sample (ffffffff810cfae3)
=> __perf_event_overflow (ffffffff810d02f4)
=> perf_swevent_overflow (ffffffff810d04e3)
=> perf_swevent_event (ffffffff810d0574)
=> perf_tp_event (ffffffff810d070c)
=> perf_trace_x86_exceptions (ffffffff810341b6)
=> trace_do_page_fault (ffffffff81537702)
=> trace_page_fault (ffffffff81534772)
199.900810: function: perf_output_begin
199.900810: function: __do_page_fault
199.900810: function: __perf_sw_event
199.900810: function: perf_swevent_get_recursion_context
199.900811: function: down_read_trylock
199.900811: function: _cond_resched
199.900811: function: find_vma
199.900811: function: bad_area
199.900812: function: up_read
199.900812: function: __bad_area_nosemaphore
199.900812: function: is_prefetch
199.900812: function: convert_ip_to_linear
199.900813: function: unhandled_signal
199.900813: function: __printk_ratelimit
199.900813: function: _raw_spin_trylock
199.900813: function: _raw_spin_unlock_irqrestore
199.900814: function: printk
199.900814: function: vprintk_emit

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