[panda-users] about scissors

Wed Apr 22 15:27:30 EDT 2015

Disregard that last bit – I goofed when converting scissors to the
new-style argument parsing. Should work fine now.

-Brendan

On Wed, Apr 22, 2015 at 3:21 PM, Brendan Dolan-Gavitt
<brendandg at gatech.edu> wrote:
> Ending a replay with rr_do_end_replay() from within the CPU thread
> does bad things (don't know why precisely). The solution is to instead
> just set the rr_end_replay_requested flag to 1. Fix pushed.
>
> I think there are still problems with the scissors though. I just
> tried to snip the win7iessl replay at start=181577170 end=318079730,
> and only got 24 instructions in the log...
>
> -Brendan
>
> On Wed, Apr 22, 2015 at 2:53 PM, Manolis Stamatogiannakis
> <mstamat at gmail.com> wrote:
>> I also had a segfault with scissors. The trimmed trace looks alright,
>> despite the segfault.
>>
>> My command line was:  ./i386-softmmu/qemu-system-i386 -panda
>> scissors:start=17401969,end=47488576,name=vlassis_vi -replay vlassis
>>
>> I added -g to the plugin flags, and here is the stack trace from the core:
>> http://pastebin.com/y6Dzr6YH
>> I may have sometime to further look this next week.
>>
>> M.
>>
>> 2015-04-22 8:36 GMT-07:00 Brendan Dolan-Gavitt <brendandg at gatech.edu>:
>>>
>>> Hi,
>>>
>>> >From the output you posted it looks like you also have the
>>> stringsearch plugin enabled ("stringsearch: added string of length 14
>>> to search set"). Could you try again with that turned off?
>>>
>>> -Brendan
>>>
>>> On Wed, Apr 22, 2015 at 2:01 AM, xiaojuan Li <xiaotan6666 at gmail.com>
>>> wrote:
>>> > Hi,
>>> > i want to reflect a problem about scissor plugin:
>>> > I found that scissor plugin did not work, cannot extract a part from the
>>> > original snp.
>>> > i use the command line:
>>> > scissors:start=4335499535,end=5244538335,name=api21-256-scissor...
>>> >
>>> > Adding PANDA arg scissors:start=4335499535.
>>> > Adding PANDA arg scissors:end=5244538335.
>>> > Adding PANDA arg scissors:name=api21-256-scissor.
>>> > adding
>>> >
>>> > /home/shentanli/pandanew/qemu/arm-softmmu/panda_plugins/panda_scissors.so to
>>> > panda_plugin_files 0
>>> > Adding PANDA arg stringsearch:name=test.
>>> > adding
>>> >
>>> > /home/shentanli/pandanew/qemu/arm-softmmu/panda_plugins/panda_stringsearch.so
>>> > to panda_plugin_files 1
>>> > emulator: registered 'boot-properties' qemud service
>>> > emulator: Adding boot property: 'dalvik.vm.heapsize' = '48m'
>>> > emulator: Adding boot property: 'qemu.sf.fake_camera' = 'both'
>>> > emulator: Adding boot property: 'qemu.hw.mainkeys' = '0'
>>> > loading
>>> >
>>> > /home/shentanli/pandanew/qemu/arm-softmmu/panda_plugins/panda_scissors.so
>>> > Success
>>> > loading
>>> >
>>> > /home/shentanli/pandanew/qemu/arm-softmmu/panda_plugins/panda_stringsearch.so
>>> > Initializing plugin stringsearch
>>> > panda_require: callstack_instr
>>> > loading
>>> >
>>> > /home/shentanli/pandanew/qemu/arm-softmmu/panda_plugins/panda_callstack_instr.so
>>> > Initializing plugin callstack_instr
>>> > Success
>>> > stringsearch: added string of length 14 to search set
>>> > Success
>>> >
>>> >
>>> >  when it reaches the 4335499535,it prints:
>>> >
>>> > api214-20-256:  4335499535 ( 62.00%) instrs.  296.73 sec.  0.89 GB ram.
>>> > Original ending prog point: {guest_instr_count=6992494441 pc=0xc00158c4,
>>> > secondary=0x00000000}
>>> > Saving snapshot at instr count 4335499535...
>>> > Beginning cut-and-paste process at prog point:
>>> > {guest_instr_count=4335499535 pc=0xc000db0c, secondary=0x00000000}
>>> > Writing entries to api21-256-scissor-rr-nondet.log...
>>> > Reached end of old nondet log.
>>> > Continuing with replay.
>>> >
>>> > then when it reaches the end, it shows:
>>> >
>>> > api214-20-256:  5244538335 ( 75.00%) instrs.  377.58 sec.  1.09 GB ram.
>>> > Ending cut-and-paste on prog point:
>>> > {guest_instr_count=5244538336 pc=0xffff0008, secondary=0x00000000}
>>> > api214-20-256:  5244538336 ( 75.00%) instrs.  377.59 sec.  1.09 GB ram.
>>> > Replay completed successfully.
>>> > Time taken was: 380 seconds.
>>> > Stats:
>>> > RR_INPUT_1 number = 634, size = 17118 bytes
>>> > RR_INPUT_2 number = 237, size = 6636 bytes
>>> > RR_INPUT_4 number = 659406, size = 19782180 bytes
>>> > RR_INPUT_8 number = 0, size = 0 bytes
>>> > RR_INTERRUPT_REQUEST number = 1343219, size = 37610132 bytes
>>> > RR_EXIT_REQUEST number = 0, size = 0 bytes
>>> > RR_SKIPPED_CALL number = 424454, size = 238156678 bytes
>>> > RR_DEBUG number = 0, size = 0 bytes
>>> > max_queue_len = 747
>>> > 746 items on recycle list, 65648 bytes total
>>> > Replay terminated at user request.
>>> >
>>> > Logging all cpu states
>>> >
>>> >
>>> > it exits.and when i check the scissor file, it is the same size as the
>>> > original one.
>>> >
>>> >
>>> >
>>> > Please correct me!
>>> > Thanks a lot!
>>> >
>>> >
>>> > 2015-04-21 7:48 GMT-04:00 xiaojuan Li <xiaotan6666 at gmail.com>:
>>> >
>>> >> excuse me,  scissors failed again:
>>> >> api214-20-256:  4268808000 ( 61.05%) instrs.  329.84 sec.  0.88 GB ram.
>>> >> api214-20-256:  4335499535 ( 62.00%) instrs.  335.77 sec.  0.89 GB ram.
>>> >> Original ending prog point: {guest_instr_count=6992494441
>>> >> pc=0xc00158c4,
>>> >> secondary=0x00000000}
>>> >> Saving snapshot at instr count 4335499535...
>>> >> Beginning cut-and-paste process at prog point:
>>> >> {guest_instr_count=4335499535 pc=0xc000db0c, secondary=0x00000000}
>>> >> Writing entries to api4-21-rr-nondet.log...
>>> >> Assertion failure @ count 2656994906!
>>> >> api214-20-256:  4335499535 ( 62.00%) instrs.  336.32 sec.  1.08 GB ram.
>>> >> ERROR: replay failed!
>>> >> Time taken was: 337 seconds.
>>> >> Stats:
>>> >>
>>> >>
>>> >> now i use taint encounter 2 errors:aborted and killed.
>>> >>
>>> >> the first one may caused malloc(),but i donnot know why killed.
>>> >>
>>> >> so i want to scissor it to a smaller one (just use the stringseach) and
>>> >> then use the smaller to taint, but scissor failed too.
>>> >>
>>> >>
>>> >> 2015-04-20 22:06 GMT-04:00 Brendan Dolan-Gavitt <mooyix at gmail.com>:
>>> >>>
>>> >>> This might be caused by a bug that was just fixed today:
>>> >>>
>>> >>> https://github.com/moyix/panda/issues/58
>>> >>>
>>> >>> Could you do a git pull and try again?
>>> >>>
>>> >>> -Brendan
>>> >>>
>>> >>> On Sun, Apr 19, 2015 at 8:29 AM, xiaojuan Li <xiaotan6666 at gmail.com>
>>> >>> wrote:
>>> >>> > HI,Brendan,
>>> >>> > I am the one sending emails asking for help about the taint
>>> >>> > segfault.
>>> >>> > Till
>>> >>> > now, it haven't been fixed.(have tried your suggestions,but seems
>>> >>> > does
>>> >>> > not
>>> >>> > work)
>>> >>> > during my solving this problem,i find another problem about scissors
>>> >>> > plugin:
>>> >>> > using qemu-system-arm  *** -replay ***** -panda
>>> >>> > "scissor:start=*,end=**,name=name" failed to get the cut one. does
>>> >>> > it
>>> >>> > have
>>> >>> > something wrong?
>>> >>> >
>>> >>> > Thanks for your patience.
>>> >>> > Best wishes.
>>> >>> >
>>> >>> >
>>> >>> > --
>>> >>> > wait and hope~~
>>> >>
>>> >>
>>> >>
>>> >>
>>> >> --
>>> >> wait and hope~~
>>> >
>>> >
>>> >
>>> >
>>> > --
>>> > wait and hope~~
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>>
>>