[panda-users] about scissors

Wed Apr 22 14:53:51 EDT 2015

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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>
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